282 Reports & Proceedings — Geological Society of London. 



has been partially exposed, at different levels and often over wide 

 areas, by denudation". A garnetiferous augite-diorite, remarkable 

 for parallel intergrowths of garnet, felspar, and augite, forms an 

 unusual variant of the Strathdearn granite. An interesting peno- 

 logical chapter by Dr. J. S. Flett gives details of the igneous and 

 metamorphic rocks, and describes kyanite-, silliraanite-, and staurolite- 

 gneisses as products of the thermal metamorphism of the schists. 



The region can boast of a magnificent range of glacial phenomena, 

 equalling in clearness and beauty those of any other area in the 

 British Isles. The Glacial Period is divided into four stages : the 

 stage of maximum glaciation, in which there was a thick ice-sheet 

 moving eastwardly ; the stage of large confluent glaciers originating 

 outside the area ; a stage of separation of the confluent "laciers 

 into independent valley glaciers ; and finally a stage of high-level 

 corrie glaciers. The retreat phenomena of the valley glaciers are 

 finely displayed in a series of overflow and marginal channels, 

 associated with lateral moraines, high-level marginal terraces, and 

 flat spreads of sand and gravel that occupied the deeper ernbayments 

 of the ice-margin. The six fine plates are all illustrative of various 

 phases of the glaciation and physiography. Perhaps the best is the 

 frontispiece, showing the great through-valley of the Lairig Ghru, 

 cutting right through the summit platean of the Cairngorm massif, 

 and fronted by the fluvio-glacial plain of the Rothiemurchus Forest, 

 which, unlike most Highland ' forests ', appears to have some 

 trees in it. 



G.W.T. 



REPORTS .A.:N-;D PBOCEEDIWGrS. 



I. — Geological Society of London. 



1. April 14, 1915.— Dr. A. Smith Woodward, F.R.S., President, in 



the Chair. 



The President referred with regret to the death of the Rev. Alec 

 Field, who was Assistant in the Society's Library and Office from 

 1900 until 1908. In the latter year he left the Society's service, 

 in order to be trained as a missionary. He was among those lost 

 on the s.s. Falaba, torpedoed by a German submai'ine on the 

 afternoon of Palm Sunday, March 28, 1915. Mr. Field was 

 returning to his post at Bida in Northern Nigeria. 



The following communication was read : — 



"Further Observations upon the Late Glacial, or Ponder's End, 

 Stage of the Lea Valley." By Samuel Hazzledine "Warren, F.G.S. 

 With Notes on the Mollusca by Alfred Santer Kennard, F.G.S., 

 and Bernard Barha-m Woodward, F.L.S., F.G.S. 



The paper is supplementary to that previously published (Q.J.G.S., 

 vol. lxviii, p. 213, 1912), and describes additional sections which 

 increase the range of the deposits. They have now been traced, with 

 the assistance that the author has received from Mr. A. Wrigley, for 



