Art. LII.—Recent Discoveries in the Neighbourhood of Milford Sound.
[Read before the Wellington Philosophical Society, 15th August, 1884.]
Messrs. Sutherland and McKay, well known as explorers and prospectors of Western Otago, have for some years past devoted their attention to the vicinity of Milford Sound, and from their principal camp at the head of that Sound, they have explored the country in almost every direction. Surrounded as Milford Sound is by impassable mountains to the east and north, the valley of the Arthur River lying southward of the head of the Sound presents the only hopeful route by which to reach the Lake District of Otago. The eastern branch of the Arthur River, above Lake Abraham, was explored to its source, but no outlet was discovered in this direction, the
valley being bounded on either hand and closed at its upper end by high and excessively rugged mountains, presenting some of the most remarkable scenery to be met with in the whole district.
The mountains on the north-east side of the valley are specially striking, and have been called by their explorers the Balloon Mountains. From the river valley these rise as vertical precipices to a height of 5,000 feet, and attain an altitude between 8,000 and 9,000 feet above sea-level. It is here that the Sutherland Falls are situate, which have a height of 5,000 feet, a considerable volume of water being precipitated from that height in an almost unbroken sheet into the valley where this is not more than 800 feet above sea-level. At the source of the more westerly branch of the river, a pass was discovered leading in the direction of the head of Bligh Sound, by which it is hoped communication may be established with some of the western arms of Te Anau Lake.
It seems certain from Maori report that by this way an available route exists, but as yet no European has reached Te Anau Lake, starting from Milford Sound,—or Milford Sound from the other end of the journey.
It is, however, probable that a route this way to Milford Sound was known to the Maoris, as on several points of it traces of temporary or more permanent camps have been discovered.
It is not with the results of these explorations that this paper more particularly deals, but with those of subsequent date made on the coast-line between Milford and Bligh Sounds.
Eighteen months ago McKay left Milford Sound, and Mr. Sutherland has since, for the most part, explored single-handed. A few days since he passed through Wellington and gave me an account of his later discoveries which, in his own words, is as follows:—
“During the month of October last I made an attempt to reach the top of Mitre Peak following the valley on its south side, hoping thus to gain the top of the ridge connecting the Mitre with the Llawrenny Peaks to the south. In this I failed, as the upper end of the valley is surrounded by precipices or smooth rock surfaces, sloping at high angles on which no footing could be found. The upper end of this valley is considerably wider than the middle and lower part forming a semi-circular basin surrounded by precipices as pronounced on the side next the Llawrenny Peaks as towards the Mitre.
“Towards the upper end of the valley blocks of marble occur in the detritus covering the low grounds, but marble was nowhere observed in situ. There is also considerable quantity of the purer hornblende rock of which samples had formerly been obtained in the lower part of this valley.
“I next determined to examine the coast-line south of the entrance to Milford Sound, and as weather availed used the boat for this purpose. Landing two miles south of Fox Point, at the mouth of a valley running
some distance back into the ranges, I explored this to its upper end considerably east of the entrance to Milford Sound. Its length may be estimated at six miles, its width as two. The valley and the ranges to the north and south are covered with heavy bush.
“For a distance of four miles back from the beach the valley is but little above sea-level, and the stream flowing through it, though of no great volume, is sluggish and navigable for boats for the four miles mentioned. Towards its upper part this valley narrows, and unlike that on the south side of Mitre Peak, does not open out to form a semi-circular basin surrounded by precipices. The mountains are nevertheless very abrupt, and many large slips choke the upper part of this valley, making travelling difficult.
“There is here a greater variety of rocks than in Milford Sound. The principal rock is schist, similar to that met with at Fox Point. Quartz is abundant, although no reefs of this were noticed. Marble and asbestos also occur, but there is an absence of the hornblende rock found in the valley south of Mitre Peak.
“Continuing to the southward I next landed at Poison Bay, and explored the valley of the river which enters the sea at that place. This stream has a volume little less than the Cleddau River at the head of Milford Sound. It drains the south and south-west slopes of the Llawrenny Peaks. Six miles from the coast the river issues from a deep narrow gorge, beyond which it divides into two branches, the largest of which has a direction at first to the south-east, but towards its source turns more to the eastward. The smaller branch rises to the north-east among the Llawrenny Peaks. Below the gorge the course of the river is between west and north-west to the sea. Its valley in this part has a breadth of a mile and a half of flat alluvial land. The hills bounding it slope to the valley at moderate angles, though here and there they are broken by deep gulches and ravines. The country in this part is heavily covered with bush.
“Blue clay-slate is the most abundant rock. This is not a mica schist, but more of a roofing slate, splitting freely into thin flagging. Marble and greenstone occur in the bed of the stream, and in the slaty beds several quartz reefs were noted.
“The valley varies but little in breadth, being as wide at its upper end as near the coast. The river enters the sea on the south side of the bay.
“Leaving Poison Bay I went five miles to the southward, and landed at Little Bay, where entering a tidal river I determined to follow this as far as I could with the boat. This river (pl. xlii.), which is about two chains in width, has on its bar a depth of three fathoms at low water, inside of which there is a greater depth. Followed inland the average width of this tidal river is maintained for a distance of one and a half miles, beyond which it expands
and forms a salt-water lake, divided into two parts by a shingle bar, dry at low water. The lower part has its greatest length across the valley, being better than a mile in this direction, and about half a mile in breadth from the outlet to the shingle bar dividing it from the upper part of the lake. In this basin the depth of water is very considerable, some twenty fathoms.
“The shingle bar, dividing the lake into two parts, and dry at low water, is about half a mile wide at low water; no river connects the two parts of the lake, but the water from the upper part flows over or percolates through the shingle, so that no principal stream is formed.
“Beyond this the upper part of the lake, better than a mile in width, extends to the eastward a distance of six miles, and is bounded on the north side by precipitous mountains not quite so nearly vertical as in Milford Sound. On its southern side the lake has a fringe of flat land, three quarters of a mile wide, between it and the mountains, which are less abrupt than on the northern side of the lake, saving towards its upper end, where they are equally so. At its upper end the lake is narrowed to less than half its greatest width, and there receives two rivers coming from the north-east and south-east respectively, much as the Cleddau and Arthur rivers enter Milford Sound.
“Near their entrance into the lake these rivers are each about a chain in width, and though the weather was fine and the rivers low, they were not fordable when I saw them. That coming from the north-east has a valley about a quarter of a mile in width, and for a mile this has a moderate fall, beyond which it has a higher slope, and appears to become a rugged mountain valley, although the mountains on either side are not remarkably abrupt.
“The stream falling into the lake on the south side is rather the largest of the two. This flows over a rough bouldery bed in a valley considerably less than a quarter of a mile wide, which terminates half a mile from the lake, beyond which the river flows in a tremendous ravine, not more than two or three chains in width, whose vertical sides rise to a height of 1,500 or 2,000 feet.
“By these two rivers a small delta has been reclaimed from the upper part of the lake; and off the mouth of the northern river a small island of shingle is dry at high water. From the sea into the lower part of the lake the tide runs in with a rate of five knots, and over the shingle bar at the rate of three knots an hour.
“The lake abounds with fish in the lower basin, and in the lower part of the upper, though none were caught at its upper end, and following them there is no scarcity of sharks, which infest the tidal river and the lake wherever other fish are found.
“Below the lake the alluvial land between it and the sea is about one and a half miles wide, heavily timbered and abounding with bird life,—wekas are especially abundant; scarcely less so are pigeons, kakas, kiwis, kakapos, and roas. Redbills and penguins are in great numbers on the shingle bar between the two parts of the lake when the tide is out, and as far as birds and fish supply it, there is no scarcity of the means of living.
“The characters of the rocks here resemble more that variety of granite found in the Cleddau River, at the head of Milford Sound, than the other localities of which the rocks have been noticed. There is yet a greater number of varieties than in the Cleddau river-bed; but in all these there is still a resemblance.”
Such is Mr. Sutherland's narrative, and I take it for granted that it is sufficiently interesting and important to merit being read here; and from this it may be inferred that besides the larger sounds excavated to such a depth that they are now deep arms of the sea extending far inland from the coast-line, there was a second series of sounds the glaciers that excavated which were connected with less extensive snow-fields,—the great glacier of Milford Sound (a branch of which filled the valley of the Arthur River) dividing these from the greater snow-fields of the Darran Mountains and their southern continuation; they thus were unable to excavate their beds to the same level.
Some of these as we see are now filled and form level lands fit for settlement, while in the case of the Salt-water Lake inland from Little Bay, this is yet a sound to all intents and purposes, owing its greater depth and length to the fact that there is here between the watershed to the Arthur River and the coast-line a greater breadth and a greater elevation of the country than further to the north, south of Milford Sound, and west of the Arthur River.
The glacier excavating this sound must have been fed from the Balloon Mountains, and is an evidence of the correctness of Mr. Sutherland's estimate, that these are higher than the mountains immediately south of Milford Sound.
This lake at Little Bay is not the only example of the kind on the west coast of Otago. Lake McKerrow, in the lower part of the Hollyford Valley and its tidal river, presents the same phenomenon on a much larger scale. That, however, belongs to the valleys of the larger glaciers reaching back to the Darran Mountains, while this has been excavated by the glaciers of the coast ranges.
The distances, as estimated by Mr. Sutherland, may not be in all cases correct, the difficulties of travelling in such a country leading to an overestimate of these.