﻿Vol. 64.] LATJEBNTIAN SYSTEM IN EASTERN CANADA. 147 



and Keewatin Series, which are the oldest stratified rocks 

 in the western part of the protaxis, has yet to be deter- 

 mined, the two not having so far been found in contact ; 

 nowhere, moreover, either east or west, has the original 

 basement upon which the first sediments were laid down 

 been discovered — these are everywhere torn to pieces by 

 the granite-intrusions of the Laurentian. 



EXPLANATION OF PLATES XI-XIII. 



Plate XI. 



Ampbibolite invaded by granite of the Methiien bathylith and partly 

 dissolved by it. Kasshabog Lake, Township of Methuen, Ontario (Canada). 



Plate XII. 



* Feather-amphibolite ' (altered sediment). Township of Wollaston, Ontario 

 (Canada). The scale shown in the plate is in inches. 



Plate XIII. 



Geological map of portions of Hastings, Haliburton, and Peterborough 

 Counties (Ontario), on the scale of 2 miles to the inch (Bancroft sheet). 

 Re-published by permission of the Geological Survey of Canada. 



Discussion. 



The President alluded to the revolution of opinion regarding the 

 origin of the Archaean gneisses since the publication of Lehmann's 

 epoch-making work on the Saxon granulites. The old idea that 

 the structure-planes of these gneisses represent the bedding of 

 original sediments has been generally abandoned on both sides 

 of the Atlantic; and the rocks in question are now recognized 

 to be, for the most part, plutonic igneous masses which acquired 

 these characteristic structures as the result of enormous pressure 

 and movement and of more or less complete recrystallization under 

 great earth-stresses. It was satisfactory to find this modern view, 

 which had been long ago applied to the Laurentian gneiss of 

 Canada, ably supported by the further evidence brought forward 

 by the Author from his prolonged investigations. Until the 

 memoir which he now laid before the "Society was in print, it was 

 hardly possible to appreciate how much it added to our previous 

 knowledge of the subject. There was one portion of it to which 

 the President called attention, as not unlikely to evoke criticism — 

 the statement that amj)hibolites of identical type could result from 

 three entirely -diff'erent sources. It was difficult to believe that the 

 type should not present more or less distinctive variations in each 

 case. But the wide experience and proved accomplishment of the 

 Author (who had returned to Canada after the Centenary celebrations) 

 entitled his conclusions to the most attentive consideration. The 

 publication of the full paper, with all its detailed proofs, would be 

 awaited with much interest. Meanwhile the Society welcomed this 



