﻿498 Canadian Record of Science. 



in the bed of the Ste. Anne River, above the Montmorency 

 Fall, as well as in patches on the face of the gneiss at the 

 fall itself. 



The Trenton, at the foot of the Falls, is overlain by the 

 Utica shales, and these pass upward into the Lorraine, 

 which extends out into the north channel of the St. 

 Lawrence. All these formations are clearly defined by 

 their characteristic fossils. 



On apparently the same horizon with the Quebec city 

 rocks are certain other areas, which for many years have 

 been in dispute as to their true horizon. Among these 

 may be mentioned the areas of black slate and limestone 

 near Farnham, which on presumed stratigraphical grounds 

 were, in the Geology of Canada, 1863, regarded as beneath 

 the Potsdam. An examination of the fossil contents by 

 Billings, however, showed that they were higher in the 

 scale; and subsequent investigations in this direction 

 have proved them to be the equivalents of the Quebec 

 city series. Along the east side of the Sutton Mountain 

 anticlinal also are other areas of slates with limestones, 

 which for a long time yielded no organic remains, and 

 these were, from their supposed relations to Upper 

 Silurian rocks in their vicinity, regarded as of that age. 

 These also, on the evidence of fossils, principally grapto- 

 lites, are now assigned to their proper place at the base of 

 the Trenton. 



The areas of these rocks are very considerable, both 

 on the east and west side of the main anticlinal. 

 Interesting developments of this group of black slates 

 and limestones are also found in close association with the 

 crystalline schists near Melbourne and Danville, where, 

 through a peculiar series of folds and overturns, these 

 rocks, which have recently been found to contain lower 

 Trenton fossils, are apparently beneath the crystalline 

 series. Like the Farnham rocks, these were also formerly 

 regarded as older than the Potsdam and supposed to be in 



