Absence of organic remains in many deposits.
Discusses presence of marine animals near icebergs.
Comments on former geological state of England.
Down. | Bromley. | Kent. S.E.
My dear Lyell
I have been very much interested by your long letter (to be forwarded tomorrow); but these subject have so much gone out of my head that I have nothing to suggest.
I cannot think much of the absence of organic remains. There were none in the vast gravel beds of Patagonia with sea-shells on surface; & none in the till of T. del Fuego, also with shells on surface; though it may have been that these till beds were formed when T. del F. was like Greenland & afterwards subsided.— Yet I confess from what little I have of late read of Greenland I have suspected what you seem now inclined to admit & what Chambers so vehemently urges. Is it certain that abundance of sea-living & swimming animals is any guide to shells &c living at the bottom? I cannot think that animals could live where icebergs are habitually grounded. I have remarked on this in Geolog. Transact Vol. VI p. 421, but I refer to this only because a statement by Wrangell seems interesting on the tranquil space of shallow sea within that where the icebergs ground.
With respect to former state of England, the Boulder which I describe at height of
803 ft in middle of Staffordshire has always seemed to me a striking case: it
is in my paper on Glaciers of N. Wales in the Phil.
I pity you having to alter & modify on this great subject: I always marvel at & admire your industry & care.—
I wish this note was better worth sending. I grieve over poor dear Glen Roy.—
Ever yours | C. Darwin
- f1 3249.f1Lyell's letter has not been found. CD forwarded it to Thomas Francis Jamieson, who referred to it in his letter to Lyell of 11 September 1861 (see Correspondence vol. 9, Appendix IX).
- f2 3249.f2See letter from T. F. Jamieson, 3 September 1861, and letters to T. F. Jamieson, 6 September , and to Charles Lyell, 6 September .
- f3 3249.f3One of the difficulties for those who viewed the `parallel roads' of Glen Roy as having been formed by the sea was the absence of marine fossils in the area. In his 1839 paper on Glen Roy, CD stated that he `attentively examined, with the expectation of finding fragments of sea shells, the matter accumulated on the shelves, and more especially the thicker beds of gravel and sand which occur at lower levels; but I could not discover a particle' of such evidence (Collected papers 1: 113). CD argued, however, that the preservation of marine fossils was an exceptional rather than a common phenomenon. In his letter to Lyell of 11 September 1861 (see Correspondence vol. 9, Appendix IX) Jamieson stated: `After what I saw in Glen Roy nothing short of the finding of marine remains will readily convince me that the sea has occupied Lochaber since the period of these shelves to a height exceeding some 600 or at most 800 feet.'
- f4 3249.f4CD had published these observations in his paper `On the distribution of erratic boulders and on the contemporaneous unstratified deposits of South America', Transactions of the Geological Society of London 2d ser. 6 (1842): 415--31 (Collected papers 1: 145--63). In this paper he accounted for the absence of marine remains in these deposits by postulating the disturbance of the accumulating till by `icebergs being lifted up and down by the tides' (ibid., p. 152).
- f5 3249.f5The reference is to Chambers 1853, in which Robert Chambers presented evidence of glaciation in Scotland and parts of England. Chambers argued against the prevailing geological opinion, put forward most prominently by Lyell and Roderick Impey Murchison, that the various indications of the action of ice in these areas, such as striation, resulted not from the action of glaciers but from floating icebergs that were subject to tidal motions. CD had also supported the iceberg interpretation. See especially Correspondence vol. 5, letter to Charles Lyell, 7 June .
- f6 3249.f6See n. 4, above.
- f7 3249.f7Wrangel 1840, p. 257.
- f8 3249.f8`Notes on the effects produced by the ancient glaciers of Caernarvonshire, and on the boulders transported by floating ice', London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science 21 (1842): 180--8 (Collected papers 1: 163--71). The erratic boulder at Ashley Heath in Staffordshire is cited as proof of the submergence of western England during the period in which floating ice abounded (ibid., p. 170 n. 11).
- f9 3249.f9Lyell discussed new evidence concerning glacial phenomena in Britain in C. Lyell 1863.