RECORD: Darwin, C. R. Geological diary: The Andes created all S. America. [Chiloe] (6.1834) CUL-DAR34.199-200 Transcribed by Kees Rookmaaker, edited by John van Wyhe (Darwin Online,

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

NOTE: 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.

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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.



June. ( [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. —


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



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, editor. 2002-. The Complete Work of Charles Darwin Online. (

File last updated 2 July, 2012