RECORD: Darwin, C. R. 6.1834. Geological diary: The Andes created all S. America. [Chiloe] CUL-DAR34.199-200. Edited by John van Wyhe (Darwin Online, http://darwin-online.org.uk/)

REVISION HISTORY: Transcribed by Kees Rookmaaker, corrections and editing by John van Wyhe 4.2011. RN1

NOTE: See record in the Darwin Online manuscript catalogue, enter its Identifier here. This document, part of the largest scientific document composed by Darwin during the voyage of the Beagle, is written mostly in ink. Marginal notes are here integrated into the text.

Reproduced with the permission of the Syndics of Cambridge University Library and William Huxley Darwin.

See the introduction to the Geological Diary by Gordon Chancellor.


199

(1)

June. (29.th). [1834] — The Andes created all S. America

The general mass of stone, walking up East side of Cheverea creek is a more or less compact, earthy yellowish substance (more or less fusible & the origin of which I have little doubt may be attributed to volcanic dust: a great deal of this consists of such a basis with a breccia of white. substance of little specific gravity, I was inclined to think this to be the nature of pumice, but it is scarcely fusible. — There are many large sple rounded concretionary masses of a calcareous stone. with broken fragments of crystals & mica. — in other places there are irregular mass of hard ash-colored, siliceo-aluminous, stone conchoidal fracture small numerous scales of silvery mica: when this occurred there were numerous veins of anhydrous gypsum: —

The whole breccia. containing patches of fuel virulent wood which emitted a flame. —

This substance although generally forming the mass of occasionally occur concretionary: as does the last variety massive: — different varieties of the volcanic mud generally occur pass into each five other in by concretionary masses: where so that a pale variety with ultimately merely formed veins between great masses angular or rounded of a darker kind. —

[sketch]

In one place on coast for 1/4 of a mile between the above rocks & at same level, a more earthy kind either with waving water lines, or amorphous with rounded pebbles (hence numerous on beach (with few large boulders, origins?) from size of egg. to a turnip

199 verso

nature of pebbles - any concretionary specimen of earth

Height of pholas

Gypsum veins:

Caves — Fresh-water fish — Huevos de los Gigantes

other fish — coals — mica — earth-quake —volcano

Post road — effect on springs — mineral

Wave? buildings fall into any one direction

His collection of shells — exact dates & time of earth-quake

200

(2)

They consist I believe entirely of altered slate: many were exactly like green rock of Wollaston Isd. — others, hornblendic others (not very well characterized) whitish or dark porphyries:

I am ignorant whether this contemporaneous or not. —

There were straight jaspery plates, running for considerable distance in straight N & S. — line.

A dip at 2.5°? to the east, of the beds. —

Pholas above high water mark.? — [sketch]

On 30 31st. [June 1834] — On the East side same strip of land, generally same sort of stone. — a laminated, blackish-grey. micaceous, soft sandy clay-slate & a yellow compact, soft earth-stone, generally underlie the breccia. — The Breccia is much coarser & contains fragments of quartz & other rocks. — These rocks I could see for a considerable height up the hill side, so that doubtless they form the whole promontory. —

Reasons for modern formations similarly with those over lava. — Modern elevations

Reexamine quartz fragments on outer coast: & [illeg] &c

Sounding off the coast of Chiloe rate of volcanic dust

Common origin of lakes


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Citation: John van Wyhe, ed. 2002-. The Complete Work of Charles Darwin Online. (http://darwin-online.org.uk/)

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