1 68 The Ottawa Naturalist. [November 



the Stoke Mt. belt, whilst the Sutton Mt. belt reveal the pre- 

 sence of "altered greenstone of an amygdaloidal character." 

 "In the microscopic section, a little primary plagioclase some- 

 times remains, but in many sections the whole field consists of a 

 secondary aggregation of chlorite, epidote, iron ore and leucoxene. 

 The amygdules usually consist ot quartz and zeolitic minerals." 

 Dresser correlates these belts with chains of volcanic rocks 

 described from Pennsylvania by the late Dr. G. H. Williams. 

 After describing the structure of the region, that author gives the 

 summarv of his results as follows : 



1. That at least the greater portion of the Pre-Cambrian or 

 crystalline belts of the Eastern Townships of Quebec is of igneous, 

 not sedimentary origin, as has been hitheito supposed. 



2. That these rocks are allied to the volcanoes of South 

 Mountain, Pennsylvania, especially to the basic types, and indi- 

 cate the continuance of this class of rocks throughout the Appala- 

 chians, as was suggested by Williams. 



3. That the sediments of the region, which probably all be- 

 long to the Quebec Group, were deposited between and upon pre- 

 existing ridges of igneous material, which are now being uncovered 

 by denudation, while the intervening valleys still remain deeply 

 filled. 



Principal Dresser confirms the anticline theory of the struc- 

 ture of these mountains, which view was first held by Dr. A. R. 

 C. Selwyn, a former member ol the Club. In the January number 

 of the Ottawa Naturalist tor iqoi. Dresser advanced the view 

 that a portion of the Pre-Cambrian belt which forms the Sutton 

 Mountain belt was of igneous origin. Some of the rocks of the 

 area examined by Dresser are important as copper-bearing de- 

 posits. This paper is one of the foremost contributions to the 

 true interpretation of the geological structure and origin of the 

 rock formations of the Eastern Townships. 



H. M. Ami 



Note to members. The winter programme is now being got 

 ready and the chairman of the Soirde Committee will be pleased 

 to receive from members of the Club the titles of the papers they 

 are prepared to read. 



