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December 28^th. [1835] — At Cone Harbor, read all this

Dark Harbor (rocked up now).

Rock all micaceous schists, much & regularly laminated, dipping within a point of WSW. ∠ very various often about 40° have seen it 20° & nearly ┴°

Rock (2437) grey, quartzose micaceous schist: which often containing numerous grains (2441) of quartz & occasional side of silvery mica

To the North of Cone Harbor, form of land perhaps point at considerable extent of the volcanic formation

Ynche Is^d December 30^th. —

Inqui Island. — N. of N. point of Tres Montes Peninsula all the rock either the same as (2447), a quartzose grey rock with grains of quartz (2442): or it passes into a finer grained variety with semi-conchoidal fracture & which is closely connected (2443) with these feldspatic

Lat: 45.48.

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X Mem: Granite at Cone Harbor

The age of the rock there are hence unquestionably the same, with the whole of Chonos. Archipel:

؟ Is not the direction of outer coast of P. Tres Montes NNW (true): ∴ // to cleavage? —

Dykes not abundant here or at Dark Harbor, only near seat of volcanic action: & at Midship Is^d. —

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(2)

rock of Cone Harbor, which were described as containing specks of quartz. — The rock here differs from Dark Harbor in form not being laminated but rather divided by numerous smooth extensive planes of fracture, which intersect each other at about angle 45°. — Hence every outlying point is ornamented with numerous fe pyramids. (this is the striking character of the coast & on a great scale perhaps accounts for such hills as the "Cone".

By gradual & perfect mineralogical transition we can trace micaceous slates into the slaty quartzose rock & this again into one which closely corresponds in every respect to what I have called "altered slates", & which the included breccia (at Cone Hill) seem render highly probable. — The dip where they have been ascertained have been similar: It is interesting as showing to what origin mica slate may be attributed. —

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