Alberta Geological Survey - Coal Geology: Coal Compilation Project - Grande Cache (NTS 83E/14)

The prime objective of the pilot Coal Compilation Project is to provide coal resource maps to stimulate and support industry exploration programs, and assist government in matters of resource management. Each map is intended to be a stand alone, unique product contributing to an overall synthesis of information. Maps generated will be at a regional or reconnaissance level. Collection of new data was limited.

This map covers the study area of NTS 83E/14 in east-central Alberta. The community of Grande Cache is the primary population centre in the study area.

Within NTS 83E/14, coal measures are deposited amid thick successions of sandstone, siltstone, shale and conglomerate stones. Known coal-bearing sequences are part of the Lower Cretaceous Luscar Group. The Luscar Group consists of sandstones, shales, conglomerates and coals, deposited predominantly in nonmarine environments. Strata of the Lower Cretaceous Luscar Group have been subjected to deformation which has produced northwesterly trending thrust faults and folds. As a result, the Luscar Group coal seams are now exposed in a series of northwest-trending thrust sheets and associated folds. Often the coal seams have been further locally folded and faulted. Depending on the severity of these local structural complexities, and acknowledging a general discontinuity of coal outcrops in the Mountain Region, coal seam correlations and evaluations can be extremely difficult. Within the map area, up to 14 seams are present within the Luscar Group. The seams have an average aggregate thickness of 24 metres and are contained within a 350+ metre thick sedimentary sequence.

In the northeastern part of the map area a good exploration database exists. The balance of the area has only been superficially examined from a coal resource/exploration point of view. Additional coal quality data need to be collected and detailed stratigraphic and/or structural studies are needed in most areas.