﻿484 Canadian Record of Science. 



portion of the area a great development of crystalline 

 rocks, comprising schists of various kinds, limestone, 

 altered slates, diorites, diabases, serpentines, etc., are 

 found, which constitute the rocks of the Sutton Mountain 

 chain, the extension northward of the Green Mountain 

 range of the state of Vermont, and these, in Canada, with 

 some interruptions, continue for many miles in the area 

 south of the St. Lawrence, reappearing again in the 

 northern part of the Gaspe peninsula. 



All the sedimentary formations throughout this area 

 are well defined by the characteristic fossils peculiar 

 to each, and can be readily recognized. These have been 

 divided into groups of strata and named according to the 

 system of nomenclature adopted by the Geological Survey 

 of the state of New York many years ago. The 

 delimitation of the several divisions of the Cambro- 

 Silurian rocks in this area presents but few difficulties, 

 other than those which are due to the fact that, over 

 large portions of the country, great deposits of clays are 

 found by which the underlying sediments are frequently 

 concealed. To the east of these fiat-lying sediments, 

 however, and separated from them by a series of faults, 

 some of which are of considerable extent, is the group of 

 strata first alluded to ; the series as a whole being highly 

 inclined, folded and sometimes overturned, and presenting 

 at many points features quite distinct from the ordinary 

 Cambro-Silurian formations, so that for many years great 

 difficulty was experienced in reconciling these with well 

 established horizons, or in finding a secure geological 

 basis for their proper disposition in the general scheme of 

 classification. 



This, it is hoped, has at length been achieved through 

 the careful work, both from the stratigraphical and 

 palfcontological standpoints, of the last ten to twelve 

 years, and it is thought desirable that a brief resume 

 of the results arrived at in this work should here be 



