The sub-Cretaceous unconformity is an important regional surface found across the Alberta Basin representing a major erosional event, which exposed Middle Devonian to the Upper Jurassic/Lower Cretaceous (Nikanassin Formation) strata. Structural modelling and zero-edge delineation of subcropping formations intersecting this surface is an integral part of a larger AGS project to create a provincial-scale 3D geological framework model of the Alberta subsurface.
The study area used for this presentation covers UTM map sheets 83G, 83F, 83J and 83K. Geophysical wireline logs for over 3000 wells were reviewed to identify the depth of the unconformity and the corresponding subcropping formation. Subcropping formations in the study area were found to include the Nikanassin, Fernie, Debolt, Pekisko, Shunda, Banff, Exshaw, and Wabamun formations.