The Cadomin East (83F/3 East) mapsheet was mapped on a scale of 1:50,000. Some 4000 meters of Cretaceous and Tertiary strata are present in the area. The largely Tertiary Coalspur Formation contains the major economic coal seams, which were mined in the past and may well be mined in the near future. In addition, the upper Brazeau Formation contains coal seams up to 4 meters thick. These Brazeau coals have been insufficiently explored to make resource calculations or to establish seam correlations.
The economic coal seams of the Coalspur Formation are present in the area in three parallel bands in the Entrance Syncline and Coalspur Triangle Zone. The Mercoal band is the southernmost, contains the Mercoal Project of Manalta and dips to the northeast. The Coalspur band is in the middle and dips generally to the southwest. The Robb band is the northernmost band and contains northeast dipping strata and is less deformed than the Coalspur band.