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Published online by Cambridge University Press: 01 May 2009
All geologists admit that the Lake-district of the North-west of England has been several times under the sea since the first upheaval of the alternating sedimentary and volcanic rocks of which it is composed; and few would be disposed to question that during the repeated processes of elevation land subsidence, whether continuous or intermittent, the sides of the mountains and valleys of this district have been long exposed, at different levels, to the action of waves, tides, and currents. We have reason to suppose that the duration of the last or intra-glacial submergence was at least as long as the time which has since elapsed; and if during the latter the sea has done so much to indent and modify our coasts, may we not expect to find the most obvious traces of its former denuding influence in regions which have risen above its level? Yet some of the pluvial, fluvial, glacial geologists of the present day would soon reduce the sea to a subordinate rank in the list of causes, were it not for the masterly advocacy of marine denudation which, with fresh arguments, may be found in the successive editions of the works of Sir Charles Lyell and Sir R. I. Murchison.
page 300 note * Amongst the two largest rakes in Cumberland are Lady's Rake, in Wallow Crag, near Keswick, and Lord's Rake, on one side of Mickledoor Chasm, Scafell. The ascent of the latter is considered a great pedestrian feat.
page 301 note * For a notice of the occurrence of fossils in ‘screes,‘ see Professor Harkness's paper On the Skiddaw Slate Series, Quart. Journ. Geol. Soc., vol. xix. pp. 113. et seq.Google Scholar
page 302 note * The most extensive screes in the Lake-district are on the south-east side of Wastwater, where nature is still very actively at work.
page 302 note † A very obvious instance of an old sea-strait may be seen in the Mickledoor Chasm, which separates Scafell from Seafell Pike. This chasm, originally a gaping fracture, has evidently been enlarged by an oceanic current.
page 303 note * In connection with this subject, it is worthy of notice that there are many ralleys and hollows of denudation in the Weald of Sussex with no streams flowing through them; while some of the valleys of Wiltshire and Dorsetshire present a series of raised beaches which embrace nearly the whole of the declivities on both sides, in such a way as to show that these valleys remain as they were left by the sea.
page 304 note * Sir C. Lyell has marked an era in the history of geological discovery by his explanation of the denudation of the Weald of Sussex; but I am not aware that any geologist has yet taken notice of a cwm now in course of being excavated by the sea at Beachy Head.
page 305 note * In a kind note lately received from Professor Sedgwiek, that venerable geologist, so far as he can now recollect, would call the Pillar Rock a mass of fine porphyry, but would caution geologists against being deceived by the look of a fractured surface—the real structure of rocks of this class being best observed where the process of decomposition is going on.
