Summary:
The Project property is located within the East Kootenay Coalfields and forms part of the Rocky Mountain Foothills structural belt, which lies to the east of the Canadian Rocky Mountain Trench.
Coal seams are found throughout the formation, although the thicker seams occur lower in the section. The formation contains from 4 to over 30 seams, which make up from 8% to 12% of the thickness of the formation. Cumulative coal thickness ranges up to over 70 m. The area has experienced moderate to intense folding and thrust faulting, which has caused repetitions and structural thickening of seams.
The East Kootenay Coalfields lie in the Front Ranges of the Rocky Mountains, which are characterized by north-to-northwest trending concentric folds and west-dipping thrust faults. Tertiary normal faults, some of which are listric and probably occupy earlier thrust surfaces, arealso a major feature.
The Crowsnest coalfield is a complex synclinorium in the Lewis thrust sheet. The major compressional features of the basin are the synclines linked by low-amplitude anticlines. A series of west-dipping thrust faults dominates the structure of the north half of the basin. The major extensional feature is the Erickson fault system, which juxtaposes Mississippian limestone and the Kootenay Group. The fault has a minimum, west side-down, displacement of 1,200 m.
Three formations are recognized within the Kootenay Group, including the basal sandstone Morrissey Formation, the coal-bearing Mist Mountain Formation, and the upper Elk Formation.
The Cadomin Formation, including the Pocaterra Creek (Mbr) unconformity, and more recent Quaternary deposits overlie the Elk Formation. The Elk Formation is the uppermost formation in the Jurassic-Cretaceous Kootenay Group and is characterized by a relative abundance of coarse elastics (sandstone and locally conglomerate) and relative lack of coal, in comparison to the underlying Mist Mountain Formation.
As reported for Teck’s nearby Coal Mountain Operation (Teck 2014), the Elk Formation is coalbearing, with very thin coal seams. The Elk Formation is generally believed to reach a maximum thickness of nearly 550 m in the Fernie basin area.
The Mist Mountain Formation lies beneath the Elk Formation and contains the economic coalbearing strata of interest in the Project area. The Formation is mainly composed of non-marine sandstone, siltstone, mudstone, shale, and bituminous coal seams of various thicknesses. The sandstone is composed of fine to coarse, angular to well-rounded grains of quartz and chert with minor amounts of lithic grains of various other rock types and is typically light to medium grey in colour. The sandstones are moderately to well sorted and generally well indurated and are visible as local cliff-forming features between the other rock units. The predominant siltstones are medium to dark grey in colour, composed almost entirely of quartz, with minor chert and lesser amounts of carbonate minerals. The Mist Mountain Formation can range in thickness from a few hundred metres to over 600 m in the upper Elk Valley.
Within the Project property, the Mist Mountain Formation averages over 500 m in thickness and contains more than 20 mineable coal seams that vary in thickness from less than 1 m to over 14 m. The limestone represents the footwall side of the major, regional, Erickson normal fault, which juxtaposes Mississippian limestone and the Kootenay Group. The fault has a minimum, west-sidedown, displacement of 1,200 m.