Page:Quarterly Journal of the Geological Society of London, vol. 27.djvu/53

 Many of the papers read during the past year have been of much interest and well serve to maintain the character of our discussions and publications. Those connected with glacial and drift- action continue to occupy an important place.

Glacial and Tertiary Geology.

The Rev. W. Bleasdell shows how a small island in the St. Lawrence has been removed piecemeal by river-ice floating off detached portions during floods ; and Dr. Brown applies the result of his experience in the arctic regions of America to the explanation of the glacial phenomena of Scotland, the sub-azoic Boulder-clay of which country he considers analogous to the deposit under the ice-cap of Greenland, while the associated fossiliferous laminated clays were formed in the fiords and bays skirting the ice-covered land.

Professor Harkness objects to former hypotheses respecting the distribution of the Shapfell Granite boulders over the high hills of Yorkshire, and suggests that their transport could only have been effected by the agency of coast-ice during a depression of the land of 1500 feet.

The superficial drift-deposits of South Hampshire and the Isle of Wight have been carefully investigated by Mr. Codrington, who shows that the unfossiliferous gravels of the higher plains were probably not of river-origin, but were spread out in an inlet of the sea, when the land stood 400 feet lower, whilst the gravels on the lower levels, with mammalian remains and flint implements, were afterwards deposited by river-action.

Mr. De Rance has described the Preglacial and Glacial deposits of Western Lancashire and Cheshire. He considers that at the commencement of the Glacial period the land stood higher than it now does, and that the higher ground was covered with an ice- cap and great glaciers, that the higher Boulder-clay is referable to this land^ice, and that the lower Boulder-clay spread over the lower ground was formed during a period of subsidence when the land- ice was floated off. He infers also that, when the land stood higher, Ireland would have been connected with "Wales, so as to render possible the migration of mammals and plants.

Mr. Searles Wood, jun., has reviewed the vexed question of the origin of the Weald Valley, and doubts the sufficiency of the various hypotheses that have been proposed to explain the denudation of that district. From the comparative absence of Lower Cretaceous or Wealden debris in the Thames valley, and the presence of Tertiary