540 Geological Society. 



material of this, bordering the river-valleys, and at greater eleva- 

 tions expanding over the higher parts of the plateau and moun- 

 tains. At Mount It-ga-clmz they are 5270 feet above the sea. The 

 author considers that the higher terraces can only be explained by a 

 general flooding of the district. Some of the wide trough-like 

 valleys of the plateau contain a silty material which the author 

 regards as a glacial mud. 



North of the 54th parallel and west of the Rocky Mountains 

 similar evidence of glaciation is obtained ; erratics are found in the 

 Peace and Athabasca basins. The fjords of British Columbia are 

 extremely glaciated, the marls being generally in conformity with 

 the local features ; terraces are scarce and at low levels. The Strait 

 of Georgia was filled by a glacier which overrode the S.E. part of 

 Vancouver's Island ; evidence is given to show that this ice came 

 from the neighbouring mountainous country. Queen Charlotte's 

 Island shows evidence of local glaciation. Boulder-clays and strati- 

 fied drifts are found, with occasional arctic shells. 



The author considers that the most probable explanation of the 

 phenomena of the whole region is to suppose the former existence 

 of a great glacier mass resembling the inland ice of Greenland, and 

 that the Glacial period was closed by a general submergence, during 

 which the drifts were deposited, and at its close the terraces cut. 



March 23. — Eobert Etheridge, Esq., F.R.S., President, 

 in the Chair. 



The following communications were read :— ■ 



1. " The Upper Greensands and Chloritic Marl of the Isle of 

 Wight." By C. Parkinson, Esq., E.G.S. 



In this paper the author described the Upper Greensand as ex- 

 posed at St. Lawrence and along the Undercliff. At the base of the 

 St. -Lawrence cliff there are hard bands of blue chert from which 

 Astaciform Crustacea have been obtained ; and quite recently, in a 

 large boulder of the same material lying on the beach, there were 

 found the remains of a Chelonian, referred by Prof. Owen to the 

 family Paludinosa, and named by him Plastremys lata. The pre- 

 sence of these freshwater organisms was thought to imply a connex- 

 ion with the Wealden continent. The chert-bed, 2 feet thick, 

 was regarded by the author as marking the boundary between the 

 Gault and the Greensand. Above it the author described 56 feet of 

 compact red and yellow sands, of which the first 20 feet are un- 

 fossiliferous, the upper 32 feet show traces of organic remains; 

 between them there is a fossiliferous zone 4 feet in thickness, con- 

 taining Ammonites injlatus, A. auritus, and species of Panopcea, 

 Cucullasa, Area, and Trigonia, and immediately below this a separate 

 band containing an undetermined species of Ammonite. These sands 

 are followed by 38 feet of alternate beds of hard chert and coarse 

 greensands, having at the bottom 6 feet of inferior building-stone, 

 surmounted by 5 feet of freestone. The latter contains Ammonites 

 restrains, and the cherts various fossils, chiefly bivalves. Clathraria 



