Figure 1: Schematic representation of the stratigraphic succession in the study area. SCU: sub-Cretaceous unconformity (heavy line). BQ deposits include the units that lie between the SCU and the base of the Ellerslie. The thickness of the BQ ranges from 0 to 70 m. The mean breath of the Horsefly valley is 20 km in the study area, while that of the BAT (B1 + B2) is approximately 8 km.