Eagle Foreland Basin Tectono-Sedimentary Element, Yukon Territory, Northwest Canada

Abstract

Abstract The Eagle Foreland Basin Tectono-Sedimentary Element (TSE) comprises two separate parts: a larger rectilinear sub-basin of Cretaceous age (Eagle Plain) and a smaller fault-bounded mid-Cretaceous–Paleogene sub-basin (Bonnet Plume) in the SE, separated from the Eagle Plain by an inlier of the Ogilvie Platform TSE. Faulted remnants of older Mesozoic clastic strata are locally preserved beneath northern parts of the Eagle Plain Sub-basin. The Eagle Foreland Basin initiated as a Cordilleran foredeep and was incorporated into the orogen during Late Cretaceous–Paleogene deformation. It preserves dominantly marine clastic strata >2500 m thick, with thickest preservation in the NW. Thermal maturity data suggest that 2000–3000 m of deposits were removed by Paleogene erosion. Petroleum potential exists, with principal active sources lying within subjacent successions. The Eagle Plain Sub-basin is an early mature to mature basin, oil and gas prone in the deeper basin, and gas prone in younger units. The Bonnet Plume Sub-basin, known for its coal-bearing strata, is largely unexplored. It contains non-marine to marginal-marine clastic strata, and is considered to be a marginally mature to mature gas-prone basin. The total mean in-place potential in the Eagle Foreland Basin TSE is suggested to be on the order of 20 MMm 3 of oil and 22 000 MMm 3 of gas.