To Charles Lyell [on or before 20 January 1847]
[Down]
My dear Lyell
That you may not suppose that I have been overrash in generalising my conclusion, I copy following passage, p. 167.1
“As in some cases it appears that where a fissile rock has been exposed to partial metamorphic action, for instance from the irruption of granite,, the foliation has supervened on the already existing cleavage-planes; so, perhaps in some instances, the foliation, of a rock may have been determined by the original planes of deposition or of oblique current-laminæ; I have, however, myself never seen such a case, & I must maintain that in most extensive metamorphic areas, the foliation is the extreme result of that process, of which cleavage is the first effect.”2 &c &c
Ever yours | C. D.
Footnotes
Bibliography
Correspondence: The correspondence of Charles Darwin. Edited by Frederick Burkhardt et al. 29 vols to date. Cambridge: Cambridge University Press. 1985–.
Phillips, John. 1856. Report on cleavage and foliation in rocks, and on the theoretical explanations of these phænomena.– Part I. Report of the 26th meeting of the British Association for the Advancement of Science held at Cheltenham, pp. 369–96.
South America: Geological observations on South America. Being the third part of the geology of the voyage of the Beagle, under the command of Capt. FitzRoy RN, during the years 1832 to 1836. By Charles Darwin. London: Smith, Elder & Co. 1846.
Summary
Quotes from South America [p. 167] on the foliation of metamorphic rocks.
Letter details
- Letter no.
- DCP-LETT-1053
- From
- Charles Robert Darwin
- To
- Charles Lyell, 1st baronet
- Sent from
- Down
- Source of text
- American Philosophical Society (Mss.B.D25.57)
- Physical description
- ALS 3pp & C
Please cite as
Darwin Correspondence Project, “Letter no. 1053,” accessed on 26 September 2022, https://www.darwinproject.ac.uk/letter/?docId=letters/DCP-LETT-1053.xml
Also published in The Correspondence of Charles Darwin, vol. 4