Natural Gas in Quebec and the Maritime Provinces
Much of the greater part of the Province of Quebec lies within the Canadian or pre-Cambrian shield. The rocks underlying this area are, excepting for a veneer of early Paleozoic strata (generally Ordovician) over relatively small areas, of pre-Cambrian age, and consist of igneous rocks and strongly metamorphosed sedimentaries, which give no prospect for either natural gas or petroleum. Certain shales and limestones were evidently bituminous in their original condition, but are now graphitic or carbonaceous.
The part of the province lying southeast of a line between the city of Quebec and the head of Lake Champlain belongs to the Appalachian Mountain region. The rocks are steeply and intricately folded, are greatly faulted, and are intruded by large masses of igneous rock. The sedimentary rocks are of Cambrian and Ordovician age and, although not so intensely metamorphosed as those of the pre-Cambrian shield, are too much altered and broken over most of the region to be considered favorable for gas or oil accumulation. The St. Lawrence lowlands lie between the pre-Cambrian shield and the Appalachian Mountains. A part of this area, a part of the Gaspé Peninsula, and the island of Anticosti are the only areas in Quebec which may be considered as having any prospects for oil and gas.
The St. Lawrence lowlands comprise an approximately triangular area between the Laurentide Mountains, the southern part of the pre-Cambrian shield on the north, and the Appalachian Mountains on the southeast. This area is limited on the west by an “isthmus”