Geology of the Paekakariki Area of the Coastal Lowland of
[Read before Wellington Branch, August 11, 1949; received by Editor, November 1, 1949.]
The subject-matter of this paper includes new data relating to the coastal lowland of Western Wellington. In 1891 McKay (1) wrote: “The low grounds and downs intervening between the coastline and the western slopes of the Tararua mountains [at Shannon and elsewhere] are formed of stratified and slightly compacted marine sands…”
The district seems to have escaped further notice until the appearance of the paper on the Ohau River area by the present writer (2) in 1910. Eight years later Cotton (3) published an alternative hypothesis of the origin of the lowland, based principally on theoretical considerations. In 1919 the present writer (4) contributed a second paper pointing out a number of discrepancies between Cotton's theory and the geological realities of the area; emphasis was laid on the longitudinal uptilt of the coastal plain (sensu stricto) northward, in addition to its lesser east to west downtilt, as well as demonstrating the basal position of the major river-fans (piedmont plain).
In 1948, Oliver (5) dealt in a comprehensive manner with a more extensive portion of the lowland tract—from Paekakariki to Palmerston North. A great body of new data was recorded and the extended area geologically mapped. His main conclusions were in agreement with those of Adkin. Certain formation outcrops, however, at the extreme southern end of the lowland strip were not noted.
General Geology and Geomorphology.
The coastal lowland of Western Wellington reaches its maximum width of 28 miles opposite the Manawatu Gorge. Southward it narrows, along a distance of 58 miles, rather regularly as far as Paraparaumu where its width is two miles. For the remaining 6 ½ miles a width of only a mile and a quarter finally tapers to the terminating point at the cliffs of Te Paripari, a little over a mile south of Paekakariki village.
The Quaternary formations of the lowland area hitherto recognized are four in number: fluviatile gravels, marine sandstone, stream alluvium, and blown sand. In areal extent the coast-bordering aeolian dune-belt (the Himatangi Formation, 6,. p. 271), comes first, covering approximately 50 per cent. of the terrain. The marine sandstone (the Otaki Formation, 3, p. 220) comes next, with stream alluvium, of varying age, a close third. The exposure of the fluviatile gravels (the Ohau Formation, 6, p. 269), the basal member of the group, is of limited extent, occurring only adjacent to the debouchures of the Manawatu, Otaki, and Ohau rivers (see Oliver,
5, Maps 1 and 2). In the present paper three more formations are recorded, all of limited thickness and areal extent but including one of considerable importance geologically.
The geomorphology of the above formations is a matter of importance in the elucidation of the development of the coastal lowland*, which is a feature of some complexity, in origin, structure, and surface configuration.
The basal fans, where exposed, present surfaces of regular and characteristic curvature. The preservation of such surfaces despite subsequent marine submergence must be attributed to conditions in which a superabundance of marine sand neutralized the abrasive action of the waves during sea advance. The covering of the basal fans (piedmont gravel plain) was thus accomplished without any discernible modification of their normal surfaces of deposition.
The blanketing of the fan surfaces by marine sand—the Otaki Formation—during the advance of the sea and the evidence of renewed deposition during its retreat as the coastal plain emerged, were considerations leading to the concept of the probable duplex major structure of the Horowhenua coastal plain (2, p. 507). During the time of still-stand, when the Otaki sea-level was at its maximum on the flanks of the Tararua foothills, the superabundance of marine sand piled up by the waves on the shoreline and immediately offshore, produced the steeper profile of the innermost part of the subsequently raised coastal plain. The flatter transverse profile of the remainder of the coastal plain surface towards the present coast—a profile (as determined by detailed measurement and levelling in the latitude of Lake Horowhenua) which has a gentle slope of apparently uninterrupted regularity—appears to indicate continuous and nearly uniform uplift, incidental eustatic rises in sea-level not leaving any permanent record here.
The emergence of the steeper innermost marginal strip of the coastal plain appears to have been followed by a temporary phase of marine abrasion and sea-advance during which the steeper initial profile was reduced and bevelled off, along much of its length, to the existing flatter upland surface conspicuous at Shannon, Levin, Otaki, and elsewhere, abutting on the slopes of the Tararua foothills. However, relict outcrops of the sandstone of the initial inner margin occur perched here and there to indicate the position of the original shoreline of maximum submergence.
It seems that it was the juxtaposition of this wave-bevelled inner portion of the coastal plain (altitude 260ft. east of Levin) with adjacent now isolated and more elevated fragments (in situ)
[Footnote] * The coastal lowland of Western Wellington has been referred to by some writers loosely as a coastal plain. The lowland is, in fact, a complex feature, geologically and geomorphologically, only portion of its area being a true coastal plain, using that term in its technical sense. A coastal plain is defined, following W. M. Davis and others, as a former sea-bottom of rather fine materials of deposition, raised and emergent as the result of secular uplift or of eustatic change in sea-level. A sea-bed surface is capable of emerging intact and unmodified when the energy of wave-action has been neutralized by a sufficient supply of waste which would have the effect of eliminating abrasion of the emerging surface.
of its constituent sandstone (more particularly that at 530ft. situated 3 miles ENE. of Levin) that led Oliver to postulate a fault at that place (5, p. 11; Fig. 39, p. 31; and Map 2, at end). As shown by the foregoing no such upthrust is necessary to explain the discrepancy in altitude in adjacent exposures of sandstone.
Stream alluvium of the district, usually ranging in age from Mid Pleistocene to Recent, but at the southern end of the lowland apparently coeval with the basal major fans, covers considerable areas of both the Horowhenua coastal plain of Otaki Sandstone and the less generally exposed surface of the piedmont plain of Early Pleistocene gravels. The surface of the alluvium takes the form of distinct minor fans and of coalescent fan-form slopes adjacent to hill-ridges, or of terraces and floodplain strips along river and stream courses. Portion of the later gravel deposits are the product of the incision of the upstream continuation of the major fans—the intermont valley-fill—by the former fan-building rivers, and the deposition of the reworked material on the downstream surface of the fans or in the trench since incised in each of them. Farther downstream where the entrenching finally peters out, a low-gradient secondary fan or fan-like deposit has been built forward by each individual river. Where, as in the case of the Otaki River, the trench incised in the main fan terminates close to the present coast, the shingle and gravels of the secondary fan deposit reach the present shoreline and replace to some extent the normal sand beach of this coast. In a manner similar to this the occasional bands and lenses of gravel observed incorporated in the Otaki Sandstone at Shannon and northward of that place (see Oliver, 5, Figs. 19 and 20, and pp. 20, 21, 39), also at Paekakariki, were carried forward and deposited. Such incorporated gravels by no means necessarily indicate oscillations of the shoreline as suggested by Oliver (op. cit., p. 39).
A Shoreline of Early Human Occupation in Horowhenua.
General considerations indicate that the earlier coast of submergence (Adkin, 2, p. 501; Oliver, 5, p. 37) of Western Wellington commenced to rise and was abandoned by the sea in the Mid Pleistocene (Adkin) or late Early Pleistocene (Oliver)* as the result of secular uplift, orogenic in character, and greatest inland and northward and diminishing seaward and to the south. The uplift produced the Horowhenua coastal plain, lithologically the Otaki Formation. The uplift was continuous and is believed to be in progress at the present day. The rate of uplift no doubt varied from time to time but not to the extent of causing physiographic breaks of sufficient duration to produce anything of the nature of successive distinct shorelines.†
The present writer (7) has briefly recorded evidence of a former shoreline or, more correctly, a series of shorelines, now well
[Footnote] * For reconciliation of this geological time difference, see below, p. 173.
[Footnote] † The evolution of the southern end of the lowland was affected and modified by other diastrophic influences and by changes in sea-level, the respective effects of which did not extend to or have marked effect upon the main part of the area to the north. The geological history of the southern portion was therefore, in some respects, at variance with one of virtual normal slow progressive uplift (see below).
inland, defined by relics of an early human occupation. The area supplying the clearest evidence is located between Lake Horowhenua and the sea. There shell middens of two age-belts can be distinguished—a recent outer and an ancient inner belt—with a space of 10 to 15 chains between the two. The outer midden belt lies behind the present foredune and extends back from it for a distance of 80 to 100 yards. These middens are attributed to the local Muaupoko tribe and accumulated as the result of a phase of food-gathering operations up to about a hundred and fifty years ago.
The older middens are scattered over a belt extending from 25 to 100 chains inland. Evidence has been given (op. cit.) for the conclusion that these older middens should be assigned to the ancient Waitaha, proved earliest inhabitants of the territory. No well-defined earliest shoreline of human occupation has left its mark, but on the basis of a proper relation to the innermost of the ancient middens, that shoreline has been placed hereabouts at 65 chains inland from the present one.
The advance, in the immediate past, of the present shoreline by uplift and progradation has been shown by recent surveys to have taken place at Waitarere and Waikawa, but no actual figures for the rate of advance are available. The provisional assumption of an advance of about two feet per annum has been adopted as a conjectural approximation to the actual rate of progression.
The final Waitaha shoreline of about 25 chains inland, with progradation at the rate of about two feet per annum, was assessed (loc. cit.) at 800 years earlier, that is, prior to 1800 a.d., the approximate terminating date of the Muaupoko independent sovereign occupation and thus the terminating date of the main mass of their midden accumulations within the line of the foredune of the present or near-present shoreline.
Turning to the antiquity of the earliest Waitaha shoreline, 65 chains inland, a calculation on the same basis as the above gives a date of 2,100 years ago, which may be deemed excessive. The date of 1000 a.d. for the termination of the Waitaha occupation of Horowhenua, i.e., about 300 years prior to the advent there of the Muaupoko (a pre-Fleet people), appears to fit into the pattern of known occupations of the area fairly well, since it allows the period of 300 years for the intervening Ngatimamoe occupation. On the other hand the incoming date of the Waitaha (put at 1,300 years earlier—300 b.c.), is open to the objection that this seems too lengthy a period for their sojourn in Horowhenua, but apart from this a very early date for them is by no means unlikely. It is evident that values on which calculations could be based are indeterminate and, almost certainly, variable; for example, the rate of shoreline advance may have altered from time to time as the result of fluctuations in the processes of progradation and/or the rate of orogenic uplift.
The chief geologic interest in the two series of midden-defined shorelines of Horowhenua is the presence in one of them of transported pumice and the complete absence of it in the other. No trace of pumice either in the form of natural fragments or of manufactured artifacts, occurs in the ancient Waitaha middens. The Muaupoko midden belt, on the other hand, lies upon a band, parallel to the
present beach, of a sand formation heavily charged with water-worn lumps of pumice of all sizes from small pebbles to boulders a foot or so in diameter. Pumice artifacts also occur, including disc-shaped net-floats and rubstones.
The significance of this pumice-deposit, confined as it is to a band parallel to and not far inland from the present shoreline, was brought to the writer's notice by C. A. Fleming, of N.Z. Geol. Survey (personal communication). His field work in the Wanganui area had disclosed a late pumice deposit ascribed to material derived from a Taupo Shower deposit of the central plateau of the North Island (8, p. 225 and map facing p. 224; 10, pp. 77–8 and map showing volcanic showers, at end). The transport of pumice debris in enormous quantities, far exceeding in amount material derived from the inland deposits by current stream erosion, seemed good evidence of the distribution of the material by the larger rivers draining from the interior during the progress of a late Taupo pumice eruption. The Wanganui River, for example, was at that time so choked with floating pumice that masses of it became stranded on the low ground on its lower course. Immense quantities reached the sea and were cast up on, or became waterlogged and were buried in, beaches washed by the southward-flowing littoral marine current. The recording of shore-bordering pumice debris in Horowhenua (7) post-dating shorelines of early human occupation was received with interest since circumstances seemed favourable for determining an approximate date for the Taupo pumice shower. A search for and detailed examination of “marker” deposits of near-shoreline pumice at other points along the coast of Western Wellington was required to throw further light on the problem.
The Paekakariki Area.
The connection of the Paekakariki area (Figs., 1, 5) with the foregoing was brought about by a casual observation made by Fleming in December, 1948, at the beach adjacent to the Centennial Inn (Fig. 1), where he noted “a deposit of decomposed pumice fragments overlying greywacke gravels” (personal communication). In undertaking the obtaining of data of the incidence of this pumice deposit the present writer observed formations underlying the extreme southern end of the coastal lowland that had previously escaped notice.
The Modern Beach.
Southward from Paekakariki the broad sand beach at and north of that place is backed by a high foredune, the toe of which had been undercut and slightly cliffed prior to the building of the modern beach. Cliffing appears to have been somewhat accelerated in recent years, during high tides and coincident stormy seas, as a series of beds of non-aeolian origin at the base of the dunes is now exposed on the seaward side in a number of places. Southward from Paekakariki the sand beach is replaced by a fully-developed shingle beach and the 'tween tides seaward slope steepens. The whole of the shingle beach material is local greywacke. Beach cusps, of characteristic development in coarse and in fine detritus, are present in both local varieties of beach.
Fig. 2 gives the principal features of profile and constituent materials of the shingle beach and its relation to the cliffed foredune. At the outer, lower portion, the slope of the beach for about eleven yards above low-tide line is of sand, and the impression is gained that the inner part—of shingle—is a separate superficial feature overlying the basal beach of sand. High-tide line is surmounted by a storm beach, also of shingle and gravel, which extends inward to and overlaps the base of the slightly cliffed foredune.
The Paekakariki beach terminates (as the coarsest part of the shingle beach) at a point 14 chains south of Centennial Inn (a useful datum point), where it abuts on a rock-platform of marine abrasion, now slightly raised in relation to present sea-level. The slightly raised bench in its nearly intact condition now ends at its junction with the lowland-fringing shingle beach, but it formerly extended (as its remnants do still) 27 chains or more farther north, overlapping the southern end of the lowland strip by that amount. This portion of the shore-platform has been more severely abraded during the period of present base-level as the result of the effects of the contiguous shingle beach.
The Coastal Section.
The apparently recent cutting back and cliffing of the fore-dune in a number of places at and south of Paekakariki has now revealed the local structure of the lowland strip. The section visible comprises an unexpected multiplicity of local geological formations. For reasons suggested below, none of these well-defined formations is of any great thickness, but all have distinctive characters and thus throw considerable light on varying past relations of sea and land.
The basal formation, showing a thickness up to 3 feet above the inner overlapping margin of the modern storm beach, consists of rather fine sea-worn pebbles and occasional cobbles of greywacke in a (usually) sparse matrix of coarse sand. Intercalated lenses and bands of the same coarse sand occur in the upper part, and the lower part is, to some extent, cemented by oxide of iron. This formation is interpreted as a beach deposit originally laid down at sea-level, and though now above, there is evidence that it had been, at one stage, depressed below sea-level.
The next formation, overlying the last, is a clean, water-laid sand, in places finely laminated, exhibiting delicate cross-bedding, and varying in thickness as the result of subsequent stream erosion from 1 ½ to about 25 feet; at the places of maximum thickness, however, the base is obscured by talus; the maximum thickness noted in exposures where both upper and lower surfaces are visible was 4 feet. On various grounds—lithology, structure, geographical position, etc.—this marine sand is identifiable as Otaki, and is an attenuated tongue of the extensive coastal plain of marine sandstone of the region northward.
Exposures of Otaki Sand occur in three slightly differing relationships in the coastal section south of Paekakariki. Where first examined by the writer at exposures at the base of the fore-dune between 9 chains and 11 chains north of the Inn, it
Fig. 5—Southern end of coastal lowland near Paekakariki. Inland cliffs
on right: Centennial Inn and dune-ridge at centre; coastal section.
modern beach, and fragmentary, slightly raised shore-platform (at
approximately low tide) to left. View NNE. from railway quarry in
Te Paripari cliffs (see map, Fig. 1).
Fig. 6—Coastal Section. Section 1 (map, Fig. 1) showing lower beach-
gravels (LP), Otaki Sand (OS), and pumiceous sand (TO) with
pumice pebble band (P).
Fig. 7—Coastal Section. Section 4 (map, Fig. 1) showing pumiceous sand
(TO) with pumice pebble bands (P, P) overlying Otaki Sand (OS) and
lower beach-gravels (LP). Inner margin of modern beach, foreground.
Fig. 8—Coastal Section. Section 5 (map, Fig. 1). Otaki Sand (OS—base
indicated) overlain by upper beach-gravels (UP), with alluvial silt
of minor stream-fan at top.
overlies the lower beach gravels and is overlain by a second water-laid sand formation (described below). About 7 ½ chains south of the Inn, it overlies the lower beach gravels, has a thickness of 4 feet, is strikingly laminated and cross-bedded, and is overlain by a second marine beach-gravel formation, which in turn is capped by the alluvial fan deposit of the Quarry Stream (Figs. 1, 8). At the debouchure of the Water-supply Stream (Fig. 1, and Fig. 3, Section 7), 15 chains south-west of Paekakariki village, the Otaki Sand is cemented by iron oxide into a coherent sandstone, equal in hardness to anything outcropping in the Horowhenua area. The base of the outcrop in the stream bank is below stream-bed level and may rest, at some depth, on an earlier fan of the Water-supply Stream. Its upper surface is overlain by the second water-laid sand, here 32 inches thick, which merges upward into light-coloured, fine alluvial silts forming the toe of the present minor fan (now incised) of the Water-supply Stream.
Between the local streams the present upper surface of the Otaki Sand stands at a higher level on the seaward dune-face than at places where it was eroded off and lowered to a still greater extent by the local streams within the range of their flow; its level in the inter-stream-course positions is 25 feet (or more) above the inner edge of the modern beach (which is approximately 9 ½ feet above low-tide level).
In addition to fine lamination and current-bedding of the laminae (in places prominent), the Otaki Sand in the Paekakariki area is characterized by its clean, even texture and the complete absence of pumice pellets and pebbles. It frequently, however, contains sporadic pebbles and cobbles of greywacke, and, in places, thin discontinuous layers and lenses of the same material. The latter occur in the vicinity of the debouchures of the local streams, but the former, the sporadic fragments, may occur anywhere in between, by lateral migration along the prograding beach of the period.
Coming now to the upper water-laid sand overlying the Otaki Sand, we find it the local equivalent of the narrow, pumice-loaded sand-belt deposit of the Horowhenua coast. The Paekakariki pumice-pebble sand is characterized by its pumiceous composition and texture, and by the presence of well-defined but discontinuous bands of pumice pebbles at more than one horizon, and by pumice fragments promiscuously scattered through it. The relative position of the pumice-pebble bands varies from place to place, the intervening sand charged with smaller and scattered fragments varying from 6 inches to perhaps 12 feet or even more. Frequently, however, a band of pumice pebbles (with, in places, an occasional pebble of greywacke) caps the underlying Otaki Sand; in other places the plane of contact between Otaki Sand and pumice sand can be placed only by the difference in composition. The upper limit of the pumice-pebble sand is difficult to fix as it seems to grade into the overlying dunes of wind-blown sand.
The upper beach-gravel formation that can be seen overlying the Otaki Sand south of the mouth of the Quarry Stream is of similar origin to the lower beach-gravel formation, but it differs from it chiefly in being composed of coarser, poorly-sorted material
with a notable proportion of angular fragments. Angular detritus was not seen in the lower beach-gravel formation.
The upper beach formation is of limited lateral extent and apparently extends forward a lesser distance from the base of the
Quarry Stream the toe of its present alluvial fan—a clayey silt 16 inches in thickness at the shoreline—caps the upper beach-gravel formation (Fig. 3, Section 5, and Fig. 8).
Of the local dunesands little need be said. They overlie in this vicinity the water-laid pumice-sand formation and portions of the recent alluvial fans of the local streams. The blown sand of the dunes was derived from a former seaward extension of the water-laid pumice-sand; hence the difficulty in defining the plane of contact between the pumiceous water-laid sand and the aeolian sand. The recent advance of the sea (prior to the late progradation of the modern beach) cut back the exposed pumiceous sands (also the underlying beds) thus removing the source of the blown sand, and the dunes are now stable except for talus on their slightly undercut seaward face*.
Summarizing, and supplying data not yet given of the measured parts of the general coastal section (see map, Fig. 1, nos. 1–7), details are as follows:—
[The section below cannot be correctly rendered as it contains complex formatting. See the image of the page for a more accurate rendering.]
|Wind-blown pumiceous sand (at top)|
|5 ft. 7 in. +||Water-laid pumiceous sand||5 ft. +|
|5 ft. 7 in. +||Pumice-pebble band||7 in.|
|Water-laid (Otaki) sand||1 ft. 6 in.|
|Lower beach-gravels (showing)||3 ft.|
[The section below cannot be correctly rendered as it contains complex formatting. See the image of the page for a more accurate rendering.]
|Wind-blown pumiceous sand (at top)|
|3 ft. 4 in. ±||Water-laid pumiceous sand||2 ft. ±|
|3 ft. 4 in. ±||Pumice-pebble band||5 in.|
|3 ft. 4 in. ±||Water-laid pumiceous sand||9 in.|
|3 ft. 4 in. ±||Pumice-pebble band||2 in.|
|Water-laid (Otaki) sand (base hidden)||9 ft. 6 in.|
[The section below cannot be correctly rendered as it contains complex formatting. See the image of the page for a more accurate rendering.]
|Wind-blown pumiceous sand (at top)|
|3 ft. 2 in. ±||Water-laid pumiceous sand||2 ft. ±|
|3 ft. 2 in. ±||Pumice-pebble band||7 in.|
|3 ft. 2 in. ±||Water-laid pumiceous sand||6 in.|
|3 ft. 2 in. ±||Single line of greywacke and pumice pebbles||1 in.|
|Water-laid (Otaki) sand (base hidden)||9 ft. 6 in.|
|Wind-blown pumiceous sand (at top)|
|6 ft. 1 in. ±||Water-laid pumiceous sand||5 ft. ±|
|6 ft. 1 in. ±||Pumice-pebble band||6 in.|
|6 ft. 1 in. ±||Water-laid pumiceous sand||3 ft.|
|6 ft. 1 in. ±||Pumice-pebble band||4 in.|
|Water-laid (Otaki) sand||1 ft. 8 in.|
|Lower beach-gravels (showing)||3 ft.|
[Footnote] * Repeated visits to the Paekakariki area show that, though the stratigraphical relationships are constant (though of varying proportions from point to point), continuous minor changes in exposure recur and beds and features may be successively obscured or laid bare. The modern beach, also, fluctuates in minor surface form and in composition from time to time according to the influence of periods of calm or stormy weather, rainfall, force and direction of wind, etc.
|Clayey silt (alluvium)||1 ft. 4 in.|
|Upper beach-gravels||3 ft. 7 in.|
|Water-laid (Otaki) sand||4 ft.|
|Lower beach-gravels (showing)||1 ft. 6 in.|
|Wind-blown pumiceous sand (at top)|
|Water-laid pumiceous sand||5 ft. ±|
|Water-laid (Otaki) sand (base-hidden)||4 ft.|
|Wind-blown pumiceous sand (at top)|
|Clayey silt (alluvium)||2 ft. 4 in.|
|Water-laid pumiceous sand with pumice pebbles||2 ft. 8 in.|
|Unconformity, with lense of fine, water-worn greywacke pebbles||3 in.|
|Water-laid cemented (Otaki) sand (base hidden)||2 ft.|
Interpretation, and Formation Names.
The lower beach-gravel formation is interpreted as being an early marine abrasion product, localized at the Te Paripari cliffs of the Paekakariki area, of the late Early Pleistocene to Mid Pleistocene shoreline of Western Wellington. The deposit accumulated as an incipient strand-plain during an interval of stillstand or of very slow uplift. For it the local formation name of “Lower Paripari” is suggested
Submergence interrupted the accumulation of the Lower Paripari Formation and by carrying it below sea-level, allowed the deposition on it of the overlying marine sand. On similarity of lithology and internal structure, as well as geographical position and relationship to the “old land,” this sand is correlated with the established Otaki Formation in Horowhenua and northward. The name “Otaki Formation” is therefore retained for the Paekakariki portion.
Overlying the Otaki Sand is another sand formation of similar marine sedimentary origin but of different lithology. The distinctive lithology connects it with, on the hypothesis of its derivation from, a Taupo pumice shower; it is a waterborne facies of the product of a Taupo pumice eruption. Despite its limited thickness and areal extent, the geographical range and distinctive lithology of this pumiceous sand stratum makes it an important horizon marker. As a formation name, “Taupo Outwash,” or, in full, “Taupo Outwash Pumice-pebble Sand” has been adopted.
The upper beach-gravel formation, derived from renewed abrasion of Te Paripari cliffs, was also built forward as an incipient strand-plain during another interval of stillstand. It rests directly on a degraded surface of the Otaki Formation. The pumiceous sand is absent here, and as the upper gravels are regarded as slightly
older than the pumiceous sand, the former is presumed to have been raised above sea-level by renewed uplift just prior to the deposition of the sand. The pumiceous sand was then deposited on a shoreline seaward of the gravels at this place, and later completely removed here by the final sea advance. “Upper Paripari Formation” has been selected as a suitable local formation name for these gravels.
To interpret correctly the sequence of Quaternary events that have left their mark in the Paekakariki area, it seems necessary to recognize and correctly assess the interaction of diverse diastrophic processes that have affected the terrain as a whole and that vicinity in particular. The working hypothesis already advanced by the present writer (4, p. 111; 10, pp. 146–8) may here be restated and developed in more detail.
The general concept is the extended contemporaneity of both epeirogenic and orogenic movements, the latter comprising two linked but opposing stresses, a major and a lesser, in operation simultaneously. The land-surface affected by these movements was the “pre-Miocene peneplain” (so called) to which the land had been reduced. Large areas of this subdued surface were submerged by Tertiary seas, other portions were gently upwarped and remained emergent. Evidence from the Port Nicholson area indicates that the Kaukau erosion-surface was part of the initial surface of the axial highland belt from which, in the North Island, the Tararua-Rimutaka collinear ranges have been carved. The whole forms part of the emergent portion of the “pre-Miocene peneplain,” or, more correctly, subdued matureland.
The Kaikoura orogenic uplift and deformation progressed to its climax at the close of the Pliocene. The drainage consequent on the uplift developed as the orogeny proceeded, the axial belt reaching a state of deep dissection at, or even prior to, the beginning of the Pleistocene. At this stage epeirogenic uplift supervened and at its maximum the glacial episode occurred. During this uplift, extra-axial areas were likewise elevated, and during pauses, the benches of partial erosion-cycles—Table Hill, Mana, Tongue Point, etc—were successively developed, each at the expense of the graded surface of the preceding epicycle.
With dissection proceeding, the initial surface of the axial belt was uplifted, tilted, and flexured into a secondary anticlinorium, finally faulted and upthrust on its eastern flank (11). Separating this deformed belt from the more uniformly uplifted and relatively gently warped superficies of the Wellington Peninsula “block,” there intervenes a long, narrow, subsiding (or relatively lagging) tectonic strip. This is the Port Nicholson-Porirua-Pukerua “sunk-land” strip. Its lateral boundaries appear to be monoclinal flexures and, in part, normal faults facing inwards (Fig. 4).
The particular diastrophic movements outlined, other than the epeirogenic movement, are visualized as being varying manifestations of the crustal forces behind the Kaikoura orogeny. The general
movement was one of uplift. It was of greatest intensity along the axial belt: stresses of lesser intensity elevated the Wellington Peninsula “block”; the interaction of these two units with perhaps some rotation of the axial segment, apparently produced a down-drag along the hinge-line of the contact, and by slowing up the uplift along that zone, gave it the semblance of a relatively subsiding strip.
The most recent effects of crustal stress in this relatively subsiding sunkland strip are three normal faults that cross it obliquely. These are respectively known as: the Wellington Fault (Cotton), the Owhariu-Kaka Fault (Quennell and Ferrar), and the Mount Welcome Fault (Adkin); their trend is sub-parallel. The inbreak of the Wellington Fault accelerated the local subsiding tendency very considerably and produced the fault-angle and, in part, the more strongly downwarped area of Port Nicholson and the Hutt Valley (Fig. 4). The Owhariu-Kaka fault-trace exhibits features of very recent movement but in part it coincides with an older fault-scarp, especially on the eastern side of Colonial Knob. Northward, the recent trace of the Owhariu-Kaka Fault intersects the older Kakaho Fault (see Fig. 4) at an acute angle, and recent movement on the northern part of the Kakaho Fault was probably due to movement on the Owhariu-Kaka line. The Mount Welcome fault-trace (Fig. 4) is one of the most recent of the local crustal fractures and there is little, if any, evidence of earlier movement on this line. It is probable, however, that the most recent movements on the northern part of the Mount Wainui Fault (Fig. 4) were produced by the northward extension of movement on the Mount Welcome Fault. The latter intersects the former at an acute angle (cf. the Owhariu-Kaka-Kakaho intersection, Fig. 4), and rejuvenation of the northern part of the older Mount Wainui Fault is indicated by notched spurs and by the postulated disruption of the Otaki Sandstone towards its (this fault's) extreme northern end, as submitted on a later page of this paper. About the end of the Early Pleistocene a second epeirogenic movement—this time of subsidence took place. This probably involved the whole of the South Island and the southern part of the North, and may have been uniform over that area, or of the nature of a slight tilt, possibly from north to south.
With sea-level thereby brought to a relatively higher altitude in relation to the diminished New Zealand land-mass (thus reduced to separate islands as now), the effects of ensuing orogenic movements together with apparent eustatic changes in sea-level became obvious. Continued orogenic uplift of the Tararua-Rimutaka axial range caused the sea to leave its late Early Pleistocene to Mid Pleistocene shoreline along the Tararua foothills and lay bare the Horowhenua coastal plain. The lesser complementary but opposing orogenic movement—i.e., the down-drag or lag of the Port Nicholson-Pukerua tectonic strip—slowed up the general upward movement, enabling eustatic changes in sea-level to produce occasional submergence of the narrow southern end of the coastal lowland.
Notes on Local Geological History.
The piedmont alluvial plain of coalescing major fans of Horo-whenua in the Early Pleistocene* extended southward as far as Waikanae. These fans were the product of the larger rivers draining from the Tararua Range during its second-cycle uplift and were deposited on an extended lowland surface reaching far to the west.
There is evidence for the belief that the smaller but conspicuous fans fringing the foothills between Te Horo and Waikanae and from south of Paraparaumu to Paekakariki, were coeval with the major fans and thus formed part of the piedmont apron of basal gravels. As the product of comparatively small streams, the lesser fans have gradients of values greatly in excess of those of the larger and flatter fans of the principal rivers, and the apexes and upper slopes of the former stand at higher levels, making them striking features of the landscape. Truncation of the toe of most of these steep southern fans by faulting took place (see Fig. 4), a derangement of equilibrium that caused them to be breached and trenched by their originating streams. Later, a renewal of fan deposition resulted in some complexity of structure and surface configuration. Over the whole lowland area, however, stability and a cessation of fan-building had been reached for a lengthy period prior to the peripheral submergence that followed that aggradation.
The period of greater elevation, marked by the episode of Early Pleistocene glaciation, was followed by this regional subsidence. In the Paekakariki area the Lower Paripari Formation is taken as being related to the new coast of submergence. The submergence gave rise, in Western Wellington, to the highest Otaki shoreline, which is assigned to times extending from late Early Pleistocene to Mid Pleistocene. A slightly qualified concept of the date of the Otaki shoreline is introduced here. In the Paekakariki area coastal abrasion and the building forward of an incipient strand-plain took place at a rather earlier date than the abandonment of the earliest Otaki shoreline at the inland hill-region of the “old land” northward in Horowhenua. A late Early Pleistocene date (Oliver, 5, p. 37) for the former and an early Mid Pleistocene one (Adkin, 2, p. 502) for the latter may well apply in the respective localities, and cover the evident time lag between the two.
The submergence of the Lower Paripari strand-plain apparently by a eustatic rise in sea-level allowed the deposition upon it of the overlying Otaki Sand. In the Paekakariki area this sand deposit was more limited in thickness and lateral extent than in the region to the north. Uplift, on a restricted scale, then laid bare the sandy sea-bed to form a narrow strip of coastal plain—the southern wing of the Horowhenua coastal plain—originally extending southward past the present lowland terminus.
[Footnote] * The divisions of the Pleistocene (and of the Quaternary as a whole) as used by the present writer (see also, Oliver, op. cit), are tentatively based on diastrophic data and on estimates of the relative space of geological time required for the several geomorphologic and geologic changes that have taken place within the area dealt with.
The most southerly exposure of Otaki Sandstone known until recently is that at Otaihanga, a mile and a half north of Paraparaumu (Oliver, op. cit.). The present writer has demonstrated (on the basis of the rather uniform longitudinal downtilt of the Otaki shoreline southward, see graph 4, p. 111), the theoretical original extension of the coastal plain (sensu stricto) as far south as a little beyond Porirua Harbour entrance. It may be assumed, however, that on account of its extreme narrowness and the unconsolidated nature of its make-up, such former extension would be very vulnerable to wave-attack and quickly removed by marine abrasion.
In the part that survived north of Te Paripari the emergent surface was channeled by local streams. A pronounced submergence then took place, entirely drowning (at the southern end of the coastal lowland only) the whole of the then eroded and irregular surface of this narrow and slightly embayed coastal plain. Upon the uneven surface renewed deposition of material washed down coastwise from the north, introduced the final component of the coastal plain strip, namely, pumiceous sand charged with pumice pebbles (the Taupo Outwash Pumice-pebble Sand). Complete local submergence is indicated by the fact that water-laid pumiceous sand overlies unconformably not only the lowest but also the highest eroded surface of the Otaki Formation to be found at and south of Paekakariki.
Immediately prior to or in part contemporaneous with the deposition of the pumiceous sand, the shoreline had again reached the base of Te Paripari cliffs. A coarse beach-deposit (Upper Paripari Formation) was built forward to form a second narrow strand-plain, but this did not attain the breadth of the earlier one.
It will be evident that a multiplicity of changes in base-level affected the Paekakariki coast and shore as slow orogenic uplift was neutralized at least twice by eustatic rises in sea-level. Following the foregoing, further slight uplift occurred and by laying bare the light pumiceous sands, provided a wind-erodable surface from which the existing dunes were derived. Sea-advance by wave-attack then took place and the shoreline was cut back to the base of the present foredune. Finally a small amount of uplift brought about the progradation of the existing beach, the shingly portion of which was derived from erosion of the earlier strand-plain deposits.
Attention is now directed to the coastal lowland north of Paekakariki where the Mount Wainui Fault (see Fig. 4) was a factor in the evolution of the present topography. The southern (known) part of this fault-line, topographically forms a prominent scarp marked by faceted spurs on the western face of Mount Wainui, and its northern extension is one of the faults bounding, in part, the Port Nicholson-Pukerua “sunkland” strip. North-north-west of Mount Wainui this fault leaves the hill country and crosses the lowland. At this point it transected the fan of the Rongo-o-te-wera Stream, downfaulting its seaward segment. Farther north, its scarp bounds the western side of the outer hill-ridge located immediately south of Paraparaumu (a hill-ridge nameless but herein referred to, for convenience of reference, as Para Ridge). Continuing north-
ward, it similarly defines the western side of Otaihanga Ridge (Macpherson, 12, map Fig. 1, section BB Fig. 2, and p. 72). At Waikanae, a gap of four miles of low ground shows no trace, but northward again, the fault truncates the older units of the series of steep minor fans previously referred to (together with the Rongo-o-te-wera fan) as being coeval with the Early Pleistocene major fans of Western Wellington. Still farther north Mount Wainui Fault transects the (major) fan of the Otaki River, downthrowing a seaward segment, and it dies out, as a topographic lineament, close to the lower course of the Otaki River.
There is good evidence of the late movement on this fault but as a crustal break it probably dates back to the Kaikoura orogenic climax. Prior to its transection of the older minor fans but subsequent to its determination of the outer hill-faces south and north of Paraparaumu, the initial Otaki shoreline had been established following the epeirogenic subsidence. A few miles north of Waikanae (e.g., at the former railway station of Hadfield*—near Fraser's Hill Road), this shoreline was certainly inland of, that is, east of, the line of Mount Wainui Fault. This is shown by the fact that Otaki Sandstone capping older minor fans there, is cut and down-thrown to the west on the line of this fault by a renewal of differential movement. This is taken as indicating that the fault, in the later stages of its inbreak, extended its length northward as a topographic break, over terrain previously intact and overrain by an unbroken formation of emergent Otaki Sandstone.†.
The sea had retired as a result of the emergence of the Horowhenua coastal plain but its southern wing was re-submerged by what appears to have been the greatest of the eustatic rises in sea-level. This occurred after the downfaulting of the outer segments of the older minor fans. It was at this juncture that the fault-scarped fan of Rongo-o-te-wera Stream was cut back by the sea to about 5 chains beyond the line of the Mount Wainui Fault. Proof of this cutting back by wave-action is given by similar wave-truncaiton of fans located immediately south-west of the Rongo-o-te-wera fan; these cliffed fans are not transected by the line of the Mount Wainui Fault and the line of their truncation trends at approximately at right angles to it.
The fault-scarped western face of Para Ridge was also part of the shoreline during this later sea-advance, but owing to its more resistant nature (greywacke, as compared with stream gravels) it was but slightly (if at all) modified by marine abrasion. The same qualification applies to the fault-defined western boundary of Otaihanga Ridge farther north. It also applies—rather unexpectedly
[Footnote] * Thus previously referred to, in 4, p. 112.
[Footnote] † Oliver (5, Table I, p. 5) gives details of a well (Fig. 10, D, p. 12) sunk on the low ground to the west of the scarp at Hadfield. The beds passed through are given as: Dune-sand, 57ft, on hard solid rock. At this place the scarp shows Otaki Sandstone and it is extremely likely that the greater part of the 57ft of sand formation on the downthrown side is Otaki Sandstone also, and not blown sand as surmised by Oliver. Prior to the faulting movement here, the two sand bodies (if identical as suggested) would be contiguous and continuous.
at first sight—to the fault-truncated series of fans at Hadfield. But there the gravel fans are protected by an exposed platform of greywacke basement on which they rest (forming an uplifted contraposed shoreline) which cheeked abrasion and has preserved them from deeper truncation under wave-attack than would otherwise have taken place. Northward of this locality the maximum shoreline of secondary sea-advance (by re-submergence of the coastal border) was apparently too transitory to allow further advance by abrasion to be effected to any notable degree.
The writer wishes to express his thanks for helpful suggestions to several members of the staff of the N.Z. Geological Survey, especially the Director (Mr. M. Ongley) and Mr. C. A. Fleming, Palaeontologist; also for the latter's acquiescence in the writing up and presentation of this paper.
1. McKay, Alex. 1894. On the prospects of Finding Coal near Shannon on the Wellington-Manawatu Railway-line, 1891. Rep. Geol. Explor. during 1892–93, Geol. Surv. N.Z., p. 1.
2. Adkin, G. L., 1910. The Post-Tertiary Geological History of the Ohau River and of the Adjacent Coastal Plain, Horowhenua, North Island, Trans. N.Z. Inst., vol. 43, pp. 496–520.
3. Cotton, C. A., 1918. The Geomorphology of the Coastal District of South-west Wellington, Trans. N.Z. Inst., vol. 50, pp. 212–22.
4. Adkin, G. L., 1919. Further Notes on the Horowhenua Coastal Plain and the Associated Physiogrnphic Features, Trans. N.Z. Inst., vol. 51, pp. 108–18.
5. Oliver, R. L., 1948. The Otaki Gandstone and its Geological History, N.Z.D.S.I.R. Geol. Mem., No. 7, 40 pp.
6. Adkin, G. L., 1948. On the Occurrence of Natural Artesian Springs in the Horowheiwa District, N.Z. Journ. Sci. Tech., vol. 29, no. 5 (sect. B), pp. 266–72.
7. Adkin, G. L., 1948. Horowhenua: Its Maori Place-names and their Topographic and Historical Background, Wellington, Department of Internal Affairs, 446 pp.
8. Grange, L. I., 1929. A classification of the Soils of Rotorua County, N.Z. Journ. Sci. Tech., vol. 11 (1929–30), pp. 219–28.
9. Grange, L. I., 1937. The Geology of the Rotorua Subdivision, N.Z. Geol. Surv. Bull. No. 37, p. 138.
10. Adkin, G. L., 1921. Porirua Harbour: A Study of its Shoreline and other Physiographic Features, Trans. N.Z. Inst., vol. 53, pp. 144–50.
11. Adkin, G. L., 1949. The Tararua Range as a Unit of the Geological Structure of New Zealand, Trans. Roy. Soc. N.Z., vol. 77, Pt. 5, pp. 260–72.
12. Macpherson, E. O., 1949. The Otaihanga Faulted Outlier and Notes on the Greensand Deposit, N.Z. Journ. Sci. Tech., vol. 30, no. 2 (Sect. B), pp. 70–83.
Note—Several geographical names have been used in this paper to facilitate brevity of description; these have not been submitted for approval to the New Zealand Geographic Board.
The Hypocreales of New Zealand
II. The Genus Nectria.
[Read before the Auckland Institute, May 24, 1950; received by the Editor, May 30, 1950.]
Fries in Summa Vegetabilium Scandinaviae, 1849, defined Nectria to include species with fleshy, brightly coloured perithecia which were either caespitose on a conidial stroma or freely scattered on the surface of the host. Saccardo (1883) divided the genus into seven sub-genera, using for the division characters such as the presence of hairs, tubercles, or a pulvinate stroma. Cooke (1884) raised Saccardo's sub-genera to generic rank and retained Saccardo's names for the genera. He restricted Nectria to include only species with a well-developed stroma upon which perithecia were borne and placed in Dialonectria other species where perithecia were scattered freely on the surface of the host. Seaver (1909) retained Cooke's sub-divisions, but transferred to Nectria speeies with perithecia scattered freely on the surface of the host tissue. He stated that Cooke's sub-division did not include the type species of the genus. Seaver erected Creonectria to include stromatic species. As Fries did not indicate any type, Petch (1938) retained Cooke's genera. Although in some species a stroma was well defined, other species showed forms where the perithecia were scattered freely on the host or were united on a pulvinate stroma. The morphology of different species showed no character sufficiently distinct to justify a generie separation. Sphaerostilbe Tulasne has been discarded as the structure of the perithecium is identical with that of Nectria, a Stilbum conidial stage was the basis for the genus. The genera Lasionectria Cooke and Nectriopsis Maire have also been discarded as the characters used for separation are ephemeral and could be missing from herbarium material. This paper lists 31 species of Nectria from New Zealand. The majority of species are saprophytes on decaying organic material, a few appear to be wound parasites when conditions are favourable, one species occurred parasitically on bark of apple trees, two species parasitised scale insects, while another three species occurred on decaying fungus fructifications. This list is not complete as collections were not sufficiently extensive over the country.
The writer wishes to thank the Director, Royal Botanic Gardens, Kew, for forwarding on loan part of the type collections of New Zealand species, to Dr. G. H. Cunningham for his advice during the preparation of this paper, and to Miss B. Hooton for Latin translations of new species.
2. Nectria Fries Summa Vegetabilium Scandinaviae p. 387, 1849.
Dialonectria Cke. Grev., Vol. 12, pp. 77 and 109, 1884; Sphaerostilbe Tul., Sel. Fung. Carp., Vol. 1, p. 130, 1861; Lasionectria Cke. Grev., Vol. 12, p. 112, 1884; Stilbocrea Pat. Bull. Soc. Myc. France,
Vol. 16, p. 186, 1900; Creonectria Seaver, Mycologia, Vol. 1, p. 183, 1909; Nectriopsis Maire, Ann. Mycol., Vol. 9, p. 323, 1911.
Perithecia superficial, scattered freely on surface of host, caes-pitose or gregarious on a pulvinate, often erumpent, pseudoparenchy-matous stroma or a byssoid subiculum. Asci eight spored, spores liberated by rupturing of apex of ascus. Spores, one septate, elliptical, oval or fusiform, hyaline or lightly coloured; pseudoparaphyses usually present.
Type Species—Nectria cinnabarina (Tode) Fr.
Key to Species.
Perithecial wall pseudoparenchymatous, cell wall hyaline, pigment present as globules within the cells.
|Spores under 15μ long.|
|Spores smooth, 8–14 × 2–4μ||1. N. ochroleuca (Schw.) Berk.|
|Spores verrucose, 9–13 × 4–6μ||2. N. grisea Dingley|
|Spores 12–20 × 4–7μ||3. N. quisquiliaris Cke.|
Perithecial wall pseudoparenchymatous, cell wall lightly pigmented, not thickened, translucent when fresh.
|Perithecia freely scattered on surface of|
|host||4. N. byssiseda Rehm.|
|Perithecia gregarious on a byssoid stroma.|
|Spores elliptical or fusiform.|
|Spores 5–9 × 2.5–4μ||5 N. manuka Dingley|
|Spores 7.5–10 × 3–4μ||6. N. berkeleyana (Plowr. and Cke.) Dingley|
|Spores 12–20 × 4–6μ||7. N. aemulans Rehm.|
|Spores oval ends blunt.|
|Spore smooth, 8–16 × 4–6μ||8. N. peziza (Tode) Fr.|
|Perithecia caespitose on a small poorly developed erumpent stroma.|
|Spore smooth, 9–26 × 4–8μ||9. N. hauturu Dingley|
|Spores verrucose, 8–11 × 5–6μ||10. N. ruapehu Dingley|
Perithecial wall pseudoparenchymatous, cell wall pigmented, thickened.
|Stroma absent or poorly developed.|
|Spores broadly elliptical, 14–20 × 4–7μ||11. N. galligena Bres. ex Strasser|
|Spores fusiform, 15–22 × 4–6μ||12. N. fragilis Dingley|
|Stroma present; perithecia semi-immersed||13. N. otagensis Currey ex Lindsay|
|Parasitic on scale insects.|
|Spores oval, rarely elliptical, 8–15 × 4–6μ||14. N. aurantiicola Berk, and Br.|
|Spores elliptical, 16–24 × 6–10μ||15. N. flammea (Tul.) Dingley|
|Saprophytic on dead bark||16. N. punicea (K. & Schm.) Fr.|
|Spores fusiform or elliptical, 14–20 × 5–7μ||17. N. coccinea (Pers.) Fr.|
|Spores tuberculate||18. N. sanguinea (Bolt.) Fr.|
|12–20 × 3–6μ||19. N. cinnabarina (Tode) Fr.|
|15–20 × 5–8μ||20. N. zelandica Cooke|
|Perithecia scattered, sometimes gregarious.|
|Spores 10–20 × 6–10μ||21. N. haematacoccus Berk. & Br.|
|Spores 20–32 × 10–14μ||22. N. illudens Berk,|
|Perithecia caespitose on an erumpent stroma.|
|Spores 16–24 × 6–10μ||23. N. balsanae Speg.|
|Spores 22–38 × 10–16μ||24. N. plagianthi Dingley|
Perithecia wall darkly pigmented and thickened, pseudoparenchymatous structure difficult to discern.
|12–16 × 5–7μ||25. N. rubi Osterwalder|
|12–25 × 6–10μ||26. N. mammoidea Phil. & Plowr.|
|12–17 × 6–8μ||27. N. tasmanica Berk.|
|13.5–16 × 5–6μ||28 N. pinea Dingley|
Perithecial wall pseudoparenchymatous, outer cells thin walled, 10–20μ diameter, inner cells 5–7μ diameter, densely pigmented and thickened.
|Spores small, under 15μ.|
|Spores elliptical, fusiform, 7–10 × 2.5–3.5μ||29. N. tawa Dingley|
|Spores elliptical, ends truncate, 9–13 × 3–4μ||30. N. coprosmae Dingley|
|Spores over 20μ long||31. N. westlandica Dingley|
1. Nectria ochroleuca (Schweinitz) Berkeley. Grevillea, Vol. 4, p. 16, 1875.
Sphaeria ochroleuca Schw. Trans. Am. Phil. Soc. n.s. Vol. 4, p. 204, 1831.
Calonectria ochroleuca (Schw.) Seaver. Mycologia, Vol. 1, p. 191, 1909. Plate 23, fig. 1.
Perithecia superficial, caespitose on a pulvinate, occasionally effuse, erumpent pseudoparenchymatous stroma, up to 2mm. diameter, globose 0·2–0·3mm. diameter, translucent, coral coloured, orange, bleaching to cream in over mature specimens, ostiole minute, umbilicate. Perithecial wall pseudoparenchymatous 50μ thick, cells 5–8μ diameter. Asci clavate or elliptical 30–50 × 5–10μ, 6–8 spored, obliquely uniseriate, biseriate at apex; pseudoparaphyses evanescent. Spores one-septate, often constricted at septa, fusiform 8–14 × 2–4μ, smooth, hyaline. Conidial stage: Conidiophoies verticillate, aggregated to form a pulvinate sporodochium, sometimes developed into a stalklike structure, orange or salmon coloured, conidia cylindrical or oval 4–9 × 2–4μ, hyaline. Verticillium tubercularioides Speg.
Type Locality: Pennsylvania, United States of America.
Distribution: North America, West Indies, Europe, New Zealand.
Beilschmiedia tawa (A. Cunn.) Hook. f. and Benth.
Auckland, Titirangi, March 1946, J.M.D.; Waipoua, May 1947, J.M.D.
Brachyglottis repanda Forst.
Auckland, Te Aroha Mt., October 1948, J.M.D.
Coprosma grandifolia Hook. f.
Auckland, Waitakere Ra. Rua-te-whenua, October 1949. J.M.D.
Corynocarpus laevigata Forst.
Auckland, Piha, July 1946, J.M.D.
Edwardsia microphylla (Ait.) Salisb.
Auckland, Piha, January 1946 (2 col.); Whangarei Heads, October 1947, J.M.D.;
Auckland city, Purewa bush, November 1948, J.M.D.
Lupinus arboreus L.
Auckland, Piha, July 1947, J.M.D.; Whatipu, June 1946, J.M.D.
Melicytus ramiflorus Forst.
Auckland, Waitakere Ra., off Anawhata Rd., June 1946, J.M.D.;
Whangarei, Parahaki, June 1948, J.M.D.
Muehlenbeckia australis Meissn.
Westland, Weheka, December 1946, J.M.D.
Nothopanax arboreum Seem.
Auckland, Waitakere Ra., off Anawhata Rd., August 1948, J.M.D.
Auckland city, December 1948, D. W. McKenzie.
Prunus persica Sieb. & Zucc.
Auckland, Massey, December 1947, E. E. Chamberlain.
Pyrus malus L.
Auckland, Mt. Albert, July 1949, A. Farmer.
Rhopalostylis sapida Wendl. & Drude.
Auckland, Waitakere Ra., Waiatarua, November 1946, J.M.D.;
Titirangi, April 1948, J.M.D.
Robinia pseudoacacia L.
Auckland city, Mt. Eden, August 1949, E. M. Hay.
Auckland, Mt. Albert, September 1948, D. W. McKenzie;
November 1948, D. W. McKenzie.
Ulex europaeus L.
Auckland, Waitakere Ra., Swanson, May 1946, J.M.D.;
Mt. Albert, November 1948, D. W. McKenzie.
This species is readily separated from N. grisea and N. quisquiliaris by its small, smooth spores. When fresh perithecia are translucent but pigment granules are absent from bleached weathered specimens. The diversity of form in the colour of perithecia and in the arrangement of the conidiophores substantiated Petch's suggestion (1938 and 1941) that N. seminicola Seaver and N. pallidula Cke. were synonyms. Field observations suggested that this species may be a wound parasite.
2. Nectria grisea nom. nov.
Sphaerostilbe variabilis Berk. & Br. J. Linn. Soc., Vol. 14, p. 115, 1875;
Sphaerostilbe hypocreoides Kalchbr. & Cooke. Grev., Vol. 9, p. 17, 1880;
Stilbocrea hypocreoides (Kalchbr. & Cke.) Seaver. Mycologia, Vol. 2, p. 62, 1910;
Sphaerostilbe henningsii Ferdinandsen & Winge. Bot. Tidsckrift Vol. 29, p. 12, 1908;
Sphaerostilbe placenta Theissen. Annales Mycologici, Vol. 9, p. 55, 1911.
Perithecia superficial, sometimes semi-immersed in tissue of the pulvinate, pseudoparenchymatous stroma 2–4mm. diameter, formed around base of stalked conidial stroma. Perithecia globose 0·2–0·3mm.
diameter, salmon, pale greyish green when dry and mature, cottony, ostiole umbilicate, distinctly pigmented. Perithecial wall hyaline, pigment granules present in cells in sub-hymenial layer, outer hyphal structure indistinct. Asci cylindrical, end rounded, 60–90 × 5–8μ, 4–8 spored, uniseriate, pseudoparaphyses evanescent. Spores one-septate, elliptical or oval 9–13 × 4–6μ, verrucose, hyaline. Conidial stage; conidiophores united into a synnema 1–3mm. high, heads globose, flesh or dark coloured 0·5–1mm. diameter; conidia oval or cylindrical 5–8 × 2μ, smooth, hyaline; Stilbum sp.
Type Locality: South Africa.
Distribution: South Africa, South America, Ceylon, Australia, New Zealand.
Habitat: Corynocarpus laevigata Forst.
Auckland, Piha, August 1946. J.M.D.
Dysoxylum specatabile (Forst. f.) Hook. f.
Auckland, Hunua Ra., October 1946, J.M.D.;
Coromandel, December 1946, J.M.D.;
Paihia, June 1948, J.M.D.;
Waitakere Ra. near Titirangi, May 1949, J.M.D.
Melicytus ramiflorus Forst.
Auckland, Auckland city, Purewa bush, August 1948, D. W. McKenzie;
Hunua Ra., Mangatawhiri Stream, October 1946, J.M.D.;
Coromandel, December 1948, J.M.D.
Rhopalostylis sapida Wendl. & Drude.
Auckland, Titirangi, Wood's Bay, July 1948, J.M.D.
The combination N. variabilis has been used to denote another species of Nectria, similarly the combinations N. hypocreoides, N. placenta and N. henningsis, therefore this species has been renamed. Types of the synonyms have not been examined but from the diagrams and descriptions in the literature they appear to be identical. The variation in colour between mature and immature species included forms which were described as different species. Patouillard defined Stilbocrea to include species with perithecia more or less buried in a fleshy stroma but like Sphaerostilbe it was associated with a Stilbum conidial stage. Morphologically these speeies are Nectria-like consequently the genus has been listed as a synonym.
3. Nectria quisquiliaris Cooke. Grevillea, Vol. 8, p. 65, 1879. Plate 23, fig. 3.
Perithecia superficial, free or caespitose, in groups of 2–10 on a small pseudoparenchymatous stroma 0·5–2mm. diameter, globose, collapsing when dry 0·2–0·4mm. diameter, farinaceous coral or flesh coloured, salmon pink when dry, ostiole small umbilicate; peritheeial wall pseudoparenchymatous 50μ diameter, cells 4–6μ diameter, walls hyaline, not thickened, pigment granules present within the cells, especially in sub-hymenial layer. Asci cylindrical sometimes clavate 35–80 × 6–12μ, 4–8 spored, biseriate; pseudoparaphyses evanescent. Spores one-septate, elliptical 12–20 × 4–7μ verrucose hyaline. Conidial stage; conidiophores verticillate, sometimes united to form a sporodochium, pale flesh coloured 0·5–0·3mm. diameter, conidia cylindrical or oval, one-celled 5–9 × 3–5μ hyaline smooth.
Type Locality: Melbourne, Australia.
Distribution: Australia, New Zealand.
Coprosma grandifolia Hook. f.
Auckland, Waitakere Ra., Rua-te-whenua, August 1949, J.M.D.
Coprosma robusta Raoul.
Auckland, Waitakere Ra., August 1948, J.M.D.
Cyathea dealbata Swartz.
Auckland, Waitakere Ra., August 1947, J.M.D.
Dysoxylum spectabile (Forst. f.) Hook. f.
Auckland, Whangarei Heads, October 1947, J.M.D.
Edwardsia microphylla (Ait.) Salisb.
Auckland, Whangarei Heads, October 1947, J.M.D. (2 col);
Auckland city, Purewa bush, August 1948, J.M.D.;
November 1948, D. W. McKenzie.
Melicytus ramiflorus Forst.
Auckland, Waitakere Ra., October 1946, J.M.D. August 1947, J.M.D.; August 1948, J.M.D.
Nothopanax arboreum Seem.
Auckland, Waitakere Ra. off Anawhata Rd., September 1948, J.M.D.
Pseudowintera colorata (Raoul) Dandy
Otago, Hollyford Valley, January 1950, J.M.D.
Schefflera digitata Forst.
Westland, Weheka, December 1946, J.M.D.
The large verrucose spores separate this species from N. ochroleuca. Perithecia are farinaceous, not cottony as in N. grisea and caespitose on the old conidial stroma. Observations suggest that the species is a saprophyte on dead wood but occasionally penetrated living tissue as a wound parasite.
Though the part of Cooke's type lent by Kew herbarium showed no mature perithecia the distinct morphological characters of the immature perithecia were identical with local collections. No conidia were found on the type labelled ‘conidial stage’ from Dunedin, New Zealand.
4. Nectria byssiseda Rehm. in Rabh.-Pazschke, Fung. extra-europ. No. 4152, 1900.
Perithecia scattered or gregarious, 3–6 perithecia united on a poorly developed, gelatinous stroma, globose or oval, collapsing when dry 0·1–0·2mm. yellow, translucent, ostiole small, not distinct. Perithecial wall pseudoparenchymatous 10–20μ thick, cells 2–6 × 2μ, cell walls not thickened but lightly pigmented. Asci clavate or elliptical 20–45 × 4–6μ thin walled, 8 spored, obliquely uniseriate or biseriate; pseudoparaphyses evanescent. Spores one-septate, fusiform, oblong or elliptical, occasionally allantoid, ends rounded sometimes constricted at septa 7–10·5 × 2–3μ verrucose, hyaline sometimes lightly tinted yellow.
Type Locality: France.
Distribution: Europe, New Zealand.
Macropiper excelsum Miq.
Auckland, Whangarei Heads, Maniha, October 1947, J.M.D. Hansford (1946) suggested that N. bakeri Rehm. and N. perpusilla Sacc. were probably synonymous with this species, while Calonectria inconspicua Whit. and N. pipericola Rehm. differed in that perithecia were hairy. All these species are parasitic on sooty moulds.
Perithecia are translucent, light coloured, often yellow, and with small fusiform ascospores. In this species the filiform spores are truncated at the ends and the thin translucent, lightly pigmented perithecial walls collapsed when specimens were dried.
5. Nectria manuka sp. nov.
Perithecia gregaria in subiculo effuso et hyalino, globosa 0·15–0·35mm. cremea vel pallide brunnea, pilosa; ostiolo minuto et umbilicato; pariete perithecii pseudoparenchymato 20–30μ crasso; cellulis 5–8 × 5–10μ; parietibus leviter tinctis, raro densatis. Asci cylindrici, interdum elliptici 35–60 × 5–6μ; 8 sporis, in apice oblique uniseriatis; pseudoparaphysibus absentibus. Sporae uniseptatae, ovatae vel ellipticae 5–9 × 2·5–4μ leves, hyalinae.
Perithecia gregarious, aggregated on an effuse, byssoid subiculum, globose collapsing, becoming pezizoid when dry 0·15–0·35mm. diameter, cream or light brown, hairy, ostiole minute; perithecial wall pseudoparenchymatous 20–30μ thick, cells rectangular or cuboid 5–8 × 5–10μ, walls lightly pigmented, rarely thickened. Asci cylindrical, sometimes elliptical 35–60 × 5–6μ thin-walled, 8 spored, obliquely uniseriate at apex, pseudoparaphyses absent. Spores one-septate, oval or elliptical 5–9 × 2·5–4μ, smooth, hyaline.
Type Locality: Mt. Albert, Auckland.
Distribution: New Zealand.
Leptospermum ericoides A. Rich.
Auckland, Mt. Albert, September 1948, D. W. McKenzie, type collection. Unknown host.
Auckland city, December 1948, D. W. McKenzie.
The species resembles N. peziza but spores are smaller and perithecia are covered with hairs. This species and the following two are characteristic of Maire's genus Nectriopsis (syn. Hyphonectria Petch) in that they possess the growth habit of a Hypomyces, but spores are typical of Nectria.
6. Nectria berkeleyana (Plowr. and Cooke) n. comb.
Hypomyces berkeleyanus Plowr. & Cooke. Grevillea Vol. II, p. 48, 1882.
Nectriopsis berkeleyana (Plowr. & Cooke) Maire. Annales Mycologici, Vol. 9, p. 323, 1911;
Hyphonectria berkeleyana (Plowr. & Cooke) Petch.
J. of Bot., Vol. 75, p. 220, 1937.
Perithecia gregarious on a vinaceous subiculum on undersurface of host pileus, pyriform or oval 0·25–0·3 × 0·5–0·2mm., ostiole papillate, perithecial wall pseudoparenchymatous 25–35μ, outer cells up to 6μ diameter, walls pigmented but not thickened, inner cells rectangular 8 × 2μ, hyaline. Asci cylindrical, ends truncate 80–95 × 3–4μ, 8 spored, uniseriate, pseudoparaphyses evanescent. Spores one-septate, oval, obovate or elliptical 7·5–10 × 3–4μ, pale yellow, verrucose.
Type Locality: England.
Distribution: England, New Zealand.
Stereum rameale Schw.
Auckland, Waipoua, September 1949, J.M.D.
The colour of this species appeared more intense than Petch (1938) described, but other characters agree with his description. In this New Zealand collection a massive subiculum covers the undersurface of the host pileus and the spores are typically oval, not apiculate is in Hypomyces.
7. Nectria aemulans Rehm. Annales Mycologici, Vol. 7, p. 539, 1909. Plate 24, fig. 9.
Perithecia scattered or gregarious on a thin, effuse, hyaline subiculum 20μ thick, globose, pezizoid when dry 0·2–0·3mm. diameter, salmon pink, translucent and hairy, ostiole papillate; perithecial wall pseudoparenchymatous 40μ thick, cells 4–6 × 5–10μ, thin walled, lightly pigmented yellow, sub-hymenial layer pigmented but structure difficult to discern. Asci elavate or elliptical thin walled 50–75 × 8–10μ, 6–8 spored, biseriate, pseudoparaphyses diffluent. Spores one-septate, elliptical or fusiform, ends truncate 14–20 × 4–6μ, smooth, hyaline.
Type Locality: Sao Lepoldo, South Brazil.
Distribution: South America, New Zealand.
Cyathea medullaris Swartz.
Auckland, Waitakere Ra., Anawhata Rd., March 1948, J.M.D.;
Henderson, Stony Creek, April 1948, J.M.D.; May 1948, J.M.D.
Hunua Ra., Moumoukai Valley, June 1949, J.M.D.
Specimens agree with Rehm's description. Both occurred on dead fern stipes. Rehm remarked that the species had the growth habit of Hypomyces. Local collections form a salmon pink mass on fallen stipes of Cyathea medullaris. Colonies are fringed with a mass of white mycelium in which perithecia are semi-immersed. Spores are longer than those of the two preceding species, and fusiform not oval as in N. peziza.
8. Nectria peziza (Tode) Fr. Summa Vegetabilium Scandinaviae, p. 388, 1849.
Sphaeria peziza Tode ex Fr. Syst. Myc., Vol 2, p. 452, 1822;
Dialonectria peziza (Tode) Cooke. Grevillea, Vol, 12, p. 110, 1884. Plate 22, 2a and b.
Perithecia free, scattered or gregarious on a poorly developed stroma, globose, collapsing and becoming pezizoid when dry 0·1–0·3mm. diameter, coral coloured, translucent, farinaceous, some-times hairy, ostiole papillate; perithecial wall pseudoparenchymatous 60μ wide, cells up to 10μ. diameter, cell walls lightly pigmented, not thickened. Asci cylindrical, sometimes clavate 60–75 × 7–12μ., 4–8 spored, biseriate at apex; pseudoparaphyses filamentous and branched. Spores one-septate, broadly elliptical or oval 9–16 × 3·5–6μ, smooth, hyaline.
Type Locality: Mecklenburg, Germany.
Distribution: Europe, North America, New Zealand.
Hoheria populnea A. Cunn.
Auckland, Titirangi, March 1946, J.M.D.
Auckland, Auckland city, Purewa bush, November 1948.
D. W. McKenzie; Titirangi, May 1948, J.M.D.
Thyronectria polytricha (Schw.) Seeler.
Auckland, Waitakere Ra., off Anawhata Rd., April 1948, J.M.D.
Perithecia are lightly coloured, translucent and thin walled often among hairlike white mycelium. Spores are broadly oval and similar to those of N. tawa, not fusiform as in N. aemulans.
9. Nectria hauturu sp. nov.
Perithecia libere sparsa vel gregaria, in stromate parvo et erum-penti, globosa 0·3–0·5mm. diameter, corallina, corruentia; ostiolo umbilicato; pariete perithecii pseudoparenchymato 120μ. crasso; cellulis densatis et leviter tinctis. Asci cylindrici vel clavati 50–90 × 8–10μ; 4–8 sporis biseriatis; psendoparaphysibus. Sporae uniseptatae, fusi-formes, ellipticae vel ovatae, 9–26 × 4–8μ, leves, hyalinae.
Perithecia scattered or aggregated into groups of 2–10 seated on a poorly developed erumpent stroma, globose 0·3–0·5mm. coral or salmon pink, collapsing when dry, ostiole umbilicate; perithecial wall pseudoparenchymatous 120μ thick, outer cells 10–20μ diameter, walls lightly thickened and pigmented, subhymenial cells 3–4μ diameter, walls thickened and pigmented. Asci clavate or cylindrical 50–90 × 8–10μ, 4–8 spored, biseriate; pseudoparaphyses filamentous, branched. Spores one-septate, sometimes unequally divided by septa, fusiform, elliptical or oval, occasionally allantoid, rarely spherical, 9–26 × 4–8μ smooth, hyaline.
Type Locality: Little Barrier Island, New Zealand.
Distribution: New Zealand.
Auckland, Little Barrier Isl., December 1947, J.M.D. type collection.
Similar to N. cinnabarina differing in that perithecia are lighter coloured and spores irregular in shape and size. Perithecia collapse when dry. They are aggregated into clusters of 3 to 10 on a small erumpent stroma.
10. Nectria ruapehu sp. nov.
Perithecia gregaria vel caespitosa in stromate parvo et pseudo-parenchymato; globosa, 0·2–0·5mm. diam., corallina, translucida; ostiolo obscuro; pariete perithecii pseudoparenchymato 55–60μ crasso; cellulis exterioribus hyalinis; cellulis interioribus leviter tinctis. Asci cylindrici 45–65 × 6μ; parientibus tenuibus; 8 sporis, oblique uniseriatis; pseudoparaphysibus absentibus. Sporae uni-septatae, late ellipticae, 8–11 × 5–6μ, verrucosae, pallide luteae.
Perithecia gregarious or caespitose on or immersed in a poorly developed pseudoparenchymatous stroma, globose 0·2–0·5mm. diameter, coral coloured darker when mature, translucent, ostiole small, indistinct, perithecial wall pseudoparenchymatous 55–60μ thick, cells 8–10μ diameter, outer cells thick walled but hyaline, inner cells pigmented. Asci cylindrical 45–65 × 6μ, 8 spored, obliquely uniseriate; pseudoparaphyses diffluent. Spores one-septate, broadly elliptical constricted at septa 8–11 × 5–6μ, sometimes non-septate, globose, 6–8μ diameter, verrucose, yellow, thick walled.
Type Locality: Mangatorutoru Stream, Mt. Ruapehu.
Distribution: New Zealand.
Coprosma pseudocuneata Oliver.
Wellington, Mangatorutoru Stream, Mt. Ruapehu, March 1948, J.M.D. type collection; Whakapapa-iti Stream, October 1949, J.M.D.
Perithecia appear in small clusters of 3–10 often on an old leaf sear at the base of a lateral branch. Spores are broader than those of N. hauturu and perithecia are immersed in the stroma similar to a Hypocrea. The perithecial wall consists of thick walled, almost hyaline cells.
11. Nectria galligena Bresadola ex Strassr. Vert. Zool.-bot. Ges. Wien, Vol. 51, p. 413, 1901.
Dialonectria galligena (Bres.) Petch. Catalogue of Yorkshire Fungi, p. 37, 1937.
Perithecia separate, scattered or gregarious in groups of 3 or 4, oval or globose 0·15–0·3 × 0·25–0·4mm., dull red, darker when mature, smooth, ostiole papillate and surrounded by a smooth ring of tissue, perithecial wall pseudoparenchymatous 50μ thick, cells 5–8μ diameter, rectangular or cuboid, walls pigmented and densely thickened. Asci clavate or cylindrical 60–100 × 8–10μ, 8 spored, obliquely uniseriate, occasionally biseriate at apex, pseudoparaphyses filamentous and branched. Spores one-septate, sometimes constricted at septa, elliptical or broadly oval 14–20 × 4–7μ, hyaline, smooth. Conidial stage; conidiophores aggregated into small, white tufted pustules, conidia cylindrical, linear, sometimes curved 3–4 septate 20–30 × 2μ Cylindrocarpon wilkommi (Lind.) Wollenw.
Type Locality: Austria.
Distribution: Europe, North and South America, South Africa, Japan, New Zealand.
Pyrus malus L.
Auckland, Whangarei, April 1925, P. E. Everett (3 col.); Auckland city, July 1946, Hort. Div.; October 1947. Anon.; New Lynn, July 1939, P. Fry; Mt. Albert, July 1948, D. W. McKenzie; September 1949, J. A. Hunter; Henderson, December 1949, Hort. Div.
N. galligena, a species which causes considerable damage to branches of apple trees, has been collected from the Auckland province. T. W. Kirk (1905) recorded apple canker from New Zealand but identified the casual organism as N. ditissima Tul. Cayley (1921) stated that the fungus responsible for apple canker in England was N. galligena, not N. ditissima. Cunningham (1925) recorded N. galligena from material collected near Whangarei.
Perithecia are small and dark coloured, a stroma is not present and asci are rounded at the apex, not truncate as in N. punicea. As the species is found only on an introduced host, it is probable that it has been introduced into New Zealand.
12. Nectria fragilis sp. nov.
Perithecia gregaria in corona erumpenti, globosa 0·2–0·4mm. diam., miniata ad colorem ferrugineum pallescentia; ostiolo papillato; pariete perithecii pseudoparenchymato 40–50μ crasso; cellulis 5–15μ diam., parietibus densatis et tinctis. Asci clavati vel elliptici; 8 sporis biseriatis. Sporae uniseptatae, ellipticae, filiformes, 15–22 × 4·5–6μ, leves, hyalinae.
Status conidialis. Conidia globosa vel elliptica, 3–7 × 3–4μ.
Perithecia gregarious in erumpent clusters of 10 or more, stroma absent; globose 0.2–0.4mm. diameter, scarlet, fading to ferruginous, wrinkled occasionally with irregular tubercles, ostiole distinct, papillate and surrounded by a disc of smooth tissue; perithecial wall pseudoparenchymatous 40–50μ thick, cells 5–15 × 5–10μ, rectangular or cuboid, pigmented and thickened. Asci elliptical or clavate, 74–110 × 10–14μ, 8 spored, spores biseriate, occasionally uniseriate at base, pseudoparaphyses filamentous, branched. Spores one-septate, elliptical, filiform 15–22 × 4·5–6μ, smooth, hyaline. Conidial stage; conidiophores stout, compacted to form a pale salmon stroma, conidia globose or elliptical 3–7 × 3–4μ. Tubercularia sp.
Type Locality: Lower Hollyford, Otago.
Distribution: New Zealand.
Habitat: Pseudowintera colorata (Raoul) Dandy.
Otago, Lower Hollyford, January 1950, J.M.D. (2 col. one being type).
Perithecia are globose, never oval as in N. galligena and sometimes covered with scalelike tubercles. Spores are arranged biseriately in the ascus, elliptical, or broadly elliptical, never oval.
13. Nectria otagensis Currey ex Lindsay in Trans. Royal Soc. Edinburgh, Vol. 24, pp. 407–457, 1867.
Calonectria otagensis (Linds.) Sacc. Sylloge Fungorum Vol. 2 addenda p. 68, 1883.
Perithecia caespitose, semi-immersed in a salmon pink, fleshy, pulvinate prosenchymatous stroma 1–3mm. diameter; perithecia globose 0·1–0·45mm. ostiole papillate and pigmented; perithecial wall pseudoparenchymatous, cells loosely aggregated 75μ thick, outer cells thickened and pigmented, sub-hymenial layer hyaline, cells thin walled. Asci cylindrical or clavate 50–120 × 6–10μ, 8 spored, uniseriate; pseudoparaphyses filamentous. Spores one-septate, elliptic-oblong, 12–20 × 4–8μ smooth, hyaline.
Type Locality: Green Island bush, near Dunedin, New Zealand.
Distribution: Australia, New Zealand.
Habitat: Melicytus ramiflorus Forst.
Wellington, Weraroa, September 1919, E. H. Atkinson; May 1923, G. H. Cunningham; Wanganui, Kahi, December 1932, E. E. Chamberlain.
Stewart Isl., February 1882, T. Kirk.
Superficially this species appears similar to species of Hypocrea for as in N. ruapehu perithecia are immersed in the stroma; but the spores are typical of Nectria. Saccardo (1883) included the species in the genus Calonectria; it seemed probable that he misinterpreted as septa the large vacuoles of the immature spores.
14. Nectria aurantiicola Berkeley and Broome. Journal of Linnean Soc., Vol. 14, p. 117, 1875.
Sphaerostilbe coccophila Tul. 1865 quad Rabenhorst Fungi Europaei Exsicc. Ed. nov. Ser. II, No. 262, p. 269; S. aurantiicola (Berk. and Br.) Petch Ann. Perad. Vol. 7, p. 119, 1920; Nectria coccophila (Tul.) Wollenw & Reinking, Die. Fusarien, pp. 34–36, 1935 (in part); N. episphaeria f. coccophila Snyder & Hausen Am. J. of Bot., Vol. 32, p. 665, 1945.
Perithecia caespitose or gregarious, superficial on scale insects, oval or pyriform 0.1–0.25 × 0.2–0.3mm. blood red, dark red, or black when mature and dry, ostiole distinctly papillate, perithecial wall pseudoparenchymatous 20–30μ thick, cells 4–6μ diameter, cell walls pigmented but not thickened. Asci cylindrical or clavate, ends truncate 55–90 × 5–8μ, 8 spored, uniseriate; pseudoparaphyses evanescent. Spores one-septate, oval, or elliptical 8–15 × 3.5–6μ verrucose, light brown.
Conidial stage, conidiophores united to form a stalklike or pulvinate stroma, coral or scarlet, conidia 6–9 septate, cylindrical, filiform, sometimes falcate, apex apiculate 60–90 × 4–5.5μ a few sporidia 3 septate, crescent shaped 12–13 × 4μ. Fusarium coccophilum (Desm.) Wollenw. & Reinking, or Microcera aurantiicola Petch.
Type Locality: Ceylon.
Distribution: North America, Europe, India, Japan, South Africa, Australia, and New Zealand.
Habitat: on scale insects on Citrus sp.
Auckland, Tauranga, October 1926, P. Everett; February 1936, W. Cottier.
On scale insects on Pyrus malus L.
Auckland, Thames, November 1926, P. Everett.
On scale insects on Meryta sinclairii Seem.
Auckland city, December 1948, D. W. McKenzie.
On scale insects on Entelea arborescens R. Br.
Auckland city, December 1948, D. W. McKenzie.
Under N. coccophila Tul. Wollenweber & Reinking (1935) included all species of Nectria with a Fusarium conidial stage which attacked scale insects. Petch (1921) separated this species from N. flammea by its smaller perithecia and spores, and absence of stroma.
15. Nectria flammea (Tulasne) comb. nov.
Sphaerostilbe flammea (Tul. Sel. Fungi. Carp. 1, p. 138, 1861; S. coccophila Tul. (1865) quoad Desm. Plantes Crypt. de France 2nd Ed. ser. I, No. 1350 et 1st Ed. ser. I, No. 1750.
Perithecia caespitose on a well developed, pulvinate pseudoparenchymatous stroma 0.5–2.5mm. diameter, formed at the base of a stalked conidial stroma, globose or pyriform, 0.2–0.3mm. diameter scarlet, darker when mature, rugose, ostiole papillate and surrounded by a distinct darker coloured area, perithecial wall pseudoparenchymatous 40μ thick, cells 3–5μ diameter, cell walls pigmented and thickened, sub-hymenial layer hyaline but mycelium evanescent. Asci cylindrical, ends rounded 100–150 × 7–10μ, 4–8 spored, uniseriate; pseudoparaphyses evanescent. Spores one-septate, sometimes constricted at septa, elliptical or oval 15–24 × 6–10μ, verrucose, light brown, thin walled. Conidial stage; conidiophores usually united into synnema, flesh coloured sometimes scarlet, translucent, spores 4–9 septate, cylindrical, filiform, usually falcate, apex apiculate 34–95 × 3–6μ, hyaline. Microcera coccophila Desm.
Type Locality: Europe.
Distribution: Europe, North and South America, South Africa, Australia, New Zealand.
Scale insects on Brachyglottis repanda Forst.
Auckland, Hunua Ra., Moumoukai Valley, October 1946, J.M.D.; Turangi, Mt. Pihanga, 2,000ft. October 1949, J.M.D.
Scale insect on Coprosma areolata Cheesem.
Auckland, Whangarei Heads, October 1947, J.M.D.
Scale insects on Coprosma grandifolia Hook. f.
Auckland, Waitakere Ra., Cascade Kauri Park, December 1947, J.M.D.
Scale insects on Dysoxylum spectabile Hook. f.
Auckland Henderson, May 1948, J.M.D.
Scale insects on Melicytus ramiflorus Forst.
Auckland, Little Barrier Isl., December 1947, J.M.D. (2 col.).
Scale insects on Ribes sativum Syme.
Auckland, Tauranga, August 1947, A. R. Grainger;
Mt. Albert, July 1948, D. W. McKenzie.
Scale insects on Solanum auriculatum Ait.
Auckland, Orakei, September 1948, D. W. McKenzie.
Scale insects on unknown host.
Wellington, Weraroa, December 1924, G. H. Cunningham.
Lloyd incorrectly identified the collection from Weraroa on an unknown host as N. illudens. In N. illudens perithecia are tuberculate and spores marked with longitudinal striae. The conidial stage is similar to that of N. aurantiicola but Petch (1921) differentiated between the two species as small curved 3 septate conidia are common in N. aurantiicola only. He recorded the conidial stage only from New Zealand material in Herbarium Kew collected by W. Colenso.
16. Nectria punicea (Kunze and Schmidt) Fries. Summa Vegetabilium Scandinaviae, p. 387, 1849.
Sphaeria punicea Kunze & Schmidt ex Fries. Syst Myc. Vol. 2, p. 415, 1822; Nectria ditissima Tul. Sel. Fung. Carp., Vol. 3, p. 72, 1865.
Perithecia superficial, gregarious on an erumpent pseudoparenchymatous stroma, translucent, gelatinous when fresh, globose 0.2–0.3mm. bright red, darker when mature, ostiole distinct, dark coloured, papillate; perithecial wall pseudoparenchymatous 20–30μ thick, cells 4–7μ diameter, walls pigmented and thickened. Asci cylindrical occasionally clavate, apex truncate when immature, 60–100 × 6–10μ, 8 spored, uniseriate, occasionally biseriate at apex; pseudoparaphyses filamentous. Spores one-septate, elliptical 14–18 × 5–8μ hyaline and verrucose.
Type Locality: Europe.
Distribution: Europe, North America, New Zealand.
Aristotelia serrata (Forst.) Oliver.
Auckland, Turangi, Mt. Pihanga 1,500ft, October 1949, J.M.D.
Auckland, Waitakere Ra., Henderson, May 1948, J.M.D.
Coprosma areolata Cheesem.
Auckland, Whangarei Heads, October 1947, J.M.D.
Coprosma foetidissima Forst.
Otago, Upper Hollyford Valley, January 1950, J.M.D.
Coprosma robusta Raoul.
Auckland, Turangi, Mt. Pihanga 2,000ft, October 1949, J.M.D.
Pittosporum colensoi Hook. f.
Auckland, Ruapehu Mt. Whakapapa-iti stream, October 1949, J.M.D.
Pittosporum eugenioides A. Cunn.
Auckland, Turangi, Pihanga Mt. 2,000ft, October 1947, J.M.D.
Wellington, Botanical Gardens, October 1922, G. H. Cunningham.
Sydow, 1924, recorded the last collection as N. galligena forma. Spores of this species are verrucose and larger than in N. galligena. When immature a thickened truncated apex protrudes above the contents of the ascus.
17. Nectria coccinea (Pers.) Fr. Summa Vegetabilium Scandinaviae, p. 388, 1849.
Sphaeria coccinea Pers. ex Fr. Syst. Mycol., Vol. 2, p. 412, 1822.
Creonectria coccinea (Pers.) Seaver. Mycologia Vol. 1, p. 188, 1909.
Perithecia caespitose on a pulvinate erumpent pseudoparenchymatous ochraceous stroma, 2–3mm. diameter, globose or oval 0·2–0·25mm. diameter, scarlet, ostiole distinct, papillate; perithecial walls pseudoparenchymatous 20–30μ thick, cells 5–10 × 8–12μ diameter, cell walls pigmented and thickened. Asci cylindrical or clavate 80–110 × 8–10μ, 4–8 spored, obliquely uniseriate, biseriate at apex; pseudoparaphyses evanescent. Spores one-septate, elliptical or fusiform 14–20 × 5–8μ echinulate, hyaline. Conidial stage; conidiophores united to form a pulvinate sporodochium, orange or red coloured, conidia cylindrical, occasionally falcate 3–6 transverse septa 28–30 × 2·5–4μ. Fusarium sp.
Type Locality: Europe.
Distribution: Europe, North and South America, Australia, New Zealand.
Westland, Weheka, Fox Glacier Rd., December, 1946, J.M.D.
Cooke (1879) recorded N. coccinea from New Zealand. Unlike in N. punicea a well defined stroma is present and spores are minutely echinulate not verrucose.
18. Nectria sanguinea (Bolton) Fries. Summa Vegetabilium Scandinaviae, p. 388, 1849.
Sphaeria sanguinea Bolt. ex. Fr. Syst. Myc., Vol. 2, p. 453, 1823; S. epishaeria Tode ex Fr. Syst. Myc. Vol. 2, p. 454, 1823; Nectria episphaeria (Tode) Fr. Summa Veg. Scand. p. 388, 1849; Dialonectria episphaeria (Fr.) Cooke. Grevillea Vol. 12, p. 82, 1884; D. sanguinea (Bolt.) Cooke. Grevillea Vol. 12, p. 110, 1884.
Perithecia superficial, scattered or caespitose in groups of 2–6, stroma occasionally present, globose, oval or pyriform, often collapsing when dry 0·15–0·25mm. diameter, scarlet, ostiole distinctly papillate; perithecial wall pseudoparenchymatous 30μ thick, cells 5–6μ diameter, mycelial walls pigmented and thickened. Asci cylindrical 48–95 × 5–6μ, 8 spored, uniseriate; pseudoparaphyses evanescent or absent. Spores one-septate, oval, often constricted at septa 6–14 × 3–5μ, tuberculate, light brown or yellow.
Type Locality: Nova-Scotia, Canada.
Distribution: Europe, North and South America, Australia, New Zealand.
Auckland, Mt. Albert, September 1948, D. W. McKenzie.
Fomitopsis hemitephra (Berk.) G. H. Cunningham.
Otago, Otautau, November 1946, G. B. Rawlings.
Auckland, Hunua Ra., July 1946, J.M.D. September 1947. J.M.D.; June 1949, J.M.D.; Little Barrier Isl., November 1947, J.M.D. (5 col.); Waitakere Ra., Titirangi, May 1948, J.M.D.
Wellington, Weraroa, September 1919, G. H. Cunningham (2 col.); Butterfly Reserve, May 1947, G. B. Rawlings.
Otago, Lower Hollyford Valley, January 1950, J.M.D.
Lupinus arboreus L.
Auckland, Piha, July 1947, J.M.D.
Unknown Sphaeriaceous fungi.
Auckland, Turangi, slopes of Mt. Pihanga, October 1949, J.M.D.; Waitakere Ra., Titirangi, June 1949, J.M.D.; Rua-tewhenua, August 1949, J.M.D.
The species was first recorded from Hawke's Bay by Colenso (1886) from material determined by M. C. Cooke as N. episphaeria. Seaver (1909) separated N. episphaeria and N. sanguinea on spore characters and the nature of the host but noted that the two species were similar. The differences in spore size and shape used by Seaver to separate the two species were present in any one of above collections. Petch's findings that the two species were synonyms was followed. Wollenweber (1931) listed Fusarium aquaeductum Lagerh. var. medium Wollenw. as the conidial stage of N. episphaeria; Snyder and Hansen (1945) renamed this conidial stage as Fusarium episphaeria. No conidial form was found in the New Zealand collections.
19. Nectria cinnabarina (Tode) Fries. Summa Vegetabilium Scandinaviae, p. 383, 1849.
Sphaeria cinnabarina Tode ex Fr. Syst. Myc., Vol. 2, p. 412, 1822.
Nectria purpurea (L.) Wilson & Seaver. Jour. Mycology, Vol. 13, p. 51, 1907.
Creonectria purpurea (L.) Seaver. Mycologia, Vol. I, p. 184, 1909.
Perithecia superficial, caespitose on an erumpent, pulvinate pseudoparenchymatous stroma 1–3mm. diameter, globose 0·2–0·4mm. diameter, vermilion, umber when overmature, tuberculate, ostiole papillate and surrounded by a distinct darkly pigmented zone, perithecial wall 40μ thick, pseudoparenchymatous cells 5–6μ diameter, walls pigmented and thickened. Asci clavate sometimes shortly stalked 45–80 × 6–12μ, 8–spored, biseriate, pseudoparaphyses filamentous, branched. Spores one-septate, elliptical or obovate, occasionally allantoid 14–17 × 3–6μ hyaline, smooth. Conidial stage; conidiophores 50–100μ long, compacted together to form an erumpent pulvinate sporodochium, scarlet or orange, translucent when fresh; conidia one-celled, oblong oval or cylindrical, sometimes allantoid 6–8 × 2–5μ
hyaline. Tubercularia vulgaris Tode.
Type Locality: Europe.
Distribution: Europe, North America, Ceylon, Tasmania. New Zealand.
Otago: Invercargill, November 1949, D. A. Richards.
Cytisus scoparius Link.
Wellington, September 1919, E. B. Levy.
Edwardsia microphylla (Ait.) Salisb.
Otago: Ravensbourne, December 1919, G. H. Cunningham.
Juglans regia L.
Canterbury: Christchurch, May 1947, G. B. Rawlings.
Otago: November 1919, G. H. Cunningham.
Prunus armeniaca L.
Otago: December 1919, G. H. Cunningham.
Prunus avium L.
Otago: February 1947, J. D. Atkinson.
Prunus persica Sieb. & Zucc.
Otago: December 1919, G. H. Cunningham.
Pyrus communis L.
Hawke's Bay, Hastings, August 1922, G. H. Cunningham.
Ribes sanguineum Pursh.
Otago, Earnscleugh, September 1949, F. O. McCarthy.
Ribes sativum Syme.
Otago: Queenstown, February 1948, J.M.D.
Kirk first recorded N. cinnabarina from New Zealand in 1905 on Prunus armeniaca L. Cunningham (1925b) recorded the species from stone and pome fruits, small fruits, horse chestnut, mulberry, silver birch, maple and broom. Up to the present this species has been recorded only on one native host, suggesting that it has been introduced on some cultivated plant.
20. Nectria zelandica Cooke. Grevillea, Vol. 8, p. 65, 1879.
Perithecia caespitose on a pseudoparenchymatous stroma 0·5–1mm. diameter, globose 0·2–0·35mm. diameter, scarlet, fading to coral sometimes farinaceous, usually tuberculate, ostiole darker coloured papillate; perithecial wall pseudoparenchymatous up to 50μ thick, cells 4–10μ diameter, cell wall thickened and pigmented. Asci cylindrical or clavate 80–100 × 8–12μ ends rounded, 4–8 spored, uniseriate, biseriate at apex, occasionally biseriate, pseudoparaphyses absent. Spores one-septate, occasionally unicellular, elliptical or oval, 12–22 × 5·5–8μ, hyaline, smooth. Conidial stage; conidiophores united to form an erumpent sporodochium, coral coloured, darker when dry, spores cylindrical, ends apiculate, foot cells well defined, occasionally falcate 29–60 × 2·5–4μ, 3–5 septate, mostly 4. Fusarium sp.
Type Locality: Little River, Banks Peninsula, Canterbury.
Distribution: New Zealand, Australia.
Hoheria glabrata Sprague & Summerh.
Otago: L. Te Anau, February 1948, J.M.D.; Arthur R., Milford Sound, February 1948, J.M.D.
Wellington, Weraroa, G. H. Gunningham. September 1919.
Although similar to N. cinnabarina this species has been separated by its irregularly shaped spores; these are broader and vary in length from 12 to 20μ. Spores from part of the type collection forwarded from Kew Herbarium were smaller than the measurements given by Cooke. Irregular warts are well developed on perithecia in the type collection and in specimens from Weraroa but are reduced to scales in collections from Hoheria.
21. Nectria haematococcus Berkeley and Broome. J. Linnean Soc., Vol 14, p. 116, 1873.
Dialonectria haematococcus Cke. Grevillea, Vol. 12, p. 110, 1883; Nectria diversispora Petch. Annales Perydeniya Vol. 3, p. 4, 1906; Hypomyces haematococcus Reinke & Wollenw. Ang. Bot., Vol. 8, p. 191, 1926.
Perithecia free, occasionally gregarious on a poorly developed stroma, globose 0·35–0·5mm. diameter, orange or scarlet tuberculate; perithecial wall pseudoparenchymatous 60μ wide, tubercles up to 100μ high, cells 10–30μ diameter, walls pigmented and thickened. Asci clavate or cylindrical 70–100 × 8μ, 4–8 spored, obliquely uniseriate, biseriate at apex, pseudoparaphyses evanescent. Spores one-septate, ovate or oval, sometimes pyriform 12–17 × 6–8μ, sometimes constricted at septa, striate and lightly tinted yellow. Conidia borne in clusters 0–4 septate, cylindrical, sometimes curved, foot cells clearly defined 16–40 × 4–6μ. Fusarium solani (Mart.) Appel & Wollenw.
Type Locality: Ceylon.
Distribution: Asia. Africa. Central and South America, New Zealand.
Hedycarya arborea Forst. f.
Auckland, Purewa bush, September 1948, D. W. McKenzie.
Knightia excelsa R. Br.
Auckland, Pirongia, December, 1945, J.M.D.
Melicytus ramiflorus Forst.
Auckland, Whangarei, June 1948, J.M.D.
Auckland, Waitakere Ra., November 1941, J.M.D.
Wollenweber (1913) interpreted the genus Hypomyces to include all species with chlamydospores in their conidial stage for he held this feature was more important than perithecial characters. He included many Nectria species in Hypomyces. Petch (1920) suggested that N. cancri Rutgers and N. coffeicola Zimmerman were synonymous with N. haematococcus. Wollenweber (1943) listed N. citri P. Henn., N. asperata Rehm., N. luteo-coccinea Hoehnel and N. victoriae P. Henn. as synonyms, but treated N. cancri as a variety of N. haematococcus.
22. Nectria illudens Berkeley. Flora Tasmaniae, Vol. 2, p. 203, 1860. Plate 24, fig. 6.
Perithecia scattered, stroma absent, globose 0·4–0·5mm. diameter, tuberculate, ochraceous, umber or scarlet, ostiole distinct, papillated; perithecial wall pseudoparenchymatous 70μ thick, tubercles 100μ high, cells large 20–30μ diameter, cell walls thickened and pigmented. Asci elliptical cylindrical, usually truncate at apex 54–160 × 10–15μ, 4–8 spored, spores obliquely uniseriate in ascus. pseudoparaphyses evanescent. Spores one-septate, slightly constricted at septa, broadly elliptical, sometimes oval, 20–30 × 10–14μ, often constricted at septa, striate, lightly tinted yellow, thick walled (1μ diameter).
Type Locality: New Zealand.
Distribution: New Zealand.
Brachyglottis repanda Forst.
Auckland. Hunua Ra., Moumoukai Valley, October 1946.
Corynocarpus laevigata Forst.
Auckland, Waitakere Ra., Henderson, January 1948, J.M.D.
Dysoxylum spectabile (Forst. f.) Hook. f.
Auckland, Little Barrier Isl., December 1947, J.M.D.
Melicytus ramiflorus Forst.
Auckland, Hunua Ra., Moumoukai Valley, October 1946, J.M.D.; Waitakere Ra., Piha Valley, June 1946, J.M.D.; September 1948, J.M.D.; Henderson, Mountain Rd., May 1948, J.M.D.; Rua-te-whenua, August 1949, J.M.D.
Wellington, Weraroa, May 1919, G. H. Cunningham.
Auckland, Swanson, November 1941, J.M.D.
Wellington, York Bay, July 1923, E. J. Butler and G. H. Cunningham.
The external appearance is similar to that of N. haematococcus but the striate spores are larger. Young perithecia are first scarlet, becoming orange or ochraceous when mature.
23. Nectria balsanae Spegazini. Annal. Soc. Cientif., Vol. 16, p. 233, 1883.
N. subfurfuracea P. Henn & E. Nym. Monsunia, Vol. 1, p. 64, 1899.
Perithecia gregarious on an erumpent prosenchymatous stroma, colonies up to 1 cm. diameter, perithecia globose or oval 0·2–0·3mm. diameter, tuberculate, red or coral, farinaceous with crystals secreted by the perithecial wall, perithecial wall pseudoparenchymatous 50μ thick cells up to 12μ diameter, walls pigmented and thickened, asci cylindrical or clavate 90–120 × 10–12μ, truncate, 6–8 spored, uniseriate sometimes biseriate at apex, pseudoparaphyses evanescent. Spores one-septate, elliptical or pyriform, ends rounded 16–24 × 6–10μ hyaline or lightly pigmented, striate.
Type Locality: Paraguay.
Distribution: South America, Africa, Java.
Hoheria populnea A. Cunn.
Auckland, Titirangi, February 1947, J.M.D.; Auckland city, April 1949, D. W. McKenzie.
Unlike N. haematococcus and N. illudens the species possesses a pulvinate stroma but perithecia are smaller and appear farinaceous with crystals adhering to the outer cells; Hoehnel and Weese (1911) listed N. subfurfuracea as a synonym of N. balsanae. Weese (1915) also suggested that N. sukanensis P. Henn., N. cainitonis P. Henn. and N. congensis Sydow. were synonyms. He stated that these species differed from N. balsanae in colour, ornamentation of the perithecia, presence or absence of a stroma, and in spore size; none of which he considered were sufficiently distinct to warrant specific separation. New Zealand collections show similar characters which appear distinct and constant. N. plagianthi was separated on spore size, in N. illudens a stroma was absent, while in N. haematococcus the spores were smaller.
24. Nectria plagianthi sp. nov.
Perithecia caespitosa in stromate erumpenti ad 1 cm. diam., globosa vel ovata 0·3–0·4mm. diam., tuberculata, aurantiaca vel testacea; ostiolo papillato, pariete perithecii 120μ crasso, cellulis 10–15 × 12–22μ, parietibus densatis et tinetis. Asci parietibus tenuibus, clavati vel elliptici 140–200 × 18–24μ, 4–8 sporis uniseriatis. Sporae ovatae vel obovatae, uniseptatae 22–38 × 10–16μ, striatae, pallide luteae.
Perithecia caespitose on an erumpent stroma, up to 1 cm. diameter globose or ovate, 0·3–0·4mm. tuberculate, orange or latericius, ostiole papillated, often collapsed in dried specimens; perithecial wall 120μ thick, cells 10–15 × 12–22μ, walls thickened and pigmented, inner cells smaller and rectangular 10–12 × 5–10μ, walls lightly pigmented. Asci thin walled, elliptical, clavate ends pointed 140–200 × 18–24μ, 4–8 spored, uniseriate. Spores one-septate ovate or obovate 22–38 × 10–16μ, striate, lightly pigmented yellow.
Type Locality: Otago, Upper Hollyford Valley.
Distribution: New Zealand.
Hoheria glabrata Sprag. & Summerh.
Otago: L. McKellar, February 1948, J.M.D.; Arthur R. Milford, February 1948.
Plagianthus betulinus A. Cunn.
Otago, Upper Hollyford Valley, February 1950, J.M.D. (type col.); Arthur R. Milford. February 1948.
The perithecia are similar to N. balsanae and are arranged on a large pulvinate stroma but the spores are much larger and are biseriately arranged at the apex of the clavate asci.
25. Nectria rubi Osterwalder. Ber. deutsch. Bot. Gesell., Vol. 29, p. 620, 1911.
Nectria mammoidea var. rubi Weese. Zeitschr. Garungsphys., Vol. 1, p. 128, 1912; Hypomyces rubi (Osterw.) Wollenw. Phytopath., Vol. 3, p. 211, 1913.
1. N. tawa. Section of perithecium and spores.
2. N. plagianthia. Ascus and spores.
3. N. galligena. Ascus and spores.
4. N. sanguinea. Ascus and spores.
5. N. aurantilcola. Section of perithecium and spores.
6. N. illudens. Section of perithecium and spores.
7. N. westlandica. Section of perithecium and spores.
8. N. grisea. Section of perithecium and spores.
9. N. aemulans. Ascus and spores.
10. N. punicea. Ascus and spores.
11. N. coprasmae. Ascus and spores.
Perithecia scattered, sometimes in clusters of 2–4 perithecia on a poorly developed stroma, globose or obpyriform 0·3–0·5mm. diameter, bright red, darkening to vinaceous brown or black when mature, smooth, sometimes wrinkled, ostiole papillated; perithecial wall pseudoparenchymatous 80–100μ, cell wall densely thickened and pigmented, structure difficult to discern, sub-hymenial layer hyaline, effuse. Asci clavate or cylindrical 80–120 × 5–6μ, 8 spored, uniseriate; pseudoparaphyses evanescent. Spores one-septate, broadly elliptical 12–16 × 5–7μ hyaline and verrucose.
Type Locality: Wadenswil, Switzerland.
Distribution: Europe, New Zealand.
Rubus ideaus L.
Nelson, Riwaka, January 1949. P. Fry; Tapawera, January 1949, P. Fry.
Wellington, Palmerston North, November 1949, P. B. Coleman.
Pethybridge (1927) described a Fusarium stage with conidia with 0–5 septa, 12–60 × 5·5–7μ, sickle shaped and borne on branched conidiophores; also he stated that Osterwalder described a violet coloured sporodochium. No conidia are present in New Zealand collections. Curtis (1946) recorded a species of Nectria causing crown-rot of raspberries in Nelson, but did not identify the species. Petch (1938) followed Weese and listed the species as a variety of N. mammoidea but stated that it possessed smaller spores. Wollenweber included the species in the genus Hypomyces as chlamydospores were present in cultures of the fungus.
26. Nectria mammoidea Philip and Plowright. Orevillea, Vol. 3, p. 126, 1875.
Perithecia superficial, scattered or caespitose on a brick red pseudoparenchymatous stroma, colonies 0·5–2mm, diameter, oval or globose 0·4–0·5mm. diameter, scarlet, rust coloured when overmature, ostiole papillated; perithecial wall thickened and pigmented, masking the pseudoparenchymatous structure. Asci cylindrical sometimes clavate, 90–120 × 10–12μ, 8 spored, uniseriate; pseudoparaphyses filamentous, branched. Spores one-septate, sometimes constricted at septa, oval or obovate 12–25 × 6–10μ, verrucose, hyaline.
Type Locality: Great Britain.
Distribution: Europe, North America. New Zealand.
Auckland; Mt. Tongariro, December 1936, G. H. Cunningham.
Unlike in N. rubi perithecia are produced on a pulvinate stroma. Cell walls of the perithecia are so densely pigmented and thickened that the pseudoparenchymatous structure was difficult to discern. Both N. rubi and N. mammoidea may be separated from N. tasmanica by their verrucose spores.
27. Nectria tasmanica Berkeley. Flora Tasmaniae, Vol. 2, p. 279, 1860.
Perithecia superficial, gregarious or caespitose on a brown pulvinate erumpent stroma, colonies 2–6mm. diameter, pseudoparenchymatous walls fuscus, thickened; perithecia globose 0·4–0·6mm. diameter, red, vinaceous brown when mature and dry, ostiole papillate and surrounded by a distinct flattened disc; perithecial wall 50μ thick, cell wall pigmented and thickened, true pseudoparenchymatous structure masked by thick walls. Asci cylindrical 80–120 × 8–10μ, 8 spored, uniseriate, pseudoparaphyses absent. Spores one-septate, broadly elliptical, oval, sometimes constricted at septa 12–17 × 6–8μ, smooth, hyaline.
Type Locality: Tasmania.
Distribution: Australia and New Zealand.
Beilschmeidia tawa (A. Cunn.) Hook, f. & Benth.
Auckland, Waipoua, April 1947, J.M.D.
Wellington, Weraroa, April 1924, G. H. Cunningham.
Cordyline australis Hook. f.
Auckland, city, Purewa bush, December 1948, D. W. McKenzie,
Coprosma grandifolia Hook, f.
Auckland, Waitakere Ra., Rua-te-whenua, Aug. 1949, J.M.D.
Leucopogon fasciculatus A. Rich.
Auckland, Waitakere Ra., Upper Piha Valley, August 1948, J.M.D.
Muehlenbeckia australis Meissn.
Westland, Wehcka, December 1946, J.M.D.
Olearia avicenniaefolia (Raoul) Hook. f.
Westland, Waiho, December 1946, J.M.D.
Pittosporum colensoi Hook. f.
Westland, Weheka, December 1946, J.M.D.
Rhopalostylis sapida Wendl. & Drude.
Auckland, Titirangi, April 1948, J.M.D.
Schefflera digitata Forst.
Otago, Doubtful Sound, February 1948, J.M.D.
Weinmannia racemosa Linn. f.
Westland, Waiho, December 1946, J.M.D.
In discussing N. tasmanica, Weese (1915) listed N. umbilicata P. Henn. N. lucida Hoehnel and N. oculata Hoehnel as possible synonyms. N. tasmanica has the distinct papillated ostiole surrounded by a distinct flattened ring. As in N. mammoidea the structure of the perithecial wall is masked by the thickened and pigmented cell wall. Perithecia are brittle since in overmature collections it was difficult to find one unbroken. Tufts of hyaline mycelium occurred among the perithecia.
28. Nectria pinea n. sp.
Sphaeria cucurbitula var. B. nigrescens Tode, Fung. Meckl., Vol. 2, p. 39, 1791; Nectria cucurbitula (Tode) Fr., Summa Veg. Scand., p. 388, 1849 (in part); Nectria cucurbitula Sacc., Michelia, Vol. 1, p. 409, 1879; Creonectria cucurbitula (Sacc,) Seaver, Mycologia, Vol. 1. p. 189, 1909.
Perithecia gregaria in stromate fusco, pulverato, prosenchymato; globosa, 0·2–0·3mm. diam., maturitate atrorubra; ostiolo papillato; pariete perithecii 15–20μ crasso; cellulis 5–10μ solide densatis et tinctis. Asci cylindrici interdum clavati 75–100 × 6–10μ; 8 sporis oblique uniseriatis, in apice biseriatis; pseudoparaphysibus filamentosis. Spores uniseptatae, ellipticae vel ovatae 13·5–16 × 4·5–6μ, leves, hyalinae.
Perithecia gregarious on a dark coloured, pulvinate prosenchymatous stroma, globose 0·2–0·3mm. diameter, red, black when mature, ostiole papillate and surrounded by a distinct, often flattened zone 8–10μ diameter; perithecial wall pseudoparenchymatous, 15–20μ thick, cells 5–10μ diam., densely thickened and pigmented. Asci cylindrical sometimes clavate 75–100 × 6–10μ, 8 spored, obliquely uniseriate, biseriate at apex pseudoparaphyses filamentous. Spores one-septate, elliptical or oval 13·5–16 × 4·5–6μ, smooth, hyaline.
Type Locality: Whakarewarewa, Rotorua.
Distribution: Europe, North America, New Zealand.
Pinus radiata D. Don.
Auckland, Whakarewarewa, September 1949, G. B. Rawlings.
There seems to have been some confusion in the literature as to the name of this species. Saccardo (1883) described sporidia within the immature ascus of N. cucurbitula and suggested that the species was synonymous with Chilonectria cucurbitula (Curr.) Sacc. and with Calonectria cucurbitula (Fr.) Sacc. Ellis and Everhart (1892) when recording N. cucurbitula stated that no sporidia were observed as described by Saccardo, while Seaver (1909) stated that the species Creonectria cucurbitula is not N. cucurbitula (Tode) Fr. but N. cucurbitula Sacc. Petch (1938) noted that this species has been confused with N. coryli. N. cucurbitula (Tode) Fr. referred to two species of Nectria, one where sporidia were produced within the ascus i.e., N. coryli Fuckel (syn. Chilonectria cucurbitula (Curr.) Sacc.) and another species which Seaver described as Creonectria cucurbitula and Petch as Nectria cucurbitula Sacc. This is a case of ‘nomen confusum’ and the later species has been renamed and redeseribed. As in N. tasmanica spores are smooth and hyaline, and perithecia are accompanied by tufts of hyaline mycelium but perithecia are smaller, thinner walled. Spores are elliptical and not as broad as the preceding species. As the species was found only on an introduced host, it seems probable that it has been introduced.
29. Nectria tawa n. sp.
Perithecia libere sparsa, globosa vel pyriformia, 0·1–0·25mm. diam., sanguinea vel ferruginea, scabrida; ostiolo papillato; pariete perithecii 30–40μ crasso; cellulis exterioribus parietibus tenuibus 15–20μ diam.; cellulis interioribus parvis 4·5μ diam., densatis. Asci clavati 30–60 × 5–10μ; 8 sporis oblique uniseriatis, in apice biseriatis. Sporae uniseptatae, fusiformes vel ellipticae 7·5–10 × 2·5–4μ, verrucosae, hyalinae.
Perithecia scattered, globose or pyriform collapsing when dry 0·1–0·25mm. diameter, scarlet or blood coloured, scabrid, ostiole
papillate surrounded by a flattened disc up to 10μ diameter; perithecial wall pseudoparenchymatous 30–40μ thick, outer cells thin walled, hyaline or lightly tinted, cuboid 15–20μ, collapsed in dried specimens which give perithecia a wrinkled appearance, inner cells 4–5μ diameter, pigmented and thickened. Asci elliptical or clavate 30–60 × 5–10μ, 8 spored, obliquely uniseriate, sometimes biseriate at apex; pseudoparaphyses filamentous, forming network within perithecia. Spores uniseptate, fusiform or elliptical 7·5–10 × 2·5–4μ, verrucose hyaline.
Type Locality: Titirangi, Auckland.
Distribution: New Zealand.
Beilschmeidia tawa Benth. & Hook.
Auckland, Titirangi, May 1940, J.M.D. (type collection);
Waitakere Ra., Rua-te-whenua, August 1949, J.M.D.
Coprosma grandifolia Hook. f.
Auckland, Bay of Islands, June 1948, J.M.D.
Coprosma lucida Forst.
Auckland, Waipoua, September 1949, J.M.D.
Coprosma robusta Raoul.
Auckland, Hunua Ra., October 1946; J.M.D.; Waitakere Ra., Mountain Rd., Henderson, May 1948, J.M.D.
Hoheria glabrata Sprag. and Summerh.
Otago, Wilmott Pass, Manapouri, February 1948, J.M.D.; L. McKellar, February 1948, J.M.D.
Olearia rani (A. Cunn.) Ckn.
Auckland, Hunua Ra., Moumoukai Valley, October 1946, J.M.D.
Phormium tenax Forst.
Wellington, Kelburn, November 1945, G. H. Cunningham.
Rhopalostylis sapida Wendl. & Drude.
Auckland, Waitakere Ra., Waiatarua, November 1948, J.M.D.
Schefflera digitata Forst.
Auckland, Bay of Islands, Paihia, June 1948, J.M.D.; Puketi State Forest, June 1948, J.M.D. Otago, Doubtful Sound, February 1948, J.M.D.
Perithecia are small, bright red, similar in appearance to those of N. sanguinea but spores are smooth, fusiform or elliptical.
30. Nectria coprosmae n. sp.
Perithecia sparsa vel caespitosa, globosa 0·15–0·3mm. pallide rubra vel brunneo-vinosa, scabrida, ostiolo papillato; pariete perithecii pseudoparenchymato 40μ crasso; cellulis exterioribus 10–20μ leviter densatis; cellulis interioribus parvis, 4–5μ diam.; solide densatis et tinctis. Asci cylindrici vel clavati 20–50 × 4–7μ; terminis truncatis; 6–8 sporis biseriatis; pseudoparaphysibus filamentosis. Sporae uniseptatae, ellipticae vel filiformes; terminis truncatis 9–13 × 3–4μ; leves hyalinae.
Perithecia scattered or caespitose, globose, occasionally pyriform 0·15–0·35mm., light red darkening to brown vinaceous when mature,
scabrid, ostiole minute, papillate, perithecial wall pseudoparenchymatous 40μ thick, outer cells 10–20μ, lightly pigmented and thickened, sub-hymenial cells small 4–5μ diameter, densely pigmented and thickened. Asci cylindrical or clavate 20–50 × 4–7μ ends truncate, 6–8 spored, biseriate, occasionally obliquely uniseriate; pseudoparaphyses filamentous forming a network within the perithecia. Spores elliptical, filiform, ends truncate 9–13 × 3–4μ smooth, hyaline.
Type Locality: Auckland, Waitakere Ra., Anawhata Rd.
Distribution: New Zealand.
Coprosma grandifolia Hook. f.
Auckland, Waitakere Rn., Huia, August 1947, J.M.D.; Anawhata Rd., August 1947, J.M.D. (type collection); September 1947, J.M.D.; Waitakere Ra., Rua-te-whenua August, 1949, J.M.D.
Perithecia were collected on bark damaged by insects. Spores are larger than those of N. tawa and the ends are truncated, pyriform and often irregularly divided by a septum.
31. Nectria westlandica sp. nov.
Perithecia gregaria, globosa 0·5–0·8 mm., brunneo-vinosa, inaequale tuberculata; ostiolo papillato; pariete perithecii 50μ crasso; pseudoparenchymato sed structura occulta parietibus cellulorum densatis et solide tinctis. Asci elliptici 95–140 × 10–16μ, evanescentes. Sporae uniseptatae, ellipticae vel naviculatae 30–42 × 9–12μ, leves, hyalinae.
Perithecia gregarious, globose 0·5–0·8mm. dark red, brown, vinaceous irregularly tuberculate, ostiole papillate, perithecial wall 50μ thick, pseudoparenchymatous but structure masked by thickened densely pigmented walls; tubercles hyaline, pseudoparenchymatous, cells thin walled and hyaline 10–12μ diameter. Asci elliptical 95–140 × 10–16μ, 8 spored, spores biseriate or obliquely uniseriate, pseudoparaphyses evanescent. Spores one-septate, elliptical or naviculate, sometimes falcate 30–42 × 9–12μ, smooth, hyaline.
Type Locality: Westland, Waiho.
Distribution: New Zealand.
Olearia avicenniaefolia Hook. f.
Westland, Waiho, November 1946. Type collection.
A species easily identified by its large elliptical spores and dense perithecial wall with small scale-like tubercles. When immature perithecia are smaller and scarlet.
Cayley, D. M., 1921. Annals of Botany, Vol. 25, pp. 79–92.
Colenso, W., 1886. Trans. N.Z. Inst., Vol. 19, pp. 301–313.
Cooke, M. C., 1879. Grevillea, Vol. 8, pp. 54–60.
—— 1884. Grevillea, Vol. 12, pp. 77–83, pp. 101–103.
Cunningham, G. H., 1925a. N.Z.J. of Agric., Vol. 31, pp. 102–103.
—— 1925b. Fungous Diseases of Fruit Trees, 382 pp.
Curtis, K. M., 1946. Annual Report Cawthron Inst. 1945–46 p. 16.
Ellis, J. B., and Everhart, B. M., 1892. The North American Pyrenomyceies, 793 pp.
Hansford, C. G., 1946. The Foliicolous Ascomycetes: Mycological Papers No. 15, Imp. Myc. Institute, Kew, Surrey, 240 pp.
Hoehnel, F., and Weese, J., 1911. Annales Mycologici, Vol. 9, pp. 422–424.
Kirk, T. W., 1905. N.Z. Dept. Agric. 13th Annual Report, pp. 412–415.
Petch, T., 1920. Ann. Roy. Bot. Gardens, Peradeniya, Vol. 7, pp. 85–138.
—— 1921. Trans. Brit. Myc. Soc., Vol 7, pp. 133–167.
—— 1938. Trans. Brit. Myc. Soc., Vol. 22, pp. 243–305.
—— 1941. Trans. Brit. Myc. Soc., Vol. 25, pp. 166–178.
Pethybridge, G. H., 1927. Trans. Brit. Myc. Soc., Vol. 12, pp. 20–23.
Saccardo, P. A., 1883. Sylloge Fungorum, Vol. 2, 938 pp.
—— 1914. Annales Mycologici, Vol. 12, pp. 282–314.
Seaver, E. J., 1909. Mycologia, Vol. 1, pp. 41–76.
—— 1910. Mycologia, Vol. 2, pp. 48–92.
Sydow, H. and S., 1924. Annales Mycologici, Vol. 22, pp. 203–317.
Snyder, W. C., and Hansen, H. N., 1945. Am. J. Bot., Vol. 32, pp. 657–666.
Theissen, F., 1911. Annales Mycologici, Vol. 9, pp. 40–73.
Weese, J., 1915. Centralblatt Bakt., Vol. 42, pp. 587–613.
Wollenweber, H. W., 1913. Phytopathology, Vol. 3, pp. 24–50.
—— 1931. Zeitschrift fur Parasitenkende, Vol. 3, pp. 269–516.
—— 1943. Centralb. fur Bakt., Vol. 100, pp. 171–207.
The Taxonomy of the Moss Archephemeropsis trentepohlioides Renn.
[Read before the Hawke's Bay Branch, May 30, 1950; received by the Editor, June 2, 1930]
This highly interesting New Zealand moss was discovered in 1928 by K. W. Allison at Atiamuri, Thermal District, North Island, and was referred by me to the late H. N. Dixon, who considered it as conspecific with the East Indian Ephemeropsis tjibodensis Goeb. This has a unique gametophyte, being without stem or leaves except for the very small bracts, and consisting only of a freely branched algalike protonema. The branches function as assimilatory organs, thus compensating for the absence of foliage. The general appearance of the New Zealand plant, when barren, is that of an alga or the protonema of some other moss. It forms small yellow-brown patches on the bark of various shrubs and lianes. The seta and capsule can attain a length of 1 cm. and 1 mm. respectively, and it is only this comparatively conspicuous sporophyte that enables the moss to be recognised in the field. Even so, it can escape notice only too frequently, and though fairly widely distributed, it has seldom been collected. Ephemeropsis tjibodensis was discovered by Goebel in Java about 1887, and has since been collected in several East Indian countries. Goebel's plants were barren, and for over ten years the little moss was only known by its curious gametophyte which, in the East Indies, usually grows on the leaves of trees in dense moist forest. Goebel quite naturally referred his discovery to the family Ephemeraceae, and created the above genus for it, but when Fleischer found fertile plants in 1898 the surprising fact was revealed that there could be no relationship here to Ephemeraceous mosses because these have a primitive, gymnostomous and sessile capsule, whereas the present plant had the capsule far exserted, with a highly developed double peristome, the whole structure indicating an undoubted affinity with Hookeriaceae. Fleischer (1929) put forward the view that the plant could not be considered as a primitive type, but that its vegetative parts constitute a reduction or reversion to what is probably the primeval gametophyte of the mosses, and that that structure was, or was closely related to, the algal genus Trentepohlia. There appears to be no other explanation to account for the association of such a highly developed sporophyte with such a primitive gametophyte. Fleischer created the family Nemataceae for the Indian moss, and its position is recognised as being in the order Hookeriales. Widely divergent views have been expressed as to the taxonomic position of the New Zealand moss. Dixon (1928) gave an account of it in which, after recognising certain differences in the gametophyte, he found the fruiting characters to be practically identical with those of the East Indian species, and arrived at the conclusion that varietal status, at the most, might be allowed if the vegetative characters proved to be constant. In a later notice (1929) he treated the two plants as
identical, at any rate from a systematic point of view. Fleischer (1929) considered that the New Zealand plant was probably a new species, and Renner (1934) in a subsequent investigation of material from Atiamuri and Ohakune, Mount Ruapehu, raised it to generic rank as Archephemeropsis trentepohlioides. It should be mentioned that Dixon, in subsequent correspondence with me, agreed that a new species was involved and was also inclined to accept the new genus, though he expressed some doubt about it. The reasons given for founding the genus are based on fruiting as well as vegetative characters, and in order to appreciate them I have studied material from the above localities and also from Marlborough, in the South Island. Taking the vegetative characters first, it is common ground that the gametophyte in the New Zealand plant differs in having the protonemal branches longer, narrower, and less divergent, and in lacking the long erect filaments (Fleischer's “Assimilationsorgane”) which function as organs of assimilation. Further differences are its longer rhizoids and the absence of the peculiar geminate and flabelliform organs of attachment (“Hapteren”) which in Ephemeropsis tjibodensis serve to secure the plant to the surface of the leaf on which it usually grows. Brood-bodies, too, occur on the protonema there, but have not been found on that of Archephemeropsis. Such differences as these are of subordinate importance, and there would be general agreement with Dixon's opinion (1928) that they would have to be supported by sporophytic characters in order to be of specific value. The differences in the sporophyte, however, are more significant. Apart from certain deviations which are either of minor importance or which, as for instance a slight roughness of the seta and a larger capsule, are (from what I have seen) not always constant in the New Zealand plant, there are two characters, stressed by Renner, which are more decisive. The first is the structure of the outer teeth of the peristome. In Ephemeropsis these are robust, long and thick, with the lamellae well developed and with the dorsal median line widely grooved, as in many Hookeriaceous mosses; whereas in Archephemeropsis they are described by Renner as very short, with the lamellae practically absent, and with the median line, as well as the transverse articulations of the dorsal plates, robustly and highly ridged. From his illustrations it would also appear that the median line, which is of the well-known zigzag type, is confined to about the lower one-third portion of the tooth, the upper part having the dorsal plates with their surfaces entire. The teeth are certainly very short, but whatever might be the taxonomic importance of the other structural differences if they were constant, they cannot be entirely relied upon here, because I have found that the peristome in the New Zealand plant does not always conform to the above description. For one thing, the ventral lamellae sometimes project, at any rate slightly, in the upper part of the tooth, and for another the median line, in the Marlborough plant especially, is often somewhat grooved, and in one case, in material from Atiamuri, I have seen a tooth actually split in the middle. The peristome characters therefore seem to be somewhat unstable, and I do not think that they support a generic separation. It seems that the endostome structure, which is very delicate, agrees with that of Ephemeropsis. There is a marked difference in the spores, because in the East Indian moss they are spherical or ovoid and
about 50μ in diameter; whereas in Archephemeropsis they consist of, or rather have (in the capsule itself) developed into 4–5-celled fusiform or cigar-shaped bodies, 100–120μ long, that exactly resemble a type of brood-body which is common amongst mosses and which, indeed, is developed on the protonema of the East Indian plant. They naturally differ in not having the specialised basal cell which facilitates the dehiscence of a normal brood-body from the protonema on which it is usually produced, but in other respects the resemblance is perfect. In Dixon's account (1928) he mentioned that he had not seen spores, but had found unicellular or bicellular bodies which he was inclined to think were brood-bodies. Fleischer (1929) considered that they were spores in process of germination, and Renner treats the fully developed structure as a type of multicellular spore. My investigation showed that before the lid falls these structures can be found in various stages of development, from unicellular oval bodies to the matured fusiform body, and even in a quite immature capsule I have found cells in process of division into as many as three cells. Incidentally, it is worth mention that I have seen more than once the commencement of germination of the mature 4–5-celled bodies. This took the form of a prolongation and narrowing of one of the terminal cells, and no doubt successive transverse walls would then be formed so as to commence the growth of a protonema. There can be no doubt that the unicellular bodies observed by Dixon and the writer are the true spores of Archephemeropsis, and that we have here a new type of multicellular spore, using that term in the sense that it is used by systematists to apply to what is in reality a young gametophyte (Chalaud, 1934). Such spores are found now and then in mosses, but the present form, consisting as it does of a short filament divided by parallel walls, is, as Renner states, something quite new. From a taxonomic point of view, however, I do not think that the character should be treated as of more importance than any other multicellular spore. The production of such spores is not in itself a decisive generic character. In for instance the genus Ulota, one species, U. membranata Malta, has them, whilst the other species have unicellular spores. It seems to me that in this case the character is not linked with other differences sufficiently important to justify more than a specific separation. I would therefore propose the combination Ephemeropsis trentepohlioides (Renn.) Sainsb. for the New Zealand plant. Investigation of the spore production and development here with fresh material would be a promising line of research on one of the world's most interesting mosses.
Chalaud, G., 1934. Observations sur les spores de Fegatella conica et leur mode de germination. Annales Bryologici, 7, 9–17.
Dixon, H. N., 1928. Miscellanea Broyologica—XI. Journ. Bot., 347–349.
—— 1929. Studies in the Bryology of New Zealand. Bull. N.Z. Inst., No. 3, pt. vi, 346.
Fleischer, M., 1929. Die Sporenkeimung und vegetative Fortpflanzung der Ephemeropsis tjibodensis. Annales Bryologici, 2, 11–20.
Renner, O., 1934. Javanische Kleinigheiten—Die Ephemeropsis von Neuseeland. Ann. Jard. Buitenzorg, 79–88.
The Occurrence of Acantholybas brunneus Breddin in New Zealand
[Read before the Auckland Institute, May 31, 1950; received by the Editor, June 2, 1950]
The local occurrence of this Coreid is probably well known to Auckland entomologists, but, as there is no reference in the literature to its presence in New Zealand, it was thought desirable to have the species identified and placed on record for the benefit of workers both in this country and overseas.
New Zealand has no undoubtedly indigenous species of the family Coreidae and there are previous records of only two other species. The detailed records of these species were made in an English publication; in this paper are included comments on them from a letter of Dr. W. E. China. It would seem likely that Acantholybas brunneus Breddin was introduced fairly recently, within the last fifteen to twenty years. It was not mentioned by Myers (1926, Trans. N.Z. Inst., 56: 449–511) or by Myers and China (1928, Ann. Mag. Nat. Hist., (10) 1: 377–394), and it seems unlikely that such a large and anomalous member of the Heteropteran fauna should have escaped observation if well established at that time. The earliest record in the author's collection is of one late instar nymph (♂), found on 18.iii.39. Other records are for 31.i.40, ii.40, xii.41 (when large numbers of both adults and nymphs were found beneath stones among weeds in shaded localities in a garden), 23.x.44, 21.xii.44, 31.xii.48, and ii.49. All these records are from Auckland. Mr. E. T. Giles recently caught eight adults (12.xi.49) among sedges in a damp and shaded position under a lemon-tree at Remuera, Auckland, where the species appeared to be abundant. This seems to be a characteristic type of habitat for the bug, nearly all the specimens taken by the author being found in shaded places in gardens, on and under mixed weeds and beneath stones. Both adults and nymphs were also on several occasions found between the leaves of lettuces taken straight from the garden. The species seems now to be well established and quite common in Auckland. The writer is unaware of any records from outside this district.
Thanks are due to Dr. W. E. China, of the British Museum (Nat. Hist.), who kindly identified the material, and from whose letter the following quotation is taken:
“The Coreids sent for determination are Acantholybas brunneus Breddin described under the generic name of Acanthocolpura (a synonym) in Ent. Nachr. 26, p. 40, 1900. The genus Acantholybas was described by Breddin in 1899 (Jahrb. Hamburg. Wissenschaftl. Anstalten 16, p. 155) for a single species, A. longulus Breddin, from Lombok. There is one other known species of the genus, Acantholybas kirkaldyi
Bergr., described from Tasmania by Bergroth (1909, Ann. Soc. Ent. Belg. 53: 185). This is the third Coreid to be recorded from New Zealand.
“The three New Zealand Coreids may be listed as follows:—
“1. Subfamily Corizinae, tribe Leptocorini: Leptocoris sp. undetermined (most likely the Australian Leptocoris mitellatus Bergr.), North Island, Taihape, collected by G. Howes (no date). Recorded by Bergroth in a letter to Myers, 1924, and published by J. W. Evans in 1928 (Ann. Mag. Nat. Hist. (10) 2: 463). The genus Leptocoris is holotropical and is rather difficult nomenclatorially, which probably explains why the species was not determined by Bergroth. It may be possible that the New Zealand Lygaeid Arocatus rusticus Stal was mistaken by Bergroth for a Leptocoris, as there is a general resemblance in colouring and shape.
“2. Subfamily Alydinae, tribe Alydini: Melanacanthus margineguttatus Distant, South Island, Tahuna, on the North Coast. Numerous specimens of Psamma arenaria on sand dunes near the sea in March, 1928, collected by J. W. Evans and E. S. Gourlay. Recorded by J. W. Evans in 1928 (Ann. Mag. Nat. Hist. (10) 2: 463). The genus Melanacanthus is restricted to Australia and M. margineguttatus occurs throughout Queensland. The above mentioned colony was thought to have been destroyed by the burning of the grass.
“3. Subfamily Coreinae, tribe Hygiini: Acantholybas brunneus Breddin. Numerous specimens in Auckland, T. E. Woodward, 1949. The genus Acantholybas (= Acanthocolpura) is recorded only from Lombok Island, Queensland, New South Wales and Tasmania. A. brunneus Breddin was described from New South Wales, but we have a specimen from the Bunya Mts. west of Brisbane, Queensland. It was probably introduced into New Zealand from Australia.”
Acantholybas brunneus is readily distinguishable from all other recorded species of the New Zealand Heteroptera, except the two species of Coreids listed above, by the following combination of features characteristic of its family:
Antennae 4-segmented, inserted on or above the line between the centre of the eye and the apex of the central lobe of the face (tylus); two ocelli; scutellum not reaching apex of clavus; membrane of hemelytron with numerous (more than five) longitudinal veins, which branch from a common vein paralleling the distal margin of the corium; rostrum not strongly curved at base; tarsi 3-segmented.
From the other two species of Coreids it is separated respectively by the following subfamily characters:
From the Corizinae (Leptocoris), in having the odoriferous apertures distinct and auricular and not concealed between the middle and hind coxae; from the Alydinae (Melanacanthus), in having the distal antennal segment stout and not greatly elongated and curved.
The following account is given as a further aid in determination. The adult is brown, with more or less of apex of distal antennal segment, apex of scutellum, the tibiae, except at apex and sometimes near base, and mottling or banding on femora, with bands most distinct on posterior pair, lighter in colour; length, ♀ 9·5–11 mm., ♂ 8·5–9 mm.;
antenniferous tubercles externally and anterior angles of prothorax produced into short, broad, spinous process; sides of head behind eyes dilated as knob-like protuberance; rostrum reaching anterior end of third abdominal sternite in ♀, posterior end in ♂; pronotal calli well developed, dark marginally; pronotum shortly collared in front, anterior margin nearly straight, sides slightly sinuate near middle, posterior angles rounded and somewhat raised, though not prominently shouldered, posterior margin nearly straight, declivous, width (♂ 2·6 mm., ♀ 3·1 mm.) twice that of anterior, length (♂ 1·9 mm., ♀ 2·3 mm.) nearly 1 ½ times anterior width; head, pro-
notum, and scutellum finely tuberculate, with short, recumbent, spinelike hairs; corium and clavus finely punctate, with similar hairs; dorsal surface of abdomen ferruginous, hairless, rather coarsely punctate; ventral surface of body more finely punctate, with dark stippling and fine, pale, recumbent, spinelike hairs; connexivum clothed with very short, fine hairs, a narrow pale posterior band in each segment; abdominal sternites II–IV mesially sulcate, shallowly so in ♀.
The late instar nymphs are similar in general appearance to adults except in wing development. The following description applies to both sexes of such a nymph (probably fifth instar): Length, 7·5 mm.; colour brown, with pale apex of antenna very clearly marked; all tibiae with pale middle region, dark at base and apex; mottling and banding of femora, tubercles and spinous hairs on head, pronotum, and scutellum, processes of antenniferons tubercles, and protuberances behind eyes, as in adult; anterior angles of pronotum less strongly produced than in adult; pale connexival areas less pronounced; wingpads, ventral surface of head and thorax, femora, and basal segment of antennae impunctate but with fine tubercles and short spinous hairs as on pronotum; dorsal surface of abdomen, including connexivum, and ventral surface of abdomen impunctate, with short, fine, pale, recumbent hairs; ventral surface of connexivum very finely tuberculate; pronotum with all margins nearly straight, posterior angles rounded and scarcely raised, posterior margin not declivous; a narrow, very slightly raised, pale median line on head, pronotum, and scutellum; wing-pads extending to posterior margin of second visible abdominal segment; dorsal lips of odoriferous apertures prominently raised, very dark, transversely wrinkled.
An earlier instar (probably second) shows the following characteristics: Length, 3·5 mm.; both surfaces of body a very pale straw-yellow ground-colour with distinctly reddish-brown mottling; antennae dark brown, except for the reddish-brown base of the third segment and the pale apical two-thirds of the fourth; darker brown markings on tylus, on each side of median line of vertex, and submarginally on thoracic tergites; epicranial suture well marked as a fine red line; connexivum with in each segment a dark brown patch and an anterior and a posterior pale area; lips of odoriferous apertures as described for later instar, but the members of each pair forming a completely united raised dark area; colour pattern of femora and tibiae as for later instar; antenniferous tubercles and anterior pronotal angles not produced; lateral margins of head behind eyes somewhat dilated, but not knob-like as in later stages; pronotum short, with anterior and lateral margins nearly straight, posterior margin convex; first 3 segments of antennae finely tuberculate, with short, spine-like, semirecumbent hairs arising from tubercles, fourth segment more densely clothed with longer hairs; a few small scattered tubercles on head and pronotum; dorsal surface of head, thorax, and abdomen with very short, scattered hairs; punctation completely absent.
A New Species of Gall Midge (Cecidomyidae) from Hebe salicifolia Forst. Leaf Galls
[Read before the Auckland Institute, June 12, 1950; received by Editor, June 14, 1950]
Leaf galls on Hebe salicifolia Forst. collected from Mayor Island, New Zealand, in November, 1948, by the Auckland University College Field Club were found to contain typical gall-midge larvae. Adults bred from the galls in December, 1948, were found to belong to the genus Dasyneura (s.l.) and are described below as a new species. Similar leaf galls have since been collected from Rangitoto Island and from the grounds of Auckland University College.
The gall takes the form of a smooth swelling along the main vein of the leaf. Usually oval in shape, the swelling is apparent from both sides of the leaf, though it is more pronounced on the lower (abaxial) surface (Fig. 1). Mature galls are about 8 mm. wide, 10 mm. long and 4 mm. thick. The length of the gall depends upon the number of larvae present. While immature galls are smooth and lack any apertures, mature galls bear a single row of exit holes on either side of the lower surface. Often empty pupal cases are found in these exit holes. Galls are usually polythalamous and contain several white larvae of the usual cecidomyid type, each with a brown, anteriorly bifid sternal process. A stem gall which commonly occurs on Hebe salicifolia is quite distinct from the leaf gall and is caused by a different species of gall midge.
Dasyneura hebefolia sp. n.
Male: Length about 1·6 mm. Antennae 2 + 15; first and second flagellar segments more or less cylindrical with a short neck; the neck of the third flagellar segment twice as long as wide and two-thirds as long as the spherical basal enlargement; the neck of the fifth flagellar segment twice as long as wide and almost half as long as the basal enlargement, the latter slightly wider than long; the neck of the tenth flagellar segment three times as long as wide and almost two-thirds as long as the more or less spherical basal enlargement; penultimate and terminal segments not entirely separated; terminal segment broadly conical. Palpi: four segmented; basal segment quadrate, second segment twice as long as wide; third segment about 2 ½ times as long as wide; the fourth segment about five times as long as wide, slightly longer and narrower than the third. Thorax: brown. Wings: the third vein reaches the margin just before the apex of the wing; fifth vein forked. Legs scaled; claws moderately curved, all toothed; empodium slightly longer than the claws. Genitalia (see Fig. 2); basal clasp segment short, stout, slightly swollen; distal clasp segment moderately curved, stout at base, tapering gradually to about one-third; dorsal lamella with wide U-shaped emargination, each lobe wide
and rounded; ventral lamella almost as long as dorsal lamella, shallow U-shaped emargination; style just longer than lamellae; harpes or ventral appendages about same length as ventral lamella, rather narrow, distal edge not smooth, with a prominence.
Holotype: Cecid. 5167, located in the Barnes Collection, England.
Paratype: Cecid. 5168, located in the collection of the Plant Diseases Division, Department of Scientific and Industrial Research, New Zealand.
Female: Length about 1·8 mm. Antennae 2 + 14–15, flagellar segments cylindrical with transverse necks; third flagellar segment three-fifths as wide as long; fifth flagellar segment very slightly shorter
and narrower; tenth flagellar segment slightly shorter and narrower than the fifth; terminal segment incompletely separated, the combined segments five times as long as wide. Palpi: four segmented; segment one quadrate; second segment twice as long as wide; third segment narrower and slightly longer than the preceding segment; segment four longer and narrower than the preceding segment. Thorax brown; claws all toothed and moderately curved. Abdomen: red when alive. Ovipositor pocket-shaped (see Fig. 3).
Allotype: Cecid. 5173, Barnes Collection, England.
Paratypes: 2 specimens in the collection of the Plant Diseases Division, Department of Scientific and Industrial Research, Auckland, New Zealand.
Other specimens in the Barnes Collection are: males Cecid. 5163–6, females Cecid. 5169, 5170–2, 5174–5.
Parasite: A small, irridescent green parasite, identified by Mr. G. J. Kerrich, of the British Museum, as Lioterphus sp. (Hymenoptera: Torymidae), was bred in large numbers from the Mayor Island gall midges.
I acknowledge with thanks the generous assistance of Dr. H. Barnes, of Rothamsted Experimental Station, who examined the type material and criticised the above description.
The American Lake Char (Cristivomer namaycush)
[Read before the Canterbury Branch, June 1, 1950; received by the Editor, June 15, 1950]
The genus Cristivomer was created by Gill and Jordan (1878) for a char which they described as differing from Salvelinus in having a toothed crest extending posteriorly from the head of the vomer and free from the body of this bone. Regan (1914) stated that this crest or posterior process was merely an extension of a structure found in typical Salvelinus and regarded the two genera as intergrading through the species fontinalis, which he described and represented diagrammatically as an intermediate form. He proposed the union of the chars in a single genus containing three groups defined as follows: the alpinus group having the posterior process on the head of the vomer but little developed and hyoidal teeth uniserial, the fontinalis group having the posterior process on the head of the vomer well developed and lacking hyoidal teeth and the namaycush group having a long posterior process and hyoidal teeth multiserial. It is also to be noted that Day (1887, p. 10 and p. 70) showed a considerable posterior process in both S. fontinalis and S. alpinus. The present writer has not had the opportunity of examining specimens of the alpinus form, but has been unable to find anything that could be regarded as a well-developed posterior process on the vomer of Salvelinus fontinalis. So far as New Zealand-grown specimens are concerned, the rearward projection occurs in the teeth and not in the bone to which they are attached. The lateral aspect of the vomer of this species is shown in Fig. 2, and a comparative figure of the same bone in Cristivomer namaycush is shown in Fig. 3. The contention of intergradation is not borne out by the present material. the long posterior process in Cristivomer being quite distinct from the arrangement in S. fontinalis.
The second character by which Regan proposed to separate his groups, namely, the hyoidal dentition, also fails in respect of Salvelinus fontinalis. It has been shown elsewhere (Stokell, 1940) that this species may or may not have teeth on the hyoid, and that when present these teeth are variable in number and degree of development. It is therefore impossible to separate fontinalis from other chars of the genus Salvelinus, and the proposed intermediate group must be abandoned. Cristivomer, however, has a multiserial arrangement of the hyoidal teeth and differs in this feature from all species of Salvelinus recorded.
The two groups are further differentiated by the number of pyloric caeca. In the seven specimens of Cristivomer available the number ranges from 128 to 164, while in ten specimens of Salvelinus fontinalis the range was found to be 26–36. Gunther (1866) records 32–52 in British char and Day (loc. cit.) widens the specification to 28–62.
In a single specimen of Salvelinus malma from North America examined by the writer the number is 26. The American representatives of the genus Salvelinus would therefore appear to conform to the specifications of the European species, and the number of caeca must be regarded as providing a useful distinction between this genus and Cristivomer. There appears no justification for uniting the two genera, although their distinctness is somewhat affected by the existence of a common feature indicative of close affinity. All chars of the genera Salvelinus and Cristivomer that have come under the writer's observation have considerably more cross-rows of scales on the body than scales in the lateral line. The lateral line scales are not composed of hard, transparent material as are those on other parts of the body, but are almost cutaneous in character. They carry no circuli and are flexibly connected. The arrangement differs greatly from that in Salmo and Oncorhynchus, in which the lateral line scales number approximately the same as the cross-rows and are similar to those on the remainder of the body except that each carries a mucus tube. Another feature common to Salvelinus and Cristivomer is the presence of well-developed mucus pits below the lower jaw, usually ten on each side in Cristivomer. Obsolete pits with occasionally some small functional ones occur in Salmo trutta and Salmo salar, but they are lacking in Salmo gairdnerii and in all observed species of Oncorhynchus. The group known as Salmo clarki has a more definite development of mucus pits than occurs in typical Salmo, and, in this feature, comes close to the chars, which it further resembles in usually having teeth on the hyoid, but it is to be noted that the scales in the lateral line, although irregularly placed in relation to the cross-rows, agree with those of typical Salmo.
A redescription of Cristivomer namaycush is given below and a photograph of a typical specimen in shown in Fig. 1.
Cristivomer namaycush Walbaum
B. 11–12. D iii–iv 8–9. A iii 9. Gill-rakers 20–21. Pyloric caeca 128–164. Vertebrae 62.
Body of vomer elevated above level of head, in section an inverted V, toothless. Head of vomer with a blade-shaped structure extending posteriorly and, in its latter part, free from the body of the vomer, the extent of the free portion variable. Teeth on head of vomer arranged in an irregular chevron, uniserial on blade. Hyoid with a long patch of small strong teeth.
Head 4·41–4·51 in standard length, maxillary extending well behind posterior of eye. Dorsal fin inserted at 0·5–0·505 of the standard length, its height 1·07–1·38 times its basal length. Pectoral extending 0·42–0·45 of the distance from its root to the ventral, ventral inserted at 0·56 of the standard length, height of ancillary 0·28–0·31 of the height of ventral. Height of anal 1·3–1·34 times its basal length, caudal peduncle 2·1–2·21 times as long as its least depth, caudal fin deeply forked. Scales small and irregularly placed, about 190 cross-rows immediately above lateral line, 128–130 scales in lateral line.
Colour greenish-grey with pale spots and short markings, belly and lower fins tending to golden. Maximum total length observed 25 inches.
New Zealand Existence
In 1906 fifty thousand eggs of this fish were imported by the New Zealand Government and hatched by the North Canterbury Acclimatisation Society at its hatchery in Christchurch. The Society's Annual Report for 1907 states that 4,000 young fish were liberated in Lake Pearson in Canterbury and a similar quantity was forwarded to Westland for disposal by Government officials. The late T. E. Donne (1927), Government Tourist Officer, at whose instigation the eggs were obtained, gives the Westland locality as Lake Ianthe and states that the Canterbury lot was divided between Lake Pearson and Lake Grasmere. A few of the young fish were retained in the acclimatisation ponds and apparently reared to maturity. The Society's Annual Report for 1910 states that 56 four-year-old fish were held at that time, and it is obvious that a second generation was bred from them, as the 1911 Report records the presence of two-year-olds. There is no account of what became of these fish, but they appear to have been disposed of by 1913, as the only salmonoids recorded as being held in ponds at that time were brown trout and rainbow trout.
The only New Zealand water from which this char has been recorded is Lake Pearson, which is situated about four miles south of Cass, on the West Coast road. This lake has an altitude of 1990 feet and appears to have been ponded partly by moraine and partly by shingle fans. It is about two miles in length and about half a mile in width except at the middle, where it narrows to a neck about 30 yards wide. The principal tributary is the Craigieburn Creek, which is so unstable in the lower part of its course that it may divide its waters between the lake and the outlet stream or flow wholly into one or the other. The Ribbonwood Creek is usually dry in the lower part of its course, but assists in feeding the lake by soakage and there are several small trickles which usually maintain a connected flow. The outlet known as Winding Creek is at the south end and flows into Broken River, a tributary of the Waimakariri, but is frequently dry for a considerable distance just below the lake.
No records of the number of char taken at Lake Pearson have been kept, but it would appear from information received from several anglers who regularly fish the water that twelve fish per year would be a reasonable estimate. The largest fish observed by the writer was 7 lb. in weight and the average for the eight specimens examined is 5 lb. These weights are much lower than those recorded in North America, where fish of 15 lb. and 20 lb. are not rare, and individuals of double these weights are taken occasionally. The small size of the New Zealand fish appears to be explainable on the grounds of unsuitability of habitat, and it is even matter for surprise that the species has established itself in a lake so different from its native waters. The great depths and extremely cold waters of the Canadian lakes, in which this fish abounds, are in sharp contrast to the conditions at Lake Pearson, which is comparatively shallow and warm. A series of soundings showed that a considerable area of the northern section is between 35 feet and 40 feet deep, with a maximum depth of 45 feet recorded about the middle transversely and somewhat south of the middle longitudinally. The neck is shallow and the greater part of the
southern section ranges from 22 feet to 32 feet in depth. At the time these soundings were taken (March 25, 1950) the surface temperature taken in shade at mid-day was 58°F., while the readings at 35 feet and 45 feet were 56·5° and 55·5° respectively. Seasonal temperatures have not been taken apart from a surface reading of 63°F. obtained on November 29, 1949. These records agree fairly closely with those of better known alpine lakes and suggest that surface readings approaching 70°F. would be obtained in mid-summer.
The growth rate of these char is much more difficult to determine than that of trout on account of the scales being smaller and the ridges more closely placed. This close placing is customary in stunted fish, the scales of which manifest little differentiation between summer zones and winter bands. In the majority of the specimens available the scales are too indefinite to justify even an approximate reading, but after examining a large number of scales of the most favourable specimen the opinion was formed that the fish was in its fifth year. This fish was 23 inches in length and the lengths attained at what appeared to be the completions of the several years were computed as 2·75 inches. 7·5 inches. 15·5 inches and 21 inches. These figures appear reasonable, but in the absence of more definite knowledge of the life history of the species they cannot be accepted unreservedly.
The condition factor of the specimens available, as obtained from Corbet's calculator. averaged 44·6, which would be quite good for trout in similar waters.
The time of spawning cannot be estimated with any precision, as the specimens available were taken early in the season. In a male measuring 24·25 inches in length, taken on November 1, the milt lobes were about 9 inches in length and 0·6 of an inch in width, and in a female of 23·25 inches, taken at the same time, the egg lobes measured 5 inches and contained eggs of up to 2 mm. in diameter.
Particulars of the stomach contents of the eight specimens examined are given in the following table. One stomach was empty.
|Philypnodon breviceps||Galaxias lynx||Larvae of Procordulia||Sundry|
|44||1||3||Small quantity of vegetable matter|
|38||14||1 beetle, 4 small stones|
|63||7||1 larva of Zantagrion, 1 caddis larva, water-weed and rushes|
Compared with the food of trout from Lake Pearson and similar waters the food listed above reveals a marked scarcity of surface insects and a preponderance of Philypnodon. Green manuka beetles (Pyronota festiva) and adult dragonflies of several species form an important part of the food of both rainbow trout and brown trout in alpine lakes, the remainder consisting largely of Procordulia larvae, caddis larvae, water-snails and sundry beetles, with fishes occupying only a minor position.
Several specimens contained the cysted parasite Eustrongylides, one natural host of which (Phalacrocorax carbo) is moderately plentiful in the locality.
The writer wishes to express his thanks to Mr. P. Hopkins for assistance in collecting the material examined, to Mr. R. S. Duff, Director of the Canterbury Museum, for access to the collection of American salmonoids in that institution, and to the North Canterbury Acclimatisation Society for information from its records.
Day, F., 1887. British and Irish Salmonidae. Williams and Norgate, London and Edinburgh.
Donne, T. E., 1927. Rod Fishing in New Zealand. Seely Service & Co. Ltd., London.
Gill, T. E., and Jordan, D. S., 1878. In Jordan, Manual Vertebrates. E.U.S. Ed. 2, 356.
Gunther, A., 1866. Cat. Fish. Brit. Mus., vol. 6.
Regan, C. T., 1914. The Systematic Arrangement of the Fishes of the Family Salmonidae. Ann. Mag. Nat. Hist., series 8, vol. 13, pp. 405–408.
Stokell, G., 1940. The Occurrence of Hyoidal Teeth in Salvelinus fontinalis. Trans. Roy. Soc. N.Z., vol. 70, pp. 161–163.
Notes on the Geological Structure of New Zealand
[Read before the Wellington Branch, June 8, 1950; received by the Editor, June 17, 1950.]
Late Cretaceous and Tertiary Fold Movements
The Kaikoura Orogeny
The Importance of Faulting in Tertiary Earth Movements
Relations of Tertiary to Older Trends
The New Zealand Recurved Arc
The Post-Hokonui Orogeny
Similarity between South-west and North-west Parts oF South Island
Original Extent of Tertiary Strata Flanking the Alpine Fault
More Detailed Discussion of Selected Regions
Further Comments on the Relations of Newer to Older Trends
Geomorphology in Relation to Structural Studies
A general north-east trend imparted in a late Tertiary orogeny is dominant both in structural plan and in physiography. Another important trend with a north-west orientation is most clearly seen in Mesozoic strata, this trend being generally attributed to an early Cretaceous orogeny, although locally there has also been renewed movement along this trend during the Tertiary. Both structural trends were at one time attributed to an early Cretaceous age and on this attribution is based Suess's original concept of syntaxes in the North and South Islands.
It has been suggested that the two trends do not run together, but that there is a distinct swing from north-east to north-west trending folds giving an arc. However, Suess's idea of syntaxis (schaarung) describes the Tertiary fold plan quite as well as the concept of arcuate structure, for the latter appears to be largely a composite feature obtained by joining the north-east and north-west trends: the key to many arcuate plans may lie in “posthumous” folding. The validity of both concepts in tectonics depends on precise definition in terms of time. A certain parallelism of trends for consecutive fold movements, particularly during the Tertiary, is evident in many parts of New Zealand, but some emphasis is placed here on folds and faults which cut at an abrupt angle across the trend of a preceding movement. Such later folds appear often to follow the axes of much more ancient folding.
The late Tertiary faults, usually with remarkably straight traces, are of great physiographic and structural importance: many show throws exceeding 3,000 feet and a throw of 10,000 feet has recently been suggested for the great Alpine Fault. Transcurrent movement
has recently been recognised in New Zealand by Wellman and Cotton, and the former has advanced in a paper as yet unpublished the hypothesis of great transcurrent movement along the Alpine Fault.
It is probably true that the strata of New Zealand are more difficult to decipher than those of western Europe and many other classic regions. The Lower Palaeozoic strata have been examined only in part and are difficult of access. Professor Benson has recently found Cambrian strata, and, with co-workers, has described a good graptolitic Ordovician succession, but no Silurian has yet been positively identified. The Devonian rocks are fossiliferous, but the relations to over- and underlying rocks are quite obscure. The Upper Palaeozoic and Mesozoic strata of New Zealand include thousands of feet of argillites and especially arkoses, commonly of greywacke facies, and their subdivision has proved difficult. Of these, the Carboniferous (if any) and Permian strata have not yet been separated, and, indeed, in some places are difficult to separate from the Trias. The Triassic and Jurassic rocks form a comprehensive and thick group, in places at least 28,000 feet thick, and sometimes grouped as the Hokonui System. All these earlier strata are distinctly more indurated, sheared, and folded than later beds, so that it is commonly possible to map the older beds as “undermass” and the later beds as “cover.” Indeed, of recent years much of the country, where Late Cretaceous and Tertiary stratigraphy and structures have presented immediate problems, has been so mapped, with consequent dearth of information concerning the undermass. Certain rocks, attributed to the Aptian and containing poor faunas, would seem, in degree of induration and diastrophic position relative to major unconformities, also to belong to the same comprehensive basement, including Triassic and Jurassic strata, and they can rarely be clearly separated from the earlier Mesozoic strata.
In many places there is passage from the upper Cretaceous to Tertiary and these two systems, in places of very monotonous lithology, and reaching locally total thicknesses of 30,000 feet, show considerable facies variations and local discordances.
In New Zealand any geologist who attempted on purely local evidence a division of strata into Primary, Secondary and Tertiary would be inclined to define his Primary as extending from the Devonian downwards, his Secondary as including the Permian and perhaps the lower Cretaceous, and his new Tertiary system would perforce include some upper Cretaceous rocks and perhaps even some Pleistocene. Moreover, the stratigraphical limits between the groups belonging to each era would be occupied by question marks, representing the times of our major orogenies which might vary slightly in age from place to place. There are no known strata bridging these time gaps within the country.
Although the lower Palaeozoic strata and their relations to some of the metamorphic rocks remain obscure, two problems have engrossed the New Zealand stratigrapher because of the great thicknesses of the formations involved. These problems are the subdivision
of the “greywackes”, particularly those of Permian* and Triassic age, and the relations of the Cretaceous and Tertiary to each other and to the older basement rocks The separation of Permian and Triassic greywackes advanced by McKay and other members of the Geological Survey has stood the test of Trechmann's and Arber's critical examinations and their units are being gradually extended by field workers at the moment. The separation of Triassic and Jurassic greywackes first attempted by Cox and McKay (1878), is also being continued, but with more difficulty.
The Cretaceous and Tertiary sequences have been shown in recent years to include strata of thick continuous geosynclinal sedimentation as well as beds with non-sequences, minor unconformities, and erosion breaks. This record for Cretaceous and Tertiary time has only been made possible by the patient palaeontological researches of Finlay and Marwick, based on thousands of specimens from many field collections, and they have so far described only in summary form the stages which they have separated and the formations corresponding to these stages (1947). The work of these two authors is the outstanding contribution to New Zealand stratigraphy during the last forty years. Without close palaeontological, and particularly foraminiferal zoning, the Cretaceous and Tertiary lithological record in New Zealand is bewildering and even misleading, for there are many beds of very different ages and similar lithology and many bands which mark diachronic boundaries. Since the dominant structural plan of New Zealand is late Tertiary in age, this palaeontological work is all-important. An examination of the recently published Outline of New Zealand Geology together with the earlier papers of Finlay and Marwick reveals a scheme of Tertiary stages probably as closely spaced as any attempted elsewhere. It is not surprising that there seem to be many minor fold movements throughout the Tertiary—a history similar to that of other Tertiary basins when studied with closely spaced stages. These movements on the whole can be regarded as reaching in the late Pliocene a marked climax generally known as the Kaikoura Orogeny.
For orogenies earlier than Tertiary, information is more meagre and as yet only two other major orogenies are separable. The great fold movement, probably of early Cretaceous age, known as the post-Hokonui Orogeny, has already been mentioned, and an important orogeny must have occurred in Devonian or Early Carboniferous times imparting a meridional strike to the lower Palaeozoic rocks. The table of orogenies, which includes other inferred movements in addition to these must be regarded as more tentative, and detailed stratigraphic evidence will not be cited here.
A lag in the publication of stratigraphical and structural studies seriously handicaps an attempt to generalize and to fill in details of fold movements. Much of the Geological Survey work (and all the work of oil geologists) remains unpublished, and although some of
[Footnote] * The recent discovery and identification of Permian fusulinids in the North Auckland district by officers of the Geological Survey is an important event. These organisms have not previously been recorded in New Zealand and Permian strata had not been mapped in the North Island.
this material is current knowledge among members of the Survey, other geologists find difficulty in placing the shorter papers of the last few years in a general structural framework. The Survey workers, engrossed in regional mapping, revealing more and more details, have hesitated to write general statements on structure likely to be soon out of date and thus would seem not to have done themselves full justice. The appearance of the new geological map represents a milestone (the useful black and white maps of Morgan  had already become out of date), and the Outline of the Geology of New Zealand, which accompanies the new map, is the most useful existing synopsis of New Zealand stratigraphy. Professor Benson, in 1921, 1922, produced admirable summaries of New Zealand geology which will long remain the stand-by of all those unfamiliar with the detailed literature. Cotton's papers of 1916 and 1925 shed further light on structure, particularly as revealed by land forms. Henderson summarised the fault pattern of New Zealand and gave a useful synopsis of the late Cretaceous and Tertiary strata of New Zealand (before Finlay-and-Marwick stages). Benson's papers of 1923 and 1924 relate the stratigraphy and structure of New Zealand to those of Australasia as a whole. Apart from these few papers hardly a single general statement on New Zealand geology appeared between Benson's papers and Macpherson's last memoir, which is a lively discussion of the author's views based on wide field experience and data collected by himself and other geologists. Confined to the Cretaceous and Tertiary movements, his work presents a synthesis of structure and covers in brief outline the relations of Cretaceous and Tertiary sedimentation to structural plan. Indeed, it renders much of this paper redundant, except that Macpherson has been more concerned with synthesizing than with describing general knowledge already familiar to the New Zealand geologist. His memoir is quoted extensively in this paper because it serves as a convenient starting point on which to examine theories concerning the structure of the country.
The next few pages comprise a running commentary on the chief views concerning structure that have been recently advanced, and omit many important references already quoted by Benson and Macpherson. A later section gives some further details for parts of the country and introduces some of the writer's own views, which can claim little originality, but maintain that further theories on the nature of late Cretaceous and Tertiary fold patterns require a closer attention to the structure formed in older orogenies.
Acknowledgments and Note on Sections
These notes were first written as a statement on recent work on the structure of New Zealand intended to help students and visitors to the country. Most of the text was completed when the new coloured geological map of New Zealand appeared (late 1948). With the object of making the paper more useful to the New Zealand student the writer has added sections based on published and unpublished information and the new geological maps formed the basis of large parts of the sections. In devising these sections the author is grateful to the following students who assisted him as follows:—Section DE,
FG, JK—Mr. P. Vella; Section NO—Mr. T. Grant-Taylor; some of Section PQ—Mr. D. McBeath. The information of unpublished theses by R. A. Couper and P. Vella is contained in Section JK.
New Zealand stage names have been retained on these sections, since several do not correspond exactly to the European divisions. The approximate correspondence is given in the legend and text.
The help of colleagues in the Geological Survey who generously offered oral information on details is acknowledged in the text.
Parts of all the sections are likely to be wrong even at the time of publication, especially those portions which were entirely compiled from the small scale geological map without access to unpublished reports. Nevertheless, it seems desirable to present them with their imperfections, for detailed studies within New Zealand have advanced far ahead of simple general statements, leaving a difficult gap for the student or stranger to bridge. To aim at great precision on various points would involve much more inquiry with consequent delay. The inspiration for these sketches lies partly in the early sections of workers on the old Geological Survey, particularly Hector. The table of orogenies is an attempt to outline in sweeping fashion the stratigraphic evidence bearing on fold movements. Professors Cotton and Kuenen have read the text critically and the writer is indebted to them for useful suggestions. Generous help, with pertinent criticism, has been proffered by Professor Benson, to whom the writer is deeply grateful. A number of his suggested improvements and additions to the bibliography have been incorporated in the text.
Whilst the information of most writers quoted in the text has contributed to the cross-sections, the most useful papers are those including sections by the following authors: Bell, Benson, Couper, Cox, Ferrar, Grange, Hector. Henderson, Hutton, McKay, Marwick, Macpherson, Ongley, Park, Vella, Williams, Willett. (Some of these await publication.)
The main structural outline of New Zealand shown on the early maps of Hector and Hutton has been little altered by subsequent work, and the two coloured geological maps now published by the Survey bring out even more forcibly the dominant trends established by the pioneers. The impression of a general north-east trend shown by the coast line and mountain chains is accentuated by the great axial range of Mesozoic strata, largely Triassic and Jurassic and including some Permian (the primary fold, p. 8, of Macpherson, 1946) that extends in the North Island from the Bay of Plenty to Cook Strait. In the South Island an axial chain which also consists of Jurassic, Triassic and probably late Palaeozoic rocks, continues from the south of Nelson Province to Mount Aspiring. This north-east trend is indeed further accentuated on the new map by the interpolation of the great Alpine Fault along the western slope of the Southern Alps, a fault which has long been known in part but whose full extent has been best demonstrated by Wellman and Willett. East of the Alpine Fault the ranges consist only of greywacke and crystalline schists, flanked farther east by Cretaceous and Tertiary sediments. West of the fault lie granitic batholiths, schists which have suffered contact as well as regional metamorphism (Benson, 1928), rocks of
age as early as Cambrian, as well as Mesozoic and Tertiary rocks—a much more varied and complicated group of rocks. This fault, then, is a radical line in the New Zealand structural plan which requires fuller discussion later. It recalls the Median Line of Japan in many respects (Yehara).
The structure shown by the strata within the axial chain, both in the South and North Islands, is little known, but the chain can be accepted as constituting a much-faulted complex anticline in the dominant late Tertiary structural pattern. An ancient erosion surface is carved on the greywacke at many localities, and at the Manawatu Gorge (North Island) this surface and its covering of Pliocene beds form a broad anticline, striking north-east and broken by a great fault on its eastern edge (Ongley, 1935). Elsewhere in the North Island the structure of this axial chain presumably showns complications based on a similar pattern. There is marked axial pitch at the Manawatu Gorge and evidence of similar axial pitch on all the erosion surfaces of the greywacke “highs” which appear below the Tertiary in the country flanking the axial range to the east. Macpherson's map shows for the North Island several anticlinal ridges with greywacke cores whose general structure can be considered as rather similar to that of the axial chain.
Late Cretaceous and Tertiary Fold-movements
The Kaikoura Orogeny
The structural interpretations generally accepted to-day differ in many essentials from those of Hector and Hutton, although the older and most recent maps appear to be similar. Hector and Hutton considered the main structural outline to be formed by pre-Tertiary fold and fault movements, but later workers have followed McKay (1884, 1892) in recognising clear evidence that the structural and topographic pattern is dominated by important late Tertiary movements. Cotton (1916, 1925), who has concentrated on the physiographic pattern resulting from these movements, appears to have been the first to realise fully the correctness of McKay's interpretations and grouped the late Tertiary movements as the Kaikoura Orogeny, giving its age as very roughly late Tertiary or post-Tertiary. Furthermore, in calling attention (1916) to stripped fossil erosion surfaces at many places separating Mesozoic and Tertiary strata, he provided a useful clue to the structural interpretation of late Tertiary folds as well as stratigraphy. The late age of many of the faults and folds having been generally conceded by all field workers, attention in recent years has been focused on the stratigraphical evidence in the shape of unconformities, erosion breaks, and local thinnings of sections, all indicative of differential movements throughout Cretaceous and Tertiary times. Macpherson sketches for the Cretaceous and Tertiary an eastern and a western geosyncline, separated by a median land mass occupying roughly the position of the present axial chain. These geosynclines are drawn as continuing along the edges of both North and South Islands. He describes the younger beds as generally tending to overlap the older ones along the geosynclinal margins on the site of the axial chain with a regression of the sea in the late Cretaceous. The evidence is
insufficient to indicate when and to what degree the axial ridge was overstepped by sediments, but for the North Island at any rate this reconstruction seems to be acceptable. It also seems likely that there was intermittent uprise of this axial chain. Such uprise may have commenced very early—probably in the Cretaceous, but certainly not later than Pliocene time, for at the Manawatu Gorge a condensed sequence of Pliocene clastics only 2,000 feet thick rests on greywacke, whilst only 10 miles to the east the Pliocene cover, representing the same time interval, has a thickness of approximately 7,000 feet.* Macpherson extends the idea of intermittent movement of anticlinal ridges to folds in the adjoining geosynclinal belts and to the marginal zones of deformation in the geosynclines. Thus he insists on the development of structural ridges which “did not attain their present amplitude (possibly 7,000–8,000 feet above adjoining synclinal troughs) in one or two folding movements, but grew by recurrent orogenic impulses.” He cites later rocks flanking the greywacke cores of such ridges as commonly marked by discordances, etc., usually absent in the adjoining troughs, where the Cretaceous and Tertiary sediments are of much greater thickness. Whilst admitting that certain anticlines may show such a continuous development, one may query whether this conception has not been extended too indiscriminately. There is evidence to suggest that certain troughs of deep sedimentation were later reversed to become conspicuous anticlines, and this must be a subject for future discussion, as must also the concept of migrating troughs. Did certain nodal axes persist as structural “highs” whilst earth waves fluctuated over neighbouring regions?
Present views, therefore, return in a minor degree to the early ideas of Hector and Hutton, but visualise a continuity in tectonic development, a blending between the views of these two authors and those of McKay, in which compromise the latter's emphasis on post-Pliocene movement is accepted. This is shown in Macpherson's sketches of a diastrophic cycle which from late Cretaceous time was marked by orogenies of lesser moment and mounting intensity culminating in the Kaikoura movements of late Pliocene (post-Castlecliffian) age. The latter, for Macpherson, “may be only an arbitrary end point, for the tilted, warped and stepped terraces at various levels and also the regional seismicity indicate that the New Zealand recurved arc still grows.” Compared with the precursor orogenies, however, the Kaikoura movements do seem to indicate great dislocations concentrated in a short time, and their importance is not entirely dependent on the inference that they mark roughly the beginning of the “Anthropozoic.” The throws on faults breaking late Pliocene strata in many places exceed 5,000 feet, and we must regard the Kaikoura as an earth-storm greater than any of the earlier movements during the Tertiary period. But the principal earth movements called Kaikoura in different localities are not necessarily contemporaneous, for it is known that the most marked movements of this earth-storm vary in date by the magnitude of a stage or two from place to place (Marwick, 1946, p. 11).
Recently in a posthumous paper Macpherson (1948) cited the evidence for an upper Senonian transgresion following post-Albian
[Footnote] * Only Opoitian, Waitotaran and Nukumaruan Stages are included in these figures. The rocks of Castlecliff age have been largely eroded recently.
movements. Locally the base of the upper Senonian (Mangatu formation) is marked by giant boulder beds. In other places it is difficult to separate upper and lower Senonian. The evidence is too complicated to be cited here.
The Importance of Faulting in Tertiary Earth-movements
Early workers in New Zealand were quick to recognise great faults, and Cotton has stressed their existence in elaborating his views on geomorphology, but he has also described folds accompanying the faults (p. 60, 1916b, p. 91, 1925). From the structural as well as the physiographic aspect, the faults are certainly remarkable, but the geologist new to the country may find the nomenclature of some local geological papers between the years, say, 1920 and 1940, a little misleading. The structure of a tract of country may be entirely described in terms of “blocks”, more or less “tilted”, but the stranger, perhaps with a bias to deciphering structure in terms of the growing anticline, comes back from the same field with a mental picture of anticlines more or less pitching or closing, broken by immense faults along one limb. Also, many of the mapped “faults” can, on closer examination, be replaced by flexures (e.g. Wellman, pages 193–194, 1946). The term “block” may be convenient, and may even be correct (although unhappy in its implications): the term “tilt”, however, is actually misleading since it cannot be construed to cover the observed swing in strike of Tertiary strata sympathetic with the swing in strike of the underlying fossil erosion plane near the extremities of a greywacke “high”. The Saxonian nature of the folding and, indeed, the general significance of folds in the New Zealand tectonic pattern was first stressed by Benson (1930) and is well illustrated in his maps of Eastern Otago (1941). To-day the field worker tends to see his faults in most places as part of a general fold pattern, and an elongated dome or anticline can be visualised as one of the dominant “ancestral” forms for many of the fault-bounded structural “highs”. The descriptions of to-day are more akin to those of the earlier geological surveyors in containing a liberal sprinkling of anticlines and synclines. The faults are usually arranged in an echelon pattern and some care is necessary in reading small-scale maps like the Geological Survey map of 1948 because the trends of faults are usually slightly oblique to the general trend of the great axial chain of greywackes shown on this map.
Relations of Tertiary to Older Trends
It is now generally agreed that the trend between north-east and north-north-east results from the late Tertiary Kaikoura Orogeny and its precursor movements, for it is the dominant strike in most Tertiary strata. Moreover, it many fields where this fold trend is dominant the belts of facies in Cretaceous and Tertiary strata are roughly parallel, suggesting sedimentation in a framework of similar trend. In certain fields the evidence even points to a parallel strike in the greywacke strata, so that hypotheses can be advanced postulating Mesozoic and Tertiary geosynclines geographically coincident and with facies aligned parallel to the succeeding Kaikoura folds. Such a concept underlies parts of Macpherson's maps. But it would be wrong to extend this picture involving continuity in strike to the whole country,
for in certain places the strikes of Triassic and Jurassic greywacke are different from those of the Cretaceous and Tertiary strata. In such places these more ancient rocks show strong isoclinal folds much broken by faults and thrusts. The strikes of the actual fold axes are difficult to determine, for pitch is often considerable, but it is clear that a regional north-west strike of axes is in many of these localities common in the Mesozoic and sometimes older greywacke, although nearby Tertiary beds may show a marked north-east strike. Thus, it has been observed occasionally that where Mesozoic greywacke abuts against faults bounding Tertiary strata, the highly sheared greywacke beds strike parallel to the fault lines, but median parts of the same masses of greywacke may show regular strikes with a roughly northwestern trend. Further data on strikes within the pre-Cretaceous rocks will be presented later.
At a first glance one is apt to cavil at Macpherson's map of late Cretaceous and Tertiary structures, because, while in some places the trend lines are based only on the Kaikoura folds and faults bounding the greywacke cores, in other places the strikes seem to be based on measurements within the more ancient strata. Such criticism is not entirely just, however, for in many places he has backed up his acceptance of the latter strikes by indicating similar trends in the neighbouring Tertiary or Cretaceous strata. Macpherson was fully aware of complications. He wrote (p. 9):
“They are late Cretaceous and Tertiary basement folds developed on a subdued mature-land (new term: Willis, 1928) of lower and middle Mesozoic rocks. Their axial trends may in some cases be inherited from an earlier diastrophic cycle, but we have so little knowledge of the internal structure of the basement folds that it is preferable to regard the surface cut on the basement rocks as a datum of reference when studying the late Cretaceous and Tertiary folds of the covering beds that envelop them. Observations show that the foldings of the diastrophic cycle concerned here arched the basement rocks along trends that diverged from the trends of an older diastrophic cycle.”
And yet, in the structure of the South Island, and particularly Southland (p. 10) the strikes in ancient rocks seem to form the most important part of his argument in favour of an arcuate structure.
The New Zealand Recurved Arc
Indeed, the main thesis of Macpherson's paper is that New Zealand constitutes a recurved arc formed in the course of the late Cretaceous and particularly late Tertiary diastrophism. He rejects the idea of Marshall (1911) that the axial chain continues on a north-east trend towards the Tonga and Kermadec Islands, and in doing so he renders unnecessary Suess's idea of a syntaxis. By means of this syntaxis Suess joined the north-east trending fold system and the north-west trending chain of the North Auckland Peninsula somewhere in the Rotorua volcanic region, whose origin could perhaps be regarded as due to this crucial junction. Macpherson swings the trend of the axial range to assume a northerly direction near the Bay of Plenty, and considers that this is coincidental with a gradual regional swing to a north-west trend. Such gradual swing in strike is well seen on the West Coast of the North Island between Mokau and the Waikato River, and the north-north-west trend of faults bounding the Hauraki graben also fits the same picture. Macpherson cites also a marked north-west
strike of Cretaceous and Tertiary strata at the north-east end of the North Island: this we must examine later. He also describes the curious Taitai formation of Aptian age as klippen, the remnants of a nappe which, in places, he interprets as thrust forty miles eastward in Senonian time, its roots being inferred to lie in the axial range. Within this arc are the centres of Tertiary and Recent volcanicity, and the pattern is in agreement with that suggested by Hobbs.
At the south end of the South Island Macpherson sees a similar arc, now bent to the south-east, and with the areas of Tertiary volcanicity concentrated again on the inner margin, namely at Dunedin and Banks Peninsula, near Christchurch. Ingeniously he visualises the boundary between the north-west striking Permian of the Hokonui syncline and the Otago schists as a great reversed fault (the Permian and Trias beds being slightly overturned near Clinton) and continues towards the north-west this great fault, on or near which peridotites and serpentinites are aligned. “It is likely that movements along this thrust have been recurrent from late Palaeozoic, possibly before, and probably up to Pliocene times” (p. 11). The trace of the thrust swings round to run into the great Alpine Fault, and we are led to infer from its curvature that the thrust may in places lie quite flat. Thus, he imagines “the ‘rolling up’ of 13,000 feet of Jurassic and Triassic and a considerable thickness of late Palaeozoic sediment along the western and south-western schist contact”. He traces sympathetic swings in strike of the rocks (mostly Mesozoic) to the south and southwest of the Hokonui syncline largely formed by these movements, and also sympathetic swings in the trend of the Cretaceous and Tertiary strata to the north-east of the Otago schists. These schists form a great dome-like mass, regarded by some as a simple anticline, but by Benson as possibly a packet of recumbent sheet folds.
The Otago schists are considered by many geologists who know them well to be quite distinct from the schists which lie west of the great Alpine Fault: there is general agreement that the strike of the Otago schists swings in the neighbourhood of Mount Aspiring from a north-west orientation to adopt a north-east orientation, the Arahura series which forms the Southern Alps being a continuation of the Otago schists. Turner and Hutton consider the Otago schists to be largely formed by the metamorphism of arkoses, often greywackes, and passage into these rock types has been observed (C. O. Hutton, 1940). The chlorite zone has been subdivided into four sub-zones by these two authors and the highest grade of metamorphism observed in the Otago schists proper does not pass the biotite zone. Turner (1935) has noted, too, that they pass into greywacke belonging to the comprehensive Te Anau series, whose precise age is as yet unknown, but is in part Permian. That the Otago schists are certainly in part Palaeozoic is indicated by Ongley's discovery at Clinton (1939), twenty miles west of Kaitangata, of fossiliferous conglomerate bearing pebbles derived from the Tuapeka series (part of the Otago schist mass) along with Zaphrentids, and a Permian age is at the moment assigned to these later beds. It is conceivable, however, that the Otago schists farther west and their formational continuation, the Arahura series, represent a much more comprehensive group, perhaps including much of the Lower Palaeozoic. Any further evidence bearing on the
total age of these metamorphosed sediments would be important. At the north-east corner of the South Island the rather similar Marlborough schists, whose petrology has been little described (Turner, in Henderson, 1935), also lie near the Alpine Fault and east of Trias-Jura rocks which Wellman has in discussion described as being remarkably similar to those of the Hokonui syncline. In tectonic position the Marlborough schists are perhaps analogous to the Otago schists.
After reading Macpherson's interpretation of the tectonics of the South Island, a comparison immediately springs to mind: the Otago schists and the Arahura series are the “schistes lustrées” of New Zealand, as Wilckens has already (1917) suggested. Macpherson condenses in a footnote concerning the Alpine Fault (p. 11) the following:
“This frontal upthrust trends north-east along the western flank of the Southern Alps. Morgan (1908, 1910) described its significant role in the growth of the Alps. Gregory (1908) suggested that an old north-west-trending range (the Palaeozoic geosyncline of this account) had been overwhelmed by the younger north-east-trending Alps. Henderson (1937) named this fault the “Alpine.” Hobbs (1944) points out that the Alpine chain has overridden an ancient coign situated to the westward. In the present account, the Alpine Fault is identified with the southern tectonic contact of the Otago schists (Maps 1 and 2), and is here regarded as a later structural feature of the major tectonic. It defines a great arcuate thrust plane that truncates late Tertiary folds with Palaeozoic cores (lower Ordovician and upper Silurian) along its north-east extension that shows much late overriding. On this extension late Palaeozoic and middle Mesozoic groups are on the upthrow side. Along what is considered its south-east extension in South Otago, late Palaeozoic, lower and middle Mesozoic (Hokonui Series), late Cretaceous terrestrial sediments, and middle Tertiary marine beds are involved on the downthrow side. A similar frontal fault defines the eastern limit of the primary or borderland fold in the North Island segment. The directions of upthrusting, however, are opposed, indicating opposed tangential forces originating within the concave regions of the recurved arc. The significant fault movements on these frontal upthrusts are late Pliocene and probably post-Castlecliff.”
We have now a picture of great thrusts, presented by Hobbs, and even a foreland obstacle. But in this connection there is one irreconcilable feature: the Alpine Fault has been mapped in many places, often with high country situated on each side of it, and its trace appears to be remarkably straight. There are none of the sinuosities we might expect on the margin of a thrust plane and no klippes. All the available evidence suggests that the Alpine Fault in so far as concerns its present surface trace is not a thrust according to the Alpine worker's usage; it cannot be compared with the Moine Thrust. The great thrust of Otago, postulated by Macpherson, seems to have passed into a reverse fault, in places remarkably near vertical, and of prodigious throw. The possibility of the Southern Alps being formed by a great overthrust cannot be ruled out entirely if such were imagined to have occurred in early or middle Tertiary time. One can conceive of later vertical faulting superimposed over an old thrust pattern and followed by erosion, but evidence to support such a view is insufficient. Indeed, the available evidence is against direct comparisons with Alpine tectonic patterns.
Henderson (1929b) develops Bailey Willis's idea of great ramp-like shear planes, and traces throughout New Zealand a pattern of faults with very arcuate plan. Whilst few dispute the existence of
great late-Tertiary reverse faults with, in places, minor true “thrusts”, the symmetrical arcuate traces which he ascribes to most of the faults are not likely to be acceptable to many field workers. His statement that “many of the blocks are highest near the central part of the fault” can be explained by the concept of the elongated dome broken on one limb by a large fault. The Alpine Fault does not appear to be resolvable into a set of arcs as his map suggests, and many of the faults in Marlborough and the North Island also appear to be remarkably straight. Professor Cotton, who has viewed some of these traces from the air, confirms this view, as does also Mr. A. Prichard, of the Public Works Department, an airman with an observant eye for earth features.
The post-Hokonui Orogeny
We have now summarised the chief points in Macpherson's paper, drawing particular attention to the curving of the arcs which, according to Macpherson, brings the strike of late Tertiary folds into approximate coincidence with the strikes shown in many pre-Cretaceous rocks. A brief resumé of what is known of earlier fold trends is now necessary, but the assignment of particular structures to specific earlier orogenies must be accompanied by reservations, for the Kaikoura movements profoundly affected the whole country, and it is difficult to assess how much of this late Tertiary folding or rotational component must be subtracted from trends visible in older rocks. It was early realised that the greywackes, whether of Palaeozoic or Mesozoic age, are usually more folded and sheared than the overlying upper Cretaceous and Tertiary sediments, and a very late Jurassic or early Cretaceous age is usually assigned to the fold movements affecting these “greywackes”. In the Ruahine Range the isoclinal folding and shearing of the greywacke, probably Mesozoic sediments and perhaps in part Palaeozoic, are in marked contrast with the smoother folds of greater wavelength broken by great faults which alone affect the Tertiary cover. The strike of the former folds, too, is quite commonly different from that of the later Tertiary folds. Morgan (Bulletin 6, pp. 36–37) recognised a dominant north-west trend in certain greywacke beds west of the Alpine Fault. These beds belong to the Greenland series, considered to be late Palaeozoic [Carboniferous (?)] by Morgan, and consist of greywacke and argillite with minor hornfelses and some schists, rocks which show the effect of contact rather than regional metamorphism. The north-west strike oblique to the strike of the great Alpine Fault and that of the Arahura strata immediately east of the fault aroused Morgan's interest.
“The rocks of the Greenland series are thrown into a number of well-developed folds. The strike direction, a few exceptional cases omitted, varies from somewhat west of north (349°) to north of west (280°) within a few degrees of a bearing of 300°. The dip is usually about 60° to 70°, but may be as low as 30°, and sometimes reaches 90°. Except that they are somewhat disturbed by the granite intrusions, and considerably affected by faulting in certain areas, the folds, compared with those of the Arahura, are wonderfully regular and free from complication.” (Morgan, 1908, p. 97).*
[Footnote] * See also p. 36, Bull. 6, where Morgan discussed the possibility of these rocks having had an original N.–S. strike, since rotated by later folding along N.E. (?) trend.
The map of Totara Survey District in the Bulletin referred to is particularly instructive in showing the abrupt change of strike at the Alpine Fault. The Greenland series extends as far as Milford Sound, according to Wellman and Willett, who also insist that the Alpine Fault separates two distinct formations, although admitting that the Greenland formation is schistose in places. The general north-west strike of the Greenland rocks is also noted by these authors. Morgan thought that this north-west trend was visible even in part of the Arahura series on going eastward from the north-east-striking Alpine Fault (p. 34, 78, loc. cit.) into strata less disturbed by the late Cretaceous and Tertiary movements. Morgan also considered the Alpine Fault to be formed during an immediately post-Hokonui (early Cretaceous) orogeny, but if active then, it has certainly been much resuscitated by late Tertiary movement. East of the Alpine Fault a north-west trend is, of course, dominant in the Otago schists and the Trias-Jura greywackes of Southland. Macpherson's interpretation suggests that this fold trend is largely Tertiary and, although he does in passing note that this late Tertiary north-west trend is partly inherited from an older trend (Macpherson, 1946, p. 9), he nowhere discusses the idea of renewed folding as particularly pertinent to his recurved arc structure. Park (1921) uses the name Hokonui for these early fold movements, affecting Permian, Triassic and Jurassic greywacke, for this trend is most clearly seen in the rocks of the Hokonui syncline. Others have applied the better name post-Hokonui since the comprehensive Trias-Jura has been called the Hokonui System.
The surface separating Mesozoic greywacke and Cretaceous-Tertiary is commonly smooth and cuts across the folds of the post-Hokonui Orogeny. This smooth erosion plane, like the post-Hokonui fold movements, must also be of early Cretaceous age and is regarded as a fossil peneplain, discussed by Cotton at some length. This surface is overlain in different places by rocks of age varying from Upper Cretaceous to Tertiary according to the local diastrophic history, and warping and dislocations of this surface are of outstanding importance in deducing the palaeogeography and tectonics of the Cretaceous and Tertiary periods. By the relation of overlying rocks to this peneplain, we can often determine how much of the north-west strike shown in the older strata is really ancient.
Unfortunately, strikes are very imperfectly known for large areas of Mesozoic greywacke and the full extent of strata showing Morgan's dominant north-west trend is not yet known, but the Otago schists and the Trias-Jura in parts of Southland show this trend very markedly. Morgan's observation that the north-west strike did appear in the Arahura Series in places some distance east from the Alpine Fault, and Park's definition of the Hokonui Orogeny, both imply that the Greenland Series and the beds with a dominant north-west strike east of the Alpine Fault, such as the Otago schists and the Trias-Jura greywackes of the Hokonui syncline, may have been folded in the same post-Hokonui Orogeny. The north-west folding of the Greenland Series in this paper is very tentatively regarded as formed by the post-Hokonui Orogeny, so that the writer considers the folds of this early orogeny to have been later cut by faults and folds of the great late
Tertiary Kaikoura Orogeny with north-east trend, and particularly by the Alpine Fault. This interpretation has little good evidence to support it, except that of all the older pre-Tertiary rocks west of the Alpine Fault only the Greenland Series shows a dominant north-west trend. Alternatively, the Greenland Series may have been folded at a different earlier period.
It may be well here to anticipate by giving a view developed further in the present paper. The likelihood of renewal of movement along old trends has been discussed by several New Zealand writers, particularly Benson (1941). Such renewed folding is here regarded as the key to the north-west striking portions of Macpherson's recurved arc ascribed largely to late Cretaceous and Tertiary diastrophism. These are likely to be resuscitated trends first stamped on the rocks in the post-Hokonui Orogeny or even earlier. Although not all the folds of one period of orogeny will show a particular trend exclusively, it is nevertheless likely that the trend will be dominant. It is probably significant that in those areas where the greywacke does not strike north-west, the regional strike in these older rocks is north or north-east and commonly parallel to that of the adjacent Cretaceous and/or Tertiary strata. The Nelson region and the west coast of the North Island require further discussion later in so far as the more ancient and Tertiary strikes are there parallel.
An attempt to disentangle orogenies even earlier than the Hokonui was made by Hutton (1900, p. 166), who postulated a Mid-Devonian folding with a north-east trend. Park (1921) revived this conception in a list of orogenies of doubtful value.
There is a great gap in our knowledge between strata containing Devonian fossils (found at Baton River and Reefton) and the Permo-Carboniferous fossiliferous strata of Nelson. The Devonian age and the north-east strike inferred for the folding were probably based on McKay's observation (1879, pp. 125–126) that a north-east strike appears in the Baton River beds, since shown by Shirley to be of Lower Devonian age.* It is possible that most of the north-east strikes recorded in these beds are due to Tertiary faults and folding. The position of these Devonian beds may be similar to the Lower Devonian beds at Reefton (Allan, 1935) described by Henderson (1917, pp. 74–77) as being intensely faulted and sheared with accompanying Miocene beds. Discarding strikes in the obscure Devonian outcrops, some more consistent results can be obtained in the north-west Nelson district from the Lower Palaeozoic strata, in places fossiliferous. In the Mount Arthur beds, in part Ordovician, and certainly all Lower Palaeozoic, a general northerly trend was recorded by McKay (1879, p. 125), and the Ordovician rocks of the original Aorere Series in Collingwood Subdivision, N.W. Nelson (Ongley and Macpherson, 1923) show a similar strike. In the so-called “Aorere” Series of Reefton, for which Macpherson and Gage suggest a Devonian age
[Footnote] * Presumably the ancient nature of this north-east strike is inferred from a section by McKay (1879) from Mount Peel to the Baton River showing the Devonian, very much folded, overlain by Tertiary also striking north-east but dipping less steeply.
(1937), Henderson considers that the original trend of plications was north-north-east, and in those parts of the Motueka subdivision (N.W. Nelson) furthest from Tertiary infaulted blocks a meridional trend appears to be prominent in folds affecting the lower Palaeozoic rocks. (Henderson and Grange, Motueka Subdivision, 1926, p. 4.) Again, in Murchison Subdivision, south of Motueka Subdivision, Fyfe (1928) finds that a meridional strike is common in the lower Palaeozoic and in Parapara, N.W. Nelson, Bell's (1907) mapping also indicates a marked northerly and north-north-westerly strike. The divergence of this, presumably the most ancient known trend, from the north-east trend resulting from Tertiary movements comes out clearly in the new Survey map of the South Island. We can temporarily assign this approximately northerly trend to some Palaeozoic orogeny, perhaps Devonian, as Hutton has suggested. Of fold movements earlier than this we know nothing.
The name Tuhuan attached to the hypothetical Devonian orogeny by Park (Bull. 23) is not a happy one, derived as it is from the many granite batholiths which Park assumed to have been emplaced in this period. Morgan described the Tuhuan granites near Hokitika (1908, p. 130) as intruded both into the Greenland schists, west of the Alpine Fault, and into the lower more gneissic members of the Arahura schists, which latter lie east of the fault and form the bulk of the Southern Alps. In that part of the field “all the main outcrops occur along or close to the great thrust-plane which separates the Arahura series from the Greenland rocks. They may be regarded, to use one of Suess's phrases, as cicatrices marking the healing of a wound in the earth's crust”. (Morgan, 1908, p. 130.) Morgan regarded the granites as batholiths emplaced in late Cretaceous or early Tertiary time. The emplacement of the Tuhuan granites may be much later than Devonian, but the writer is inclined to regard it as pre-Triassic. Quite provisionally, we can regard all the granites and associated dyke rocks north of Hokitika as being of similar age to the Tuhuan granites. These granites remain a barely touched field of research in New Zealand, and if the theory of granitization is invoked, boundless possibilities are presented concerning the age of the granitization and of the hypothetical sediments that have suffered metasomatism.
Associated with the Ordovician in the north-west and south-west of the South Island are greywackes presumably of Lower Palaeozoic age of which little is known. They have in places been confused with the Greenland Series, but is is probable that most of them have suffered older fold-movements than the Greenland rocks.
At the south-west end of the South Island lies a tract of country whose structure is largely unexplored, but apparently consisting mostly of metamorphic rocks. The oldest known strata are richly fossiliferous Ordovician argillites and greywackes which are found at Preservation Inlet (Benson and Keble, 1936; Benson, 1933). They strike approximately slightly west of north with assymetrical folds, their steepest limbs dipping to the east. Northwards the rocks seem to pass along the strike into spotted phyllites, mica-schists and para-
gneisses with which are associated calc-silicate hornfelses (Benson, p. 401). Marbles and hornblende-gneisses of various types have been found in the country between the Ordovician of Preservation Inlet and Milford Sound (Marshall, 1907; Turner, 1939), and it is likely that they are contained in a vast suite of paragneisses of unknown but possibly Palaeozoic age. The Ordovician rocks are described by Benson as cut by granitic batholiths elongated in an approximately northwest direction. To the east and south-east the metamorphic rocks closely associated with the Ordovician show numerous lit-par-lit injections associated with granodiorites. It seems likely that these “grano-diorites” stretch uninterruptedly to the shores of Lake Te Anau and the neighbouring Lake Manapouri, where Park (1921) in rapid reconnaissance mapped them as the Clinton River intrusives. This group seems to include a great variety of vaguely defined rocks such as diorites, granodiorites, hyperites, trondhjemites, paragneisses and smaller granitic masses, on which the only adequate petrographic work is that of Turner (1937). Though his study in detail was confined to Lake Manapouri, Turner came to the conclusion that certain of the rocks were definitely paragneisses of basic composition, whilst others were plutonic rocks. At Lake Te Anau many of Park's “diorites” show extremely regular banding, recalling that of sediments, and Dr. Turner, in conversation with the writer, has expressed the opinion that they may also prove to be paragneisses. The whole of this territory is, therefore, worth examination in the light of the granitization hypothesis. Park (1921, p. 42) was of the opinion that the Clinton River rocks were intrusive into the Permian, but the evidence for this has not been clearly described. Benson (1921, p. 10, footnote) accepted the evidence of Park and Moir that part of the “diorites” invades annelid-bearing greywacke (Triassic or Permian?) in the Darran Mountains and the Hollyford Valley, north of Lake Te Anau. The age of the Clinton River complex may then be either Palaeozoic or (more unlikely) as late as post-Triassic, and the complex may be of very different age in different places. In general, it would appear that all the oldest known rocks show a nearly meridional strike varying to north-north-west or north-north-east locally, and the Clinton River complex appears to be very closely associated with these older rocks. The writer is inclined to regard all this complex as Lower Palaeozoic and not later than Upper Palaeozoic.
Similarity between South-west and North-west Parts of the South Island
Whether or not the Clinton River complex is partly of Mesozoic age, all the country lying between Lake Te Anau and the south-west corner of the South Island recalls roughly in its structural and stratigraphical ensemble the north-west corner of the island. If the south-west corner represents a coign—a foreland—for Hobbs, so also must the mass of ancient rocks at the north-west extremity. Ignoring detail and theorising sweepingly, a similar pattern can be seen in the south-west and north-west parts of the island, thus:
|Ancient mass of Fiordland embracing fossiliferous Ordovician, schists, marbles, granite batholiths, and the Clinton River complex.||Ancient rocks of north-west Nelson (including fossiliferous Cambrian, Ordovician, Devonian, marbles, schists, granite batholiths.|
|Waiau Tertiary syncline.||Tertiary syncline south-west of Nelson.|
|Hokonui syncline of Permian, Triassic and Jurassic rocks.||Syncline of Permian and Triassic rocks at Nelson.|
|The great “Otago thrust.”||The Marlborough schists.|
|The Otago schists.||The Alpine Fault.|
The positions of the two thrusts do not fit into the pattern nicely.
The writer is aware that this parallelism is already envisaged in part or in whole by colleagues in the Geological Survey, notably Mr. H. Wellman, who first insisted in conversation on a close similarity between the stratigraphy and structure of the Hokonui and Nelson synclines. The position here assigned to the Alpine Fault in the Nelson district, namely as continuing along the Wairan Fault east of the Marlborough schists, is that drawn on the Survey map,* and may be queried by those who know this field more intimately. One merit in the scheme is that folded Tertiary beds fit into part of the picture, so that we are certainly dealing to some extent with late Tertiary diastrophism. On such parallels are based Hobbs’ suggestion of Alpine analogies and Wellman's interesting but tentative and unpublished discussions of possible immense transcurrent displacements. Until more detailed supporting evidence is forthcoming, the suggested parallels must be treated with great reserve, for they are partly dependent on comparing metamorphic rocks on which the petrographic information is very incomplete.
Original Extent of Tertiary Strata Flanking the Alpine Fault: Movement on the Fault
Park believed the Clinton River complex to continue south-eastwards into the Longwood Mountains, east of the Waiau River, and reappear on the coast at Riverton and Bluff; Macpherson (p. 10 and map) believed the outcrop of the complex to swing in a northwesterly directed curve through these points, and he deleted for purposes of clarity the Tertiary strata known to be of some thickness at the mouth of the Waiau Valley. In this manner he partially obliterated the southern extremity of the Waiau syncline, which has a general northerly orientation. Presumably geophysical evidence obtained at Orepuki, at the mouth of the Waiau River, partly justifies this procedure, but one is still inclined to consider that the general orientation of the Waiau Valley is more significant of late Tertiary diastrophic trends than is the strike of the Clinton River complex. The rocks of the Clinton River complex cannot be younger than early Mesozoic (and may well be much older), and Macpherson's view seems to accept the strike within this formation besides the trend of its margins, as indicative of late Tertiary trend lines. It is likely that Macpherson is referring to the Waiau syncline when he writes (p. 11): “In a minor fold of the major syncline late Cretaceous and early Tertiary terrestrial sediments and post-Eocene marine beds are involved. However, the Tertiary syncline although it curves with the regional arcuate structure, does not generally follow the major syncline or axes in the Mesozoic sediment, except where the major syncline peters out to the north-west.”
[Footnote] * Macpherson places the continuation of the Alpine Fault west of the Marlborough schists, but the Geological Survey map places it east of the schists.
Following the Waiau syncline to the north, the Tertiary strata are seen to be folded between the Permian beds prolonging the southern limb of the Hokonui syncline and the rocks of the Clinton River complex. Tertiary strata can also be followed, deeply involved in the older rocks, over the Homer Saddle and Lake Fergus, immediately north of Lake Te Anau (Wellman and Willett, p. 299; Benson, 1935, p. 9). We can tentatively regard these mid-Tertiary beds as formerly continuous with those mapped along the coast west of the Alpine Fault in South Westland.
If we are to accept Macpherson's view concerning the great “Otago thrust”, it would have to be regarded as tectonically a much more significant branch than the seaward prolongation of the Alpine Fault, although Wellman and Willett insist on the dominance of the latter in their field mapping. The writer, however, would prefer to see any southern prolongation of this fault as following the western side of the Waiau Valley; for the displacement would then be defined in terms of deformed Tertiary strata. There has been great movement on the Alpine Fault in late or post-Tertiary time, although it may have been initiated in earlier times, but the latest movement on Macpherson's Otago overthrust, if such really exists, cannot be ascribed to late-Tertiary diastrophism: a glance at the geological map indicates that near the Mataura River, some fifty miles north-north-east of Bluff, Oligocene strata spread over any possible trace of the Otago thrust.
Wellman and Willett in their instructive paper also discuss the Tertiary history of the Southern Alps, pointing out that little is known of the surface on which the Tertiary strata were deposited, and that land on the site of the Southern Alps may well have existed before the Tertiary period. The distribution of “mid-Tertiary beds and the absence of lower Tertiary beds suggests that in mid-Tertiary time the lower Tertiary sea transgressed both along the southern part of the West Coast and eastward over western Otago and parts of adjoining Southland. The sea may not have extended over what is now the higher part of the Southern Alps,… the Alps have nevertheless since been elevated along a pre-Tertiary and possibly Mesozoic trend line.” (The Alpine Fault was regarded by Morgan as chiefly early Cretaceous in origin.) “The schist belt which lies along this line may represent a positive unit which has been intermittently uplifted in a similar manner at other times in the past.” The same authors point out that the Tertiary beds are most intensely deformed along the line of the Southern Alps (p. 303), and they postulate an uplift of about 10,000 feet along the Alpine Fault in later Tertiary time (approximately mid-Pliocene, but believe like most writers, particularly Benson and Cotton, that after this uplift the surface was reduced to a late mature surface of low relief. The present physiography of the Alps is ascribed to erosion of this peneplain (Wellman and Willett, p. 304), but the throw of 10,000 feet need not be necessarily concentrated into later Tertiary time, for the estimate of Wellman and Willett is based on the deformation of a peneplain surface alone, there being no Tertiary outliers immediately east of the Alpine Fault. The same authors also point out that the Tertiary beds where deeply involved in faults, as at the outcrops intervening between the Waiau Valley and the Tertiary of Jackson Bay, are so indurated as to be easily confused with the rocks of the older undermass (p. 303).
Greenstones of various types, including serpentinite, peridotite, talc schist, tremolite schist, etc., are aligned parallel to but not along the trace of the Alpine Fault, and their occurrences have been summarised by Benson (1926, pp. 42–44). C. O. Hutton has also described serpentinites and gabbros in the Livingstone Range, in western Otago (1937); and Turner, peridotites and serpentinites in the Cascade Valley (1930), South Westland.
Many of the rocks occur as intrusions, generally of sill-like character, commonly in schists belonging to the Otago schists or Arahura Series, or sediments of Mesozoic age belonging to the comprehensive Hokonui System, so that they have been provisionally correlated with the post-Hokonui fold movements, probably early Cretaceous.
Occurrences of greenstone that must have been emplaced at other periods are also known. At Auckland, Turner and Bartrum (1928, pp. 871–873) describe serpentinites and other ultrabasics as intruded in an orogeny later than the Cretaceous beds and preceding the deposition of the first Tertiary, presumably an early Tertiary orogeny (Bartrum, 1934; Benson, 1924, p. 130). They also describe (1928) pillow lavas, serpentinites, etc., of early Tertiary emplacement in the North Cape area. Fleming (1947) describes a serpentinite in contact with Oligocene and Miocene sediments near the Mokau River and gives good evidence for regarding its present position as due to a diapir thrust.
There are many other occurrences which cannot be mentioned here, and a complete restatement concerning all the greenstones of New Zealand and their relations to structure is highly desirable, for the concept of diapirism has been insufficiently considered.
More Detailed Discussion of Selected Regions
Suess's Syntaxis in the North Island: Waiapu
Suess, following the information of previous writers, attempted to explain by syntaxis the existence of north-west-striking strata near strata with a north-east strike, but Morgan has demonstrated that for the South Island any conception of simple syntaxis is untenable, the two fold trends being sharply separated by the Alpine Fault.
Macpherson demolishes Suess's syntaxis in the northern part of the North Island by suggesting that the strikes of all the Cretaceous and Tertiary strata swing to follow a north-west trend. He substitutes a curved arc and discards “faulty structural concepts such as branching fold trends”.
Curiously enough, Macpherson, although he derives much of his evidence from the Waiapu subdivision, north of Poverty Bay, has made little mention of some interesting structural features which he and Ongley had already described in the Waiapu Bulletin. The accompanying reduction from the maps of these two authors shows the structure very clearly. Their description is as follows (p. 19): “Over a wide area in Hikurangi and west Mata survey districts the Raukumara beds (Albian?-Cenomanian), the oldest rocks of the subdivision, are compressed into steep, narrow and vertical folds, trending north. Southwest in north Arowhana S.D. and north-east in Mangaporo S.D., the
same beds are folded less intensely and regularly, trending nearly east”. More precisely, the strike in Arowhana S.D. is usually nearer to west-north-west and in Mangaoporo generally east but often east-north-east.
“The Tapuwaeroa beds (Senonian) are extremely contorted, but their distribution as mapped clearly shows that they have been compressed into broad folds trending east-south-east. A well-marked syncline extending along the Tapuwaeroa valley and reaching the coast,… crosses the middle of the subdivision.” “An anticline on the south flank of the Tapuwaeroa syncline crosses the middle of Mata S.D.…” “The Mangaoporo anticline to the north is not so clearly marked…” “The Tertiary beds in the south-eastern part of the subdivision are broadly folded almost at right angles to the east-west folds of the Cretaceous rocks.” (Italics added by the present writer.) “A syncline twenty miles long and five to seven miles wide strikes diagonally north-east through Tutamoe S.D. into the south-west corner of Mata S.D. Along its south-east flank the beds rise into a well-marked anticline extending through south-east Tutamoe and north-west Tokomaru.” “The structure of the Tertiary beds in the north-east of the subdivision is dominated by faults rather than by folds.” “Innumerable faults traverse the Cretaceous beds… most of them are subparallel with, and no doubt were formed during, the east-west folding of the older rocks. In the northern part of the subdivision the faults that break the Tertiary beds have nearly the same trend. Farther south the later faults are mostly parallel with the folds in the Tertiary strata.”
A glance at the map confirms that the principal folds affecting only Cretaceous rocks strike approximately west-north-west and show axial pitch east-south-east. Considerable erosion also followed the deposition and folding of the beds which Ongley and Macpherson mapped as “Mangatu”. The Miocene beds were laid on all the earlier formations with unconformity strikingly shown in the south-west part of the subdivision, where a great thickness of Mangatu beds (Senonian plus early Tertiary) is preserved in a syncline and cut out on an anticlinal crest. Since the lower Miocene beds belong to the Southland Series (Finlay and Marwick, 1947) and the Mangatu beds of Ongley and Macpherson include several lower Tertiary as well as upper Cretaceous stages, this great unconformity sheds light on the curious absence of the Upper Oligocene (Pareora Series of Finlay and Marwick) at many localities along the east coast of the North Island. Major earth movements with considerable planation must be postulated immediately before or during this time.
Ongley and Macpherson clearly realised that the folds affecting Tertiary beds ran athwart those earlier folds which affected only lower beds. And yet the strike in Tertiary strata swings markedly to an approximate easterly orientation on approaching the axis of the Mata anticline. It seems highly probable that near this anticline we have evidence of either three superimposed trends or of a cross-trend formed contemporaneous with dominant north-east folding over most of the region. The east-south-easterly pitch of folds in the Cretaceous beds may have preceded the Pareora planation, but can be
more conveniently regarded as an early expression of the second folding along an approximately north-east trend.
Now, evidently in a pattern showing such a diversity of trends formed within a small area and in a comparatively short lapse of time it is difficult to aver that trends definitely curve, for one may be joining the fold trends formed at different periods in a pattern which is essentially criss-cross. It may be legitimate to group the dominant structural outlines produced by several fold movements within a certain lapse of time as constituting an arc, but the existence of such an arc by no means invalidates Suess's idea of the north-east trend continuing towards the western edge of the Tonga deep. A glance at the new Geological Survey map gives no indication of the major structural swing postulated by Macpherson: instead, a major anticline striking north-east appears to be abruptly broken by west-north-westerly faults. To quote Ongley and Macpherson again: “The structure of the Tertiary beds in the north-east of the subdivision is dominated” [the writer's italics] “by faults rather than folds”, but the faults actually chop abruptly across the folds and there is no clear evidence of a swing in strike. Furthermore, if we accept a dominant pattern of folds and faults developed in the course of several consecutive fold movements as constituting an arc, the term syntaxis must be equally valid for apparently branching folds formed during several similar movements. Moreover, Fleming (unpublished) has recently cited important evidence, based on submarine contours, for believing that the Taupo graben can be traced as a trench for hundreds of miles towards the Kermadec Islands. Following Healy's discovery of marine Pliocene strata at Matata and Ohiwa, on the Bay of Plenty, Fleming considers that the trench must, at least in part, have been formed very late in Pliocene or even in Pleistocene times.
The Taitai Nappe
Macpherson regarded the Taitai rocks (of Aptian age), apparently overlying younger Cretaceous rocks, as evidence for an eastern over-thrust of some forty miles, also noting that the klippe-like masses appear to be concentrated in or near the Tapuwaeroa syncline. The emplacement of this nappe is regarded by Macpherson, very tentatively, as immediately anterior to the later Senonian, and there is stratigraphic evidence for a regional orogeny at this time, although there is no very pronounced early-formed north-east or north-striking fold and fracture pattern in the Cretaceous rocks such as might be expected with Macpherson's postulated thrust. The school of Grenoble, and particularly Schneegans, have returned to the concept of immense gravity slides of rock-masses as an explanation of some nappe structures, a process which was originally suggested in Schardt's revolutionary papers on the Pre-Alps and which Lugeon and Schneegans describe. If the Taitai rocks really represent klippen, such a process* can readily be imagined as causing their emplacement as a result of an east-south-easterly tilt suggested by the pitch of folds affecting only Cretaceous rocks. The concentration of the klippen in the Tapuwaeroa syncline is also readily explained. This process
[Footnote] * Wellman invokes a Miocene landslide to explain the position of curious outcrops of coal measures at the Fox River head waters. Nelson Province (1946).
seems more in keeping with the regional tectonics than one of tremendous compressive folding in late Cretaceous time.
The interpretation of the Taitai rocks in Waiapu as klippen may, however, be completely denied, for the evidence is doubtful, and if the rocks are truly Aptian a diapir remains a possible explanation.
The example of Waiapu serves as a warning not to be dogmatic regarding constancy of trend throughout the movements of Cretaceous and Tertiary times. It is important, nevertheless, that where the Cretaceous and Tertiary strata show a dominant north-east strike, a comparatively simple pattern results with little or no cross-folding or faulting. On the other hand, where a north-west strike is common in Cretaceous and Tertiary rocks the pattern is always more complex, with some evidence of movement producing two strikes, often at right angles to each other. The Waiapu district also introduces us to Tertiary structural patterns that, although dominated by north-east strike, show minor transverse faults and folds.
The North Auckland Peninsula and the Auckland Region
The North Auckland Peninsula has been covered in some detail by Geological Survey bulletins, but both the structure and stratigraphy remain obscure in many places. The strata include Mesozoic greywackes, Cretaceous argillites, and Tertiary sandstones and mudstones, with also many Tertiary lava flows, and the Tertiary strata show many overlaps and unconformities. The outcrops, moreover, are very deeply weathered.
At the time of mapping, correlation by Tertiary fossils was on uncertain grounds. To add to the difficulties, it is likely that in some places the Tertiary beds were deposited in earlier-formed fault-angle depressions, whereas in other places the faulting followed the deposition of the Tertiary strata; but it is difficult to separate everywhere the structures according to age.
The dominant faults, those bounding the main outcrops of Mesozoic greywacke and adjacent Tertiary beds, strike mostly north-west, but there are numerous important cross fractures, some striking northeast and many roughly east-north-east. Comparatively few strikes of strata are recorded on the map and those few have a bewildering diversity, suggesting folding along varying trends, but some of the strikes and dips recorded in the Tertiary strata may well be primary dips due to sedimentation or compaction. The relations of the lavas to underlying rocks are also obscure and the whole region calls for a synthetic statement by a worker knowing the field intimately; but at the moment it seems clear that the north-west fabric is very considerably complicated by a cross fabric. Ferrar's (p. 33, 1925) description of quartzite “coulisses”, nearly vertical beds in the Triassic-Jurassic rocks, implies that their north-west trend was imparted in an orogeny preceding the deposition of the late Cretaceous strata, presumably the post-Hokonui (early Cretaceous) orogeny.
The vicinity of Auckland city has been described by Professor Bartrum and his students over a period of years (Turner, Searle, Laws, Firth, Lyons, and the authors of several unpublished theses). Firth's description of the Papakura-Hunua region immediately south
of Auckland City exemplifies clearly the Tertiary structures typical of the whole region. He describes two sets of faults, forming on the map a set of rough parallelograms, but he recognises clearly that the movements on faults parallel to one direction are in some places earlier, in others later, than movements on faults belonging to the other set. For such a structural pattern the term “block-faulting” in its strict sense seems very apt, as indeed it does also for the Tertiary structures over most of the North Auckland Peninsula. Bartrum in a synopsis (1949) of the Tertiary history of Auckland City gives evidence for alternating submergence and emergence. The Pareora series is absent and the base of the Waitemata sandstones (of early Miocene age) consists of great boulder beds containing igneous material from the “lost” hinterland which lay west of New Zealand. The Waitemata beds near Auckland show in places conspicuous but irregular folds formed possibly by sub-aqueous slumping, as suggested by Kuenen and Shepard during a visit to the city.
The Hauraki graben is bounded by faults striking approximately north-south, and these are cited by Macpherson as evidence for the general swing in strike which appears clearly along the west coast, and whose existence we have queried on the east coast. East of the Hauraki graben lies the Coromandel Peninsula, largely formed of Tertiary volcanic rocks, and the Geological Survey Bulletins on this region have generally agreed that the volcanism is likely to have commenced along early-formed fractures on the lines of those which now bound the graben. (A convenient and elementary summary by Bartrum, 1930, is listed.)
No attempt is made here to describe the Tertiary and Recent volcanicity of the North Island other than to note that the general concensus of opinion dates the graben of Taupo as formed later than the earliest volcanic outbursts, with fault movement continuing till the present day (Grange, p. 55, 1937). On the other hand it is evident from Healy's description (cyclostyled itinerary for the Pacific Science Congress, 1949) that considerable faulting occurred in the early Pliocene, and that the late Pliocene volcanicity is likely to have originated along such fractures.
The West Coast of the North Island
The West Coast between the Waikato and Mokau rivers is remarkable for the strong meridional strike shown by the Mesozoie greywacke (including fosailiferous Triassic and Jurassic beds). The Tertiary strata, dipping much less steeply, also show the same strike. The latter form several fault-bounded folds clearly marked on Macpherson's map (1946), which distinguishes three principal anticlines, with also one prominent syncline of Tertiary strata as described in the recent Te Kuiti bulletin by Marwick (1946). This field has been covered in detail by several workers, including Ferrar, Grange, Henderson, Marwick, Ongley, Taylor, and Williamson. Their results from adjoining areas tally closely in stressing the great thickness of Mesozoic strata (approximately 28,000 feet), with a lesser thickness of Tertiary beds (approximately 4,000 feet in Te Kuiti region). Cretaceous strata, of considerable thickness on the eastern side of the island, are entirely absent to the west, and the Upper Oligocene (Pareora Series), absent to the east, outcrops on the western side.
It is worthy of note that the cross fractures throughout the southern part of the coastal belt covered by the Te Kuiti bulletin, some 30 miles wide and 30 miles long, are subordinate and of little throw, but increase in number and size north of Kawhia Harbour (i.e. approaching Auckland), where they appear as two sets of faults showing a strike either dominantly east-north-east or north-north-east.
The stretch of comparatively homogeneous fold pattern seen in the Te Kuiti district is the most convincing evidence for the swing of strike required by Macpherson in his postulated arc structure.
Macpherson prolongs the axis of the Tertiary folds southward and east of Mount Egmont and runs them out to sea with a slight curvature.
Wellman, in oral description, has stressed stratigraphical similarities between the Mesozoic rocks of this Waikato-Mokau stretch and the Mesozoic rocks near Nelson, in the South Island, and considers them to have formed part of one geosyncline existing in both Mesozoic and Tertiary times. The rocks of both groups show in general parallel strikes, although the Mesozoic beds are more highly folded than the Tertiary. Wellman's interpretation seems acceptable, and there appears to lie between the Te Kuiti region and Nelson a tract of country where the north-west element in the folds affecting the Mesozoic is entirely suppressed.
Marwick (1946, p. 11) points out that in Te Kuiti district the principal fold movements appear to have occurred in late Miocene post-Tongopurutan times: “The movements presumably represent the Kaikoura Orogeny (Cotton, 1916) and indications are that, here, they were completed relatively early, perhaps before the end of the Miocene and at the latest in the early Pliocene (Waitotaran). After the orogeny, there ensued a fairly long period of stability during which the soft Tertiary rocks were stripped from the high blocks and peneplained… Then came an uplift of several hundred feet… In the Upper Pliocene the vast quantities of ignimbrite that invaded the subdivision from the south-east filled the main valleys and submerged much of the low country…”
South of Mount Egmont, only Pliocene and later beds are visible and they show a general slight south-westerly down-tilt, to be correlated with some differential uprise in the axial range in the vicinity of the Taupo region (M. Te Punga, unpublished thesis). Fleming has redescribed the whole classic Wanganui area of Pliocene sediments in an unpublished bulletin, and has told the writer that although the Pliocene beds must be generally interpreted as smoothly dipping, there are traces of minor folds with axes likely to be coincident with those of folds mapped by Macpherson (1946) to the north. Fleming therefore deduces some very late, but minor, folding.
The Axial Chain in the North Island
The structure of the axial chain is most imperfectly known and the dominant trends on maps are obviously north-east, following enormous faults, many of them formed in very late Tertiary times (post-Castlecliffian, i.e. late Pliocene or even Pleistocene).
A few scattered observations made by the writer suggest that within the least disturbed greywackes and argillites of the axial range there are stretches showing a general north-west strike, which may vary from
west-north-west to north-north-west, although the more sheared grey-wackes on the margins of great late Tertiary faults appear to show a north-easterly strike. This slight evidence is too inconclusive as yet, however, to substantiate a theory of the existence of a general ancient north-west strike within the greywackes forming the axial chain of the North Island.
These greywackes are certainly in part Mesozoic in age, as indicated by the discovery of a single vertebra of an ichthyosaur at Wellington (Benson, 1921), but the stratigraphy is for the most part obscure. Forming a tectonic unit quite distinct from those on the west coast in the Mokau-Waikato area, these rocks may be partly older and perhaps include some Palaeozoic strata.
East Coast of the North Island, from Hawke Bay to Cook Strait
East of the axial chain, the north-east trend already seen in the Tertiary strata north of Poverty Bay continues markedly impressed on all the upper Cretaceous and Tertiary strata from Poverty Bay to Cook Strait. This part of the country is already covered by reconnaissance reports by McKay and more recently, in detail, by Henderson and Ongley in Gisborne and Eketahuna subdivisions, by several other officers of the Geological Survey, and by oil geologists.
In general, from Hawke Bay to Cook Strait, the facies of late Cretaceous and Tertiary sediments appear to be aligned in belts roughly parallel to the north-east strike of the late Tertiary folds, indicating that some folding or faulting along this trend had probably already occurred in early Cretaceous and/or earlier times.
The structure revealed by Cretaceous and Tertiary beds in many places consists essentially of very elongated domes which, although broken by great faults on their eastern limbs, show a truly anticlinal disposition of the erosion surface, which separates the greywacke cores of the folds from the Tertiary cover.
The region constituting the Dannevirke Subdivision, east of the Manawatu Gorge and the Ruahine Range, is of stratigraphic interest in containing localities which show a complete passage from the late Cretaceous through Paleocene to Eocene stages as demonstrated by the detailed examinations of foraminifera carried out by Finlay. The localities of complete passage are concentrated on the margins of a major anticline in the centre of Dannevirke subdivision, while anticlines east and west give good evidence of non-sequences, unconformities and clastic deposition in the late Cretaceous and early Tertiary. It appears likely that during pre-Pliocene time there was progressive overlap of Tertiary sediments towards the axial chain of the Ruahine Range, with the deepest sedimentation near the major central anticline.
The Upper Oligocene (Pareora Series) is completely absent south of Hawke Bay, and its presence further north is doubtful. In parts of Waiapu and Poverty Bay district, Henderson, Macpherson, and Ongley have found prominent conglomerates developed at the base of beds representing the lower Miocene (Southland Series). The Pareora Series is absent in many other parts of New Zealand and obviously about Late Oligocene time some fold movement occurred which, although subordinate to the post-Pliocene movements, must
yet have been considerable. Again the influx of coarse clastics in the late lower Miocene (Upper Southland) makes a second period of widespread precursor movement at that time very likely.
The concentration of the greatest thickness of Pliocene beds west of the major anticline, and in places the eastward overstep and truncation of early Pliocene members by later ones, suggest that the main trough of Tertiary deposition migrated markedly westwards, with movement at the beginning of the Pliocene, through the influence of early development of the major anticline in the centre of the Dannevirke subdivision. Such movement seems to have continued intermittently during the Pliocene. The principal trough of Pliocene deposition seems to have lain between the early-rising central anticline and the Ruahine Range already largely emergent. Here, then, is a tract of country where the concept of the persistent “high” appears to be invalid, although there is good evidence of an anticline persistent throughout late Cretaceous and Eocene times on the present coast east of the major anticline.
This widespread early Pliocene movement inferred by the writer in Dannevirke subdivision can be compared with the movements described by Marwick in Te Kuiti as “before the end of the Miocene and at the latest in the early Pliocene”. They can be accepted as approximately contemporaneous, and both areas flank the axial chain, although the Te Kuiti subdivision is more distant from it. Now, in all the region from Hawke Bay to Cook Strait, the Pliocene beds have been very considerably folded and faulted by very late Pliocene movement and the writer has in this field restricted the term Kaikoura to these late movements. It appears, therefore, that along the axial chain and near it, great post-Pliocene fold movements occurred, but that farther away, on the west coast, these movements had the effect only of imparting a westward down-tilt, with folding very subordinate.
The axial chain shows remnants of an old erosion surface to which Waghorn, Cotton, and Ongley (1935) have called attention, and this is dated by the fact that it is covered by very shallow water Pliocene sediments in a few places. At the Manawatu Gorge these Pliocene beds form an anticline on an axial depression on the range, and Fleming and the writer (1941) have considered this to be a strait in Pliocene time. In another paper (as yet unpublished) the writer calls attention to this transverse depression, which appears to be ancient and yet has continued as a region of maximum axial pitch until recent times. The local strike within the greywacke strata is roughly parallel to the course of the transverse river. The Dannevirke major syncline flanking the Ruahine Range appears to have been already an elongated basin at the end of Pliocene time and the writer interprets the course of the Manawatu in this syncline east of the Ruahine as directly consequent. In its early history it is inferred to have drained the shrinking mud-flats of the infilled Pliocene basin towards and westward through the strait.
Lower Cretaceous (Aptian) Strata and the Post-Hokonui Orogeny
Macpherson's conception of the Taitai overthrust has already been discussed, but the Aptian age ascribed to the rocks of the Taitai series is of more general importance as it may affect the dating of the great
post-Hokonui Orogeny. The genera Maccoyella and Aucellina, considered to be Aptian (Finlay and Marwick, p. 17, in “The Outline of the Geology of New Zealand,” 1948), have not been found at Taitai, but at Koranga, some thirty-five miles west-north-west of Poverty Bay, and Aucellina in rocks of similar lithology in southern Hawke Bay. Large tracts of unfossiliferous greywacke and argillite on the south-east side of the North Island have been provisionally assigned to the Taitai series owing to resemblances in lithology and degree of induration. An abundance of basic igneous pebbles is supposed tentatively to characterise the conglomerates among these strata, but in degree of induration and of deformation, and by general lithology the rocks ascribed to the Taitai series over large tracts are indistinguishable from those which in the axial range are ascribed to the comprehensive Trias-Jura group. If the Aptian age is valid, some of the post-Hokonui movements may well be of age as late as post-Aptian, judging from the deformed state of the Taitai rocks. But it may well be that two orogenies were concentrated into the period between late Jurassic and post-Aptian time.
Outliers of Tertiary near Wellington: Wellington: Cook Strait
Apart from the Pliocene beds at the Manawatu Gorge, two other occurrences of Tertiary beds are known in the axial ranges. One of these, described by Macpherson (1949), is near Paraparaumu on the west coast some 37 miles north-east of Wellington, where beds of Lower Oligocene age occur in an infaulted block bounded by greywacke on all sides. The other beds, at Makara, near Wellington, appear to be of Pliocene age (Gage, 1940) and may be infaulted in the greywacke. These outcrops give evidence of the former extent of Tertiary beds now almost completely removed and of the great Tertiary movements which have dislocated them.
Cotton has described many of the geomorphic features around Wellington. Both the peneplains and the faults there are likely to be largely of post-Pliocene date and give evidence of great differential movement. But little is known of the earlier geological history of the Wellington district, since the approach appears to lie only in a patient mapping of highly crumpled and sheared greywackes or in a geomorphic attack through the correlation of peneplain remnants which lack Tertiary cover.
A zone, or zones, of red rocks, some of which are variolites, appears at several points along the Rimutaka Ranges, but at the moment it is premature to link all the outcrops of red rocks as marking an approximate strike line. H. Fyfe (unpublished) has recently shown that some of these red rocks in the Rimutaka Ranges are pillow lavas, in occurrence similar to those at Wellington (Broadgate, 1916; Benson, 1921, p. 18; Wellman, 1949), but at other localities they are jaspillites and possibly radiolarites.
The recently published geological maps indicate that it is quite feasible to conceive of the axial ranges as continuing across Cook Strait, and the latter may mark either a region of marked axial pitch or some transverse fracture. Certainly, L. C. King's (1939) suggestion of a lateral displacement in the nature of continental drift is unnecessary and is based more on correlation by physiography than on correlation of structural features. Some more detailed pictures of the relations of
structural elements in the North and South Islands to each other is, nevertheless, desirable, and C. A. Fleming has developed views (as yet unpublished) based partly on submarine morphology of Cook Strait which will help to fill this need.
The South Island: Canterbury, Marlborough, and Westland
The whole of the north-east side of the South Island, including Marlborough and most of the Canterbury province, is dominated by north-east-striking folds and faults formed chiefly by the late Tertiary movements and broken by a few cross faults of almost east-west trend. Indeed, it was in this region that McKay first recognised the importance of the late Tertiary orogeny. Reconnaissance reports by Fyfe and Healy give further descriptions of stratigraphy and structure.
Cretaceous and Tertiary stratigraphy has been described in considerable detail, but is outside the scope of this note; and the structural implications of the stratigraphy must be left to some other worker more conversant with the region.
For the region west of the Alpine Fault, the writer is unable to add much to the outline given earlier. The Greymouth coalfield has been surveyed in detail by officers of the Geological Survey and a detailed bulletin by Gage awaits publication. H. W. Wellman's studies on rank in the West Coast coals are also unpublished. The Tertiary strata of the West Coast yield good evidence indicating considerable mid-Tertiary earth movements. Wellman (1945) describes at Ross, south of Hokitika, a section through the Tertiary beds in which Pliocene (Waitotaran) strata rest with marked unconformity on Lower Oligocene, these earlier sediments, according to Wellman's tentative section, being folded into a recumbent syncline formed by movements preceding the Pliocene (Waitotaran). Gage (1945) and Gage and Wellman (1944) discuss further Tertiary sequences in Westland which contain conglomerates indicating earth movement during Tertiary time, as does also Wellman's description of the Fox River headwaters (1946). It seems likely that this area suffered locally movements comparable to those cited for Late Oligocene (Pareora), for Miocene (Upper Southland), and for early Pliocene times in southern Hawke Bay. These writers alone are able to synthesise this great field adequately.
Otago and Southland
Macpherson's views on the Otago and Southland districts have already been briefly outlined, and it is interesting to consider his views on late Cretaceous and Tertiary diastrophism in relation to earlier fold trends in that region.
It has long been known that the north-west trend of the Otago schists and the Hokonui syncline is of ancient origin. Cotton (1917, pp. 429–430) early recognised pre-Cretaceous faulting at the Shag Valley. Benson (1941, p. 216) summarises the position as regards the early history of the Shag Valley fault-zone, which strikes north-west and reaches the east coast some thirty miles north of Dunedin, as follows: “The fact that it has brought into apposition the Palaeozoic (?) Otago or Maniototo schist on the south-west with the Early Mesozoic (?) greywackes, etc., on the north-east, which were reduced
to a common peneplain level by the earlier Cretaceous erosion, indicates movement with a southerly upthrow during the closing Jurassic orogeny. Paterson (1941) pointed out that the semi-talus character of the oldest Upper Cretaceous rocks near Shag Point indicates the existence of a rejuvenated fault-scarp on the north-east side of this fault-zone.” Late Cretaceous and Tertiary marine sediments were later deposited across this ancient fault-zone. “Renewed movement, this time with a northerly upthrow, occurred in mid-Tertiary times,” and after the upthrown greywacke and the marine Tertiary sediments had been reduced to a common peneplain level, a “flow of basalt flooded over this peneplain crossing the (by then) obliterated fault trace …”
This north-west trend can be followed a considerable distance south and west from the Shag Valley Fault into the Otago schists and into the great Hokonui syncline of Triassic and Jurassic rocks. That the trend is in the first place of ancient origin is demonstrable in many places; the lineation of the Otago schists, both throughout Central and Eastern Otago as well as in the Shag Valley, as Turner and Paterson have shown by petrofabric analysis, is between north-west and north-north-west. The main metamorphism of the Otago schists has been reasonably placed by Turner (pp. 75, 189, 190, 1940) as late Palaeozoic or early Triassic, but he does consider it possible that part of the metamorphism may have been produced during the great post-Hokonui Orogeny. There is a distinct difference in the degree of metamorphism shown by the schists and by all rocks of known Triassic age, so that if we were to assume (an assumption not necessarily valid) the periods of deposition of the sediments now appearing as Otago schists to be approximately coeval, it may be suggested as most likely that metamorphism preceded the deposition of the Clinton conglomerate of Permian or even Carboniferous age (Ongley, 1939).
Mackie (1936), by a detailed study of bedding planes, schistosity planes, and joints within the schists and greywackes of Northern Otago, also demonstrates a north-west strike in that region.
Both the Otago schists and the Trias-Jura greywackes showing the north-west strike are in many places unconformably overlain by late Cretaceous beds showing a marked north-east strike. To the north of the Shag Valley the strike of the Cretaceous and Tertiary beds appears to persist as approximately north-west for some considerable distance through North Otago and South Canterbury; but south of Dunedin the strike in Cretaceous and Tertiary beds becomes very markedly north-east to north-north-east and this strike continues along the coastal belt to Kaitangata. Benson (1941) describes this region, summarising the work of others and giving as well much new structural detail. Turner (1940, p. 189) notes the tilting of the schists across a general north-east to north-north-east strike and observes that it has not affected the quartz fabrics of the Otago schists except, possibly, in the immediate vicinity of late Tertiary faults.
Cotton (1917) and Benson (1935) drew attention to widespread remnants of the great Cretaceous peneplain carved on the Otago schists, where is has been buried and exhumed. The plateau so formed is broken in many places so that Cretaceous and/or Tertiary strata are found in fault-angle depressions. In some places as at the Shag Valley already cited, it is evident that much faulting of the peneplain preceded as
well as followed the deposition of these later sediments; but at other places the faulting and folding may be entirely late Tertiary in date. Along the eastern fringe of Otago the peneplain surface carved on the schist shows a general south-easterly dip, in places interrupted by north-east-striking faults, and the schists dip under Cretaceous and Tertiary sediments which also strike north-east. The lowest of these beds, of upper Cretaceous age (at Kaitangata), consist largely of coarse conglomerates with interstratified sands, and thick seams of sub-bituminous coal; they are evidently terrestrial, but are only locally developed and are succeeded in some places (e.g. Kaitangata) conformably, in others unconformably, by a widespread thick series of quartz conglomerates containing rare marine fossils. These strata represent the denudation of an immediately adjacent land mass consisting almost entirely of the Otago schists, which are rich in quartz layers. Ongley's mapping for the Kaitangata bulletin, supported by detailed study of the coalfield (Lillie and Jenkins, unpublished report), shows that a major anticline follows the coast, with a core of schist well exposed in places. The thickest concentration of Cretaceous beds appears to lie between this anticline and the gently-south-east-dipping peneplain carved on the Otago schists to the east of a broad topographic depression which continues from Kaitangata almost to Dunedin. This depression, elongated along a north-east trend, is essentially a faulted syncline, and it formed the chief area of deposition in Cretaceous and Tertiary times. Benson remarks that “the present depression … is parallel to and at most a few miles west of the mid-Cretaceous faultbounded depression. Once again, the tectonic character of eastern Otago seems remarkably persistent”. Throughout his paper he points out evidence of repeated faulting and folding such as that already cited at the Shag Valley.
Benson (1935, 1941) has recognised also a late Tertiary peneplain which he considers, and Cotton admits (1938), may be widespread, though evidence may yet be forthcoming that very considerable areas of the interior plateau of Otago are formed by the exhumed fossil surface (of pre-Miocene, possibly Cretaceous, age) mentioned earlier instead of by the late-Tertiary peneplain (Raeside). In the Dunedin district Benson traces the faulted portions of this late Tertiary peneplain by means of covering lava flows. The surface, also with a gentle south-eastward dip, truncates the Cretaceous fossil peneplain generally at a slight angle, and may have been originally continuous with the peneplain described by Wellman and Willett as extending over the Southern Alps east of the Alpine Fault.
A further feature of Benson's paper (1941), whose main object is a detailed description of the igneous rocks, is the separation of eastern Otago into three tectonic districts according to the amount of deformation suffered. The least deformed district, occupying the eastern part of the field, is almost devoid of late Tertiary igneous rocks. The moderately deformed district which roughly follows the line of the great depression already described, contains many igneous rocks, chiefly of normal basaltic composition, and also many alkaline basic rocks, but the variety is not as great as in the strongly deformed central district around Dunedin. In this last, the alkaline rocks, earlier described by Marshall, occupy an important place and the rock types vary through numerous varieties from very basic olivine basalts to
phonolites, probably including also hybrid rocks. There are also many agglomerates and tuffs, giving evidence that this district constituted the main centre of volcanicity coincident with the maximum tectonic disturbance.
Benson's conception of the regional tectonics is “a series of broad but broken asymmetric folds of late or post-Tertiary age, in which many of the steeper limbs have been more or less replaced by faults,” as was shown by Cotton (1917, b, p. 252), in other parts of Otago. Benson notes that “usually the western limbs of the anticlines have the gentler slopes and provide the stripped and partially dissected back-slopes of broken anticlines or fault-blocks, the eastern and steeper limbs passing into fault scarps.” In the southern portion of the field, at Kaitangata, however, he remarks that the coastal anticline shows a steeper limb dipping to the west. Possibly this feature results from a depression of the basin to the west caused by the infilling load of Cretaceous conglomerates. The Tapanui Range also presents its steep face towards the west (Cotton, 1948, Otago's Physiography, pl. II) at the base of which a meridional strip of Tertiary beds is preserved in a syncline or fault-angle depression of the Otago plateau surface.
One of the most peculiar tectonic accidents in New Zealand has been re-examined by C. O. Hutton (1939). On the shores of Lake Wakatipu, at Bob's Cove, is an overturned sequence of Tertiary strata, 1,450 feet thick, forming, according to Hutton's interpretation, an upfold and a downfold, and flanked by the Otago schists. “Extending from the edge of Lake Wakatipu, for approximately 22 miles in a direction slightly east of north, is a narrow strip of the Tertiary sediments, never more than 150 feet thick, which have been caught in and thrust under the schists, by, it is believed, an easterly directed overthrust” (p. 73). The schist on each side of this Moonlight Thrust fault dips west at approximately 60°. Hutton's view that these sediments are compressed in a great thrust fault seems the only reasonable explanation. If the sequence at Bob's Cove is really inverted, as Hutton shows, then the upfold and downfold, which appear to have strong south-westerly pitch, represent respectively a syncline and an anticline, both upside down. The most logical conclusion to be drawn from Hutton's map is that the Tertiary beds at Bob's Cove represent only the inverted sedimentary cover of the western mass of schist. The Tertiary strata appear to be involved in schist, possibly to a depth of 3,000 feet or more (p. 85), and since the overpush appears to be directed eastwards it may be an important tectonic feature whose full significance in the regional tectonic pattern has been rather neglected.
Further Comments on the Relations of Newer to Older Trends
Macpherson, in postulating a swing in the strike of the late Cretaceous and Tertiary folds to assume a north-west trend throughout Otago and Southland, is obviously reasoning from the regional structural plan and partly from the evidence of tectonics, i.e. folds in growth during these periods. But it remains an open question to what extent the latter evidence supports the north-west swing of strike as being a dominant feature of the late Cretaceous and Tertiary diastrophism. The north-east strike of eastern Otago seems to be relegated to the category of minor cross fracture and folding accom-
panying principal movements along a north-west strike, whose former existence he admits.
Besides those in the eastern Otago region, however, many other infaulted blocks of Tertiary sediments located as basins within the broad mass of the Otago schists are elongated in a direction between north-east and north. The Bob's Cove Tertiary beds fall in this category. The structure at such localities is very often one of fault-folds, as in eastern Otago, rather than simple block-faulting. In Southland, the Waiau Valley follows a prominent syncline whose strike is very roughly north-south. Further east, also in Southland, Macpherson (1937) has described in the Centre Bush district a syncline of Tertiary beds which strikes very slightly west of north, very roughly parallel to the trend of the Waiau syncline. This syncline seems to cut quite athwart the north-west strike shown in the more steeply dipping Mesozoic rocks on its flank.
Macpherson has recognised these complications in writing his synthesis, but has regarded them as details. Nevertheless, in general, the north-west recurving of the are has less to commend it in terms of deformed Tertiary strata than has a general north-east to north trend for late Cretaceous and Tertiary diastrophism. It may be suggested, indeed, as for the Waiapu Subdivision, that when the late Cretaceous and Tertiary movements are grouped together there is no one dominant trend over the whole period and that what we see as a dominant north-west structure is essentially old and only partly resuscitated. Although outstanding, it is not immediately indicative of the magnitude of the fold movements confined within late Cretaceous and Tertiary times.
If a dominant and essentially Tertiary trend is sought in this cross-cross pattern, it seems preferable to imagine that it is east of north, swinging in places to north, continuing the enormous displacement represented by the Alpine Fault probably along the edge of the Waiau Valley for some distance. It is considerably modified by renewed north-west fold movements and the northerly swing may be a resultant between the two trends. The main folding of the basement of Otago schists and Trias-Jura sediments can then be relegated to an early Cretaceous or even older orogeny.
Connecting the Waiau Valley with the Southland Plains to the east, the graben of the Ohai coalfield appears to represent a Tertiary north-west valley as well as a Recent drainage course, and there has been great renewed late Tertiary movement here along an old trend of Cretaceous or earlier origin. This trend cuts across the principal Tertiary trend of the Waiau Valley. Here as in Otago there seems to be close relationship between a geomorphic feature and the growing fold.
The strike pattern in several parts of New Zealand then appears to be extremely complex: in some places a persistent axial strike may exist for a long time with the facies belts aligned roughly parallel to the strike along which movement is continually renewed. In other places, as in Waiapu and between Kaitangata and Dunedin, folding and faulting took place along one trend, followed by some planation, then tilting of the planed surface, so that an axial pitch was imparted to the folds already formed, and this tilting was followed by folding at right angles to the former trend. The time intervals between such oscillation of trends varies considerably from place to place.
The frequency of change of trend from time to time is indicated by the degree of complexity shown by a pattern of cross fractures, etc. The chief trend imparted by the late Pliocene movements is usually very markedly north-east or north-north-east. The swings of the New Zealand recurved are indicate areas where renewed movement along the north-west trends probably occurred fairly late in the Tertiary, but it is not yet definitely established that such movement is synchronous with the late Pliocene movements.
Writers who discuss the lineament pattern of the earth (e.g. Sonder) have sometimes attached especial importance to the directions north-east and north-west, suggesting that they are of planetary significance. The position is summarised by Umbgrove (p. 298): “There are good reasons to believe that the planetary lineaments date from a very early period of the earth's history. If this assumption is correct, it follows that these features, when buried under younger strata or tectonic structures become revealed again in the overlying cover. In this way some of the oldest features of our globe have been repeatedly rejuvenated. And they have to be considered as active elements even in the youngest tectonic zones of our globe.” The remark seems very appropriate to the structure of New Zealand. “It is a rather widespread belief that the origin of faults with a certain well-defined strike dates from a special period, whereas faults with a markedly different strike would date from another well-defined period. In certain areas this conviction is founded on sound arguments …” “If, however, the set of dislocations is not merely of local interest, but belongs to a system of planetary significance, then … we are only justified in saying that at a special moment a certain set of dislocations with a special direction of strike was inherited by the rocks under consideration from some older tectonic structure hidden in the structural units underlying them.”
Although hypotheses of thrusting and over-riding movement during late Cretaceous and Tertiary times are advanced to explain the structures in different parts of New Zealand, well-described examples of great overthrusts are surprisingly lacking. Low angle thrust planes formed in earlier orogenies are well known, particularly in the Mesozoic greywackes and in the Ordovician of Fiordland: most described examples have been inferred to be comparatively small, possibly only because the stratigraphy of the older rocks is too little known to indicate the existence of overthrusts of large dimensions. Overthrusts formed during late Cretaceous and earlier Tertiary movements may have been concealed by later Tertiary sediments, although more evidence of such thrusts might be expected to appear on maps if they existed. But for the latest Tertiary movements—those of late Pliocene age or later—there is little authentic evidence of great thrust planes, although much of the country where dominant faults separate Tertiary and undermass rocks has been mapped in detail. The great faults termed “thrusts” are all reverse faults and the majority of the faults appear at the moment to be very nearly vertical. The apparent exceptions of the Taitai klippes (emplaced during the Cretaceous) and the example quoted by Wellman can be interpreted as gravity-slide structures.
immediately applicable to the New Zealand pattern. Indeed, assuming a wildly speculative attitude, one might suppose that New Zealand lies on the intersection of two of Lake's great circles, those on which he located the centres of his ares of small circles.
Geomorphology in Relation to Structural Studies
The field worker in New Zealand carries a considerable amount of geomorphological ideas in his mental baggage, although his object may be solely structural and stratigraphical description. Many of the faults are first recognised by studying the physiography, and only later are they proved to dislocate strata. The recognition of ancient peneplains and fossil erosion surfaces, both Tertiary and early Cretaceous, is found to be essential in structural analysis in New Zealand, and the dislocations suffered by these surfaces are in many places the only reliable evidence bearing on the late Tertiary movements.
Recent transcurrent movement on faults in New Zeland is best demonstrated by the curious drainage pattern adjacent to the Alpine Fault near Jackson Bay. Wellman and Willett describe the Recent river courses along this fault as showing a remarkable displacement to the north-east immediately west of the Alpine Fault, the displacement for twelve rivers giving an average figure of 0·8 miles. Such transcurrent displacement over a long period could have produced lateral displacement on a great scale (compare Kennedy, 1946). H. Wellman has recently advanced the suggestion that dextral movement of approximately 300 miles along this fault has displaced the rocks west of the fault to the north-east. Thus he would account for the great distance separating areas of similar structure and stratigraphy on each side of the fault. An assessment of Wellman's view must await publication of his detailed evidence. Cotton (1947), in discussing the Alpine Fault, points out that some of the transcurrent movement along this north-east-striking fault could be absorbed by buckling along axes at right angles to the fault, and he cites the gentle south-westerly dip of a freshly cut marine platform, and other geomorphic evidence of local drowning, in support of this theory. It is instructive to compare the fold sequence of Waiapu with Cotton's suggestion for the recent pattern of warping. Such a mechanism can explain much of the New Zealand fold and fault pattern. Cotton (1948) also describes very clear geomorphic evidence at the Hope Fault near Hanmer, which shows transcurrent displacement of at least 8 feet, and for the fault in the axis of the valley of the Silver Stream near Wellington City, which shows a horizontal displacement of 130 feet. Faulting has continued intermittently on this line to the present day, and earthquake traces have been formed in very recent times.
This note has discussed geomorphology only insofar as it bears directly on the larger structures affecting Pliocene and older rocks and where other methods of approach have also been employed. There remains a wide field of geomorphological description covered by a voluminous literature, mostly by Cotton, and all more or less influenced by his teachings. The writer finds it impossible to summarise this aspect of the work. Certain of these papers are fundamental to understanding the large-scale structures, particularly in districts where the other
geological evidence is obscure. The vicinity of Wellington City is a typical example of such a district, and Cotton has devoted a number of papers to describing the downwarped Port Nicholson depression with a great late Tertiary fault bounding its western edge and running from the coast of Wellington along the Hutt Valley. Other important geomorphological papers bearing directly on the geological structure are cited in the list of references given below.
These topics are covered at length in Cotton's books, and a short paper by that author divides New Zealand into Geomorphic Provinces (1945).
In general, most recent papers tend to see a closer connection between tectonics and physiography. Thus, Cotton interprets the Hutt River as a stream initially installed in a fault-angle depression and thinks many major streams may be installed in early formed wrinkles of the earth's crust. From such streams directly reflecting tectonic pattern, he distinguishes others which he would define as structurally controlled, streams which have “worked down to find structural weaknesses” and, therefore, not directly indicative of the first-formed terrestrial pattern (1947). He has recently recognised a number of warpings of recent surfaces, some of them taking the form of gentle anticlines and synclines, but most of these have not yet been described in the literature. Interesting evidence of such warpings is cited by Cotton in the itinerary for a geological excursion in the North Island (Pacific Science Congress, 1949). This warping, or buckling, takes the form of gentle undulations with axes roughly oriented north-west, and is well seen near the Mohaka River (Hawke Bay). These recall the buckling which Cotton describes in discussing the Alpine Fault; but they have not been correlated with active trans-current faulting.
By combining geomorphology with detailed structural studies, there is good reason to hope that some continuity will be established between the palaeogeography of the later Tertiary and the morphological features of Recent times, even in those places where, as in large parts of the New Zealand region, fault and fold movements have intervened.
The structural plan of New Zealand is dominated by great folds and faults formed in late Tertiary times and generally ascribed to the “Kaikoura Orogeny”. Increasing evidence indicates that in some places the most considerable movements were concentrated into late Pliocene, possibly even early Pleistocene time, but that important precursor movements also took place earlier in the Tertiary, In other places the principal folding seems to have ceased in early Pliocene or even Miocene time, with only minor tilt and warping movements in the late Pliocene.
The rocks most deformed by Tertiary movements appear to be those which show evidence of late Pliocene movement, particularly in regions flanking the axial chain where Mesozoic and Palaeozoic strata are exposed.
The dominant strike of the Tertiary folds, particularly where of late Pliocene age, is north-east to north-north-east, but locally the
|N.Z. Stratigraphic Terms||Continued earth movements along faults|
|local tilts and gentle warpings|
|major orogeny—Kaikoura orogeny||Folds, generally of considerable wave length, and great faults formed.|
|(Wanganui) Pliocene||Castleolifflan Nukumaruan|
|(Wanganui) Pliocene||minor fold movements and tilting||e.g. in Hawkes Bay.|
|(Wanganui) Pliocene||Waitotaran Opoitian|
|minor fold movements and tilting||e.g. in Te Kuiti. Taranaki is locally transgressive over Southland.|
|Miocene||Southland||minor orogeny in Upper Southland widespread||Great influx of coarse conglomerates in Upper Southland which locally (e.g. Waiapu) rests unconformably on Lower Southland.|
|transgression of Lower Southland very extensive|
|Oligocene||Landon||uplift or minor folding widespread||Local absence of Pareora (e.g. Hawkes Bay) indicates emergence at beginning of Pareora or its removal immediately after Pareora time.|
|Eocene Paleocene||Arnold Dannevirke|
|minor local fold movements, ultra-basics in Auckland||Locally (e.g. Eastern Hawkes Bay) Eocene conglomerates rest unconformably on Upper Cretaceous.|
|Cretaceous||Senonlan||Mata||minor orogeny, probably widespread. The north-east elongation of Cretaceous and Tertiary belts facies may be due to this orogeny.||Upper Senonian in some places marked by unconformity with great boulder beds resting on Lower Senonian.|
|Cretaceous||Neocomian||Major orogeny Hokonui or post-Hokonui orogeny, or two orogenies—one late Jurassic and the other post-Aptian not yet separated.||Close isoelinal folding and thrusting N.W. strike in Permian, Trias and Jurassic of Hokonui syneline and Otago schists. This orogeny usually attributed to very late Jurassic or early Cretaceous, but Aptian strata appear to be equally deformed.|
|Jurassic||Hokonui System||Conglomerates with large boulders at base of Carnic (e.g. Te Kuiti).|
|minor orogeny widespread|
|Permian||Maitai System||Carboniferous strata not yet separated. Marked meridional strike in lower Paleozoic, steep folds and great faults. Devonian probably unconformable on Ordovician at certain localities (e.g. Mt. Arthur).|
|Devonian||minor or major movements widespread|
|Silurian*||Inferred from presence of coarse conglomerates in Mid Cambrian.|
The table of orogenies is a very generalised statement and the detailed stratigraphic evidence bearing on the minor “orogenies” is only slightly covered in the text of this paper. It seems likely that, as more precise evidence becomes available, the “major orogenies” will have to be spread out to cover longer periods of time, thus losing much of their present “sharpness,” which is partly subjective. Although many of the “minor orogenies” as a result may fit into a picture of continuous movement leading to a final “major orogeny,” the latter must be retained as representing maxima of fold movement concentrated into comparatively short time.
[Footnote] *Not definitely known to exist in New Zealand.
Tertiary strata strike north-west, and in several places the evidence suggests that such a strike follows that of an older pre-Tertiary fold pattern.
The great faults formed by the late Tertiary movements have throws often exceeding 3,000 feet, and remarkably straight traces, appearing to be mostly vertical or high-angle reverse faults: there is no evidence suggesting great recumbent folding or nappe-formation in the Tertiary orogenic sequence, although minor overthrusts are known.
The Triassic and Jurassic strata are strongly folded and broken by faults formed in pre-Senonian time. The formation of these has been ascribed to the post-Hokonui Orogeny to which is generally ascribed a late Jurassic or early Cretaceous age. Since more recently an Aptian age has been ascribed to beds which are hardly less deformed than the Jurassic strata, it seems possible that this post-Hokonui Orogeny may be in part immediately post-Aptian in age. In many places the strata deformed by these Mesozoic movements show a north-west strike which may be cut across by later Tertiary north-east striking folds and faults. But this north-west strike is not shown everywhere by the Triassic and Jurassic strata. As yet it has been impossible to advance any adequate synthesis of the Mesozoic fold pattern and information on earlier orogenies is even more obscure.
It seems likely that there was a great late Devonian or immediately post-Devonian orogeny imparting a generally meridional strike to the lower Palaeozoic strata, but the latter are so much cut by Tertiary faults that the suggestion can only be very tentatively advanced.
A general tendency for folds of one age to show a common trend is accepted, although there are many local exceptions. Attention is focused on certain regions where the evidence suggests a considerable change in the trend of folds and faults formed even within a comparatively short space of time, because the time factor in tectonics combined with the idea of posthumous folding appears to shed light on these more abrupt swings in trend ascribed to “syntaxes” and to “arcuate structure”. In the north-east of the North Island, folding of thick Cretaceous and early Tertiary beds along an approximately north-west trend was followed by emergence, planation, subsidence, and sedimentation, and then, after an interval of approximately four Tertiary stages, by folding along a north-east trend, but it is likely that during this interval minor folding along both trends occurred locally. Nevertheless, the dominant trend of the late Tertiary folds in this part of the North Island is north-east and is consistent with the old idea of Marshall and Suess that an anticlinal ridge is likely to continue towards the Kermadec and Tonga Islands. There is no clear evidence of an arcuate swing in the north-east part of the country, because the major fold pattern is only broken by great cross-faults, striking west-north-west. The north-east strike formed by late Tertiary folding is dominant throughout the whole length of the eastern side of the North Island, formerly the site of a geosyncline.
An axial chain of Mesozoic greywacke and the great Tertiary and Recent volcanic centre of Rotorua separate the eastern belt from the western Tertiary geosyncline of Macpherson. This axial chain was partly emergent during long periods of Tertiary sedimentation in the western and eastern geosynclines. In the western belt a true arcuate
swing in strike of both the Triassic and Jurassic strata of the under-mass and of the covering Tertiary beds can be observed; to the south the beds strike approximately north-south and, on going northwards, swing more and more towards a north-westerly trend. But the amount of cross-faulting at Auckland and in North Auckland suggests that the strata also adjusted themselves along a roughly north-east line of faulting and minor fold-movements: the result in Auckland is a pattern of parallelograms. The region where the trend of the western belt diverges from that of the eastern must be located very roughly at the north end of the South Island. The term syntaxis can probably be applied to this convergence of trend if one considers only late Miocene to early Pliocene fold movements because a late (post-Pliocene) fold movement affecting the eastern belt profoundly had much less effect in the western belt.
Suess (p. 233) accepted the idea that two independent dissymmetrical mountain chains converged in the southern part of the South Island, forming a syntaxis (schaarung). Morgan, on the other hand, rightly insisted that on the West Coast the north-east striking trends cut across an older north-west trend at the great north-east-striking Alpine Fault, and it is now quite clear that the north-east trend was largely formed in a late Tertiary orogeny, although this trend may also follow an older one. According to Suess (p. 131) the superposition of a newer set of folds over more ancient folds did not constitute a syntaxis (schaarung), so that the idea of syntaxis would be inapplicable to the West Coast, for the time gap in this case is very considerable.
In the southern part of the South Island—which is the part chiefly cited by Suess (p. 233)—the evidence for syntaxis on the map appears to be stronger, but the outstanding folds affecting Tertiary strata trend dominantly north on the west side and north-east on the east side. The northern trend indicates a swing in the strike of Tertiary strata deposited in a western geosyncline and this swing is likely to be dictated by later movement along an old Palaeozoic trend, perhaps Late Devonian, known in the rocks of the Palaeozoic undermass which are exposed to the west. In addition, there have been local movements, in places considerable, along a north-west strike, but as great north-west folding occurred in early Cretaceous time, the movements are essentially posthumous and the amount of Tertiary regional movement along these trends may not have been so very great, although the north-west direction appears conspicuously on a map.
In Southland, a north-west-striking graben cutting across an anticline with a general northern orientation appears to mark a Tertiary and Recent valley as well as probably an old tectonic feature. The Manawatu Gorge also marks a Recent river coincident with an axial depression and a Tertiary strait. Paréjas has indicated that in parts of Europe points of maximum axial pitch or elevation may be aligned transverse to principal folds, and these points may all show some palaeogeographic characteristic in common. These lines he has named transversals. Both the examples cited are likely to represent small transversals. Paréjas's findings may be significant, not only in palaeogeography, but in deciphering the older tectonics of a belt showing one very outstanding strike formed in a later orogeny.
The amount of renewed movement along north-west trends in the southern part of the South Island is so marked that the Tertiary grain can in places be regarded as showing two trends at right angles to each other. To what extent movement occurred along both trends simultaneously is unknown. Conceivably movement along the Alpine Fault and renewed movement along the north-west trend of the Hokonui syncline occurred at the same time, giving a “syntaxis”.
It is possible that a dynamics of folding, planation, tilt along the old fold axes and later folding or faulting at right angles to them may be repeated many times. Cotton's suggestion of warping to absorb trans-current movement along great faults fits into the same picture. Pro-
bably for one particular age of folding one trend is markedly dominant, but the folding over several ages—say within the late Cretaceous and Tertiary—may show many fluctuations from one extreme to the other. It seems likely that the repetition of folding along old trends may, particularly when the trends are so commonly north-east and north-west, be associated with the influence of some deeper texture in the earth.
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The Syenite and Associated Rocks of the Mandamus-Pahau Area, North Canterbury, New Zealand
Indiana University,1 Bloomington, Indiana, U.S.A.
[Read before the Wellington Branch, June 8, 1950; received by the Editor, June 19, 1950]
The intrusive rocks of the Mandamus-Pahau area consist of syenite and gabbro with associated sills of related composition. The rocks are distinctly alkaline in composition (alkali-lime index 52·5), which is shown by the presence of biotite and alkali feldspar in the gabbro and of alkaline pyroxenes and amphiboles in the syenite and trachytic rocks. It is believed that the syenitic rocks were derived by differentiation from the same magma as the gabbro. The syenite solidified under a comparatively thin cover, and gas pressure in the last stages of solidification was sufficient to shatter the roof of the intrusion, with the formation of an igneous breccia of fragments of roof rock and syenite in a trachytic matrix. The igneous rocks were probably intruded in the Lower Cretaceous, during the later stages of the Hokonui orogeny.
Igneous activity accompanying the Hokonui orogeny was slight. Over the large areas of rocks which were deformed during this orogeny, both in the North Island and in the South Island, remarkably few occurrences of igneous rocks have been reported. Most of these are very minor, being narrow sills or dykes, and few have been accurately dated; some at least are probably of Tertiary age and unconnected with the Hokonui orogenic movements of early Cretaceous date.
It is on this account that the present study of the intrusive rocks of the Mandamus-Pahau district was undertaken. The occurrence of syenite intrusive into greywacke in this area has been known for many years, being first recorded in the literature by von Haast in 1871, and later mentioned by Hutton (1877) and Speight (1918). However, it has never been the subject of detailed investigation, although it is readily accessible and comparatively well exposed. I visited the district for the first time in 1936 and was impressed by the fine section through the syenite intrusion provided by the gorge of the Mandamus River. However, it was not until 1944 that I had the opportunity to examine it in detail. Field work was carried out intermittently between 1944 and 1947, and a general description of the geology of the area has recently been published (Mason, 1949). This paper describes in detail the igneous rocks and the problems which they pose.
The largest intrusion is the syenite, which forms a roughly oval mass about four miles long and up to a mile wide, extending along
[Footnote] 1 The field work was done while I was Lecturer in Geology at Canterbury University College. The laboratory investigation of the rocks was begun at that time, and was completed at Indiana University.
the Hurunui Peak ridge nearly to the Hurunui River (Fig. 1). It is well exposed at many places, particularly in the gorge of the Mandamus River. Around Hurunui Peak itself an interesting igneous breccia is associated with the syenite. It is not separated from the syenite on the map illustrating this paper. About a mile to the north-east of the last outcrops of syenite a small area of gabbro is exposed in the bed of Hut Creek, a tributary of the Dove River. Associated with these plutonic rocks are a number of sills extending outwards from the plutonic bodies to distances of up to three miles. They are particularly well exposed in the Dove River and its tributaries, where they have been mapped in detail, and many were noted along the ridges, especially between the Dove and Glencoe rivers, and around the headwaters of Hut Creek and Cascade and Awatui streams; on the ridges and hill slopes, however, many such small intrusions were noted only from “float”, and many more are doubtless concealed by the soil cover. For this reason the map does not give a true picture of the abundance of these sills, as only those whose outcrop could be located accurately are recorded thereon.
It should be mentioned here that a number of small sills and dykes intruding the greywacke crop out along the Pahau River east and north of this area. Although some of these may be connected with the intrusions described here, the majority appear to be distinct, and a cursory examination of their petrology and field relations suggests that some at least represent feeding channels of the basalts and agglomerates which form part of the Tertiary sequence.
Description of the Rocks
A. The syenite
The syenite is the major igneous rock of the area. It forms the core of the Hurunui Peak ridge, which separates the valley of the Dove River from the Culverden depression, and extends across the Mandamus River nearly to the Hurunui River. Its outcrop is roughly oval, with a maximum length of four miles and a maximum width of half a mile. It is particularly well exposed in the gorge of the Mandamus River and that of Coal Creek and crops out at many places along the hill slopes.
In hand specimen (Fig. 2) the syenite is a dull white rock speckled with irregular grains of dark green ferromagnesian minerals and sometimes with lustrous plates of black biotite. The rock is markedly porous even on superficial examination, with numerous angular cavities (sometimes partly filled with yellow-brown natrolite) between the feldspar laths. This porosity accounts for the friable nature of the rock in most outcrops; in many places the rock disintegrates into its individual mineral grains on rubbing between the hands, and looks more like a poorly consolidated sandstone than a plutonic rock. Fresh outcrops have a speckled black and white appearance, but where the rock has been subjected to weathering, the ferromagnesian minerals have been largely removed and the rock has a rusty-white colour; large weathered outcrops seen from a distance show a distinctly reddish colour which often serves to differentiate them from neighbouring outcrops of greywacke. The syenite varies little in grain size and texture over its whole area; no pegmatitic phases were seen, and the
fine-grained selvages against the greywacke are never more than a few inches thick.
Under the microscope the feldspar is usually grey and turbid from beginning kaolinization. It is generally a fine-textured microperthite, although in some specimens the microperthite structure is scarcely detectible and the feldspar is best described as a cryptoperthite. The ferromagnesian minerals are aegirine, biotite and alkaline amphibole. Aegirine (X ∧ c = 8°) is the most abundant ferromagnesian mineral; sometimes the aegirine grains have a core of colourless or pale green augite. The biotite is very strongly pleochroic from yellow-brown to practically opaque. The alkaline amphibole is less common than the other ferromagnesian minerals and is absent from some thin sections; it often replaces pyroxene; it has extinction angle Z ∧ c = 20° and pleochroism × = greenish-brown, Y = reddish-brown, Z = dark brown, and is probably barkevikite. In some specimens a little riebeckite was seen replacing aegirine. Accessory minerals are apatite in very small amount; black opaque material, probably magnetite; and rare enhedral titanite. A little natrolite occurs in the interstices of the feldspar laths. A small amount of secondary calcite and a little opal is present in cavities. The mode of the analyzed specimen is given with the analysis (Table I).
Occasional variants of the syenite were found. One specimen collected from near the edge of the intrusion on the north side of Hurunui Peak was practically free from ferro-magnesian minerals and carried occasional grains (< 5%) of primary quartz. Within a few inches of the contact with the greywacke the syenite is fine-grained (average grain size of equigranular feldspar 0·15 mm.) and in hand specimen has the colour, texture, and jointing of fine-grained greywacke. A thin section of a specimen from this marginal facies at the contact in Coal Creek shows that it has a similar mineralogical composition to the main mass of the syenite except that the ferromagnesian mineral is entirely alkaline amphibole (Z ∧ c = 22°, × = pale yellow, Y = yellow, Z = bluish-green, γ–α = 0·012). This section also showed occasional grains of titanite, strongly pleochroic (yellow to reddish-brown).
The mineralogical and chemical composition of the rock shows that the rock is a typical syenite in the broad sense of the term. It is distinctly alkaline, as shown by the presence of aegirine and alkaline amphibole, and is comparable with the umptekites and nordmarkites. Indeed, the rock is a nordmarkite as this term is defined by Barth (1945, p. 85) “… Nordmarkite [is] a syenite or quartz-syenite containing alkali feldspar (perthite or anorthoclase) without determinable amounts of plagioclase.” It is very similar in composition to some of the type nordmarkites of the Oslo region.
The structural classification of this syenite intrusion is not clearcut. It is transgressive to the general strike (about N.–S.) of the country rock. It is possibly a stock, although the noncommittal term pluton is perhaps preferable.
B. The gabbro
The presence of the gabbro was first inferred from the finding of pebbles of this rock in the gravels of the Mandamus and Dove Rivers.
When these were traced to the outcrop it was found that this rock has a very limited distribution. It crops out for about half a mile along Hut Creek, a tributary of the Dove River about two hours walking distance beyond the end of the road at Island Hills station. Along the banks of Hut Creek terrace gravels conceal the gabbro, and the surrounding hill slopes are of greywacke. Erosion has proceeded far enough to unroof the intrusion along the bed of the creek only. The creek is roughly at grade where it flows over the gabbro, but drops into a shallow gorge below the intrusion; the resistant nature of the gabbro compared to the country rock is evidently responsible for this.
On account of the limited exposure little can be said about the field and structural relations of the gabbro to the country rock. A normal intrusive contact is exposed in Hut Creek between the gabbro and a fine-grained greywacke. The greywacke is slightly reddened close to the igneous rock, but otherwise not noticeably altered. The gabbro is finer in grain for a few inches from the contact. The structural nature of the intrusion can hardly be deduced from the field relations, but it may be described as a stock. The general coarse grain of the gabb [ unclear: ] suggests it is the product of the slow cooling of a considerable body of magma.
In hand specimen the gabbro has a distinctly porphyritic appearance, due to the presence of prominent crystals of augite, which may reach 10 mm. in greatest dimension, although the average is about 5 mm. The groundmass is plagioclase feldspar. Small flakes of biotite, occasional olivine crystals, and metallic grains of magnetite and ilmenite can be seen with a hand lens.
Under the microscope the rock is seen to consist essentially of augite and plagioclase (average composition about An45) with minor amounts of biotite, olivine, and black opaque material (magnetite and ilmenite), and a small amount of apatite (see Table 2). Some brown hornblende was observed in a few specimens. A few grains of feldspar of low refractive index (< 1·540), probably anorthoclase, were observed in a concentrate of light minerals from the analyzed gabbro. The proportion of augite to feldspar varies considerably from thin section to thin section, but this is probably due to the coarseness in grain of the rock. The rock is very fresh, olivine being the only mineral to show signs of alteration; occasionally it is partly or wholly changed to green serpentinous material. The augite is pale purplish-brown in colour, and somewhat pleochroic, suggesting a moderate titanium content; its optical properties are α = 1·687, β = 1·692, γ = 1·715, (+), 2V = 45°, which from Hess's data (1949) indicates a composition of Wo40En42Fs18. The olivine is optically negative, with an axial angle of 88°, corresponding to a composition of Fo82Fa18, considerably more magnesian than the augite, as would be expected if the olivine were the first to crystallize. The biotite generally mantles the ilmenite and magnetite and is strongly pleochroic from pale yellow to almost opaque, suggesting a high titanium content.
Over its limited exposure the gabbro appears to be fairly uniform, although it is occasionally somewhat finer in grain than the typical material described above. The only aberrant type was collected near the boundary against the greywacke at the upstream end of the gabbro. This rock is much lighter in colour than the normal gabbro and in
hand specimen shows plagioclase laths averaging about 3–5 mm. in length; it is completely without augite phenocrysts. In thin section the rock is seen to consist for the most part of feldspar, with accessory magnetite, ilmenite and apatite. It is practically free from ferro-magnesian minerals. Some secondary calcite is present. The outcrop of this rock is small and isolated, and its field relationship to the normal gabbro is not visible. It is either a variant of the gabbro or a dyke cutting the gabbro.
Both mineralogical and chemical composition indicate that the rock of this intrusion, although gabbroic in appearance and general features, cannot be strictly classed with the gabbros, the average composition of the feldspar being andesine rather than labradorite. To call it a diorite would be misleading; in effect it is an andesine gabbro, if such a name were not to some extent self-contradictory. Its closest relative among named rocks is kauaiite, described by Cross (1915, p. 16) from the island of Kauai in the Hawaii group. The rock name kauaiite has recently been more precisely defined on a mineralogical basis by Barth (1945, p. 31) and applied to some rocks of the Oslo region originally classed as essexites. The Hut Creek gabbro shows a close relationship both in chemical and mineralogical composition with the original kauaiite from Kauai and the Oslo “essexites”.
C. The hypabyssal rocks
The hypabyssal rocks of the area are mainly sills intruded along bedding planes in the greywackes and argillites. They are generally quite thin, the thickest measured being 16 feet; the average thickness is about four feet. They occur in an area surrounding the intrusions of syenite and gabbro and fall off rapidly in numbers on going outwards from these intrusions. The situation is complicated along the Pahau River by the presence of small intrusions for the full length of the river, far beyond the limits of this map. These are not dealt with in this paper, as they are probably not directly connected with the syenite and gabbro, and some are quite distinct, apparently being feeding channels through which Middle Tertiary basalts and agglomerates were extruded.
These hypabyssal intrusives are best exposed in the banks of the Dove and Mandamus rivers, and along the ridges in the area. They are particularly abundant along the Dove River, in Hut Creek, and in the vicinity of Charing Cross. Only those actually observed in place are recorded on the map, which is therefore not a true record of their abundance. Undoubtedly many are concealed by soil and vegetation, and some types were collected only as pebbles and as float.
The principal rock types are porphyries and porphyrites, although a variety of other types, mainly carrying porphyritic augite and/or olivine were collected. The porphyries are grouped around the syenite and are evidently directly connected with it (compare analyses of syenite and porphyritic trachyte), the porphyrites around the gabbro.
The sills associated with the syenite, which are well exposed in the lower course of the Dove River, are porphyritic trachytes very similar in chemical composition (Table 3) to the syenite itself. In hand specimen the rocks show feldspar phenocrysts up to 5 mm. long
in a grey stony groundmass. The phenocrysts are of anorthoclase (2V = 45°–50°), the groundmass consists of the same feldspar in laths about 0·2–0·3 mm. long with a distinctly trachytic texture. In most of these trachytes feldspar makes up about 80% of the rock, and the remainder is entirely or almost entirely amphibole; in a few sills the amount of mafic minerals is very small and the rocks approach bostonites. When the amphibole is well-crystallized, as in the analyzed specimen, it is generally an alkaline type with blue-green to green-brown pleochroism, but it is often an exceedingly fine aggregate of brown colour, which can only tentatively be identified. In some of these trachytes a little opaque material (mostly pyrite) is present, and a little (± 1%) interstitial quartz was observed in most thin sections. Some secondary carbonates are generally present.
The plagioclase porphyrites are found in the eastern and northern parts of the area, around the gabbro intrusion, to which they are clearly related genetically. They are especially abundant and well exposed in the lower part of Hut Creek, below the gabbro, and in the adjacent part of the Dove River. Similar types are evidently abundant around Charing Cross and in the headwaters of the Awatui and Cascade streams, judging from the large amount of float in this part of the district, but solid rock is largely concealed by the mantle of waste. These plagioclase porphyrites are fairly uniform in appearance and composition; in hand specimen they show feldspar phenocrysts 4–5 mm. long in a grey or brownish-grey stony groundmass. Under the microscope the feldspar is found to be plagioclase (An45–50); feldspar phenocrysts and groundmass make up 60–80% of most specimens, and the remainder is often a yellow-brown mesostasis, probably chlorite or amphibole. Some opaque material (magnetite, pyrite, and ilmenite) is generally present, and sometimes apatite. Most of these plagioclase porphyrites show considerable amounts (± 10%) of secondary carbonate.
The plagioclase porphyrites as described above are the commonest sills associated with the gabbro, but some sills contain augite phenocrysts in addition to those of plagioclase, and more rarely the plagioclase phenocrysts are entirely absent. A few grains of olivine, often altered, are found in the augite-rich types.
Of particular interest among the sills are the rare lamprophyric types which have only been found within or close to the syenite. Where the syenite is well exposed, in the gorge of the Mandamus River, it is seen to be cut in some places by numerous small intrusions, generally not more than about a foot thick. They are composed of dark, aphanitic rock and are lamprophyric in character, being comprised essentially of orthoclase, biotite, and blue-green amphibole, in uniform-sized crystals about 0·1–0·3 mm. long, the ferromagnesians exceeding the feldspar in amount. Rosiwal analysis of a typical specimen gave the following result (in weight %):
|Orthoclase (possibly a little sodic plagioclase also)||33%|
|Amphibole and biotite (in approximately equal amounts)||64%|
|Opaque (mostly pyrite)||2%|
a composition which may be described as a hornblende minette.
An interesting rock type was collected on the Hurunui Peak ridge about 60 chains east of the trig, station. The outcrop was a small isolated one and its geological relations could not be observed, but it appears to be a sill or dyke cutting the syenite. In hand specimen the rock is dense and black, with a few very small crystals visible to the naked eye; its fracture is almost glassy. Thin sections show phenocrysts of sanidine, sodalite, brown hornblende, aegirine, and magnetite in an almost opaque groundmass; under high magnification the groundmass is seen to consist of colourless material thickly peppered with small dark equant crystals which are probably a ferromagnesian mineral. At first glance the colourless groundmass appears isotropic, but in parts it shows vague birefringence suggesting beginning crystallization of feldspar; it is probably a devitrified glass. Table 4 gives an analysis of this rock; it is interesting for the high content of nepheline shown in the norm, the highest that has been recorded for rocks from this area. Some of the nepheline in the norm is represented by sodalite phenocrysts, but a considerable proportion is occult in the groundmass. It is difficult to find a satisfactory name for the rock, but sodalite phonolite fits it best. This rock is similar in chemical composition (except for H2O+) to heronite, an analcitic dyke rock from Heron Bay, Lake Superior (Coleman, 1899).
D. The igneous breccia
The igneous breccia occurs in association with the syenite and is not differentiated from it on the map, mainly because it covers a comparatively small area around Hurunui Peak, and the actual contact with the associated syenite was nowhere seen. It forms the crest of Hurunui Peak itself and is found on the spurs leading down from this point. It makes prominent outcrops, but its field relationship to the syenite is obscured by the mantle of waste. It appears to be a capping over the syenite intrusion and is interpreted as having been formed by the shattering of the roof of the magma chamber by gas pressure in the last stages of crystallization of the syenite.
This igneous breccia is a mass of angular fragments in a fine-grained groundmass. These fragments range in greatest dimension from a foot down to a fraction of an inch, and consist mainly of syenite and trachyte with subordinate greywacke and argillite. The groundmass weathers more rapidly than the fragments, so that they stand out in relief on weathered surfaces (Fig. 3).
Under the microscope the groundmass is seen to be almost entirely feldspar laths, generally very small (up to 0·01 mm. long) with minute grains (< 0·005 mm.) of what appear to be an alkaline amphibole peppered throughout. Flow structure is generally marked in the groundmass. Sometimes the breccia carries numerous equi-dimensional feldspar crystals about 1 mm. long.
Table 5 gives an analysis of material from the summit of Hurunui Peak (chosen to determine the composition of the groundmass and hence as free of fragments as possible), and shows that its composition is very close to that of the syenite and trachyte. The same magma from which the syenite and trachyte were formed evidently gave rise to the igneous breccia. The analysis shows somewhat higher alumina than the analyses of the syenite and the trachyte. This gives rise to
the 3·75% corundum in the norm, and may be due to the presence of some argillite fragments in the analysed sample.
The presence of this igneous breccia is of particular significance for deciphering the conditions under which the syenite itself crystallized. The composition of the syenite and the composition of the groundmass of the igneous breccia correspond so closely that they must have formed from the same magma. The presence of the igneous breccia is believed to indicate that the syenite crystallized under a comparatively thin and weak roof. As the syenite crystallized the remaining magmatic liquid became more highly charged with volatiles (chiefly water) until the pressure was sufficient to cause an explosive shattering of the roof (partly greywacke and argillite and partly previously solidified syenite). The rapid expulsion of the remaining magma into this shattered mass cemented it together into this igneous breccia, at the same time giving rise to the remarkable porosity and friability of the syenite.
Nature and Origin of the Rocks
The chemical affinities of the rocks are perhaps most simply and clearly expressed by the alkali-lime index, as introduced by Peacock (1931). By plotting the analyses of the igneous rocks of this area the alkali-lime index is found to be 52·5, which would place these rocks in Peacock's alkali-calcic group, not far from the boundary with alkalic group, which is at an alkali-lime index of 51. This correlates well with the mineralogy of the rocks themselves. In general terms the alkalic group and the alkali-calcic group are distinguished mineralogically by the occurrence of feldspathoids in the former and their absence in the latter. The Mandamus-Pahau intrusive rocks are free from feldspathoids (except for the sodalite phonolite, which probably represents an extreme differentiate) but are distinctly alkaline in character, as evidenced by the biotite and the small amount of anorthoclase in the gabbro, and the alkaline pyroxenes and amphiboles in the syenite and trachytes.
The relationship of the Mandamus-Pahau intrusives—geological, mineralogical, and chemical—suggests that they have differentiated from a common parent magma. The visible amount of the syenite is very much greater than that of the gabbro (it is of course dangerous to draw conclusions regarding the absolute amounts of the different intrusives on the basis of surface exposure). With these circumstances in mind, the writer suggests that the parent magma of the intrusive rocks of the Mandamus-Pahau area was intermediate in composition between the syenite and the gabbro, and that the gabbro represents an accumulation of early-formed crystals from this magma. This accumulation of early-formed crystals was separated from the remaining liquid by pressure due to crustal movements, and this liquid was injected into higher levels in the crust and formed the syenites and trachytes.
This concept of the origin of the syenite and trachytes as the products of crystallization of a magmatic liquid from which the products of early crystallization had been removed is supported by certain criteria developed by Bowen (1937). He points out that the laboratory study of silicate systems indicates that the residual liquids from the fractional crystallization of complex silicate magmas must be enriched
in alkali-alumina silicate; the alkali-alumina silicate system (NaAlSiO4–KAlSiO4–SiO2) may thus be referred to as petrogeny's “residual” system. The laboratory study of this system has shown that it has a well-defined valley in the fusion surface, which is, of course, the composition area of the liquids having the lowest temperature of crystallization in the system. Bowen showed that the composition of many igneous rocks rich in alkali-alumina silicates, when plotted in terms of the NaAlSiO4–KAlSiO4–SiO2 system, fell within this valley in the fusion surface, thus indicating that crystal ⇄ liquid equilibrium had been the dominant control in the production of these rocks, i.e. they represented the residual liquids of crystallizing magmas. Benson (1941) applied Bowen's criteria to the salic rock types of the Tertiary igneous rocks of the North Island, Banks Peninsula, and the Dunedin district, and showed that the idea that these rocks represented the solidification products of residual magmatic liquids was thereby supported. Bowen's scheme of plotting has been applied to the Mandamus syenite, trachyte, and phonolite, and the result is shown in Fig. 4. This figure shows that the composition of the alkali-alumina silicate in these rocks falls in the low-melting region of the diagram; for the syenite and the trachyte the points fall near the minimum between albite and orthoclase, and the point for the phonolite practically coincides with the lowest temperature in the diagram. This strongly supports the belief that these rocks represent late fractions of a magma whose evolution has largely been that of differentiation by fractional crystallization.
Comparison with Other Areas
The intrusive rocks of the Mandamus-Pahau area show a marked resemblance to some of the classic types of the Oslo region. The syenite can be matched chemically and mineralogically with the nordmarkites of the Oslo region, and the gabbro is strictly comparable with the well-known Oslo essexites which Barth (1944, pp. 26–31) has shown not to be essexites at all, since they contain no nepheline; they are alkaline gabbros which may be classified as kauaiites, the original kauaiite being described from Kauai, in the Hawaiian Islands (Iddings, 1913, p. 173; Cross, 1915, p. 16). The Mandamus-Pahau intrusives are of course, small in comparison to those of the Oslo region and are very much less diversified, but in both regions the major types are similar, suggesting parent magmas of comparable composition.
Within New Zealand the Mandamus-Pahau rocks show chemical and mineralogical resemblances to those of the Dunedin district, although the rocks of the latter district are mainly extrusives. The rocks of the Dunedin district are somewhat alkaline (alkali-lime index 50·1), which is reflected in the presence of numerous feldspathoidal types which are absent in the Mandamus-Pahau area. However, if the feldspathoidal types are omitted, the alkali-lime index for the rocks of the Dunedin district is then practically identical with that for the Mandamus-Pahau rocks. The similarities are particularly marked in the trachytes which are common to both areas. The trachytes described by Marshall (1906, 1914) from North Head and Portobello are mineralogically and chemically comparable with those of the Mandamus-Pahau area.
Fig. 1—Geological map of the Mandamus-Pahau area: the figures give the location of the analysed rocks: 1, syenite; 2, gabbro; 3, trachyte: 4. phonolite; 5, igneous breccis. (The Tekon Road ends at Island Hills Station, although it is not shown beyond the Mandamus River, in order to avoid crowding the map.)
Rocks related both in geological occurrence and in chemical and mineralogical composition probably occur in the mountains to the south of the Mandamus-Pahau area, around the headwaters of the Waipara River. Benson (1942), pp. 177–8) has briefly described pebbles of doleritic and teschenitic types collected from the gravels of the Waipara River. They resemble the gabbro of the Mandamus-Pahau area in the presence of biotite and of minor amounts of alkali feldspar. Syenitic and trachytic types have not been observed.
Thomson (1912, 1919) described briefly some intrusive rock types from the Inland Kaikoura mountains. The rocks he described were mainly dolerites with alkaline affinities, similar to the gabbro described in this paper. A visit to this area in 1946 showed that the intrusive rocks cover a large area, extending from the headwaters of the Swale to those of the Muzzle River, and are considerably diversified in type. The syenite and gabbro from the Mandamus area are petrographically similar to some of the rocks from the Inland Kaikouras. Too much should not be made of this similarity, however, since the igneous rocks of the Inland Kaikouras have yet to be studied in detail and their mutual relations deciphered.
The closest analogies with the Mandamus-Pahau rocks are afforded by the small area of intrusive rocks at Onawe, in Akaroa harbour. These rocks, which were described in detail by Speight (1923, 1940), consist of gabbro and syenite, and some of the trachyte dykes of the Akaroa area are probably co-magmatic. The alkali-lime index of the Onawe rocks is 50.5, indicating that they re slightly more alkaline in general character. However, thin sections of the Onawe syenite and gabbro are very similar to sections of the syenite and gabbro from the Mandamus-Pahau area.
Much of the resemblance between the Mandamus syenites and trachytes and similar rocks at Onawe and in the Dunedin district may be due to their being all “residual magmas” in Bowen's sense, i.e. a final differentiate from the fractional crystallization of a large body of magma. The marked resemblances, however, suggest that the original magma in all those localities was similar, and that the same processes of differentiation were active in each ease.
The Age and Correlations of the Intrusions
The intrusion of these rocks was probably associated in time with the Hokonui orogeny. They are injected into greywackes and argillites whose are has not been directly established by fossil evidence, but which are correlated on lithological and structural similarities with fossilifereous rocks of Triassic and Jurassic age in other parts of Canterbury (Mason. 1949). Pebbles of syenite and trachyte occur in the basal Tertiary conglomerates (Mangaorapan. i.e. Lower Eocene) in Coal Creek. On this evidence intrusion was post-Jurassic and pre-Eocene. It appears most probable that the intrusion accompanied or followed closely the orogenic movements that brought to a close the long period of Hokonui sedimentation. The fact that the syenite often shows strong jointing like that o the surrounding greywacke suggests that it has been subjected to similar forces, and that hence it was intruded before the orogenic movements were completely spent.
From this discussion the time of intrusion would be correlated with the Hokonui orogeny, and would thus be Lower Cretaceous. An alternate hypothesis, which would be difficult to prove but which cannot be ruled out on the available evidence, is that intrusion took place at the end of the Cretaceous period. A widespread break in the sedimentary sequence occurred in North Canterbury at the end of the Cretaceous. Over a considerable area, post-Hokonui sedimentation begins with Mangaorapan beds. This stratigraphic break, though not at all comparable with that due to the Hokonui orogeny, is nevertheless an important one, and it must be borne in mind when attempting to date this igneous activity.
As mentioned in the introduction, igneous rocks associated with the Hokonui orogeny are rare. The large areas of Triassic and Jurassic rocks, both in North and South Islands, are monotonously free of associated igneous rocks. Probably the most extensive occurrence of intrusions in these rocks is that of the Inland Kaikoura mountains, which has yet to be mapped and examined in detail. Thomson considered that the igneous rocks of the Inland Kaikoura mountains were intruded in Clarentian (Lower Cretaceous) times. If this dating is correct, and the Mandamus-Pahau rocks are the same age, this implies that the Mandamus-Pahau rocks were intruded after the end of the Hokonui orogeny, rather than during the later stages of the orogeny itself.
Unfortunately, little evidence is available for dating the Onawe syenite and gabbro, which show such marked resemblances to the Mandamus-Pahau rocks. What evidence there is, however, does not conflict with the postulate that the intrusives in both areas may be of the same age. Speight's opinion (1940) was that the Onawe rocks are part of an older and distinct substratum belonging to an earlier epoch than that of the main mass of the Akaroa volcano; however, he made no statement as to their probable age.
General History of the Intrusion
It is believed that the rocks described in this paper were all derived from a common magmatic source by a process of differentiation by crystallization. The nature of the source magma is a matter of conjecture, but it was presumably such that both the gabbro and the syenite rocks were derived from it, the gabbro representing an accumulation of the early formed crystals and the syenite the crystallization product of the remaining magmatic liquid. This concept of the syenitic rocks as being the products of crystallization of a residual magmatic liquid is supported by the way in which the composition of the salic material in the actual rocks when plotted on the NaAlSiO4—KAlSiO4–SiO2 diagram of Bowen (1937) falls in the low-melting “residual liquid” section (Figure 4). The points representing the rocks from this district occupy an area on Bowen's diagram corresponding to that set out by Benson (1941, p. 542) for the salic portion of the residual magmas of the Dunedin petrographic province.
In view of the absence of rocks intermediate between those of gabbroic and syenitie composition it is believed that the residual liquid from which the syenitie rocks were formed was isolated by crustal stresses from the early formed crystals of augite and plagioclase which
Fig. 4—Compositions (less anorthite) of the salic portions of syenite (1), trachyte (2), and phonolite (3), from the Mundamus-Pahau area.
now constitute the gabbro. This “squeezed-out” residual magma then crystallized itself as microperthite, with some ferromagnesian material. As this residual magma cooled and crystallization proceeded the concentration of volatiles, particularly water vapour, in the still liquid fraction increased greatly. During this period part of the magma was injected along bedding planes in the country rock to form the numerous trachytic sills extending out from the intrusion. When the greater part, perhaps 80–90%, of the residual magma had crystallized, and the magma chamber contained a mush of crystals of microperthite and ferromagnesian minerals with liquid in the interstices, the pressure of volatiles was sufficient to shatter the relatively thin roof of the intrusion. This explosive release of pressure drove most of the remaining liquid out of the mush of crystals into the fragmented roof, where it solidified as the matrix of the igneous breccia. The forcible expulsion of the residual fluid from the interstices of the syenite gave it the remarkably porous and friable character.
|Weight%||Mol. Prop. × 100||Norm||Mode (Weight%)|
|TiO2||0.64||0.80||ne||1.76||Natrolite and calcite||3.9|
|ZrO2||nt. fd.||∑ sal||86.66|
|99.91||C.I.P.W. System: I. 5. 1. 4.—Nordmarkose Shand System: XSkLβ—Peralkaline Syenite Density: 2.62 (low, because of porosity of rock)|
|Weight%||Mol. Prop. × 100||Norm||Mode1 (Weight%)|
|SiO2||47.78||79.55||or||6.73||Plagioclase2 (average An45)||51|
|100.48||C.I.P.W. System: III. 5. 3. 4.—Camptonose.|
|-O = S||0.05||Shand System: XVmM’γ—Metaluminous Sub-Gabbro.|
|100.43||Density = 3.04 (analysed specimen; other samples, richer in mafic minerals, gave values up to 3.27).|
[Footnote] 1 Subequal amounts of aegirine, biotite, and alkaline amphibole
[Footnote] 1 Rosiwal analyses of different thin sections of gabbro show the following range in mineral composition: Plagioclase 26–53%. augite 30–60%, olivine 4–10%, biotite 2–9%, ores 4–8%; the figures given represent an average for a number of sections.
[Footnote] 2 Includes a small amount of interstitial anorthoclase.
|Weight%||Mol. Prop. × 100||Norm||Mode (Weight%)|
|100.31||C.I.P.W. System: II. 5. 1. 4.—Umptekose.|
|-O = S||0.15||Shand System: DSkLβ—Peralkaline Trachyte.|
|Density = 2.67.|
|Weight%||Mol. Prop. × 100||Norm||Mode (Volume%)|
|99.46||C.I.P.W. System: II. 6. 2. 4.—Essexose.|
|-O = Cl||0.12||Shand System: DUmLβ—Metaluminous Phonolite.|
|Density = 2.66.|
|Weight%||Mol. Prop. × 100||Norm||Mode (Calculated)|
|99.86||C.I.P.W. System: I. 5. 1. 3.—Phlegrose.|
|Shand System: DSpLβ—Peraluminous Trachyte.|
|Density = 2.66.|
I should like to express my appreciation to the residents of the district for their many kindnesses to me during the field work, particularly Mr. and Mrs. A. G. Groome, of the State Forest Service. Balmoral, Mr. and Mrs. W. A. Lake, Cascade Station, and Mr. and Mrs. A. C. Shand, Island Hills Station. They generously placed both transportation and accommodation at my disposal. I am also grateful for the assistance and companionship of a number of my students who accompanied me in the field on different occasions. This paper owes much of its substance to the chemical analyses of the major rock types. Four of these analyses were made at the Dominion Laboratory by Mr. T. A. Rafter, thanks to the co-operation of the Director of the New Zealand Geological Survey and the Director of the Dominion Laboratory, and one by Mr. M. C. Coller, chemist to the Geology Department, Indiana University. I am very much indebted to Mr. Rafter and Mr. Coller for the care with which these analyses were carried out. I would also like to express my thanks to Professor R. S. Allan, for his advice on many aspects of the problems encountered; and to Professor F. J. Turner, for helpful discussion of the petrology of these rocks.
My thanks are also due to the Hutton Fund of the Royal Society of New Zealand for defraying part of the cost of the work by a grant.
Barth, T. F. W., 1945. Studies on the igneous rock complex of the Oslo region. II. Systematic petrography of the plutonic rocks. Skrifter Norske Vid.- Akad., Mat.-nat. klasse, 1944, no. 9, 104 pp.
Benson, W. N., 1941. Cainozoie petrographic provinces in New Zealand and their residual magmas. Am. Jour. Sci., vol. 239, pp. 537–552.
—— 1942. The basic igneous rocks of eastern Otago and their tectonic environment. Part 3. Trans. Roy. Soc. N.Z., vol. 72, pp. 160–185.
Bowen, N. L., 1937. Recent high-temperature research on silicates and its significance in igneous geology. Am. Jour. Sci., vol. 233, pp. 1–21.
Coleman, A. P., 1899. A new analcite rock from Lake Superior. Jour. Geol., vol. 7, pp. 431–436.
Cross, W., 1915. Lavas of Hawaii and their relations. U.S. Geol. Surv. Prof. Paper 88, 97 pp.
Haast, J. von, 1871. On the geology of the Amuri district, in the provinces of Nelson and Marlborough. Rept. Geol. Expl. during 1870–71, Geol. Surv. N.Z., pp. 25–46.
Hess, H. H., 1940. Chemical composition and optical properties of common clinopyroxenes, Part I. Am. Mineral, vol. 34, pp. 621–666.
Hutton, F. W., 1877. Report on the geology of the north-east portion of the South Island, from Cook Straits to the Rakaia. Rept. Geol. Expl. during 1873–74, Geol. Surv. N.Z., pp. 27–58.
Iddings, J. P., 1913. Igneous Rocks, vol. 2, 685 pp.
Marshal, P., 1906. The geology of the Dunedin district. Quart. Jour. Geol. Soc., vol. 62, pp. 381–423.
—— 1914. The sequence of lavas at the North Head, Otago. Quart. Jour. Geol. Soc., vol. 70, pp. 381–423.
Mason, B., 1949. The geology of Mandamus-Pahau District, North Canterbury. Tranx. Roy. Soc. N.Z., vol. 77, pp. 403–428.
Peacock, M. A., 1931. Classification of igneous rock series. Jour. Geol., vol. 39, pp. 54–67.
Speight, R., 1918. Structural and glacial features of the Hurunui Valley. Trans. N.Z. Inst., vol. 50, pp. 93–105.
—— 1923. The intrusive rocks of Banks Peninsula. Rec. Canterbury Mus., vol. 2, pp. 77–89.
—— 1940. The basal beds of the Akaroa volcano. Trans. Roy. Soc. N.Z., vol. 70, pp. 67–76.
Thomson, J. A., 1912. On the igneous intrusions of Mt. Tapuaenuku, Marlborough. Trans. N.Z. Inst., vol. 45, pp. 308–315.
—— 1919. The geology of the Middle Clarence and Ure Valleys, East Marlborough, New Zealand. Trans. N.Z. Inst., vol. 51, pp. 289–349.
Vegetative Anatomy of Carpodetus serratus Forst.
[Read before the Otago Branch, June 13, 1950; received by the Editor, June 22, 1950.]
Carpodetus serratus is a small tree common throughout the New Zealand lowlands. It was first described in Characteres Genera Plantarum, by J. R. and G. Forster, in 1776. The genus has been assigned to the Saxifragaceae (e.g., 31) but it is one of those transferred by Hutchinson (19) to his new family Escalloniaceae in the order Cunoniales, since he considers that woody genera should be separated from herbaceous Saxifragaceae. In the present flora (7) Carpodetus is said to be monotypic and endemic in New Zealand, but both Schlechter and Reeder (25) have referred species from New Guinea and adjacent areas to it, Reeder describing or mentioning as many as nine.
Apart from brief reference by Solereder (31) nothing appears to have been published respecting the anatomy of any of these species. This paper records salient features of the vegetative parts of C. servatus and pays special attention to those considered to be significant in phylogenetic classification.
The work was carried out in the Botany Department of Otago University, and thanks are due to Dr. G. T. S. Bavlis for criticism and advice.
The primary stem structure (Pl. 38, A) has few noteworthy features. The epidermis bears frequent unicellular cutinised hairs (Fig. 1a)
Text Fig. 1—(a) L.S. hair on young stem. (× 235.) (b) T.S. portion of outer part of young stem showing origin of phellogen beneath a hair base. (× 240.)
and at wide intervals stomata of the normal type described by Haberlandt (18) for Narcissus biflorus and Helleborus. As in woody Angiosperms generally (11), there is not a typical endodermis, but a more or less definite ring of cells about the stele is regarded as such, since
in very young seedlings Caspary's bands were seen in this layer. The bundles of primary vascular tissue vary in size, the median leaf trace bundles being the largest, and showing marked radial arrangement of the primary xylem—a condition attributed by Esau (13) to repeated periclinal division of the procambial cells. Wood elements comprise annular, spiral, scalariform and dotted types. The spiral, annular and some of the scalariform and dotted cells are tracheids, but others of the last two types have end walls and are thought to be vessel segments. This possession of tracheids in primary, but not in secondary wood, is not abnormal (14). The primary phloem, in addition to sieve tubes, companion cells and parenchyma, contains peripherally groups of 2–10 small angular cells comparable with those described by Artschwager (1) from the potato, though in the present case consisting only of what he terms “conducting parenchyma.” These conducting parenchyma groups also occur in the stele between the collateral primary bundles. When traced longitudinally they were found to branch and anastomose and ultimately to fuse with the collateral bundles. The pith is solid and lignifies early.
The leaves are alternate with one-half phyllotaxis. The node Pl. 38, A) is trilacunar with the lateral traces each about a quarter of the circumference of the stem away from the larger median trace. These features of leaf arrangement and vascular supply are regarded as primitive (10, 29, 30), but the leaf itself, since it is not compound and lacks stipules, is not of the most primitive form in Angiosperms (10, 19).
The phellogen arises in the cortical layer immediately beneath the epidermis; appearing first, as is usual (11), at points where lenticels will develop. These are initiated mainly under hairs (Fig. 1b), stomata having little guiding and no limiting influence on their formation. The lenticels (Fig. 2) are small and rather greater in
transverse than in longitudinal extent. This is considered to be a primitive orientation (32). The complementary tissue is compact, the structure corresponding with Devaux's second type (9). The original phellogen persists throughout life of the tree, dividing slowly and maintaining only a thin cork layer seldom more than ten cells thick (Pl. 38, B). However, a wide zone of phelloderm is formed which matures into irregular masses of radially arranged stone cells (Fig.
Text Fig. 3—(a) L.S. secondary phloem showing companion cells and a sieve tube. (× 440.) (b) T.S. small region of lignified phloem showing a lignified companion cell c.c. (× 665.) (c) L.S. lignified phloem to show lignified companion cell and a dead sieve tube. (× 425.) (d) T.S. portion of periderm in mature stem showing phellogen (stippled) and phelloderm stone cells. (× 140.)
3d) separated by loosely packed parenchyma cells which increase by radial divisions to accommodate the tangential stresses set up by the expanding stele. Cells of the persisting primary cortex show still more active radial division. Like the phelloderm this tissue becomes partially converted to stone cells. Lignified primary cortical cells can be distinguished from the phelloderm stone cells since in the former lignification occurs only after radial divisions have given these cells a marked tangential seriation.
In cross section the secondary phloem recalls the well-known arrangement of Tilia. Expanding multiseriate rays separate tapering masses of sieve-tubes, companion cells, phloem parenchyma and uniseriate rays, but there is no fibre in the active phloem. The older phloem, however, is converted into tapering tongues of selerenchyma. and small patches of lignified cells also appear in the intervening ray tissue. Sieve-tube elements are narrow and tapered without definite end walls (Fig. 4a). The overlapping ends of successive elements are interconnected by several sieve plates, and smaller sieve plates occur elsewhere along the cell where it comes laterally in contact with another sieve-tube (Fig. 4d). They conform with Hemenway's first type (12) which is considered a primitive one (20). Callus
Text Fig. 4—(a, c) Complete sieve tubes. (× 80.) (b) Lower end of (a) showing sieve plates. (× 400.) (d) Portion (indicated) of (c) showing sieve plates on lateral wall. (× 400.) (e, f) Vessel segments from stem wood. (× 85.) (g) L.S. vessel segment tip to show bordered perforations (left), and nature of pitting between vessels and wood parenchyma (right). (× 680.) (h) Vessel segment from wood of exposed root. (× 90.) (i) Vessel segment from wood of buried root. (× 135.)
was not observed, but the material was all collected in winter, and it is possible that it might be present at other times of the year since it does not necessarily persist after death of the cell (12). Each sievetube element usually has several companion cells which are remote from one another (Fig. 3a). Phloem parenchyma is abundant. Between sieve-tubes and parenchyma cells are numerous pits that are often large. Uniseriate rays extend from the wood without change of cell structure except that the walls are not lignified in the phloem. The multiseriate rays are derived from compactly arranged rectangular initials. The ray cells soon round off, then broaden tangentially, and finally divide into tangential rows of cells in the same manner as cortical parenchyma. In these rays only scattered cell
groups become lignified, whereas nearly all parenchyma accompanying the vertical phloem elements is ultimately converted to stone cells. Sieve-tubes do not lignify, but neither they nor any unlignified parenchyma are greatly crushed. Apparently the thin cork and the capacity of cortex and periderm cells for radial division prevent the usual pressure developing between secondary wood and bark. It is noteworthy that a good many of the old companion cells do lignify (Figs. 3b, 3c), a phenomenon that does not appear to have been observed previously, it being usual for these cells to die and collapse along with their sister sieve-tube element (12).
The secondary wood is almost white in colour, with obscure growth rings, but prominent rays along which it invariably splits as it dries. The wood is diffuse-porous (Pl. 39, A), annual ring boundaries being defined by the contrast between summer and spring wood vessel diameters. Ray cells broaden tangentially in the summer wood. No tracheids are present, the vertical conducting cells all being vessels (Figs. 4e, 4f). By Chattaway's (6) standards these vessels are very numerous, and their thin-walled, angular segments have a “small” tangential diameter and are “extremely long.” (For actual measurements see Table of Descriptions.) Segment end walls are very oblique, often with tails, and with numerous narrow, fully-bordered perforations (Fig. 4g) which are always scalariform. The vessel pitting is opposite. Except for this last feature, which is considered slightly more advanced than sclariform pitting, the vessel segment is primitive in every respect (14, 15, 16). Very oblique end walls are the rule in woods such as Carpodetus which are not storied (5). The bulk of the tissue between the vessels is comprised of fibres (Fig. 5), which by Chattaway's standards are “very long” and “thin” walled. Pitting is fairly evenly distributed, on all walls, the pit chambers easily visible, borders strongly developed, and the inner apertures narrow and included. Such fibres are classed as fibre-tracheids (26) and considered to be a somewhat primitive type (2). As Priestley (23) has established as generally true, pits are not formed between fibres and other elements (Fig. 5). Vertical parenchyma are diffuse (Fig. 5), the cells in similar vertical series to the phloem parenchyma. Ray structure conforms with Krib's (22) heterogeneous type I, which both he and Barghoorn (3, 4) consider the most primitive in Angiosperms. In this type the uniseriate rays are high and composed of vertically elongated cells. The multiseriate rays possess high uniseriate tips identical with the uniseriate rays, and are in their multiseriate parts parallel-sided with elongated lateral cells (Pl. 39, B). Primary multiseriate rays are, of course, of interfascicular origin. Secondary ones were observed to arise by two of the methods described by Barghoorn (3, 4)—i.e., by widening of a uniseriate ray or by coalescence of several such rays, and they are occasionally split apparently by changeover from ray to fusiform initials in the cambium. On Chattaway's standards these rays are “very broad” and “extremely high.”
Table of Description of Secondary Wood
A description of wood in C. serratus has been prepared following the plan suggested by Rendle and Clarke (27, 28). It is based on four trees between 30 and 50 years old growing in a variety of situa-
Text Fig. 5—T.S. secondary wood of stem. Typical cells are lettered: vessels (v), vertical parenchyma (p), fibres (f), uniseriate rays (r). (× 700.)
tions in Otago and Southland. From each tree five samples were selected at equal intervals from the base of the trunk up to branches about five years old, care being taken to keep sufficiently far from the pith to avoid variability described by Desch (8). It should be noted that Barghoorn (4) states that ray heights and widths should be used with great care, if at all, in wood identification.
|Total Segment Length||1041.0μ||220.21μ||88.991μ|
|(25 measurements of each from each sample—total: 500 of each)|
|(b)||Number: Vessels more or less evenly distributed. Range from 40–110, but mostly 50–80 pores or groups per square millimetre. (2 counts from each sample—total: 40)|
|(c)||Grouping: Vessels solitary or in groups of 2–4, about 60% solitary and about 35% in pairs. (60 counts from each sample—total: 1200)|
|Mean Fibre Length||=||1653.0μ|
|Standard Deviation of Means||=||166.2μ|
|(25 measurements per sample—total: 500)|
|(a)||Height: Multiseriate rays vary from 450μ–13200μ with about 00% from 1400μ–3000μ. Uniseriate rays vary evenly from 150μ–4150μ. (25 measurements per sample—total: 500)|
|(b)||Width: About 75% are uniseriate. The multiseriate rays vary from 2–16 cells in width, with about 55% from 5–8 cells, and about 15% 2 cells wide. (50 measurements per sample—total: 1000)|
The root system is composed of laterals, there being no persistent tap-root. These roots vary from 4-arch to polyarch, and always contain some pith which eventually lignifies. The initial phellogen forms well out in the cortex. and as in the stem is persistent and forms much phelloderm. There is little lignification of the phelloderm, but an almost complete sclerenchyma ring is formed further in by lignification of the old phloem parenchyma, outer parts of many phloem rays and the inner layers of the cortex. (Pl. 38, C.)
Secondary wood in roots that are exposed above the ground appears to differ from stem wood only in having broader rays (Pl. 39, C) (Fig. 4h), but subterranean roots have much larger vessels and correspondingly narrower multiseriate rays, fewer and thinner-walled fibres and more abundant vertical wood parenchyma (Pl. 39, D). Vessel segments in buried roots are shorter, including some very short vessels (Fig. 4i), a form never found in stems, and growth rings are more obscure. The precise extent of histological differences between stem and root wood, and between exposed and buried root wood is the subject of a separate investigation, and no statistical data will be presented here
The three leaf traces unite in the petiole to form the usual arc of vascular tissue. This has no sclerenchyma associated with it, but the midrib and main veins possess a sclerenchyma sheath. The principal features of the lamina are shown in Fig. 6. The uppermost layer of palisade mesophyll, which amounts in all to from 2–4 layers, is intermittently replaced by clear hypodermal cells, as has been noted by Solereder (31). This hypodermis is not responsible for the mottled appearance of the foliage. This is due to a higher chlorophyll content of the mesophyll adjacent to large veins. Hairs and stomata are of the type already described from the stem, the latter being without subsidiary cells and confined to the lower epidermis. C. serratus is one of the New Zealand trees which possesses smaller leaves in juvenile than in adult trees. Juvenile leaves do not possess hypodermis and have no more than two palisade layers. Unpublished work by Johnston (21) has established that they have a closer vein network and more stomata per unit area than adult leaves.
Discussion and Summary
The fullest account of wood structure in the Cunoniales is by Record (24), who states that the Escalloniaceae are the only family in the order which combine conspicuously large rays with scalariform vessel perforations and strongly bordered pits in the wood fibres. The existence of all these features in C. serratus confirms the classification of the genus in that family. The Cunoniales occupies an early place in Hutchinson's evolutionary tree for woody Dicotyledons. The vegetative anatomy of C. serratus confirms that position, since this species exhibits a primitive condition in almost every feature to which phylogenetic significance has been attached—viz.:
Vessel segments thin walled, angular, long and narrow with very oblique end walls often tailed, and numerous narrow, fully-bordered perforations which are exclusively scalariform.
Fibres of the fibre-tracheid type.
A ray system conforming to Krib's heterogeneous type I.
Apotracheal wood parenchyma.
Long, tapered sieve tubes interconnected by several sieve plates.
A trilacunar node.
Leaf trace insertions in contact.
Open bundle system.
Features which show a slight evolutionary advance are absence of tracheids in secondary wood, and opposite pitting of vessels. It has been contended that diffuse-porous woods are primitive, but Gilbert (17) points out that it can hardly be claimed that there is a general advance towards ring-porosity since this feature is confined to trees of the N. Temperate zone.
The cortical system in both stem and root is characterised by a phellogen arising near the exterior and producing little cork but
much phelloderm. The phelloderm, though partially converted to stone cells in the stem, retains great tangential elasticity through radial division of its parenchyma. Old secondary phloem thus persists uncrushed, and certain companion cells therein undergo lignification along with the phloem parenchyma—a most unusual occurrence.
The leaf is of a normal mesophytic type. Adult leaves possess an intermittent colourless hypodermal layer. Attention is drawn to the fact that though there are substantial differences, mainly in size and frequency of component elements, between stem and buried root wood, these differences largely disappear if the root is uncovered.
1. Artschwager, E. F., 1918. Anatomy of the Potato Plant with special reference to the Ontogeny of the Vascular System. Jour. Agr. Res., 14: 6.
2. Bailey, I. W., 1936. The Problem of Differentiating and Classifying Tracheids, Fibre Tracheids, and Libriform Wood Fibres. Trop. Woods, 45.
3. Barghoorn, E. S., 1940. The Ontogenetic Development and Phylogenetic Specialisation of Rays in the Xylem of Dicotylcdons. I. The Primitive Ray Structure. Am. Jour. Bot., 27: 10.
4. —— 1941. The Ontogenetic Development and Phylogenetic Specialisation of Rays in the Xylem of Dicotyledons. II. Modification of the Multiseriate and Uniseriate Rays. Am. Jour. Bot., 28: 4.
5. Chalk, L., and Chattaway, M. M., 1935. Factors affecting Dimensional Variations of Vessel Members. Trop. Woods, 41.
6. Chattaway, M. M., 1932. Proposed Standards for Numerical Values in Deseribing Woods. Trop. Woods, 29.
7. Cheeseman, T. F., 1925. Manual of the New Zealand Flora, ed. 2. Govt. Printer, N.Z.
8. Desch, H. E., 1932. Anatomical Variations in the Wood of some Dicotyledonous Trees. New Phyt., 31.
9. Devaux, H., 1900. Recherches sur les Lenticelles. Ann. Sci. Nat. Bot., 8 sér., 12.
10. Dormer, K. J., 1945. An Investigation of the Taxonomic Value of Shoot Structure in Angiosperms with Especial Reference to Leguminosae. Ann. Bot., N.S., 9.
11. Eames, A. J., and MacDaniels, L. H., 1925. An Introduction to Plant Anatomy, ed. 1. McGraw-Hill.
12. Esau, K., 1930. The Development and Structure of the Phloem Tissue. Bot. Rev., 5: 7.
13. —— 1943. Origin and Development of Primary Vascular Tissues in Seed Plants. Bot. Rev., 9: 3.
14. Frost, F. H., 1930. Specialisation in Secondary Xylem of Dicotyledons. T. Origin of Vessel. Bot. Gaz., 89.
15. —— 1930. Specialisation in Secondary Xylem of Dicotyledons. II. Evolution of End Wall of Vessel Segment. Bot. Gaz., 90.
16. —— 1931. Specialisation in Secondary Xylem of Dicotyledons. III. Specialisation of Lateral Wall of Vessel Segment. Bot. Gaz., 91.
17. Gilbert, S. G., 1940. Evolutionary Significance of Ring Porosity in Woody Angiosperms. Bot. Gaz., 102.
18. Haberlandt, G., 1928. Physiological Plant Anatomy. Engl. trans. from 4th German ed. by M. Drummond. MacMillan & Co.
19. Hutchinson, J., 1926. The Families of Flowering Plants. I. Dicotyledons. MacMillan & Co.
20. Jeffrey, E. C., 1917. The Anatomy of Woody Plants. University of Chicago.
21. Johnston, J. G., 1948. A Comparison of Adult and Juvenile Foliage of Carpodetus serralus Forst. with Special Reference to Xeromorphic Characters. Unpublished Thesis.
A. T.S. stem of seedling showing leaf traces. (× 100.)
B. T.S. bark of mature plant showing living and lignified phloem, lignified and non-lignified cortical cells, phelloderm and lenticel. (× 35.)
C. T.S. bark from subterranean root, Shows cork, phelloderm, lignified zone, and living phloem. (× 48.)
22. Kribs, D. A., 1935. Salient Lines of Structural Specialisation in the Wood Rays of Dicotyledons. Bot. Gaz., 96.
23. Priestley, J. H., 1930. Studies in the Physiology of Cambial Activity. II. The Concept of Sliding Growth. New Phyt., 29.
24. Record, S. J. Classification of Various Anatomical Features of Dicotyledonous Woods. Trop. Woods., 47.
25. Reeder, J. R., 1946. Notes on Papuasian Saxifragaceae. Jour. Arnold Arboretum, 27: 3.
26. Reinders, E., 1935. Fibre-Tracheids, Libriform Wood Fibres, and Systematics in Wood Anatomy. Trop. Woods, 44.
27. Rendle, B. J., and Clarke, S. H., 1934. The Problem of Variation in the Structure of Wood. Trop. Woods, 38.
28. —— 1934. The Diagnostic Value of Measurements in Wood Anatomy. Trop. Woods, 40.
29. Sinnott, E. W., 1914. Investigations on the Phylogeny of the Angiosperms. I. The Anatomy of the Node as an Aid in the Classification of Angiosperms. Am. Jour. Bot., 1: 7.
30. Sinnott, E. W., and Bailey, I. W., 1914. Investigations on the Phylogeny of the Angiosperms. III. Nodal Anatomy and the Morphology of Stipules. Am. Jour. Bot., 1: 9.
31. Solereder, H., 1908. Systematic Anatomy of the Dicotyledons. Engl. trans. by Boodle, L. A., and Fritsch, F. E., Oxford.
32. Wetmore, R. H., 1920. Organisation and Significance of Lenticels in Dicotyledons. I. Lenticels in Relation to Aggregation and Compound Storage Rays in Woody Stems. Lenticels and Roots. Bot. Gaz., 82.
New Zealand Ichneumonidae
Paper No. 1
The Genus Netelia Gray (Paniscus of Authors) (Tryphoninae: Phytodietini)
[Read before the Nelson Institute, June 19, 1950; received by the Editor, July 4, 1950.]
The systematics of the Ichneumonidae have in the past been rather confused, but the recent works of Dr. H. K. Townes and others have made considerable advancement, especially in the definition and arangement of the higher categories, into which the family is divided. In dealing with the New Zealand fauna the nomenclature of the higher groups will be based on the work of Townes, whose valuable contributions have clarified the systematics of the family considerably.
Systematic Position and Nomenclature of the Tribe Phytodietini
Cushman (1924) in his revision of the Paniscini (= Netelini = Phytodietini) restricted the tribe to two genera Paniscus (= Netelia) and Parabates, on account of the type of egg and larval development, and transferred the tribe from its classical position near the Ophionini to a position near the Tryphonini. Townes (1938) agreed with Cushman, but considered that the tribe Netelini (Paniscini) showed even closer relationship with the genus Phytodietus, and for this reason he proposed that the genus Phytodietus be placed with the genus Netelia (= Paniscus) in the tribe Netelini. According to the rules of nomenclature the name of the tribe takes the name of the oldest included genus, which in the present case is Gravenhorst's genus Phytodietus, established in 1829. Netelia was established by Grey in 1860, accordingly, the tribal name will have to be Phytodietini.
Two tribes are represented in the New Zealand fauna, which may be separated by the following Key:
Key to New Zealand Tribes
|Propodeum with both transverse and longitudinal carinae; legs stout||Tryphonini|
|Propodeum without carinae, or with a pair of transverse crests; legs slender||Phytodietini|
This tribe is characterised by Townes (1938, p. 173) as follows: Head transverse, eyes large, malar space short; clypeus separated from face, the apex truncated or emarginate; flagellum slender, tapering with 30 to 60 segments; scape twice as long on inner side as on outer side; prepectal carina ending about halfway up the mesopleuron; sternaulus wanting; mesonotum strongly convex; mesothorax deep and strongly developed; propodeum rather evenly convex, without carinae
or transversely striate on its basal half above and with a somewhat curved transverse carina on each side just above its middle; discocubital vein strongly curved basally; areolet triangular, usually higher than wide, subpetiolate or shortly petiolate, rarely absent; second intercubital with a bulla below; second recurrent strongly curved, interstitial or nearly interstitial with second intercubitus, a bulla at its top and another just below its middle; apex of front tibia evenly rounded, without a suggestion of a tooth; spurs of front tibia long and slender, the comb-bearing part occupying less than one half of its length; tibia and tarsi with many conspicuous bristles; tarsal claws densely pectinate, with eight to fifty long teeth; petiole straight, gradually enlarged towards the apex, its spiracles before the middle; glymma deep; abdomen more or less compressed beyond the third segment; epipleura well developed on all segments; ovipositor from about one-fifth as long, to as long as, the abdomen; the tip tapering, not notched; female subgenital plate not strongly developed; ovipositor sheath transversely ridged, densely clothed with rather long hair; penis compressed.
Townes (loc. cit., p. 174) gives the following key for the separation of the two genera included in this tribe:
Key to Genera.
|Lower tooth of mandibles as long as upper tooth; clypeus rather narrow; eyes not exceptionally large, weakly or or not at all emarginate at antennae; ocelli not large, lateral ocellus not close to eye; nervellus broken below middle; body less slender; ground colour usually black; inner surface of squama of male genitalia not specialised.||Phytodietus|
|Lower tooth of mandibles much shorter than upper tooth; clypeus broad; eye very large and usually strongly emarginate at antennae; ocelli large, the lateral ocellus touching or close to the eye; nervellus broken above middle; body slender; ground colour tawny; inner surface of squama of male genitalia usually with special structures||Netelia|
Only two species are known from New Zealand, belonging to the genus Netelia. One is endemic while the other is a widespread Australian species.
Genus Netelia Gray, 1860
Cushman (1924, p. 21) has previously pointed out “The fact that Ichneumon luteus is the only species mentioned by Schrank in connection with Paniscus and is also the type of the genus Ophion would seem to make necessary the synonymising of Paniscus with Ophion.” Under strict interpretation of the International Code of Zoological Nomenclature, Paniscus Schrank is isogenotypic, and therefore synonymous with Ophion Fabricius. Townes (1938) synonymised Paniscus Schrank with Ophion Fabricius, and used Netelia Gray for Paniscus of authors. Cushman (1947, p. 437) referring to Townes’ action in synonymising Paniscus with Ophion states: “… although I feel that this action was too precipitate, and probably will not receive the support and following of the majority of the contemporary specialists on the Ichneumonidae, his action seems to have blocked the preservation of Paniscus in the sense sanctioned by well over a hundred years of usage, and I follow him in the use of Netelia.” From the above remarks it will be at once apparent that there is no
alternative but to synonymise Paniscus with Ophion and to substitute for Paniscus, in the traditional sense, Gray's genus Netelia.
These insects, as are all Phytodietini, are external parasites on lepidopterous larvae. There is a reference in the New Zealand literature to one of our species parasitising locusts (Miller, 1919); this observation is probably an error and requires confirmation. The eggs are very large and are attached externally to the body of the host by a pedicel which is thrust through the skin of the host. In oviposition the egg itself is not enclosed in the ovipositor, but is attached to it by the enlarged base of the pedicel. Structurally the ovipositor is rather unique; it is attenuated at the apex beyond a more or less distinct ventral enlargement. (Fig. 1.) This type of ovipositor occurs in all groups of ichneumonids that produce stalked eggs.
Occiput margined; lower tooth of mandibles much shorter than upper tooth; clypeus broad; eyes very large, and usually strongly emarginate at antennae; ocelli large, the lateral ocelli touching or close to the eyes; scutellum basally carinate on either side; spiracles of basal segment of abdomen placed distinctly before centre; areolet triangular; nervellus broken above the middle; ovipositor exserted; body slender; ground colour tawny; all tarsal claws pectinate.
The nomenclature of the New Zealand species of Netelia has in the past been rather confused. Although only two species are known at present from New Zealand, four specific names appear in the literature.
In 1876 Smith described a female from Otago which he named Paniscus ephippiatus. Cameron in 1898 described Paniscus foveatus from a female collected at Greymouth; this species is identical with Brulle's species Paniscus productus originally described from Tasmania in 1846. Smith in 1878 published another description of Paniscus ephippiatus from a female collected in Canterbury. Dalla Torre in his catalogue of 1901 considered that Smith had dealt with two species in his 1876 and 1878 description of ephippiatus and consequently raised the species described in 1878 to specific rank under the name Paniscus smithii. But there is no doubt that Smith's two descriptions refer to the one and the same species, as Hutton many years ago indicated in his Catalogue of Diptera, etc., published in 1881. Hutton in 1904 lists two species, Paniscus productus and foveatus, treating ephippiatus as a synonym of productus. Subsequent authors have confused the nomenclature and identity of the two species, as named specimens in the various collections have shown.
The two New Zealand species may be separated by the following Key:
Key to New Zealand Species of Netelia
|Face and frons yellowish brown to pallid yellow; mesothorax and mesosternum uniformly brown; nervellus index from 1.79 to 2.08||N. productus|
|Face and frons brown; ocular area, mesothorax and mesosternum black or clouded with black; nervellus index from 2.40 to 2.92||N. ephippiatus|
Netelia ephippiatus (Smith)
Paniscus ephippiatus Smith, Trans. Ent. Soc. Lond., 1876, p. 478, female; Smith, loc. cit., 1878, p. 3, female; Hutton, Cat. N.Z. Diptera, etc., 1881, p. 126; Cameron. Mem. Manch. Soc., 42, pt. I, 1898, p. 35; Cameron, Trans. N.Z. Inst., 33, 1901, p. 105; Dalla Tore, Cat. Hymen., III, pt. I, 1901, p. 78.
Paniscus productus Hutton, Index Faunae Nov. Zeal., 1904, p. 102; Miller, N.Z. Journ. Agric., 19, 1919, p. 203, fig.
Paniscus smithii Dalla Torre, Cat. Hymen., III, pt. I, 1901, p. 80.
This species was first described by Smith in 1876 from a female collected in Otago, and two years later another female collected from Canterbury was described under the same name by the same author. Hutton gives both descriptions in his 1881 catalogue, but erroneously gives the locality for the 1878 specimen as Dunedin. Hutton was of the opinion that both descriptions referred to the one and the same species. Cameron records it from Greymouth (1898) and from Wellington (1901). Morley (1912) examined a specimen from Auckland. Female
Head brownish-yellow or light brown; ocular area and tip of mandibles black; ocelli and eyes nigger-brown; antennae brown, the apical 24 joints of a darker greyish-brown; pronotum pale yellowish-brown; mesonotum with three wide longitudinal bands of black, separated by the notauli; mesostern black; legs yellowish-brown; spines brown to blackish-brown; claws nigger-brown; abdomen, first tergite basally light brown darkening to brown towards apex; second tergite and basal part of third tergite brown, remaining part of third tergite and the posterior tergite dark brown shading to black; ovipositor dark brown to black; wings hyaline, veins and stigma brown to dark brown.
Ocelli large, posterior ones sub-contiguous with eyes, anterior ocellus separated from eyes by its diameter, and the same distance from antennal scrobes; frons finely but distinctly striolated, bordered by a lateral carina, running parallel with the inner border of the eyes, nearly glabrous; face slightly wider than long, weakly convex in centre, clothed with fine whitish pubescence and finely punctate; clypeus more especially along anterior border; flagellum with 53 joints and all coarsely punctate and clothed sparsely with longish white bristles, entirely clothed with short and fine pubescence, the joints becoming gradually shorter, the apical joint is about a quarter the length of the third joint. Scutellum prominent, oblong, narrowed towards apex, lateral carinae present, the whole surface punctate; propodeum finely, transversely striolated, strong carinae along the lateral posterior borders terminating anteriorly in a prominent spine-like process; mesostern with median sulcus deep; pleural sclerites distinct; all tibiae spined, the spines short, sharply jointed, and are more numerous on posterior tibiae; claws with strong pectinations; abdomen, first tergite, long and straight, gradually widening towards apex, the spiracles placed about one-third from base; second tergite slightly more than one-half the length of the first and sub-equal to the third tergite in length; apical spurs of posterior tibiae long, the outer the larger of the two; gastroeoeli shallow and minutely punctate; wings with areolet triangular, with only a small gap at the base of the outer side (Fig. 9); nervellus index 2·40 to 2·92 (Figs. 6 and 5).
This species is closely allied to N. productus; indeed, it is rather difficult to detect macroscopical structural details that will separate one from the other, except, of course, by colour, which is fairly constant in density and distribution.
Miller (1919, p. 203) records and figures this species under the name Paniscus productus as attacking the New Zealand flax grub (Xanthorhoe praefectata). There is no doubt that the species he refers to is N. ephippiatus, for in describing this insect he states: “On the back, behind the head, is a large blackish spot, and another beneath the thorax between the front and middle legs, while the abdomen darkens towards the apex, in some cases being almost black.” The accompanying figure is undoubtedly this species. Miller (1930, p. 282) again referring to this species as attacking Xanthorhoe praefectata states: “… the parasite does not destroy the caterpillar until after pupation so that the injury by the caterpillars to the flax is not hindered.” The same author also observed that P. productus does not confine its attacks to O. praefectata but infests other species of caterpillars as well.
Gourlay (1930, p. 5) does not record Miller's observations, and does not include N. ephippiatus in his list.
The females are far more abundant than males, which are extremely rare in collections. The females especially are attracted by artificial light.
This species is probably generally distributed throughout both islands. Specimens have been examined from the following localities: Dunedin (type locality), Canterbury, Greymouth, Nelson, in the South Island, and Wellington, Paihia, and Auckland in the North Island and the Chatham Islands.
The relative seasonal abundance of adults of Netelia ephippiatus is shown in graphical form in Fig. 10. The data upon which this graph is based were obtained from information accompanying specimens in the various collections that have been made over the past thirty years. The total number of specimens from which data were obtained was 58.
Netelia productus (Brulle)
Paniscus productus Brulle, Hist. Nat. Ins. Hymen., IV, 1846, p. 156 (female from Tasmania); Dalla Torre, Cat. Hym., III, pt. I, 1901, p. 156; Hutton, Index Faunae Nov. Zeal., 1904, p. 102; Gourlay, Dept. Sci. and Industr. Res. Bull. 22, 1930, p. 5.
Paniscus foveatus Cameron, Mem. Manoch. Soc., 42, pt. I, 1898, p. 36; Hutton, Index Faunae Nov. Zeal., 1904, p. 102; Dalla Torre, Cat. Hymen., III, pt. I, 1901, p. 78.
Brulle originally described this species from Tasmania in 1846. Cameron in 1898 described it as new under the name Paniscus foveatus from Greymouth, New Zealand.
Head yellowish-brown tinge, especially behind eyes and on frons and caput; face usually a pallid-yellow; ocular area light brownish-red
or orange-brown; ocelli and eyes red-brown, eyes shaded with black; tips of mandibles black; antennae uniformly brown, not normally appreciably darkening apically, mesonotum brown, in some specimens faintly infuscated with darker brown; metanotum dark brown; abdomen red-brown, usually not appreciably darker towards apex; mesosternum brown; legs red-brown clothed with golden pubescence; claws dark brown; wings hyaline, veins and costa dark brown, stigma light to reddish-brown.
Frons finely but distinctly striolated, bordered by lateral carinae; face slightly wider than long and convex in centre; clothed with fine pubescence; face more closely punctured than clypeus; flagellum is usually 57 segmented; notauli grooves well marked; scutellum prominent, much narrowed towards apex, with strong lateral carinae and with the surface minutely punctured; propodeum finely transversely striolated, carinae posteriorly strong, terminating anteriorly in a prominent spine-like process; pleurae sclerites distinct; spines on tibiae as in N. ephippiatus; claws strongly pectinate; areolet of anterior wing triangular, usually more widely open along outer side (Fig. 8).
Male similar to female.
This species, at least in the case of the females, is slightly larger than N. ephippiatus, and differs from that species by the absence of black on the vertex, mesonotum and mesosternum, accompanied by a darkening of the apical portions of the abdomen. In the majority of specimens examined the propodeum may be slightly more convex and their lateral keels more distinct, and more deeply impressed at base, this depression being almost bifurcate, through the centre being raised. The lower part of the mesopleura is not depressed as it is in N. ephippiatus, also the stigma of the fore-wings is usually a lighter brown.
Very close to N. ephippiatus. A species described from Fiji (Netelia fijiensis) would appear to be also closely related to the forms described here.
Gourlay (1930, p. 5) records this species as parasitising Melanchra composita and Aletia unipuncta, the parasite attacking the host larvae, the parasitic larvae emerging from the host larvae to pupate. Given (1944) figures an egg of a Netelia species found on the larvae of the white butterfly (Pieris rapae) at Nelson. A female of this species taken at Nelson on March 27, 1950, when placed in a cage with a larva of Cirphis unipuncta, laid three eggs on the larva. One was placed about halfway up in the suture separating the head from the first thoracic segment, a second lower down in the suture between the meso- and metathoracic segments, and a third attached at the base of a mesothoracic leg. The eggs were of large size, black in colour with a relatively long pedicel, and were very firmly attached to the surface of the larva. Within twelve hours of being laid the eggs hatched, the young larvae remaining between the two halves of the egg case, the egg splitting longitudinally. Unfortunately the caterpillar died and further observations on the development of the parasite were not possible. Both the egg figured by Given and the present eggs show difference in size and shape compared with those of a Netelia figured by Vance (1927).
The relative seasonal abundance of adults of Netelia productus is shown in Fig. 11. As in the case of N. ephippiatus, collections made over the past thirty years were tabulated by months and the graph constructed from the resulting frequency distribution. The total number of specimens from which data were obtained was 47.
Australia, Tasmania and New Zealand. It is generally distributed throughout both islands of New Zealand; adults have been recorded from the following localities: Canterbury, Westland, Nelson, and Marlborough in the South Island, and Paihia, Whangarei, Manguiti, and Taupo in the North Island.
Notes on the New Zealand Species of Netelia
The two species of Netelia occurring in New Zealand are easily distinguished by their colour; structurally they are very similar. Two characters that have been found to be fairly constant are the incompleteness of the outer border of the areolet (Figs. 8 and 9) and the relative lengths of the upper and lower portions of the nervellus in the hind-wing (Figs. 6 and 7). In respect to the second character, 32 specimens of ephippiatus and 39 specimens of productus collected from widely separated localities were measured and the results are presented graphically in Fig. 5; this character is easily observed and will serve in doubtful cases as a reliable criterion for the separation of the two species.
A species described by Brues (1922, p. 19) from Fiji, which is closely related to productus, shows sexual dimorphism in that the males have the aciculations of the propodeum more clearly indicated medially and by the white face and orbits as well as the larger ocelli, while the lower outer side of the areolet is more distinct. The size of the ocelli and the aciculations of the propodeum show slight variations in the New Zealand forms, but few constant differences can be detected between the sexes.
There are several specimens of Netelia that at present I am unable to place satisfactorily; in particular there is a large female collected at Manguiti, on March 8, 1916. This may be a distinct species, but I have refrained from naming it until further specimens are obtained. There are certain indications, from the material I have examined, that when more information on the biology and habits of the species of Netelia is available, the present species may possibly be conveniently separated into several well-marked sub-species, based on slight but more or less constant structural details associated with seasonal and host distribution within New Zealand.
In the case of N. productus it is of interest to record the manner in which the Nelson and Kaikohe material was collected. The Nelson specimens were collected from the windows of a house at night, the insects being attracted by the light. This material consisted of eleven females and two males. The Kaikohe specimens, comprised entirely of males, were collected by sweeping herbage and long grass during the evening just before dark. Dr. R. A. Cumber, who collected this material, observed these insects on or near the ground probably hunting for females.
Townes (1938) groups the Nearctic species of Netelia into several sub-genera. The New Zealand species belong to his typical sub-genus Netelia, but they do not appear to conform to any of his species groups included in this sub-genus, although they show affinities with the Leo group.
Definition of Terms
The terms used in this paper are illustrated in the various figures and are self-explanatory. Measurements were taken under a microscope with an ocular micrometer; they are only approximate. The nervellus ratio is the relative lengths of a and b in Figs. 6 and 7.
Specimens from the Cawthron Institute, Entomological Research Station, Dominion Museum, Auckland Museum, and the Canterbury Museum collections were studied.
This work was done at the Entomological Research Station, Nelson, under the direction of Dr. D. Miller, to whom I owe many thanks for much advice and for aid in securing the loan of material. To Dr. Henry K. Townes, of Cornell University, Ithaca, U.S.A., for valuable assistance, without which, my work would have been much less complete. I also wish to acknowledge the great assistance rendered in collecting or in the loan of material, by the Directors of the Canterbury, Dominion, and Auckland Museums, Mr. E. S. Gourlay, of Nelson, Dr. R. A. Cumber, of Foxton, Dr. T. E. Woodward, of Auckland, and Professor Elwood Montgomery, of Purdue University. I wish also to acknowledge the great assistance rendered to me by Miss Shirley E. Armstrong, Librarian, Entomological Research Station, Nelson, in procuring literature and checking references.
Brues, C. T., 1922. Phyche, 29: 21.
Brulle, G. A., 1846. Hist. Nat. Ins. Hymen., 4: 156.
Cameron, P., 1898. Mem. Manch. Soc., 43: 35 and 36.
—— 1901. Trans. N.Z. Inst., 33: 105.
Cushman, R. A., 1924. Proc. U.S. Nat. Mus., 64: 1–48.
—— 1927. Ibid., 96: 47–482.
Dalla Torre, K. W., 1901. Cat. Hymen., III, Pt. 1, 80 and 156.
Given, B., 1944. N.Z. Journ. Sci. Tech., 26 (A): 94–96.
Gourlay, K. S., 1930. N.Z. Dept. Sci. Ind. Res. Bull. No. 22: 5.
Hutton, F. W., 1881. Cat. N.Z. Dipt., p. 126.
—— 1904. Index Faunac Nov. Zeal., p. 102.
Miller, D., 1919. N.Z. Journ. Agric., 19: 203.
—— 1930. N.Z. Journ. Sci. Tech., 11: 282.
Smith, F., 1876. Trans. Ent. Soc. Lond., 1876: 478.
—— 1878. Trans. Ent. Soc. Lond., 1878: 3.
Townes, H. K., 1938. Lloydia, 1: 168–231.
—— 1944. Mem. Amer. Entom. Soc., no. 11, Pl. 1, 129–142.
Vance, A. M., 1927. Ann, Ent, Soc. Amer., 20: 405–417.
The Geology of Whangarei Heads, Northland
[Read before the Auckland Institute, May 10, 1950; received by Editor. July 10, 1950]
General Description of Area
Outline of Stratigraphy
Ancient Buried Pre-Waipapa Basement
Earlier Tertiary Extrusions
Dacites of Parahaki Series
Wairakau Andesite Series
Magmatic History and Relationships
Clastic Dykes in Onerahi Limestones
Recent Coastal Uplift
The following paper deals with an area previously described as part of the Whangarei-Bay of Islands Subdivision by the late Dr. H. T. Ferrar (1925) of the New Zealand Geological Survey, but adds information not available in the Survey Bulletin and deals with certain problems not there discussed. The writer wishes to acknowledge the hospitality extended to him whilst in the field by Mr. and Mrs. N. Baker, of “Manaia Gardens.”
The area studied comprises part of the peninsula on the south-east coast of Whangarei Harbour; its northern limit is a line which runs north-east from a little north of Parua Bay to Taihururu Inlet, while to the south and east it is bounded by the open sea.
The area may conveniently be divided for purposes of description into two subequal portions, one north and the other south of an east-west fault along the northern shore of McLeods Bay, each with relatively distinctive geomorphic and geological characters. The northern half is essentially greywacke (? Trias-Jura) terrain with subdued topography seldom over 150 feet in elevation. The southern half is downthrown relatively to the other and is characterised by widespread steeply rising volcanic masses which reach an elevation of as much as 1610 feet (in Bream Head) and commonly are fringed by lowlands of soft Upper Cretaceous or Early Tertiary sediments. Andesitic agglomerates or breccias are prominent in these volcanic masses and have been eroded into bizarre bluffs and pinnacles which make elevations such as Mount Manaia individually recognizable from very far afield.
The shore lines of the area present highly contrasting elements; that which margins Whangarei Harbour shows all the characters
of fairly recent submergence followed by considerable infilling of embayments, amongst which Parua Bay is remarkable on account of the abnormal constriction of its entrance (Fig. 4). South of Urquharts Bay, near the entrance to Whangarei Harbour, bold bluffs fringe the shore and continue east for nearly four miles facing the open sea, unbroken but for two small, shallowly re-entrant bays, Smugglers Bay and Peach Cove, and at many places hundreds of feet high. At Bream Head they turn north-west for a little over one mile, to be replaced by the long sandspit of Ocean Beach, which continues north west for a little over four miles to where the slopes of Kauri Mount initiate a further stretch of steep sea-cliffs. Behind this sandspit there is a belt of sand-dunes about half a mile in maximum width and then a zone of variable width which earlier was swamp or lagoon, but now is largely drained and laid down in pasture. The intricate ramifications of the inland margin of this zone of “swamp” represent the initial shoreline of the sub-recent emergence.
Metalled roads of variable quality give access to the bases of most of the higher elevations. The various volcanic masses in particular are often crowned by scrub or native forest, this latter particularly extensive on Manaia and Bream Head Ranges.
The earlier work on the district, in particular from the time of Cox (1877) onwards to his own time, is dealt with by Ferrar (1925). Bartrum (1925, 1935, 1936, 1937, 1948) has subsequently written about various topics mentioned later in this paper.
Outline of Stratigraphy
The basement rocks are greatly disordered greywackes, with minor argillites, which have been referred by Ferrar (1925) to the Waipapa Series, established by Bell and Clarke (1909) at Whangaroa further north, and may tentatively be included in the Hokonui (Trias-Jura) System. Waipapa sedimentation was ended by vigorous folding and uplift in the early Cretaceous, which were followed by the extensive erosion that is well known to have reduced most of New Zealand to a mature land, if not a peneplain. Widely throughout North Auckland there was submergence after these events and, in our local area, blackish shales and concretionary greenish sandstones of the Upper Cretaceous Otamatea Series of Ferrar (1934) were deposited. Evidence is not conclusive, but it is reasonably certain that, near Whangarei, uplift quickly ended this period of sedimentation, for the next beds in succession are those of the Onerahi Series of Ferrar (1920), which include amongst less calcareous phases the well-known globigerinid “hydraulic” limestone of which upper horizons at least are Middle Bortonian (Middle Eocene) on foraminiferal evidence (Finlay and Marwick, 1947).
Ferrar (1925) has shown that Onerahi sediments were acutely folded and eroded before the next series of marine sediments was laid down, namely the Whangarei Series with varied sandstones and a strong limestone which usually is markedly echinodermal. This limestone has been accepted on foraminiferal evidence as Waitakian (Mid-Oligocene), but Mr. J. Healy, of the New Zealand Geological Survey, has kindly given information, not yet in print, that at Whangarei he has found beds beneath the limestone which are Whaingaroan (Lower Oligocene) or possibly even earlier.
No marine sediments, other than those of sub-Recent or Recent age, of later date than the Whangarei beds are yet known in the Whangarei Heads area.
This history of the main vulcanicity can be briefly given: small extrusions of limburgite separate the basement greywacke from the conglomeratic basal phase of the Whangarei limestone on the north shore of McLeods Bay and there are in addition extensive dacites (plagioclase-rich “rhyolites”) which also may be pre-Whangarei, though the evidence is not conclusive. Various dykes with the compositions of quartz andesites on the north shore of McLeods Bay are almost certainly pre-Whangarei, for they have not been seen to pass up into Whangarei beds in the adjacent sea-cliffs. The main mass of andesites presents no evidence suggestive of its age, though on lithology it has long been correlated with the andesitic fragmentals of Waitakere Hills, west of Auckland City, now known to be Altonian (Lower Miocene). Reasons are given later for doubting this correlation. A fairly large mass of granodiorite-porphyry at Big Point on the southern shores of Bream Head Range intrudes Onerahi beds and has been classed as pre-Whangarei by Bartrum (1925); and by Ferrar (1925), who regarded it as the intrusive equivalent of the dacites. Recent discoveries by the writer have shown, however, that near Peach Cove, east of Big Point, identical granodiorite-porphyry intrudes the fragmental andesites of Bream Head Range. In addition, the relations between dykes of highly acidic quartz andesites and normal andesites near the south end of Ocean Beach seem most reasonably to be interpreted as indicating that the acidic rocks pierce the others.
It is clear from these facts that the order of succession from acidic to basic of Whangarei igneous rocks given by Bartrum (1925) was not as uninterrupted as he had concluded from the evidence then available to him.
The various formations, series or beds* of the writer's area are described in the following order:
Ancient buried pre-Waipapa Basement.
Waipapa Series (? Trias-Jura).
Otamatea Series (Upper Cretaceous; Senonian).
Onerahi Series (Mid-Eocene; Mid-Bortonian).
Whangarei Series (Lower to Mid-Oligocene; ? Whaingaroan-Waitakian).
? Pliocene Conglomerates.
1. Ancient buried pre-Waipapa Basement
Bartrum (1937) has described different fairly high grade metamorphic rocks and associated plutonic igneous rocks which are ubiquitous as xenoliths in many of the andesitic dykes of Whangarei Heads and occur in especial abundance in garnetiferous intrusions on the north shore of McLeods Bay. He has recorded similar schists from
[Footnote] * No attempt has been made to distinguish between these terms in this paper.
Middle Jurassic conglomerates at Kawhia (Bartrum, 1935) and from xenoliths in serpentinites near Silverdale and Wellsford, north of Auckland (Bartrum, 1948).
The schists from “Whangarei Heads agree in grade of metamorphism, according to Bartrum, with the higher grade schists of southernmost Westland and Fiordland, so that they may be regarded as coming from an early Palaeozoic mass of considerable extent.
2. Waipapa Series (? Trias-Jura)
As mentioned in an earlier section, these rocks may well be included provisionally in the Trias-Jura Hokonui System, which is so widespread farther south throughout New Zealand.
The typical local rock is a quartzo-feldspathic fine-grained greywacke with small included pellets of very fine-grained andesitic lava and crystals of more or less wholly chloritized ferromagnesian minerals. Professor Bartrum informed the writer that this phase of greywacke is that almost ubiquitous in his experience of Auckland and North Auckland. As mentioned by Ferrar (1925), small masses of manganese ore occasionally rest in pockets on the surface of the greywacke and were mined many years ago at Parua Bay.
On the north shore of McLeods Bay, the greywacke includes, in addition to the general characteristic stringers of quartz or rarer calcite, local enrichments in or veins of epidote and irregular lenses up to five inches deep of spherulitic red jasperoid quartz. In the same locality it also shows phases which, in thin-section, are seen to consist largely of chlorite, with grains of quartz and a little epidote, and appear to represent earlier, fairly basic, igneous tuff. Veins of epidote may reach as much as an inch across in some of these “greywackes” and are themselves transected by stringers of quartz. The host rock consists essentially of quartz and chlorite with very little epidote; in the veins this last mineral fills the median portions of the fissures with quartz on the margins, but in narrow veinlets these relative positions are reversed. The facts indicate that the beds suffered early fracturing which permitted, at all events at deeper levels, the formation of veins of epidote, probably largely at the expense of earlier plagioclase. Subsequently, there was again the formation of fissures which were infilled in the main by quartz.
Towards the eastern end of this same north shore of McLeods Bay, the greywacke includes a dislocated and much shattered dyke of dolerite, about ten feet in width, which so greatly exceeds any other igneous rock of the area—even including pre-Whangarei limburgite—in the degree of alteration of its minerals that it is thought likely substantially to pre-date other local igneous rocks. Bartrum (Ferrar, 1925) has recorded finding serpentine near the same locality when with the Geological Survey, but has informed the writer that he has been unable to re-locate it during many subsequent visits. Presumably, therefore, it has long been buried by the advance of bay-head filling.
3. Otamatea Series (Upper Cretaceous; Senonian)
In 1925 Ferrar did not separate from his comprehensive Onerahi Series, beds which later he placed in his Otamatea Series. This series included the Batley Beds in which Marshall (1926) found abundant ammonites, enabling him to fix the age as Senonian. Indeed, at
Urquharts Bay, Ferrar (1925) has mapped as Whangarei beds, sandstones from which Professor Bartrum* has since obtained fairly large fragments of Inoceramus. The present writer has not found this shell, but he has found other macro-shells in the same beds; these include Ostrea sp., Nuculana (Saccella) sp., and two indeterminate genera of gastropods.
Lithology is often a dangerous basis for correlation, but in failure, so far, of evidence from palaeontology except that just mentioned, it has been resorted to with confidence when there has been the association of blackish shaly mudstone with greensandstones characterised by major concretions, for this association is almost invariable in Otamatea beds from Orewa, about fifteen miles north of Auckland City, to Hokianga in the far north. (See, for example, Ferrar, 1934.)
As Ferrar (1925) did not recognize Otamatea beds at Whangarei Heads, and as many of the occurrences are so limited that they cannot readily be shown on a small-scale map, it has been considered advisable to list them approximately in order from north to south as follows:
At the most easterly part of the southern shore of Parua Bay.
In the water-table of the road to Whangarei about ½ mile from where it leaves McLeods Bay.
Greensandstones occasionally may be seen, swept free of shore debris, immediately north of the outcrop of Whangarei beds near the mid-east shore of McLeods Bay. They have shed a few concretions up to about 5 ft. in diameter.
Crushed black “shales” at Whangarei Heads wharf on the typical mudstones occur along with limestone of the Onerahi Series between the granodiorite-porphyry intrusion and the andesitie fragmentals of Bream Head Range, south shores of McLeods Bay.
Crushed black mudstone alongside the main road immediately north of High Is., Taurikura Bay. Greensandstones, though not exposed, are evidently present, for large characteristic concretions lie at the shore below.
Blackish mudstones in the shore-platform and at the roadside near “the natural jetty,” Taurikura, and south-east of there in McKenzies Bay.
A very small occurrence of mudstones on the southern fringe of the dacite between McKenzies and Urquharts Bays.
On the south shores of Urquharts Bay and thence towards the saddle leading to Smugglers Bay.
At Big Point on the southern shores of the area, where the
As blackish mudstones associated with a series of andesitic dykes a little north of the southern end of Ocean Beach.
As compact, very fine-textured conglomerate traversed by andesitic dykes about ¾ mile north-west of No. 10.
Highly glauconitic greensands in a small quarry at the end of the road about 1 ½ miles north-west of No. 11 probably belong to this series.
In addition to the occurrences of what are confidently regarded as Otamatea beds listed above, there are numerous places, especially
[Footnote] * Private communication.
along the north shore of Taurikura Bay, where black shales appear, intermixed often with material resembling the Onerahi limestone, as the crushed borders of intrusions.
At the Parua Bay occurrence (No. 1) black mudstones are associated with greensandstones from which concretions up to 6 ft. in diameter have been eroded, while not far distant is limestone of Onerahi type which is shortly overlain by “crystalline” limestone referable on lithology to the Whangarei Series.
The best section of Otamatea beds is that on the south shore of Urquharts Bay (No. 8) where steeply dipping greensandstones containing concretions which may reach 6 ft. in diameter appear to be folded in an anticline. Black mudstones appear on the slopes of the saddle leading to Smugglers Bay, though Onerahi limestone outcrops near the saddle itself. An approximate estimate shows that the Otamatea beds at this locality are not less than 220 ft. thick.
Concretions in Rocks of Otamatea Series
Highly characteristic, round concretions occur in greensandstones and range up to 8 ft. in diameter (Fig. 7). They largely consist of grains of quartz cemented by calcite and silica. Some show a central nucleus 8 in. or so across, while calcite-filled radial septarian cracks are not infrequent, the calcite sometimes in perfect rhombohedra. Occasionally imperfect cone-in-cone structure occurs in irregular bands within a concretion. Small concretions of barite found loose on shores may be shed from the Otamatea beds and not infrequently show cone-in-cone which sometimes simulates rosettes.
At McGregors Bay, Taurikura (opposite High Is.) and near Whangarei Heads wharf (east of Darch Point) there are a few irregular carbonate concretions, not over 4 ft. in maximum dimension, with solution-pitted, reddish-yellow surfaces.
Mr. R. N. Seelye, Chemistry Department, Auckland University College, very kindly carried out a partial chemical analysis of a sample from one of the concretions at Taurikura with the following results:
|A22O3 + Fe2O3||5·06|
|Residue insol. in H.C.2||4·62|
Abundant CO2 was given off during digestion in acid.
A thin section of the material shows that the various bases are combined to give the one mineral, which constitutes a fine-grained holocrystalline rock.
Relation of Otamatea Series to other Series
Although no contact with the Waipapa greywacke is visible in the Whangarei Heads area, the Otamatea beds followed the epi-Hokonuian orogeny and subsequent peneplanation in the earlier Cretaceous and thus rest highly unconformably upon the older rocks.
Ferrar (1934) in the Rodney-Dargaville Subdivision and Turner and Bartrum (1928) in the Takapuna-Silverdale area, found little evidence of physical unconformity between the Otamatea and succeeding Onerahi Series. Harrington (MS.) also failed to distinguish a break between beds equivalent in age to those of the Otamatea Series
and those of Onerahi facies in the South Hokianga district. Yet Finlay and Marwick (1947) have referred the “hydraulic limestone,” more particularly as developed in the Kaipara region, to the Mid-Bortonian stage (Mid-Eocene), so that, unless there are hydraulic limestones developed at two different horizons. Onerahi beds must be unconformable to the Otamatea ones.
Suggestion of such unconformity is, indeed, presented in the writer's area at a small headland ¾ mile north of the southern end of Ocean Beach, for a matrix of argillaceous limestone indistinguishable from that typical of the Onerahi beds includes well-rounded but unsorted pebbles and boulders up to 2 ft. 6 in. in diameter of a sandstone indistinguishable from the concretionary greensandstones of Otamatea Series. (Fig. 8.)
4. Onerahi Series (? Mid-Bortonian–Mid-Eocene)
The beds referred to this series by the present writer are mainly an argillaceous limestone (the “hydraulic limestone” of local usage) and occasional siliceous or argillaceous phases associated with the more calcareous rock. A greensand exposed in a small quarry at the end of Robinsons Road, which runs from Taurikura towards Ocean Beach, may also belong to this series instead of to the Otamatea Series to which it has provisionally been referred above.
The inclusion of these beds with the Onerahi beds of Ferrar (1934) is based purely on lithology; as already mentioned, Finlay and Marwick (1947) have placed them in the Mid-Bortonian, but this correlation is doubtful in view of recent discoveries of the Geological Survey.*
Though invariably greatly disordered by acute compressive forces, the Onerahi beds fail to show any decipherable structure in the writer's area, for bedding lamination is not present.
A little north of Calliope wharf, near Urquharts Bay, and, to a less extent a few chains south of the outcrop of Whangarei beds towards the middle of McLeods Bay, the Onerahi beds include interesting sedimentary dykes which are dealt with in detail in a later section.
5. Whangarei Series. (Lower to Mid-Oligocene. ? Whaingaroan to Waitakian)
This series includes basal conglomerates, which generally are fine in texture, argillaceous or glauconitic sandstones and limestone of varied purity which is crystalline in appearance owing to the abundance of broken echinodermal remains that it contains. The beds outcrop at Whangarei Heads wharf at the south shore of McLeods Bay, near Darch Point south-west of this, at the middle and northern shores of McLeods Bay (Fig. 10) and at various localities on the shores of Parua Bay. In contrast with the preceding Onerahi beds, they are relatively little disturbed except by faults.
Ferrar (1925; 1934) has shown that folding and erosion followed the deposition of the beds of Onerahi Series, so that Whangarei strata rest unconformably either on these latter or on the Trias-Jura greywacke basement.
[Footnote] * Personal communication from Mr. B. F. Hay.
Towards the east end of the southern shore of Parua Bay, Otamatea beds are followed first by those of Onerahi Series and these latter by 8 feet of coarse basal conglomerate of Whangarei Series with greywacke pebbles between 1 in. and 2 in. in diameter set in a plentiful matrix of echinodermal limestone. This is followed upward by grey sandstone which dips at 20° to the south-west and, in thin section, shows, in addition to grains of quartz, a little glauconite and abundant broken tests of Foraminifera. About 100 yards to the west of this section, the series abuts on greywacke and shows a sinuous strike with a dip of 70° to a little east of north. In conjunction with the steep rise of the greywacke in adjacent sea-cliffs and hill slopes to a height of over 300 ft., this disposition of the Tertiary beds strongly suggests that the beds are involved in a fault which strikes approximately parallel to the contact between the two series.
Near Whangarei Heads wharf, the Whangarei beds rest on black shales which appear to belong to Otamatea Series, but on their eastern margin they are succeeded by “hydraulic” limestone of Onerahi Series. They comprise about 150 ft. of beds which are undisturbed but for minor folding and associated faulting and consist of sandstones which become increasingly calcareous from the base up until they include a fairly pure flaggy limestone. In thin section this latter shows a varied assortment of Foraminifera, broken echinodermal remains, Polyzoa and occasional fragments of corals, calcareous algae and lamellibranch shells, along with grains of quartz and a little glauconite. Occasional thin layers are greatly enriched in a species of Amphistegina.
In their exposure near the mid-east shore of McLeods Bay the Whangarei beds show an alternation of sandstone layers in a sea-cliff about 18 ft. in height; some of the bands are fairly richly calcareous and they show in thin section numerous broken tests of Foraminifera. The writer failed to find, however, any horizon that afforded a micro-fauna that was of any use for determining the age of the beds; occasional broken macrofossils were found, especially in conglomeratic calcareous phases on the north shore of McLeods Bay, where the beds have been downthrown to the south along an east-west fault. At this last locality the basal Whangarei beds overlie a flow of limburgite and include boulders as much as 2ft. 6 in. across of this latter rock.
6. ? Pliocene Conglomerates
Ferrar (1925) has recorded stream gravels in a terrace 40 ft. above sea-level at the eastern base of Mt. Manaia and has suggested that they may be Pliocene. They contain no internal evidence of age, so that they may well be of the age to which Ferrar has assigned them.
7. Pleistocene Beds
Amongst the beds included here are early stream fans which flank the steep slopes of Mt. Manaia Range at the southern part of the eastern shore of McLeods Bay. They have been cut back into low terraces by wave action in the past, but shallowing of embayments of the initial shore-line of submergence has led to reversal of type of wave activity and there has been recent substantial progradation in front of the terraces.
Amongst other Pleistocene deposits there are elevated beaches which will be described later, and somewhat consolidated dune sands which appear from beneath modern dune sands at Smugglers Bay and Ocean Beach, often showing an earlier soil with plant roots around which concretions of impure limonite may occur. These consolidated dune sands appear here and there over a very extensive area at Ocean Beach and, particularly towards the southern end of this latter, are locally surfaced by very numerous pebbles averaging about 1 ½ in. in diameter and often carved into ventifacts. These stones cover areas several acres in extent at heights reaching over 60 ft. above sea-level and include representatives of almost every local type of rock. They contrast in size and lack of sign of having been heated by fire with the firestones common around Maori middens of the locality and are believed by Professor Bartrum* to represent stones originally cast up on the adjacent sand beach by waves and gradually blown up the slopes of modern sand-hills by the winds of powerful gales. Subsequent deflation has removed the loose sand from them and caused them to be aggregated on the surface of older consolidated sands which have resisted deflation.* It may be mentioned that some countenance is given to Professor Bartrum's views by the presence of sporadic well-rounded pebbles up to 2 in. in diameter, without any indication of sorting, in early partly-consolidated dune sands at Smugglers Bay. These sands show characteristic large-scale cross-bedding and in thin section are seen to be well-rounded. About 80 per cent. of the grains are of plagioclase along with augite, hornblende, magnetite, a little quartz and tiny pellets of fine-grained andesite.
Such consolidation as is shown by the sands of these Pleistocene dunes is generally due to the oxidation of grains of magnetite.
It is obvious that some changes of conditions must have occurred to permit first of all the fixation of these early dunes and development upon them of a substantial soil horizon, and then later their covering by readvance of sand in recent times. The cause of the early cessation of supply of sand may well have been slight submergence, which perhaps completed the movement of depression that gave rise to the embayed shore-lines of North Auckland. Sub-Recent elevation up to a maximum of 15 ft. is shown freely around the local area by uplifted beaches; this may have inaugurated the phase of sand-dune formation that is now more or less in progress.
8. Recent Deposits
Recent deposits include narrow beaches and other bay-head fillings in suitably sheltered bays and the modern dune sands of Smugglers Bay and Ocean Beach.
Some comparison was made by the writer between the modern beach sands of these localities and the sands of the modern dunes. The grains of the beach sands are often well rounded, though not to so high a degree as those of the dunes. Mechanical analyses showed, as was to be expected, that the sands from the western portions of the dunes at Ocean Beach contain a much higher proportion of smaller grains than the beach sands. Near an outcrop of Onerahi limestone the dune sands contain grains of this limestone to the extent of as much as
[Footnote] * Personal communication.
8·6 per cent. by weight. This has led to cementing and partial local fixation of such dunes. Elsewhere, where temporary pools of water have collected in hollows after rain, sheets of moderately coherent sandstone have formed, either as a result of cementing by the calcium carbonate of included shell fragments (which, however, were not observed), or, more likely, by the settling of colloidal and other particles of dust which would have adhesive properties
Apart from igneous rocks already described by Bartrum (1937) as represented along with varied metamorphic types amongst xenoliths that occur widely in andesitic intrusions, the igneous rocks of the Whangarei Heads area fall into the following groups:
Pre-Onerahi intrusions in the Waipapa greywacke series.
Early Tertiary (pre-Whangarei) limburgitic extrusions.
Dacites of Parahaki Series (Ferrar, 1925).
Wairakau Series (Ferrar, 1925) of varied andesitic intrusions, agglomerates and minor flows.
Granodiorite-porphyry of Big Point and Peach Cove on the southern shore of Bream Head Range.
The present writer made thin-sections of practically all of the different igneous rocks that he encountered, but found in most cases little if anything to add to the descriptions given already by Bartrum (Ferrar, 1925).
1. Pre-Onerahi Intrusions in the Waipapa Greywacke Series
When at work for the Geological Survey, Bartrum (see Ferrar, 1925) collected a specimen of dunite-serpentine from the east end of the north shore of McLeods Bay. He has informed the writer that he has not been able to re-locate it in the course of at least twenty subsequent visits. The writer made diligent but unsuccesful search, and it is to be presumed that the outcrop found early by Bartrum has subsequently been covered by beach debris.
Not far distant to the west of the locality mentioned, there are two greatly shattered outcrops of what appear to be dissevered portions of one and the same 10 ft. dyke of dolerite intrusive into greywackes. It has shared in the folding of these latter rocks and, therefore, precedes the epi-Hokonuian (Earlier Cretaceous) orogeny.
2. Earlier Tertiary (pre-Whangarei) Limburgitic Extrusions
As mentioned on an earlier page, a flow of limburgite underlies the basal conglomerate of the Whangarei Series at several points on the north shore of McLeods Bay. Its depth is unknown, for it is found only as boulders up to 3 ft. in diameter uncovered on the shore platform by the erosion of the overlying sediments. Identical rock also occurs as boulders in a cut of the Parua Bay-Pataua Road about ½ mile south-west of Pukenamu. Hutton (1943) stated that this latter rock is identical with a limburgite at Kawarau Gorge, Central Otago. Apart from lacking phenocrystic augite, it is precisely the same as the rock from McLeods Bay. This latter has numerous phenocrysts of augite and of olivine almost wholly replaced by yellowish-green serpentine and carbonate in a fine-grained matrix which consists essentially of augite and iron ore, with minor plagioclase
and rare brownish hornblende, enwrapped by a small amount of colourless isotropic residuum which, judging by the norm from analysis, appears to be analcite. Bartrum (Ferrar, 1925) overestimated the proportion of plagioclase in this rock, for he classed it as a basalt, though recognizing its equivalent near Pukenamu as a limburgite.
Mr. M. Ongley, Director of the New Zealand Geological Survey, very courteously arranged for analyses of both rocks at the Dominion Laboratory. These were carried out by Mr. F. T. Seelye, who kindly also worked out norms and classification according to the C.I.P.W. system. They are appended below along with others for comparison.
Limburgite (N.1382), north shore of McLeods Bay, Whangarei Heads. IV.”2.2(3).2.2—Montrealose. Analyst: F. T. Seelye.
Limburgite (N.1383), ½ mile S.W. of Pukenamu, Whangarei Heads. IV.”2.2(3).2.2—Montrealose. Analyst: F. T. Seelye.
Limburgite, Riquewihr, Vosges. (Friedlander and Niggli, 1931, p. 399.)
Limburgite (Rosenbusch). (Daly, 1933, p. 21.)
3. Dacites of Parahaki Series (Ferrar, 1925)
These rocks have fairly extensive outcrop on the eastern shore of McLeods Bay, whence they extend inland at least as far as the nearby
road. They next occur farther south between McKenzies and Urquharts Bay and then again on much of the ridge that runs north from Busby Point and east of there on the western and southern flanks of Busby Head. There is also a further occurrence of unknown extent on the south-east flank of Mount Stewart.
These dacites are acidic rocks and range in silica from 70·89% to 67·98%, in potash from 4·26% to 2·19%, and in soda, conversely to the potash, from 2·62% to 4·31% (Ferrar, 1925). The proportion of plagioclase to potassic feldspar increases with the percentage of soda. Bartrum (Ferrar, 1925) has adequately described the petrography of the rocks and has mentioned the remarkable fluxional banding shown by those at McLeods Bay. The only information that the writer would add is that the dacite of the wave-cut shore platforms at Smugglers Bay contain not infrequent xenoliths of an earlier more acidic dacite.
The dacites at McLeods Bay have weathered very deeply to a clay which is being used extensively in Auckland in the ceramic industry. Usually this clay is white, but locally it shows vivid pink tints. The ferromagnesian mineral of the parent rock is biotite, which has become bleached during late stages of weathering to a pearly product which closely resembles white mica and in thin section is seen often to be closely crowded by sagenitic clusters of needles of rutile. Yellowish grey to greenish nodules of a clay mineral which closely resembles halloysite in macroscopic properties are abundant in the clay. Mr. I. McDowall, of the New Zealand Pottery and Ceramic Research Association, Wellington, has made full investigation of this clay and very kindly furnished the writer with his unpublished results. The analyses that he forwarded are interesting in that they show that the final product of weathering contains decidedly more silica and less alumina than are present in the intermediate product in which “mica” persists. The alumina has perhaps been carried away in colloidal form by downward percolating waters.
Ferrar (1925) regarded the dacites of Whangarei-Bay of Islands Subdivision as Eocene, but later, in dealing with the Dargaville-Rodney Subdivision, he stated (Ferrar, 1935) that this is incorrect and that they probably are Pliocene, for he found (Ferrar, loc. cit., p. 58) that near Waipu they have been extruded by way of a fault plane which he believed was formed during the Pliocene Kaikoura orogeny.
Doubtless, certain of the North Auckland dacites may well be Pliocene, but others definitely are Lower Miocene or earlier, for they occur plentifully in Altonian (Lower Miocene) conglomerates near Auckland.*
In a discussion later in this paper on clastic dykes (p. 26) it is shown that there is strong suggestion that certain, if not all, of the dacites at Whangarei Heads are post-Onerahi and pre-Whangarei. If this is correct, they were extruded between the Middle Eocene and the Lower Oligocene.
[Footnote] * Professor Bartrum informed the writer that rocks from these Albany Conglomerates which were described by him as rhyolites almost certainly are dacites.
4. Wairakau Series (Ferrar, 1925) of Andesitic Intrusions, Agglomerates and Minor Flows
Analyses published by Bartrum (1925) and his descriptions in the Geological Survey Bulletin (Ferrar, 1925) have shown that the rocks included here range from varied, relatively acidic, quartz andesites to normal types. Small intrusions abound, radiating irregularly from the many centres of andesitic eruption and normally of rock indistinguishable from extrusive phases. In addition, there are coarsely porphyritic intrusive types which are best described as porphyrites. They are usually present in bodies of considerably greater size than those of normal andesitic appearance. The considerable mass of Mount Stewart consists of such porphyrite and it is very doubtful if it is truly an intrusion; it is not unlikely to be the core, uncovered by erosion, of an early large tholoid.
The porphyrites and the quartz andesites universally have characters that distinguish them, apart from texture, from the normal andesites, for they invariably contain garnet and also numerous xenoliths of the igneous and metamorphic rocks that have been described by Bartrum (1937). The quartz andesites in addition are usually characterised by biotite, which does not appear in the normal andesites. It appears from these facts that the latter must originate from different magmatic sources from the others; it is difficult to understand why almost without exception they lack the xenoliths which are so prominent in members of the other group, for obviously the magma that gave rise to them must have arisen through the same basement rocks as the others. It possibly is the case that, as the normal andesites are associated with eruptive centres of considerable size, the uprising magma had sufficient volume and heat to assimilate any fragments broken from basement rocks through which it passed.
The normal andesites form agglomerates varied by occasional flows in the elongated Manaia Range, in Mount Aubrey southwest of Mount Manaia, in Bream Head Range and in Lions Head on the southwest margin of Urquharts Bay. In Manaia Range the agglomerates show good bedding with an easterly dip of about 25°; this appears to indicate that the fissure from which issued the eruptions that built the range was located west of the present crest of this latter, and that the western half of the original volcanic edifice has been removed by erosion, the debris being deposited in an early substantial valley which is now represented by McLeods Bay. Such erosion would be facilitated owing to the fact that soft Onerahi sediments, which rise to over 200 feet above modern sea-level, outcrop almost to the base of the precipitous western slopes of the range.
Near where the road to Parua Bay from Whangarei Heads turns east away from the shore of McLeods Bay, there is a conical mound of andesitic lava isolated amid sediments which appear to be mainly those of the Onerahi Series. Its time-relation to the eruptions that built the nearby Manaia Range is obscure, for its rock is petrographically distinct from that of the range.
A distinctive feature of the various accumulations of andesitic agglomerate is the manner in which they frequently are cut by wide-spaced prominent joints which in turn have controlled the topographic
expression of the agglomerate masses, so that bizarre pinnacles such as those of Mount Manaia are common.
Towards the eastern extremity of Bream Head Range a number of vertical holes 2 ft. to 3 ft. across at the surface, but widening downwards, and of unknown but very considerable depth, occur in andesitic agglomerate in a narrow belt about 100 yards in length. About six of these holes were seen by the writer, but a number of others had been closed by Mr. Crook, the owner of the property on which the holes occur. They are at a height of several hundred feet above sea-level but are not far distant from the shore-line and appear to be due to collapse at points of intersection of major joints along which waves have excavated tunnels at sea-level. Unfortunately, the precipitous coast at this locality is practically inaccessible, so that the writer was unable to see if such tunnels exist.
Amongst the numerous dykes of normal andesite in the Whangarei Heads area there are one or two that deserve special mention. One that arouses a good deal of popular interest is the “natural jetty” at the shore at Taurikura (Fig. 12). This is a vertical dyke about 6 feet in width and jointed in horizontal columns about 9 inches across. It has been intruded into blackish-grey mudstone of the Otamatea Series and now forms a miniature hogback which runs out like a jetty for perhaps three chains into the sea at high tide with its sides plastered by a thin selvedge of “baked” mudstone adhering to the igneous rock.
Another intrusion with interesting features is one about 60 feet in width which is intruded into blackish-grey Otamatea mudstone and forms a small rocky headland near the south end of Ocean Beach. An early dyke of andesite has been intruded into the mudstones, baking them and attaching them to its sides. Subsequently the fissure has been reopened and a second intrusion of andesite practically identical with that of the first has arisen, finding its way between the earlier dyke and the invaded mudstone. The skin of baked mudstone has, on the whole, adhered to the wall of the earlier dye and the result is that a relatively straight vein of black argillite can be traced more or less continuously in the igneous rock for over 100 yards, averaging perhaps 4 in. in width, but sometimes thinning to a mere film and at others thickening considerably and sending out narrow tongues for several inches into what is taken to be the earlier intrusion (Fig. 11). In one wave-eroded chasm a considerable wedge of argillite, 3 feet or more across at the base, penetrates the invading andesite.
The metamorphic effects of the various intrusions upon invaded sediments seldom exceed induration, while adjacent to the walls of the dykes the sediments very commonly show shearing and brecciation which have intermixed varied facies of sediment. It is clear that the exposures in the main are superficial portions of the dykes. On the north-west slope of Busby Head, which is a western part of Bream Head Range, however, Bartrum (Ferrar, 1925) found that Onerahi limestone in contact with andesite had been sufficiently metamorphosed to contain numerous very minute garnets. Also, on the western slopes of Mount Stewart, adjacent to the road between Taurikura and McKenzies Bay, “baked” limestone of the Onerahi Series exhibits prominent spherulites a little over ⅛ in. across and includes rare
crystals of sphalerite.* Similar but smaller spherulites appear occasionally in the same type of rock a little west of Whangarei Heads wharf in McLeods Bay.
Age of Wairakau Series
The age of the Wairakau andesites is uncertain and, further, it is probable, from considerations of magmatic history, as already stated, that the quartz andesites and porphyrites have a magmatic source distinct from that of the normal andesites and need not, therefore, have been contemporaneous with these latter.
All these intermediate intrusions penetrate both Otamatea and Onerahi beds. The normal andesites have not been found locally in association with Whangarei strata, so that their relation to these latter is not shown. They have long been correlated on lithology with the Manukau Breccia Series of Waitakere Hills, Auckland, which are now found by Dr. H. J. Finlay† on foraminiferal evidence to belong to the Altonian (Lower Miocene) stage.
For certain of the quartz andesites the position, however, is different, for on the northern shores of McLeods Bay several very large intrusions of these rocks, intersecting greywacke on the shore, almost certainly fail to pass up into Whangarei beds which rise for 80 feet or more above the greywacke. Talus has obscured actual contacts, but it is reasonably certain that, had the dykes invaded the Whangarei strata, their passage would have been indicated by blocks of their rock in talus and other signs. Such indications, however, are absent, so that early members of these quartz andesites almost positively are pre-Whangarei. Yet other highly acidic quartz andesites have relations to the normal andesites of a small headland near the south end of Ocean Beach which are best interpreted as indicating that a series of these light-coloured acidic dvkes there penetrates the normal andesites.
If these latter are correctly assigned to the Altonian, it is clear that intrusions of quartz andesites have occurred over a very long period of time, namely from a time in advance of local Whangarei sedimentation, which at latest is Waitakian (Mid-Oligocene), to the Altonian (Lower Miocene).
An alternative to acceptance of this conclusion, and it would appear to be a preferable one, is to discard the previously accepted correlation of local fragmental andesites with the Manukau Breccia Series and instead to correlate them with similar “First Period” rocks of Coromandel Peninsula. These latter overlie sediments of the Torehine Series (? Lower Eocene) from which Dr. Brian Mason has recently collected Foraminifera regarded as Waitakian by Dr. H. J. Finlay.†.
5. Granodiorite-porphyry of Big Point and Peach Cove on the Southern Shores of Bream Head Range
A little west of Big Point there is a large intrusion of granodiorite-porphyry, shown by analysis to be the analogue of local dacites, which
[Footnote] * Personal communication from Professor Bartrum.
[Footnote] † Personal communication.
Fig. 11—Argillite “Dyke” in Anuesite, so. Photo.? Prof. J. A. Bartrum.
Fig. 12—“Natural Jetty,” Taurikura Bay—dyke of augite-andesite intrusive into Onerahi sediments. Photo.: Prof. J. A. Bartrum.
Fig. 13—Photomicrograpn of Globigerinal lime-stone (Whangarei), Whangarei Heads Wharf. Little glauconite. Ordinary light. Magnification: 55 diams. Photo.: Prof. J. A. Bartrum.
Fig. 14—Photomicrograph of Pleistocene Sandstone, Smugglers Bay, showing plagioclase (white) with ferromagnesian minerals and fragments of andesite. Ordinary light. Magnification: 38 diams. Photo.: Prof. J. A. Bartrum.
Fig. 15—Photomicrograph of limburgite from boulders near Pukenamu Hill, showing phenocrysts of serpentinized olivine set in a matrix of augite and iron-ore with minor hornblende, feldspar and glass. Ordinary light. Magnification: 55 diams. Photo.: Prof. J. A. Bartrum.
Fig. 16—Photomicrograph of granodiorite-porphyry, from near Peach Cove, showing phenocrysts of plagioclase, quartz and biotite set in a groundmass of equidimensional orthoclase, quartz and plagioclase. Ordinary light. Magnification: 38 diams. Photo.: Prof. J. A. Bartrum.
has been described by Bartrum (Ferrar, 1925). It invades and “bakes” Onerahi limestones which are excellently exposed in a neighbouring rill, but not more than 400 yards to the north-east there are blackish shales of the Otamatea Series which intervene between the mass of granodiorite-porphyry and the steep slopes of the andesitic mass of Bream Head Range. Bartrum (loc. cit.) regarded this intrusive rock as the magmatic equivalent of the dacites, which Ferrar (1925) believed on such field evidence as was then available to be earlier than the andesites of his Wairakau Series. The granodiorite-porphyry, therefore, was considered post-Onerahi and pre-Wairakau.
A recent discovery by the present writer shows, however, that this is not correct, for he found on the south-west shore of Peach Cove a flat-lying dyke of granodiorite-porphyry, identical petrographically with that at Big Point and varying in width from 8 feet to 25 feet, which clearly intrudes into andesitic fragmental rocks of the Wairakau Series. The two intrusions of this acidic rock are so close together that it is unlikely that they are other than contemporaneous, and they must be regarded as post-Wairakau in date. This being so, it is clear that the order of appearance of the igneous rocks of the Whangarei area given by Bartrum (1925) in proffering variation diagrams needs emendation in the light of present knowledge.
Magmatic History and Relationship
In describing the igneous rocks of the Whangarei-Bay of Islands Subdivision, Bartrum (Ferrar, 1925) accepted Ferrar's belief, based on the field evidence then available, that, apart from the pre-Whangarei limburgite on the north shore of McLeods Bay, the dacites were the earliest of the igneous rocks of the subdivision, classing as contemporaneous with them the granodiorite-porphyry of Big Point. Variation diagrams based on an excellent series of analyses showed that the rocks dealt with were members of a differentiation series. These were believed to maintain a regular order of decreasing acidity from the acidic dacites to sub-Recent olivine basalts, omitting from the series, however, the pre-Whangarei limburgite.
It has been shown above that this regularity of succession does not in fact exist; granodiorite-porphyry and some highly acidic quartz andesites (at Ocean Beach) alike have been found to post-date normal andesites. There thus has been alternation in time of injection or extrusion of more acidic and less acidic rocks in the early stages of the magmatic cycle of the Whangarei region; this cycle has closed with the emission of widespread basalts.
From his work on Keweenawan lavas, Broderick (1935) concluded that the presence of oxidized minerals at the upper levels of the flows indicated that volatile transfer played an important part in the differentiation of these lavas. Plotting the percentages of alkalies against the silica, he found that the curve cut across similar curves for the classical Katmai and Lassen Peak Series at the lower silica end and that only later did it turn and parallel these latter for the higher silica ranges. He believed, therefore, that the differentiation of the Keweenawan rocks was not wholly by differentiation as Bowen (1928) believes was definitely the case for the Katmai and Lasaen Peak rocks.
The present writer plotted a corresponding curve for the Whangarei Heads rocks, using the analyses published by Bartrum (1925; Ferrar, 1925) and found that it parallels those for Lassen Peak and Katmai. There is thus no need to invoke any other agency for the origin of the local rocks than crystallisation-differentiation.
The alkali-lime index of the Whangarei Heads rocks on the method of Peacock (1931) is approximately 62. This means that, at a point on the variation diagram where the silica percentage is 62, the sum of the alkalies equals the percentage of lime. In this respect also there is correspondence with the Lassen Peak series, where the alkali-lime index is similarly 62.
If the analyses of the Whangarei Heads limburgite published herein are included with those of the other rocks of the region, the curves of the various oxides in the variation diagram depart from the relatively smooth curves obtained when these analyses are omitted. This applies particularly to the curves for alumina, magnesia and ferrous oxide and results from the high proportions of augite and olivine in these limburgites. Bowen (1928) has shown that, if we assume that basalt is the parent magma, the composition of rocks such as these limburgites must be determined by that of a mesh of accumulated down-sunken crystals. In the case of the local limburgites, however, it is clear from the texture, which is characterised by an abundant fine-grained mesostasis enwrapping phenocrysts of olivine and augite, that crystal-settling had only limited importance in the genesis of the rock. A far more probable explanation is that involved in the reaction upon early separated hornblende which has sunk into a hotter liquid (Bowen, 1928, p. 270), whereby olivine and pyroxene, with perhaps some calcic plagioclase, are precipitated together with nepheline and probably leucite. The magma must then have been extruded before these reactions could be reversed.
Clastic Dykes in Onerahi Limestones
Two series of interesting clastic dykes enclosed in limestone of the Onerahi Series occur on the shore, one about 80 yards and other about 160 yards north of Calliope (Urquharts) wharf (Fig. 9). The first consists of highly angular material, averaging perhaps ¾ in. in average dimension, which is almost wholly derived from the Mesozoic greywacke series, and is present in irregular flat-lying seams not exceeding about 8 inches in depth. The other, more northerly, dykes contain in addition to the greywacke a large proportion of the limestone host in small fragments and a moderate number of fragments of dacite, some of them as much as 8 inches in average dimension and a few fairly well rounded by attrition. Dacite microscopically identical with that of these included blocks occurs in bluffs at the back of the shore, although any possible contact is obscured by debris dumped during construction of the adjoining coastal road.
At this northerly occurrence of the dykes, there is a central mass of breccia about 2 feet across and 4 feet in length, with a visible depth of 1 foot, from which two main subsidiary dykes, one 15 feet and the other 25 feet in length, come off in a meridional direction. These branch dykes vary from as little as an inch in breadth to as much as 1 foot at various parts of their length and in turn give rise to
branching and re-branching stringers. Excavations made by the writer suggest that all are practically vertical.
The rock fragments in the dykes average under 1 inch in maximum dimension and tend to have their long axes parallel to the dykes, though there is no sign of any assorting. They are tightly interlocked and cemented one to another and to their walls by calcium carbonate. There is no sign of the dykes having been affected by earth movements since they were formed.
Similar but shorter dykes also occur close to the south side of Hollingworth's boat-slip near the middle of McLeods Bay.
Origin of Constituent Materials of the Clastic Dykes
The hydraulic limestone and dacite of the dykes have their parent masses close at hand, as mentioned already, but the presence of rocks of the greywacke series cannot be so easily explained, for, although these latter rocks undoubtedly underlie the area concerned, they do not outcrop nearer than the north shore of McLeods Bay, 4 ½ miles to the north-west, where they appear in an earth-block which has been upfaulted with reference to the adjacent southern block not less than 200 feet.
It is clear from the marked angularity of the greywacke fragments in the dykes that they cannot have been transported by water from so far afield as these north-western outcrops of the parent rock. There are, however, three other possibilities:
They may have been eroded from some bed of breccia in yet undiscovered post-Waipapa rocks near at hand.
They may have come from an early outcrop of greywacke which now is hidden beneath volcanic rocks or sea-waters.
The fragments may have been brought up from the buried greywacke basement along planes of shearing and represent, therefore, components of a friction-breccia.
Before discussing these possibilities, it is necessary to decide, if possible, whether the dykes were filled by injection from below or from above. Lahee (1931) lists as evidence of infilling from below such features as upturned strata in wall-rock; upward thinning and final upward termination of the dykes; flow structure parallel to the walls in the filling; inclusion of wall-rocks in the dykes; considerable size and continuity of some of the dykes and similarity of their material to underlying rocks. Admittedly, several of these criteria apply to the dykes in question, but they could equally well support the hypothesis of filling from above.
Objections to the theory of filling by injection from below in consequence of pressure include the absence of fine-grained interstitial matrix that would appear essential for mobility of the mass, and the omission, so far as could be determined, of fragments of Otamatea beds, which are stratigraphically below those of the Onerahi Series. Yet these objections are not insuperable, for earlier finegrained matrix may have been strained off from the mesh of coarser fragments by pressure, whilst it is known that an erosional interval separated Otamatea from Onerahi sedimentation. Otamatea strata may well have been removed from the area concerned prior to the emplacement of the Onerahi beds and, therefore, of the dykes.
With so much uncertainty as to the interpretation of the facts, the writer is inclined to prefer the hypothesis that early dyke fissures were infilled from above, being led to do so because of the incorporation in the dykes of blocks of dacite, which occasionally are well rounded, for dacite overlies the limestone that is the host-rock of the bodies discussed.
If this conclusion be accepted, the source of the fragments of greywacke must be sought either in rock of this kind which outcropped at the time of formation of the dykes, though not now visible, or in a breccia of post-Waipapa age. The process of formation of the dykes conceivably could have been more or less as follows:
Onerahi limestone fissured by some means, whether by tension resulting from broad up-arching or by earthquakes or other cause, formed either the shore-platform of an area or the bed of a stream and was covered by a sheet of drift which included all the components of the dyke-filling; the fissures were filled by such drift and the constituent fragments of the filling were cemented firmly by calcium carbonate available in the limestone. Subsequently the balance of this sheet of debris was removed before the area in question was deeply buried by sheets of dacite later than the early flows of that rock that supplied the dacitic material found in the dykes.
Some support for this particular theory of origin is given by the fact that the clastic dykes nearer to Calliope (Urquharts) wharf, and those near Hollingworths at McLeods Bay, appear to be merely plastered on the Onerahi limestone and may well represent remnants of the sheet of drift invoked.
Age of Clastic Dykes
These dykes do not include fragments of Whangarei strata, so that they appear to be earlier than these latter which, on unpublished information from Dr. H. J. Finlay, contain basal members at least Whaingaroan (Lower Oligocene) in age, although the limestone, which is practically the lowest member at Whangarei Heads, is about Waitakian (Middle Oligocene). Since the dykes transect Onerahi beds which are regarded as Bortonian (Middle Eocene), their age, therefore, is between the Middle Eocene and the Lower Oligocene.
The dykes in their turn may be taken as throwing light on the question of the date of the nearby dacites, for, on the facts given above, these latter appear to be pre-Whangarei and post-Onerahi. This conclusion, however, is only tentative, for it is possible that these dacites belong to a very much later period and that any early cover of Whangarei beds in the area concerned was removed by erosion prior to the emission of the dacites and to the formation of the clastic dykes. This question is also discussed on an earlier page.
Recent Coastal Uplift*
S. Percy Smith (1881) noted the occurrence of beaches raised about 15 feet above modern sea-level at many parts of the coastline of North Auckland. In the writer's area there is only one example of fairly
[Footnote] * No attempt has been made to distinguish between eustatic and diastrophic movements,
recent uplift to a height as much as 15 feet, but there are several which show it to the extent of 4 feet or 5 feet (Fig. 6).
The 15-foot uplift is shown at Smugglers Bay on the southern shores of the area described in this paper and Professor Bartrum has pointed out to the writer that the beach concerned appears to date from an earlier period than those at lesser heights, for in the past there has been substantial recession of the low bluff of weathered dacite which underlies the beach, although to-day its base normally is protected from waves by a narrow fringe of dune sand.
It is by no means improbable, according to Professor Bartrum, that this “uplifted” beach actually represents a feature developed prior to the sub-Recent submergence that has affected North Auckland. If this be so, it probably was uplifted during a phase of fairly rapid and considerable elevation which, as Turner and Bartrum (1928) have shown, occurred near Auckland City immediately before the sub-Recent submergence to which it was sub-equal in amount. This uplift may well have extended to the Whangarei area and, if so, the “uplifted” beach now discussed may be regarded as a “palimpsest” feature which was not covered by sea waters when the submergence took place.
This beach averages about 3 feet in depth and contains rare leached shells amid well-rounded boulders averaging about 4 inches, but up to 9 inches in diameter, which are mainly of dacite, which occurs in adjacent hill-slopes and sea-cliffs, but also includes occasional granodiorite-porphyry brought by waves, as is the case also with modern beach boulders, from Big Point, 1 ½ miles to the east. No boulders of andesite were found with the others, possibly because andesites not far distant to the east are closely jointed and have been broken sufficiently small to be carried off-shore by waves. Above the boulder beach there is talus of angular blocks of dacite fallen from adjacent hill slopes, while below it there is a surprisingly plane surface, eroded in dacite and dislocated 18 inches by a small sub-vertical fault, which is seen to represent the plane of a sub-horizontal joint or shear traceable clearly in bluffs to the west.
Sub-Recent Uplift of 4 feet to 5 feet
This is demonstrated by an interesting rock-platform of the storm-wave type of Bartrum (1926; 1935), which is now undergoing reduction of its surface to bring it into conformity with modern sea-level, and by raised beaches in the following localities.
In a small cove ¼ mile west of Smugglers Bay.
A little south-east of Home Point and north of Busby Point.
About 1 mile west of McGregors (High) Is., Taurikura, in the banks of a small stream.
The storm-wave platform is a horizontal bench of dacite about 80 yards in maximum width, with its surface about 2 feet above high-water level and remarkably plane except where interrupted by gashes worn by waves along major joints. Professor Bartrum has informed the writer that, when he first saw the platform in 1919, its surface did not appear to be inundated by other than exceptional storm-waves and was surmounted by numerous honeycombed pinnacles of rock up to 3 feet in height. Many of these show in a photograph taken as
late as 1930, though all are now obliterated (see Fig. 5) and storm-waves beat freely upon most of the platform.
The first of the raised beaches in the list given above is a storm-beach of fairly recent date, for, although its surface is well grassed, there are fragments of shells preserved in its highly pervious material. This latter ranges from boulders about 8 inches across to small pebbles and extends as a strip 30 feet or less in width which hugs the adjoining hill-slopes for about 80 yards. About 4 feet below its low cliffed face there is a modern storm-beach of similar coarse material. This higher beach is not merely one built with sea-level as to-day before off-shore waters were shallowed by deposition, but is due to uplift, for the adjacent shore is an irregular hard-rock platform which passes into waters which appear to deepen rapidly, if one may judge by the growth of giant kelp.
The second on the list of uplifted beaches is very similar to the last. The third, however, has very limited exposure; above a planed surface of weathered andesite 2 feet above high-water level there is a 2 foot deposit of water-worn pebbles about 1 ½ inches across followed by finer drift and then a layer of shells of a few inches in depth immediately below a mask of soil.
Adjacent to the south-east shore of McLeod's Bay there are stream fans which have been cliffed by waves and could easily be mistaken for raised beaches. It is clear, however, from the nature of their material, which locally shows excellent large-scale lens-and-pocket bedding, that they are not such beaches. Bartrum (1948) has recently drawn attention to the fact that the pebbles and cobbles in these fans show a degree of rounding which is surprising in view of the insignificant length of the streams responsible for their deposition.
Early in this paper it was noted that the area described was roughly divisible into northern and southern halves by a fault trend ing approximately east and west which followed the northern shore of McLeods Bay and caused downthrow of the southern region relative to the northern. This fault is demonstrated by considerable crushing, even to the extent of developing friction-breccia, on the north-east shore of McLeods Bay and by downthrow of Whangarei beds to levels far below the surface of greywacke of the upthrow block on which undoubtedly they once rested. Towards its western end this fault curves from an earlier N.E.–S.W. course to turn to the west and cause the downthrow both of basement greywacke and its partial cover of Tertiary beds in the low peninsula that forms the southern head of the entrance to Parua Bay.
Another fault trends north-west from the north-east shore of McLeods Bay, intersecting that just described, to pass to Parua Bay by way of a low saddle between the volcanic mass of Trig. station M and a greywacke ridge which rises abruptly on the north-east side of the saddle to about 200 feet above this latter. There is an inlier of Onerahi limestone well exposed in the valley of a small stream at the north-west end of this fault and another small one of Onerahi or
[Footnote] * Addendum by Professor J. A. Bartrum.
Otamatea beds on the line of the fault near where it intersects the shore of McLeods Bay.
From suitable viewpoints to the south it can be seen that the surface of the greywacke, overlain by the volcanic rocks of Trig. station M, declines markedly to the north-east towards the line of the N.W.–S.E. fault described and thus indicates that the earth-block of which it is in part the surface has been down-tilted in that direction.
Taking into account the displacements suffered by greywacke surfaces, both faults described above have throws which approximate 200 feet in the vicinity of McLeods Bay, but it is likely that this figure increases very materially eastwards, in the case of the east-west fault, particularly where it separates the elevated Kauri Mt. block of grey-wacke from much younger beds to the south.
The only other fault of note for which definite evidence exists is one on the south-east shore of Parua Bay which has downthrown Whangarei and underlying Onerahi and Otamatea beds to the north. Its trend is not clearly defined and the amount of its downthrow is not determinable for the thicknesses of the downthrown sediments is not known. Trig. stations M and N are conical elevations of finegrained andesitic rocks which appear to represent lavas. If it is safe to assume that the period of andesitic eruption is not later than Altonian,* (Lower Miocene), the andesites of Trig. stations M and N throw light on the date of adjacent faulting. Whangarei beds of probable Waitakian age (Middle Oligocene—Finlay and Marwick, 1947) have been displaced by the fault and had been eroded from the greywacke basement before these andesitic masses were erupted. If these assumptions are correct, faulting must have occurred subsequent to the Middle Oligocene and before the Lower Miocene, that is in Upper Oligocene times.
If it be claimed that the faults are to be regarded as a phase of the Pliocene Kaikoura orogeny, the andesites discussed cannot be earlier than later Pliocene. This appears to be most unlikely in view of the evidence of similar rocks from Coromandel Peninsula, from the Waitakere Hills and in the Parnell Grit near Auckland, where they are known with certainty to be Altonian (Lower Miocene) in age, and from their free incorporation in other Altonian beds known as the Albany Conglomerates which occur in a fairly extensive area a little north of Auckland.
It has been mentioned on earlier pages that there is evidence of the existence beneath the Mid-Mesozoic greywackes, which are the oldest rocks actually exposed in Whangarei Heads area, of metamorphic rocks probably of early Palaeozoic age and of plutonic igneous rocks not known in situ in Northland. The deposition of the greywackes and associated argillites was terminated in the early Cretaceous by the epi-Hokonuian orogeny by which these sediments were complexly folded. After long continued erosion, which in places attained peneplanation (Cotton, 1916). our area was submerged in the Upper Cretaceous (Senonian) and received the near-shore and
[Footnote] * Ferrar (1934) suggested, though not on secure evidence, that andesites of the Dargaville-Rodney Subdivision are Pliocene.
somewhat deeper water sediments of the Otamatea Series. From as yet incomplete evidence from the Hokianga and other regions further north, it appears likely that in those northern regions deposition continued with almost negligible interruption until at least Bortonian (Middle Eocene) times, but in our area uplift and erosion appear to have separated the Otamatea and succeeding Onerahi beds of Bortonian (Mid-Eocene) age. These latter locally are mainly argillaceous globigerinid limestones deposited probably in warm sea waters of only moderate depth.* About the Upper Eocene these beds were strongly folded with the accompaniment nearer Auckland and at North Cape of injection of ultrabasic rocks now represented mainly by serpentines.
After this post-Onerahi orogeny there was substantial erosion and there then came depression of the land relative to sea-level, at first at almost inappreciable rate, so that in favourable basins or other areas freshwater coal measures accumulated such as those near Kamo and Hikurangi, a little north of Whangarei. Soon, however, the rate increased and marine transgression began in the Whaingaroan (Lower Oligocene), or possibly a little earlier, allowing the deposition of the lowest beds of Whangarei Series upon less-elevated portions of the subsiding land-mass. In our local area Upper Eocene erosion had left the surface of this land-mass constituted here and there by Otamatea or Onerahi strata and elsewhere by Mid-Mesozoic grey-wackes from which these later rocks had been stripped. There is reason to believe that at Whangarei Heads the resurrected greywacke surface, which probably constituted higher portions of the subsiding land, was not submerged until Waitakian (Mid-Oligocene) times, when conglomeratic phases of the well-known Whangarei limestone accumulated, locally covering limburgitic lavas which had been erupted in the meantime. In addition, intrusions of quartz-mica andesite and, it is believed, extrusions of dacites had begun prior to the deposition of local Whangarei sediments. Soon after this latter, major faulting appears to have taken place, at an earlier date, therefore, than that of the late Pliocene Kaikoura orogeny of Cotton (1916). This conclusion, however, hinges on the date of eruption of the considerable bodies of andesitic rock which are so prominent a local feature.
There is reason for believing that these andesites may not correlate, as has earlier been taken to be the case, with those of Altonian (Lower Miocene) date in the Waitakere Hills near Auckland, but with the earlier, “First Period” similar rocks of Coromandel Peninsula.
Subsequent to Whangarei (Mid-Oligocene) times and quite apart from the uncertainty about the time of outbreak of andesitic vulcanism, there is a long unbridged gap in the local geological record, for no marine beds of post- Whangarei date are known from Whangarei Heads. From evidence at Dairy Flat, near Auckland, however, it has recently become known that near Auckland there was a considerable time-interval after the Waitakian (Mid-Oligocene) before marine sedimentation recommenced and the Waitemata beds (Lower Miocene) of the southern region were laid down.
[Footnote] * On account of the lengthy discussion that would be required, no attempt has been made to co-ordinate events with Macpherson's (1946) structural scheme, which incidentally appears to face many difficulties in its detailed application to North Auckland geology.
At Whangarei Heads, of post-Tertiary events, only those of sub-Recent time are decipherable. These include substantial uplift, prior to the widespread submergence that has affected Northland, which resulted in deepening of stream valleys, then the submergence as the penultimate event and finally uplift of a few feet.
The writer wishes to acknowledge his great indebtedness to the late Professor J. A. Bartrum for his work in preparation of this manuscript for publication. Although in failing health during his last year at the University, the Professor's thoughts were continually with his students and an amazing amount of work was accomplished, at the expense, finally, of his life. Professor Bartrum was an able and conscientious teacher and a sincere friend; and he will long be remembered with endearment by those who were fortunate enough to study under him.
Baktrum. J. A., 1925. The Igneous Rocks of North Auckland, New Zealand. Gedenkbock Verbeek. Verhandelingen Geologisch—Mijnbouwkundig Genootschap voor Nedcrland en Kolonien. Geologische Serie, Deel 8, pp. 1–16.
—— 1926. “Abnormal” Shore Platforms. Journ. of Geol., vol. 34, pp. 793–806.
—— 1935. Shore Platforms. Aust, and N.Z. Ass. Adv. Sc., vol. 22, pp. 135–143.
—— 1936. Spilitic Rocks in New Zealand. Geol. May., vol. 73, pp. 414–423.
—— 1937. Interesting Xenoliths from Whangarei Heads, Auckland, New Zealand. Trans. Roy. Soc. N.S., vol. 67, pp. 251–280.
—— 1948. The Rate of Rounding of Beach Boulders. Journ. of Geol., 56, no. 6 (Nov., 1947).
—— 1948. Inclusions of Igneous and Metamorphic Rocks in the Serpentinite of Harper's, near Wellsford, North Auckland. N.Z. Journ. Sci. and Tech., vol. 29(1)B, pp. 18–32 (1947).
—— and Turner, F. J., 1928. The Geology of the Takapuna-Silverdale District, Waitemata County, Auckland. Trans. N.Z. Inst., vol. 59, pp. 864–902.
Bell. J. M., and Clarke, E. de C., 1909. The Geology of the Whangaroa Subdivision. N.Z. Geol. Surv. Bull., no. 8.
Bowen, N. L., 1928. The Evolution of the Igneous Rocks. Princeton.
Broderick, T. M., 1935. Differentiation in Lavas of the Michigan Keeweenawan. Bull. Geo. Soc. Am., vol. 46, no. 4, pp. 503–558.
Cotton, C. A., 1916. The Structure and Later Geological History of New Zealand. Geol. Mag., dec. 6, vol. 3, pp. 243–249, 314–320.
Cox, S. W., 1877. Report on the Geology of the Whangarei District. N.Z.G.S. Rep. Geol. Explor. during 1876–77, no. 19, pp. 95–190.
Daly, R. A., 1933. Igneous Rocks and the Depths of the Earth. McGraw-Hill.
Ferrar, H. T., 1920. Whangarei Subdivision. N.Z. Geol. Surv. 14th Ann. Rep., C.-2c, pp. 4–5.
—— 1925. The Geology of the Whangarei-Bay of Islands Subdivision. N.Z. Geol. Surc. Bull., no. 34.
—— 1934. The Geology of the Dargaville-Rodney Subdivision. N.Z. Geol. Surv. Bull., no. 34.
Finlay, H. J., and Marwick) J., 1947. New Divisions of the New Zealand Upper Cretaccous and Tertiary. N.Z. Journ. Sc. and Tech., vol. 28, pp. 228–236.
Friedlander, C., and Niggli, P., 1931. Beitrag zur Petrographie der Vogesen. Schw. Mineralog-Petrograph. Mitteil, vol. 2, pp. 365–411.
Hutton, C. O., 1943. Limburgite from Nevis Bluff, Kawarau Gorge, Central Otago. Trans. Roy. Soc. N.Z., vol. 73, pp. 58–67.
Laiiee, F. H., 1931. Field Geology. McGraw-Hill.
Marshall, P., 1926. Upper Cretuceous Ammonites of New Zealand. Trans. N.Z. Inst., vol. 56, pp. 129–213.
MaoPherson, E. O., 1946. An Outline of Late Cretaceous and Tertiary Diastrophism in New Zealand. Dept. Sc. Indus. Res., Geol. Memoir, no. 6.
Peacock, M. A., 1931. Classification of Igneous Rock Series. Journ. of Geol., vol. 39, pp. 54–67.
Smith, S. P., 1881. On Some Indications of Changes in Level of the Coastline in the Northern Part of the North Island. Trans. N.Z. Inst., vol. 13, pp. 398–419.
Permian Fusulinid Foraminifera from the North Auckland
Peninsula, New Zealand
[Read before the Wellington Branch, August 10, 1950; received by the Editor, August 12, 1950.]
In March, 1950, Mr. R. F. Hay, New Zealand Geological Survey district geologist, collected fossiliferous rocka from a locality near the entrance of Whangaroa Harbour on the east coast of the North Auckland Peninsula, and sent them in for examination. After having ground and studied fifty thin sections, the writer was able to recognise three species of neoschwagerinid fusulines, two of which are widely known in the Permian of the Orient.
As this is the first record of fusulines in New Zealand and also the first record of Palaeozoic fossils in the North Island, this paper is offered as a preliminary announcement of the discovery, leaving the more detailed account until a later date.
Accompanying the fusulines are smaller calcareous and arenaceous Foraminifera, Ostracoda, Polyzoa and (personal communication from Miss H. Leed, N.Z. Geological Survey) corals of the Subfamily Waagenophyllinae.
These fossils were found in blocks of limestone composed largely of fusulines and fragments of spilite and associated with spilitic pillow lavas.
Locality: No. 505 of collectors R. F. Hay and A. A. Sommerville (G.S.5074). Prov. Mile Sheet ref. N 8/301888, Whangaroa S.D., near the east end of Marble Bay.
The following species of fusulines were identified (hypotypes are kept in the New Zealand Geological Survey collections):
Genus Verbeekina Staff
1909. Neues Jahrb., Beil., 27: 476
Haplotype: Fusulina verbeeki Geinit
Verbeekina sp. Plate 50, fig. 4
There are several rather obscure specimens, apparently juveniles, which can be identified as the genus Verbeekina. The figured specimen is from slide T1000/f1012.
Genus Neoschwagerina Yabe
1903. Jour. Geol. Soc. Tokyo, 10 (113): 5
Orthotype: Schwagerina craticulifera Schwager
Neoschwagerina margaritae Deprat. Plate 50, fig. 5
1913. Neoschwagerina margaritae Deprat, Mém. Serv. Géol. d'Indochinc. 2 (1): 58, pl. 8, fig. 10; pl. 9, figs. 1–3.
Several specimens of this distinctive Neoschwagerina are present. The sagittal growth rate corresponds very closely with the growth rate of Deprat's specimens and the minute proloculum (0·06 mm.) makes
the resemblance almost complete. The figured specimen is from slide T1000/f1046.
Genus Yabeina Deprat
1914. Mém. Serv. Géol. d'Indochine, 3 (1): 30
Orthotype: Neoschwagerina (Yabeina) inoueyi Deprat = Neoschwagerina
globosa Yabe = Yabeina globosa (Yabe)
Yabeina multiseptata (Deprat). Plate 50, figs. 1, 2
1914. Neoschwagerina (Sumatrina) multiseptata Deprat, Mém. Sern. Géol. d'Indochine, 1 (3): 53, pl. 3, figs. 2–8.
This species is extremely abundant, comprising the greater part of the rock, and agreeing well with Deprat's descriptions in the large proloculum (0·43 mm.–0·53 mm.) and slow rate of uncoiling and in the intermediate Yabeinid-Sumatrine characteristics. The keriotheca is thin and sometimes absent between the septula, but alveolar canals are present in every specimen, even if reduced in number. The axial septula are narrowly compressed and are often swollen at the distal ends, numbering as many as ten in a single chamber. The ratio of length to diameter varies considerably (from 1·24: 1 to 2·39 : 1) but the variations in axial and sagittal growth rates fall fairly well within those given by Colani (1924, graph 22, fig. 3, graph 9, fig. 3). The figured specimens are from slides T1000/f1026 (axial section) and T1000/f1006 (sagittal section).
Yabeina sp. Plate 50, fig. 3
There are a few sagittal sections of a fusuline which is very similar to the figures of the species identified by Deprat (1912, Pl. 4, fig. 4) and Colani (1924, Pl. 23, figs. 31, 33) as Neoschwagerina globosa Yabe and later renamed N. douvillei by Ozawa (1925, p. 55). However, the single unrecrystallized sagittal section has six axial septula between each septum in later whorls and the primary axial septula are distally swollen, solid and non-alveolar as in typical Yabeina. The keriotheca is thicker than that of Y. multiseptata and is well supplied with canals. Because of inadequate material it seems inadvisable to attempt a specific identification at this stage. The figured specimen is from slide T1000/f1009.
Since the discovery at Marble Bay, further Permian fossils have been found in a specimen of chert presented to the old Colonial Museum in 1872 by “Mr. Barstow, R.M.” and labelled “Fossiliferous chert, Russell. Bay of Islands.” Although this rock is unsuitable for thin sectioning, fusulines and smaller Foraminifera and corals are well exposed on the weathered surfaces. The fusulines belong to the Neoschwagerininae and although specific identification seems hardly possible, the presence of secondary spiral septula between the primary ones makes possible the recognition of axial sections of Yabeina.
The North Auckland fusulines are contained in rocks which were included by Bell and Clarke (1909) in their Waipapa Series, a series of argillites, cherts, quartzites, greywackes and contemporaneous igneous rocks, excessively jointed, fractured and faulted, running along the east coast of the North Auckland. Peninsula. Bell and Clarke's assumption, on purely lithological grounds, that these rocks were late Palaeozoic or early Mesozoic can now be confirmed as they are certainly, in part, Permian.
Fig. 1—Yabeina multiseptata (Deprat), 1914. Axial section, × 10.
Fig. 2—Y. multiseptata. Sagittal section, × 10.
Fig. 3—Yabeina sp. Sagittal excentric section, slightly oblique, × 10.
Fig. 4—Verbeekina sp. Oblique sagittal section, × 40.
Fig. 5—Neoschwagerina margaritae Deprnt, 1913. Excentric axial section, × 10.
The Neoschwagerinidae are an exclusively Permian family, confined mainly to the Orient and Tethyan regions, but also known from West Australia and British Columbia. The implication of a connection between the Permian seas of the North Auckland area and the warm Tethyan-Oriental seas of that period is clear and confirms the southeastern extension of the Permian Tethyan sea postulated by Benson (1923, p. 31) in his palaeogeographic map of the Permian of the Australasian Region.
Deprat and Colani, in their work on the fusulines of the Orient, reported Yabeina multiseptata and “Neoschwagerina globosa” (= N. douvillei) in the highest fusuline zones of Southern China, Indo-China, Yunnan and Japan and believed them to be Upper Permian. Neoschwagerina margaritae was characteristic of a horizon which they classed as Middle Permian. Later workers, however, have thrown doubt on the Upper Permian ages assigned to many fusuline rocks of the Orient, and Hanzawa (1944) correlates the Yabeina-zone of Japan, containing Parafusulina and Codonofusiella, and the Maokou Limestone of South China, containing Sumatrina, Yabeina and Neoschwagsrina, with the Word of Texas which he regards as the equivalent of the Artinskian. Hanzawa notes, however (p. 2), that Yabeina and Sumatrina may possibly extend to the capitan, as they are associated with Codonofusiella, which is confined to the Capitan in Texas.
The Word is generally regarded by American workers as post-Artinskian and of Mid-Permian age (accepting a pre-Sakmarian, pre-Wolcampian Permo-Carboniferous boundary). Sherlock (1947) argues for a two-fold division of the Permian and places the Word in the upper part of the Lower Permian.
As the North Auckland fusulines have reached the same advanced stage of development as the yabeinid forms of Japan and South China, there seem good grounds for regarding them as Wordian or possibly Capitanian in age.
The writer wishes to acknowledge his indebtedness to Professor W. N. Benson, who was most helpful in making available much of the literature necessary for this study.
Bell, J. M., and Clarke, E. de C., 1909. The Geology of the Whangaroa Subdivision. N.Z. Geol. Surv. Bull. No. 8 (n. ser.).
Benson, W. N., 1923. Palaeozoic and Mesozoic Seas in Australasia. Trans. N.Z. Inst., 54: 1–62.
Colani, M., 1924. Nouvelle Contribution à l’étude des Fusulinidés de l'Extremême-Orient. Mém. Serv. Géol. d'Indochine, 11 (1).
Deprat, J., 1912. Etude des Fusulinidés de Chine et d'Indochine et classification des calcaires a Fusulines. Mém. Serv. Géol. d'Indochine, 1 (8).
Hanzawa, S., 1944. Stratigraphic distribution of the fusulinid Foraminifera found in South Manchuria and Japan. Jap. Jour. Geol. and Geog., 19 (1–4): 1–10.
Ozawa, Y., 1925. Palaeontological and stratigraphical studies on the Permo-Carboniferous Limestone of Nagato. Part 2. Palaeontology. Jour. Coll. Soi. Imp. Univ. Tokyo, 45 (6): 1–90.
Sherlock, R. L., 1947. The Permo-Triassic Formations. Hutchinson's, London.