Page:Quarterly Journal of the Geological Society of London, vol. 32.djvu/276

204 there is with regard to those extensive coast-beds which occur all along the coast from Yarmouth to Cromer, and especially what evidence we have as to the so-called Upper Boulder-clay on the coast being really newer than the great mass of the drift of high Suffolk.

Prof. thought that the question raised by Mr. Maw had been thoroughly discussed at the last meeting of the Society. He had had much pleasure in listening to Mr. Penning's paper, because that gentleman seemed to have aimed at getting rid of the infinite refinements in the classification of these beds as Upper, Lower, and Middle Glacial deposits, these things being generally treated in such a manner as to produce, at least in the popular mind, a notion that these deposits are of as great importance as Upper and Lower Silurian, for example, with beds thousands of feet thick. He thought that the effects of Glacial action had been immensely exaggerated, and believed that all the great features of the country existed before the Glacial period.

The (Mr. Evans) considered Mr. Penning's paper of great importance from two points of view—first, with respect to the sequence of the Glacial beds, and, secondly, with regard to the Cambridge valley. He thought that the author's views as to the southern part of the Cambridge valley would be borne out when he came to examine the portion north of the Lark, and further north in the neighbourhood of Brandon, where he would be able to trace the connexion between the Glacial and Postglacial gravels. With regard to the ice-cap, there were certain points that deserve great attention, especially the question whence are derived the materials of the Boulder-clay. These seem to be in great measure derived from the Upper Cretaceous and Tertiary beds in the neighbourhood. And in some cases unworn flints show glacial scratches; hence he suggested that inquiry should be made whether they were due to local glaciers.

The, in reply, stated that the Cambridge valley was excavated in Preglacial times. There is no evidence of extended denudation in Glacial times, but only of local unconformity.