Reports and Proceedings — Geological Society of London. 93 



II.— January 5, 1898, — Dr. Henry Hicks, F.R.S., President, in the 



Chair. 



Professor Judd drew attention to the outline geological maps of 

 England and Wales on the scale of 30 miles to the inch, for the use 

 of schools and colleges, presented by John Lloyd, Esq. These were 

 reproduced, by permission of the Science and Art Department, from 

 the maps in use at the Royal College of Science, South Kensington. 



The following communications were read : — 



1. " On the Structui-e of the Davos Valley." By A. Vaughan 

 Jennings, Esq., F.L.S., F.G.S. 



Evidence is brought forward to show that the level area, about 

 four miles in length, near Davos is occupied by superficial deposits, 

 and that the lateral talus-fans there have been cut through at 

 a relatively recent date since their accumulation ; that the northern 

 end towards Wolfgang is blocked by moraine-material of great 

 thickness, but for which the Davoser See would drain north to the 

 Landquart, carrying with it the waters of the Fluela and Dischma ; 

 that the contour-lines suggest the former existence of a far larger 

 lake stretching south towards Frauenkirch, and that in that part 

 there is proof of the previous existence of a great detrital fan 

 sufficient to account for the existence of the lake in question. 



It is shown that the former ice-movement was not from the 

 present watershed between the tributaries of the Landwasser and 

 Landquart, but from a spot farther south. 



The author concludes that the main vallej^-systems were marked 

 out in Pre-Glacial times, and that at one time there was a water- 

 shed somewhere between Davos Platz and Frauenkirch. During 

 the Glacial Period moraine-material was heaped up across the valley 

 below the Hornli, and held up the waters to the south, forming 

 a great lake of which the pi*esent Davoser See is a relic, the outflow 

 being probably over a low saddle near the present Wolfgang ; 

 during this time a great moraine and detrital fan existed across the 

 valley to the south, and the lake for a long time was thus prevented 

 from draining in that direction. After the Glacial Period the 

 northern moraine was subjected to little erosion, but the southern 

 one, formed from the first of looser material, was rapidly cut back 

 by the Sertig Bach, and in time the barrier was so weakened as to 

 cause that end of the lake to be tapped, and at that time the terraces 

 opposite Frauenkirch may have been levelled, while the flow over 

 "Wolfgang would be stopped, and the Fluela and Dischma streams 

 turned southwai'd ; the Landquart would then cut away the margins 

 of the talus-fans which had been accumulating in the lake. 



2. " Sections along the Lancashire, Derbyshire, and East Coast 

 Railway between Lincoln and Chesterfield." By C. Fox-Strangways, 

 Esq., F.G.S. (Communicated by permission of the Director-General 

 of H.M. Geological Survey.) 



The portion of the line considered in this paper occupies a distance 

 of about forty miles, and runs nearly at right angles to the strike of 

 all the beds from the Lias to the Coal-measures. 



