RECORD: Darwin, C. R. 1.1834. Geological diary: C. Virgins. CUL-DAR34.186-187. 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, 2015. RN3

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.


186

C. Virgins

Jan. 26th. [1834] Lower 5/8 of cliff blue-grey fine grained substance. — Above earthy & white matter curved & tortuouslt interstratified — as also it is with the lower bed — the bronw earthy looking bed of twisting white lines with shells or pebbles —

I could see no gravel

Plain very level 150 (?) 200 feet high

Mt Aymond porphyry

On north side of first narrow high table land wh runs & becoming more irregular to Aymond from Cape Gregory shore of actual narrow & uneven on both sides & appears like white alluvium with pebbles?

St of Magellan

it is a gut of 300 feet in traversed valley which runs between Cape Gregory table land (probably north of Skyring Water) & hills in Tierra del Fuego

Slate? — Range not NE & SW? —

186 verso

St of Magellan formed before upheaval of Oyster bed by deficiency of deposit caused by water of ocean setting through wider entrance of Obstruction Sound. Skyring Water — &c &c

Bay of St Gregory. — Indians say there is high level plain with little gravel. —

Sweepstake Foreland, high perpendicular cliffs white.

[sketch]

with horizontal lines but one marked one oblique. —

on opposite point sand or fine matter covered by white bed which has cut into it

187

[sketch] white sand

High land behind C Gregory stretches but in broken pieces oblong, falls of much to the West

Pebbles at beach Cape Gregory those of Tierra del F slate &c

Cape Monmouth range slate?

Elizabeth same as other headlands

direction of land impressed when communication was open between Otway water & Straits. —

Capt King however about parallelism of hills, islands & straits, all consequent on Sts. —

Action of sea on coast in the upper parts much stronger before the 500 feet elevation of Patagonia. —

187 verso

Jan. 30th. [1834] — The cliffs of Elizabeth are about 100 feet high, composed of white detritus earth with angular & semi-rotted pieces of rock chiefly slates & hornblende rock, also some syenite, white quartz & greenish & yellowish feldspathic rock. — few masses pieces larger than a man head. — not arranged in the slightest order; after an irregular mass, there will perhaps be a bed of arranged gravel, then other mass with signs of deposition. —

generally upper parts show most of the latter action. — At the foot present sea, many boulders of syenite & greenstone. from the cliffs?? — It is evident this Martha Ids Sweepstake Foreland opposite coast. — both orders of 1st narrow part of same & continuous formation (Hence Guanaco &c). — No porphyry pebbles ([sign for therefore] anterior deposit? or the above have not reached this far South? — Valley of Sts of Magellan bounded by Gregory & Monmouth plains, filled up by sudden aluvium, lowest part present course. — Curious resemblance with detritus of B. Channel & Goree sounds, also from the West rocks. — This great alluvial plain, has chiefly been subject to alluvial action. —

Did it happen at elevation of country, water rushing through the channel of Magellan & Beagle & leaving at most entries great beds. —


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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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