Blanket Bay, Doubtful Sound (G 14): A dark greenish-grey rock, showing on the broken surface abundant cleavage planes of hornblende. In thin slices pale-green hornblende composes more than half the rock. Shows some secondary corrosion, as evidenced by the rounded inclusions of quartz. Around and between the hornblendes fine granular quartz and oligoclase angular grains completely interlocked. A few small plates of brown mica and some crystals of clear rutile. A few crystals of pale-pink garnet.
Dea's Cove, Thompson Sound (G 26): A finely foliated rock, with conspicuous hornblende, with cleavage planes parallel to the foliation planes. Section shows abundant pea-green hornblende, not highly pleochroic. It constitutes five-sixths of the rock. It contains some rounded quartz inclusions, but less noticeably than the rock from Anita Bay and Bowen Falls. The hornblende also contains inclusions of brown rutile. The colourless minerals are quartz showing undulose extinction and oligoclase with bent lamellÆ. In some specimens (G 25) there are inclusions of rounded grains of colourless rutile in great abundance.
Anita Bay (G 20, G 23): Hornblende schist. A dark rock with conspicuous cleavage planes of hornblende. In thin slices the hornblende crystals are pale-green, not strongly pleochroic, sometimes with thin laths of brown mica round the margin. The rest of the rock is fine-grained, consisting of a mixture of hornblende and quartz, which often shows evidence of a flow movement round the larger crystals, producing an eye structure. There is a little magnetite in the fine-grained part. Other specimens from near the same locality have no large crystals of hornblende, but sphene is rather plentiful in them.
The rocks from Anita Bay described in a previous paper* were hartzbergite and dunite. The hartzbergite showed an apparent change from silicate to carbonate in some of the crystals, especially in those of enstatite. A further inspec-
[Footnote] *Marshall, Trans. N.Z. Inst., 1904, p. 481.
tion of specimens which before examination by microscope were thought to be marbles showed that these rocks were only a further and more completely changed hartzbergite, for they contained a large quantity of unchanged rounded grains of olivine (Plate XXIII, fig. 1). These white rock-specimens were found on the beach; none have yet been found in situ. The margins of crevices penetrating the hartzbergite showed, however, a far more complete carbonation than other parts of the rock.