Geophysics and geochronology of the crystalline basement of the Alberta Basin, western Canada

Abstract

Although progressively muted by the increasing thickness of Phanerozoic sediments in the Alberta Basin, the geophysical signature of tectonic domains in the Canadian Shield can be traced nearly to the Foothills of the Canadian Cordillera. A combination of potential field data for Alberta and U–Pb zircon and monazite age determinations on drill core samples of crystalline basement recovered during hydrocarbon exploration was used to subdivide the basement of the Alberta Basin into 22 distinct domains. The Canadian Shield was used to ground truth the interpretation of the geophysical signatures and infer possible kinematic relationships between basement domains. Ages of crystalline basement range from 1.7 to 3.2 Ga and demonstrate that a large expanse of 2.1–2.4 Ga crust is present in northern Alberta. This suggests a continuum of tectonic activity and crust formation(?) in Alberta rather than the 2.6 Ga and 2.0–1.8 Ga episodicity apparent in the exposed Canadian Shield.