174 Geological Society: — 



protection accorded to the high lateral valleys by ice, which even 

 nowadays still lingers there. Examples from the Maloja district of 

 the Engadine are cited as conflrmator}* of this. The best-preserved 

 of these ' hanging valleys ' in three districts examined by the 

 author all face north-eastward, and show protection by ice ; others 

 not so protected have begun to cut back their gorges to an accordant 

 grade with the main valley. Examples of other types of ' hanging 

 valleys ' not due to the overdeepening of the main valley are given, 

 and proofs of the greater power of water to excavate over ice are 

 assigned. 



June 18th.— Prof. Charles Lapworth, LL.D., E.R.S., 

 President, in the Chair. 

 The following communications were read : — 



1. 'The Great Saint-Lawrence-Champlain-Appalachian Fault of 

 America, and some of the Geological Problems connected with it/ 

 By Henry M. Ami, M.A., D.Sc, F.G.S. 



The extent, earth-movements, and striking characteristics of this 

 fault-line and of the geological formations which occur along this 

 line of weakness in the earth's crust, with special reference to the 

 formations in British North America, were discussed. 



Recent investigations in the succession of faunas and geological 

 formations in Eastern Canada have emphasized the fact that those 

 formations which occur to the south and south-east of this great 

 dislocation are strikingly like the geological formations referable to 

 the same geological systems in Great Britain and Western Europe. 

 The fault, as it is traced to-day, appears to divide the geological 

 formations of the Maritime Provinces and Canada into two distinct 

 geological provinces — one, east of the fault, in which the several 

 formations resemble both lithologically and palaBontologically the 

 British succession ; the other, to the west of this great fault, 

 where there occurs the typical American or epicontinental type of 

 succession. 



2. ' The Point-de-Galle Group (Ceylon) : Wollastonite-Scapolite- 

 Gneisses.' Bv Ananda Iv. Coomaraswamv, Esq.. B.Sc, F.L.S., 

 F.G.S. 



The chief rock-types vary from basic pyroxene-sphene-scapolite- 

 rock, through intermediate rocks composed of pyroxene, scapolite, 

 and wollastonite, with felspar and quartz subordinate or abundant, 

 to acid types made up of orthoclase-microperthite or coarse-grained 

 quartzo-felspathic rocks. They differ from the normal types be- 

 longing to the Charnockite Series in their somewhat coarser grain, 

 in the presence of wollastonite, scapolite, and sphene, the existence 

 of definite dykes and segregation-veins crossing the foliation, and in 

 the absence of garnet, hypersthene, original mica, and hornblende ; 

 but they resemble the series in the variability of chemical and 

 mineralogical composition, in the conspicuous foliation, the common 

 strike, the petrological character of the acid types, and in the local 

 tendency to graphic structures. The foliation, dykes, weathering, 

 and relationship to the Charnockite Series are described ; and an 



