Darwin, C. R. Geological diary: Between Rio Lucia and Mount. [7.1832] CUL-DAR34.2 Edited by John van Wyhe (<em>Darwin Online</em>, http://darwin-online.org.uk/)

RECORD: Darwin, C. R. 7.1832. Geological diary: Between Rio Lucia and Mount. CUL-DAR34.2. Edited by John van Wyhe (Darwin Online, http://darwin-online.org.uk/)

REVISION HISTORY: Transcribed by Kees Rookmaaker, corrected and edited by John van Wyhe 11.2011. 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. Where pencil was used instead this is noted in the textual notes. Marginal notes are here integrated into the text. See the Beagle diary pp. 199, 212.

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

Between Rio Lucia & Mount —

a bed of impure ~~first~~ sand hardened. penetrated by veins & stalactites of a white substance, composed of particles of silex in a friable calcareous base. — I say stalactites, because — they are long vertical cylinders & evidently formed by the matter — penetrating the crack & cavities of sand. — This rested on Mica slate & Phyllade. —

I should imagine the general thinly covering of earthy matter in Banda Oriental — now occasion forming as shown by the bones of oxen & horses. — is formed by the degradation of this bed of sand: at the opening of Rio St. Lucia is a

2 verso

is an irregular granite. in which a reddish feldspar is predominant.

The same rock occurs to the East of the city: —

Las Pichas. a considerable formation of syenite & feldpar red rock handsome: decompsing in the line of fracture —& hence angles weavy — they have the appearance of boulders.

u l / [nib tests?]

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