Provenance of the Aptian McMurray Formation: Insights from Detrital Zircon Geochronology

Abstract

The McMurray Formation of the Athabasca Oil Sands hosts one of the largest hydrocarbon resources on Earth, yet the provenance of the sediment itself remains poorly constrained. As the first detrital zircon provenance study from the oil sands, new uranium-lead (U-Pb) detrital zircon ages provide important insights into Early Cretaceous paleogeography, continental-scale sediment transport, and assist in the correlation of incised valley deposits. 27 samples dated using laser ablation–multicollector–inductively coupled plasma–mass spectrometry (LA-MC-ICP-MS) reveal two sets of three distinct detrital-zircon signatures. Each set is documented and grouped into three chronofacies, interpreted to reflect derivation from the Canadian Shield, the Appalachians, and the Cordilleran orogen. Several hypotheses are presented to answer the question of when and how sediments from eastern North America were transported to western Canada. These data are combined with subsurface correlations and chemostratigraphic data to demonstrate the complexity of valley fills and examine the relationship between different valley deposits.