RECORD: Darwin, C. R. n.d. [Note on rates of denudation]. CUL-DAR205.9.347. Edited by John van Wyhe (Darwin Online, http://darwin-online.org.uk/)
REVISION HISTORY: Transcribed by Christine Chua and edited by John van Wyhe 10.2021. RN1
NOTE: The brown crayon number '22' indicates that this document was filed by Darwin in his portfolio for the subject of Palaeontology: extinction.
Reproduced with permission of the Syndics of Cambridge University Library and William Huxley Darwin. The volume CUL-DAR205.9 contains notes on palaeontology and geology [regarding theory of evolution].
[347]
22
Cefn Crib [Monmouthshire] section, across Forest of Dean.
9 miles 5000 ft that with having 3 1/4 aside 10,000 ft & also wide
so say 10 miles wide & 6000 ft thick
Assume cliff of 500 ft wd be denuded 1 inch in century along whole line
Therefore cliff of 6000 ft wd be denuded 1 inch in 1200 years
But we have 10 miles to denude
1760 yards in miles [x] 36 [=] 10560 [+] 5280. [=] 63360 inches in miles [x] 10 [=]
633600 inches in 10 miles [x] 1200 [=] 760,100,000 years required to denude the above cliff of Silurian, Old Red & Carboniferous sheets
* Before when was the denudation effected?? Commenced subsequent to Carboniferous
[347v]
The Denudation may & perhaps did commence before Carboniferous & may have been affected at any time
Citation: John van Wyhe, ed. 2002-. The Complete Work of Charles Darwin Online. (http://darwin-online.org.uk/)
File last updated 25 September, 2022