I have been delighted with Prescott, of which I have read Volume I. at
your recommendation; I have just been a good deal interested with W.
Taylor's (of Norwich) "Life and Correspondence."
On your return from York I shall expect a great supply of Geological
gossip.
LETTER 482. TO C. LYELL. [October 3rd, 1846.]
I have been much interested with Ramsay, but have no particular
suggestions to offer (482/1. "On the Denudation of South Wales and the
Adjacent Counties of England." A.C. Ramsay, "Mem. Geol. Survey Great
Britain," Volume I., London, 1846.); I agree with all your remarks made
the other day. My final impression is that the only argument against
him is to tell him to read and re-read the "Principles," and if not
then convinced to send him to Pluto. Not but what he has well read the
"Principles!" and largely profited thereby. I know not how carefully you
have read this paper, but I think you did not mention to me that he does
(page 327) (482/2. Ramsay refers the great outlines of the country to
the action of the sea in Tertiary times. In speaking of the denudation
of the coast, he says: "Taking UNLIMITED time into account, we can
conceive that any extent of land might be so destroyed...If to this be
added an EXCEEDINGLY SLOW DEPRESSION of the land and sea bottom, the
wasting process would be materially assisted by this depression" (loc.
cit., page 327).) believe that the main part of his great denudation
was effected during a vast (almost gratuitously assumed) slow Tertiary
subsidence and subsequent Tertiary oscillating slow elevation. So
our high cliff argument is inapplicable. He seems to think his great
subsidence only FAVOURABLE for great denudation. I believe from
the general nature of the off-shore sea's bottoms that it is almost
necessary; do look at two pages--page 25 of my S. American volume--on
this subject. (482/3. "Geological Observations on S. America," 1846,
page 25. "When viewing the sea-worn cliffs of Patagonia, in some parts
between 800 and 900 feet in height, and formed of horizontal Tertiary
strata, which must once have extended far seaward...a difficulty often
occurred to me, namely, how the strata could possibly have been removed
by the action of the sea at a considerable depth beneath its surface."
The cliffs of St. Helena are referred to in illustration of the same
problem; speaking of these, Darwin adds: "Now, if we had any reason
to suppose that St. Helena had, during a long period, gone on slowly
subsiding, every difficulty would be removed...I am much inclined to
suspect that we shall hereafter find in all such cases that the land
with the adjoining bed of the sea has in truth subsided..." (loc. cit.,
pages 25-6).)
Public-domain text, read in full here on John Shaqi.
Reviews
Reviews
No reviews yet
Be the first to share your thoughts on this work.
Elsewhere in the archive
Join the Discussion
Join the discussion
Sign in to leave a comment or review.
Sign InorCreate an account