﻿FroUems m Quebec Geology. 497 



a few points it would appear that, along the crests of 

 some of these the underlying L(5vis beds are disclosed. 

 The areas of such underlying strata must, however, be 

 comparatively small. 



A development of black shales and limestones is seen 

 along the upper part of the north side of the Island 

 of Orleans. These are separated from the slates of 

 the Levis by a fault, which appears to be the continuation 

 of that seen along the north side of the city of Quebec. 

 The strata of the Levis division here appear to rest 

 conformably upon the rocks of this series, but there is 

 a difference in the physical aspect of the two series as 

 well as in the character of the contained fossils in the two 

 divisions. The northern, and apparently underlying 

 portion, is undoubtedly the same as that seen in the city 

 of Quebec, the age of which has been stated to be that of 

 the lower Trenton. This group of rocks appears at a 

 number of places along the south side of the lower 

 St. Lawrence in such close relations to the overlying 

 Sillery as to have led. to the conclusion on the part 

 of some observers that it really occupied a lower 

 stratigraphical position. The presence of several faults 

 between the strata of the two series is plain, and the 

 fossils obtained from the apparently underlying beds 

 show conclusively that the underlying member is really 

 the higher in the geological scale. These beds also 

 apparently belong to the lower part of the Trenton. 



To the north of the St. Lawrence, below the city 

 of Quebec, these peculiar developments of strata do 

 not appear. The Trenton along the south flank of the 

 hill range of the Laurentian rests directly upon the 

 crystalline rocks of that system. The lower beds of the 

 Trenton here consist of a thin dcA-elopment of arkose 

 strata resembling very closely a quartzite, but the upper 

 portion of this has been found to contain the characteristic 

 fossils of the formation. These quartzose beds appear 



