Preliminary Map No. 28: Geology of the Estella-Kootenay King Area
(082G/11, 12, 13, 14)
View Map (PDF, 3 MB) (1:25 000)
Preliminary Map 28 describes the geology and mineral occurrences of the Estella-Kootenay King area (82G/11, 12, 13, 14) in the Hughes Range of southeastern British Columbia. The map is at 1:25 000 scale and includes a legend, cross sections and diagrams portraying paleo-directional structures, such as cross beds. It represents work done in 1976 and 1977. An updated version of the geology is presented in Preliminary Map 36.
The oldest strata in the area are within the Helikian (Proterozoic) Purcell Supergroup. The lowest unit exposed consists of siltstones and quartzites of the Fort Steele Formation. These are overlain by the Aldridge Formation with a lower unit consisting mainly of finely laminated argillite and siltstone, a middle unit of dominantly quartzite and siltstone interlayered with dark argillite, and an upper unit of argillite with minor siltstone. The overlying Creston Formation consists mainly of siltstone, argillite and quartzite with colours ranging from white to green to purple and locally abundant mud cracks, cross beds and grades beds. Above is the Kitchener-Siyeh Formation, which consists primarily of dolomite, siltstone, and siltstone-argillite couplets. Gateway Formation quartzite and siltstone are overlain by massive to amygdaloidal andesitic lava and all the older rocks are cut by Purcell sills and dikes.
Cambrian dolomite and marble overlie the Proterozoic rocks. The only intrusive rocks in the area are Cretaceous (?) quartz monzonite and syenite.
Large scale overturned folds are offset by north-south faults and east-west cross faults. Reverse faults are generally steeply inclined and shallow normal faults or slides occur.
The past producing Estella and Kootenay King deposits are within the map-area. Estella is classified as a polymetallic vein deposit with commodities Ag-Pb-Zn±Au. The veins also carry cadmium and copper values. Kootenay King is classified as a sedimentary exhalative deposit with commodities Zn-Pb-Ag. The deposit also has values in cadmium, copper and gold.
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