The Coal Ridge occurrence coal seams are located approximately 900 metres south of the peak of Mount Gorman, east of Gorman Creek along the British Columbia–Alberta border, approximately 123 kilometres south-southeast of Tumbler Ridge.
The region is underlain by an assemblage of sedimentary rocks consisting mainly of continental margin and shelf facies rocks. This assemblage was deposited on and to the west of the Ancestral North American craton. These sedimentary rocks, for the most part typical continental margin slope and basin facies, range in age from Hadrynian to Upper Cretaceous. Structurally these rocks are part of the Foreland thrust and fold belt of the North American Cordillera.
The coal measures of the region occur mainly in Cretaceous sediments deposited unconformably on older slope and basin strata. These sediments were subjected to fold and thrust tectonics, which also affected the older rocks.
Only the lowest four coal seams in the Lower Cretaceous Gates Formation (Fort St. John Group) are present in the Coal Ridge area. They are interbedded with siltstones, sandstones and mudstones. Beds dip southwest, strike northwest and consist of a remnant of the northeast limb of a large and gentle syncline. No other folds or faults are apparent. The Lower Cretaceous Gething Formation (Bullhead Group) contains a seam approximately 3.05 metres thick at the top of the formation.
The lowest coal seam (#1), which lies immediately above the Torrens sandstone, is 1.8 to 2.7 metres thick in outcrop at Coal Ridge, though it ranges from 3.7 to 9.1 metres in adjoining areas (average 6.1 metres).
Seam #2 is approximately 3.7 to 4.6 metres thick and approximately 15 metres above coal seam #1. The thickness of the sandstone between coal seams #1 and #2 is apparently highly variable since the two seams are only 4.5 to 6 metres apart in outcrop in Wolverine Creek, approximately 4.8 kilometres to the north.
Seam #3 is thinner (0.3 metre) and locally up to 1.5 metres thick and lies approximately 27 metres above seam #2.
Seam #4 is 5.5 to 6.1 metres thick in outcrop at Coal Ridge; it averages 9.1 metres in adjoining coal licences. This seam lies approximately 21 metres above seam #3. There is only 3 to 9 metres of sandstone overlying seam #4 on Coal Ridge.
The seams, on a dry basis, contain from 16.57 (seam #4) to 35.40 per cent (seam #1) ash, 22.24 (seam #1) to 26.09 per cent (Gething seam) volatile matter, 42.36 per cent (seam #1) to 54.91 per cent (Gething seam) fixed carbon and 0.31 (Gething seam) to 0.37 per cent (seams #1, #2 and #4) sulphur.
Preliminary reserve calculations indicate between 4.0 and 4.5 million tonnes of raw coal reserves present in the area (seams #1, #2, #4 and the Gething seam; Coal Assessment Report 549).
