13 



nearly horizontal or gently dipping strata ranging in age 

 from lower Ordovician to uppermost Silurian. The 

 measures rest on the Pre-Cambrian and abut against the 

 edge of the upland area of the Canadian Shield. 



Along the southwestern shore of the St. Lawrence, the 

 strata, striking in a northeasterly direction, are closely 

 folded, in a large measure overturned, and are traversed 

 by many dislocations, along some of which the strata 

 from the southeast are thrust over the beds to the north- 

 west. In age these measures range from late Ordovician 

 to Cambrian; they belong to the Quebec group and differ 

 lithologically and faunally from the nearly horizontal 

 strata of the islands and north shore of the St. Lawrence 

 and from which they are separated by a great fault or 

 zone of faulting that strikes in a southeasterly direction 

 beneath the waters of the St. Lawrence as far as the 

 neighbourhood of Quebec city and from there, continuing 

 with the same general direction, runs through the land 

 area to Lake Champlain and beyond. 



The band of the Quebec group which borders the St. 

 Lawrence below Quebec, varies in width from 6 miles to 

 35 miles (9.6 to 56 km.). On the southeast these rocks 

 are bounded by a great area of strata that in the main, 

 range in age from Devonian to Silurian. Such measures 

 form the greater part of the peninsula of Gaspe and, 

 stretching to the southwest from the upper part of Chaleur 

 bay, occupy the northwestern portion of New Brunswick. 

 Along their northwestern boundary, these measures in 

 places overlap the Quebec group strata, in other places 

 have been thrust over them, while along the mountainous 

 axes of the Gaspe peninsula a narrow zone of Palaeozoic 

 igneous rocks and deformed strata possibly of Pre-Cambrian 

 age, intervenes. 



The strata of this essentially Silurian and Devonian 

 area, are folded along axial lines which, in the southwest, 

 strike to the northeast but which in the Gaspe peninsula 

 swing to an easterly course. In certain districts, the 

 strata lie in open folds, but perhaps over the greater part 

 of the region the folding is closer and in many places the 

 beds are crumpled and highly faulted. 



In Gaspe, the Silurian and Devonian measures occupy 

 an area having a breadth of 70 miles (no km); to the 

 southwest, in New Brunswick, the area is approximately 

 150 miles (240 km.) wide. In the southeastern part of 



