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Letter 1052

Darwin, C. R. to Sharpe, Daniel

[19 Jan 1847]

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    Comments on letter by Bernhard Studer ["Remarks on the geological relations of the gneiss of the Alps", Edinburgh New Philos. J. 42 (1846–7): 186] and on article by DS ["On slaty cleavage", J. Geol. Soc. Lond. 3 (1847): 74–105]. Discusses geological cleavage and foliation.

Transcription

Down Farnborough | Kent

Tuesday

My dear Sir

I do not know whether you look at the Edin. New. Phil. Journal, but if not, do read a very short letter from Studer at p. 186 of last Number. I have been pleased with it, as it confirms my facts & views on the “foliation” of gneiss &c. being quite distinct from stratification: Studer does not seem to have perceived that foliation is only much developed cleavage.—

I often think over what little I was able to understand of your Paper, & I anxiously look forward to read it in extenso.— [DIAGRAM HERE] cleavage A cleavage A cleavage A

When non=cleaving beds intervene between those with cleavage, have you ever noticed very carefully the lines of junction? do the edges of the cleavage planes ever indent in ever so small a degree the bases or tops of the intercalated non=cleaved beds. If you have time to send me one single line, just inform me on this head—

believe me | Yours very truly | C. Darwin

    Footnotes Add

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    f1 1052.f1
    The date of the letter and identity of the correspondent are based on CD's letters to Bernhard Studer, 20 January [1847], and to Daniel Sharpe, [23 January 1847].
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    f2 1052.f2
    Studer 1847b, published in the January issue of the Edinburgh New Philosophical Journal. The printed letter, originally addressed to James David Forbes, reported observations that had led Studer to conclude that the laminae in Alpine gneiss could not be sedimentary strata. See also letter to Bernhard Studer, 21 March [1847], n. 4.
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    f3 1052.f3
    Sharpe 1847, which was first read at a meeting of the Geological Society on 2 December 1846. CD attended this meeting (Correspondence vol. 3, Appendix II).
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    f4 1052.f4
    Sharpe evidently sent a manuscript version of the paper to CD (see letter to Daniel Sharpe, [23 January 1847]). Sharpe had previously discussed his views with CD in November 1846 (Correspondence vol. 3, letter to Daniel Sharpe, [1 November 1846]).
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