﻿[ 154 ] 

 XXII. Proceedings of Learned Societies* 



GEOLOGICAL SOCIETY. 



[Continued from p. 78.] 



June 22, 1870. — Joseph Prestwich, Esq., F.R.S., President, 



in the Chair. 



fFHE following communications were read : — 

 •*- 10. " On an altered Clay-bed and Sections in Tideswell Dale, 

 Derbyshire/' By the Eev. J. M. Mello, M.A., F.G.S. 



The author describes the sequence of the rocks seen in a quarry 

 in Tideswell Dale as follows : — Beneath a thin layer of surface-soil 

 is a bed of Toadstone, containing concretionary balls, and much de- 

 composed above ; beneath this is Toadstone in large blocks of inde- 

 finite shape, very hard, dark-green, and apparently doleritic, nine 

 or ten feet thick, passing downwards into a coarse and much de- 

 composed bed, partly amygdaloid, partly vesicular, about 1 foot 

 thick. Beneath the Toadstone rocks, and without any sharp line of 

 demarcation, is a thick bed of indurated red clay, 3 yards in thick- 

 ness, presenting a regularly prismatic columnar structure, resting on 

 a thin bed of greenish-yellow clay containing fragments of lime- 

 stone, which covers beds of good Derbyshire marbles containing 

 corals. The author suggests that the columnar clay-bed may 

 perhaps be a local development of that which forms partings in the 

 limestone near Litton Tunnel. 



11. " On the Physics of Arctic Ice as explanatory of the Glacial 

 Remains in Scotland." By Dr. Robert Brown, M.A., F.R.G.S., <fec. 



In this paper the author entered into an extended inquiry how far 

 the formation of the boulde: -clays and other glacial remains in 

 Scotland and the rorth of England can be accounted for on the 

 theory of a great ice-covering having at one time overlain the country 

 in much the same manner as it does now Greenland and other 

 extreme Arctic countries. Taking the hypothesis of Agassiz as his 

 groundwork, Dr. Brown entered into a minute description of the 

 present glacier-system of Greenland, and the nature of Arctic ice- 

 action, and into an inquiry how far glacial lemains in Britain 

 correspond with those at present in course of formation in G een- 

 land and at the bottom of Baflin's Bay, Davis Straits, and the 

 fjords and bays adjoining these seas. These inquiries were com- 

 menced in the year 1861, and have been continued at intervals 

 ever since, up to the present summer, in various portions of the 

 Arctic regions, the continent of Europe, in Great Britain, and in 

 North America across to the Pacific. The result of these extended 

 researches have led him to conclude : — 1. That the subazoic boulder- 

 clay corresponds with the moraine profonde which underlies g'a-oiers, 

 and in all likelihood is the immediate base on which the ice cap of 

 Greenland rests. 2. That the fossiliferous, lamiraied, or brick-clays 

 find their counterpart in the thick impalpable mud which the sub- 

 glacial streams are pouring into the sea, filling rp the fjords, even 

 shoaling the sea far out, and, in some cases, absolutely turning tue 



