The Complete Work of Charles Darwin Online

RECORD: Darwin, C. R. n.d. Where rocks not much metamorphosed the cleavage probably has never separated ingredients. CUL-DAR42.78. Edited by John van Wyhe (Darwin Online, http://darwin-online.org.uk/)

REVISION HISTORY: Transcribed by Christine Chua and edited by John van Wyhe 1.2022. RN1

NOTE: See record in the Darwin Online manuscript catalogue, enter its Identifier here. Reproduced with permission of the Syndics of Cambridge University Library and William Huxley Darwin. The volume CUL-DAR42 contains notes for Darwin's book South America (1846).

[78]

Where rocks not much metamorphosed the cleavage probably has never separated ingredients – ∴ cleavage never parallel to strata. (strata merely denoting changes of nature.) – where in metamorphosed it has always (?) been strong enough. –

Concretion of definite proportion in Metamorphic??

--- not def --- in sedimentary. (Balls of mica ca orbicular granite

[78v]

splendid argument for separation of strata of Hornblende, & lamellar in Primary rocks, is the separation of thick strata [sketch] 4 ft thick of calcareous strata, it is but inclining there & pollen is explained.

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