Geol Fldwk 2000.vp

This study documents the distribution of Selenium (Se) in the Jurassic-Cretaceous Mist Mountain Formation of southeastern British Columbia and in various materials segregated by the five coal mines in the area. This study is preliminary and will be followed up by more detailed and focused studies. The Mist Mountain Formation, which is part of the Kootenay Group (Table 1), outcrops extensively in the east Kootenays and varies in thickness from 25 to 665 metres (Gibsons, 1985). Typically 8% to 12% of the thickness of the formation is coal and in places this is distributed in over 30 seams. The rest of the formation is composed of non-marine siltstones, mudstones and sandstones. The formation is underlain by the Morrissey Formation, which is a sandstone unit that forms the footwall to most of the mining activity. This formation is underlain in turn by the Fernie Formation composed predominantly of marine shales. The Mist Mountain Formation is overlain by the Elk Formation, a non-marine sandy formation containing thin sapropelic coal seams.