Introduction to special issue of Canadian Journal of Earth Sciences: The Alberta Basement Transect of Lithoprobe

Abstract

From outcrops in northeastern Alberta to exposures within structural culminations in the Canadian Cordillera, the crystalline basement that lies buried beneath the Phanerozoic Alberta Basin of western Canada represents a significant part of the Canadian Shield, ca. 750 000 km2. The advent of modern high resolution aeromagnetic data and U–Pb geochronology have opened the doors for the next era of investigation of the crystalline basement of the Alberta Basin. Aeromagnetic data and geochronology provided important physical and temporal links to the exposed Canadian Shield, which allowed its structural framework to be extrapolated into the subsurface. The most recent chapter in this evolving story has been the Alberta Basement Transects of Lithoprobe, a 12-year program, which has used multi disciplinary geoscience studies to further elucidate the nature, history, and geometric characteristics of basement domains beneath the Alberta Basin. This special issue is the second in a three issue set of publications that synthesize the results of over a decade of Lithoprobe research in the Alberta Basin. The first issue, published in the Bulletin of Canadian Petroleum Geology, concentrated on the shallow sedimentary record and new insights gained from linking deep seismic reflection profiles with the evolution of the sedimentary succession. The present issue presents a crustal perspective and concentrates on the results from mapping, geochronology, igneous petrology, and seismic investigation of the crystalline basement of the Alberta Basin. The diversity of disciplines covered in this issue address questions about the evolution of the crust and mantle of western Canada and offer unique perspectives on the insight gained from the merger of reflection seismology, magnetotellurics, potential field studies, and field based observations. New breakthroughs in mantle dynamics and its role in sedimentary basin formation, as well as our ability to image mantle structure and relate it to surface tectonic processes, are important steps forward.