Exploration and Mining in the Kootenay-Boundary Region, British Columbia
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Exploration and mining in the Kootenay-Boundary Region, British Columbia Fiona Katay1, a 1 Regional Geologist, British Columbia Ministry of Energy and Mines, 1902 Theatre Road, Cranbrook, BC, V1C 7G1 a corresponding author: [email protected] Recommended citation: Katay, F., 2015. Exploration and mining in the Kootenay-Boundary Region, British Columbia. In: Exploration and Mining in British Columbia, 2014. British Columbia Ministry of Energy and Mines, British Columbia Geological Survey, Information Circular 2015-2, pp. 29-65. 1. Introduction Kootenays (Jersey-Emerald, Jumping Josephine, Swift The Kootenay-Boundary Region, in the southeast corner Katie, Thor, Willa, LH) of the province (Fig. 1), offers a variety of mining and exploration opportunities, and is accessible by well-developed 2. Geological overview infrastructure. Five operating coal mines produce most of Plate tectonic processes have operated along the western Canada’s coal exports. The historic lead-zinc-silver Sullivan margin of North America for over 2.5 billion years, and Mine is in the region, and exploration for base metals and the tremendous mineral endowment of British Columbia precious metals continues to be a focus. Several mines produce is intimately linked to these processes (e.g., Nelson et al., industrial minerals including silica, magnesite, gypsum, and 2013). The Canadian Cordillera is a collage of allochthonous graphite. terranes, parautochthonous terranes and autochthonous In 2014, total exploration spending and drilling increased basement, containing diverse rocks and structures, and hence, relative to 2013 (Fig. 2), with about $50.4 million spent on metallogenic styles. exploration. Exploration drilling (approximately 125,000 m) The Kootenay-Boundary Region (Fig. 1) contains increased for metals projects relative to 2013, whereas coal autochthonous and parautochthonous elements of exploration drilling was scaled back. With lower coal prices, ancestral North America (Laurentia) including: Archean drill programs in the coal mines were cut, and spending was to Mesoproterozoic basement rocks; Proterozoic rift and focused on mine development and mine evaluation projects intracratonic basin successions (Belt-Purcell and Windermere (Fig. 3), mainly on Environmental Assessment requirements for supergroups); Paleozoic to Jurassic passive-margin, shelf, and mine expansions. Coal production increased from 25.6 Mt in slope carbonate and siliciclastic successions that were deposited 2013, and is expected to be close to 27 Mt for 2014. Highlights on the western fl ank of the ancient continent (Kootenay terrane, for 2014 include: and North American platform); and Jurassic to Cretaceous • approval of the Elk Valley Watershed Management Plan foreland basin deposits. It also contains parts of the Slide • continued advances in major mine expansion plans Mountain terrane, which records mid- to late- Paleozoic back- at operating coal mines, with several projects in pre- arc extension that split the western fl ank of ancestral North application of Environmental Assessment (Elkview America to form the Slide Mountain ocean, and Quesnellia Baldy Ridge Extension, Line Creek Burnt Ridge and its basement (Okanagan subterrane) which, entirely exotic Extension, Fording Swift) and the Greenhills Cougar Pit to North America, accreted to the continental margin in the Extension nearing pre-application middle Jurassic (Nelson et al., 2013). • advances in new coal projects such as Crown Mountain Historically, the Canadian Cordillera has been divided into (NWP Coal Canada Ltd.), which entered pre-application fi ve northwest-trending physiographic belts. The Kootenay- stages of Environmental Assessment, Coal Mountain Boundary Region includes two of these belts (Fig. 4), the Phase II (Teck Coal Limited), which is nearing pre- Rocky Mountain Foreland belt, which consists mainly of application, and continued exploration drilling at Michel unmetamorphosed sedimentary successions that were thrust Creek (CanAus Coal Limited) northeastward in thin-skinned sheets, and the Omineca belt, • the Kootenay West gypsum mine (CertainTeed Gypsum which includes more deformed and higher grade (greenschist Canada Inc.) entered pre-application of Environmental to amphibolite) siliciclastic and volcanic rocks, and basement- Assessment cored gneiss domes (Monger, 1999). The Omineca belt and the • base metal exploration in the Belt-Purcell Basin in the Rocky Mountain Foreland belt are separated by the Southern East Kootenays (Vine, Sully, Ptarmigan) Rocky Mountain Trench (Fig. 4), which formed during Tertiary • base and precious metal exploration in the West transtensional collapse (Monger et al., 1982; Nelson et al., 29 Exploration and Mining in British Columbia, 2014. British Columbia Ministry of Energy and Mines, British Columbia Geological Survey IC 2015-2 Katay Rocky Mountain Foreland Belt ALBERTA Omineca Belt Moberley Silica )" <! J&L <! Zim Frac Sand Golden )" Horse Creek Silica 0 25 50 100 Revelstoke km Driftwood <! <! Magnesite Teddy Glacier )" Mount Brusiloff <!Thor N Invermere ! )" Elkhorn ¯ Ptarmigan< Kootenay West Bingay Main Jumbo Graphite (! (! )" Fording River ! <! Canal Flats )"Greenhills S"4J Slocan Silver Findlay<! <! Elkford )"Line Creek <!<! LH Willa (! Black Crystal Elkview )" Crown Mountain (! Sully Sparwood <! Kimberley <! Michel Creek Mt Heimdal <!<! Marten Phosphate Fernie (! Nelson Cranbrook )" Coal Mountain <! (! <! Kenville Daylight Zinger Bul River Jumping <! <! <! Coal Mountain Phase II Josephine <!Yankee Dundee Vine <! Castlegar <! Coal Creek Gold Drop Salmo Iron Range <! ! Swift Katie <! Greenwood )" Trail Winner <! <! Creston <! Jersey-Emerald BRITISH COLUMBIA Lexington Grand Rossland Gold U.S.A. Forks LEGEND Mines TERRANES )" Coal )" Industrial mineral Intermontane Region Boundary S Care and maintenance OK - Okanagan Proposed Mine Major Roads QN - Quesnellia (! Coal Railroad (! Metal SM - Slide Mountain (! Industrial mineral Ancestral North America ! Communities Projects NAb - NA deep water basin <! Coal NAp - NA platform <! Metal <! Industrial mineral Fig. 1. Mines and selected exploration projects, Kootenay-Boundary Region, 2014. Terranes from Nelson et al. (2013). 30 Exploration and Mining in British Columbia, 2014. British Columbia Ministry of Energy and Mines, British Columbia Geological Survey IC 2015-2 Katay 60 2013). The Rocky Mountain Trench Fault is a normal fault a) 55.0 50.4 on the eastern edge of the trench, with approximately 5 km of 50 west-side-down displacement. 43.0 42.0 40 38.5 35.5 2.1. Tectonostratigraphic elements and terranes 30 28.0 2.1.1. Laurentian basement (ancestral North America) Archean to Mesoproterozoic Laurentian basement rocks 20 extend beneath the Cordillera west of the southern Rocky Millions of of Dollars Millions 15.5 14.0 14.5 Mountain Trench (Fig. 5). Northeast-trending basement 10 structures infl uenced both Cordilleran tectonism and metallogeny (e.g., McMechan, 2012; Nelson et al., 2013). For 0 example, the Moyie-Dibble Creek fault has been interpreted by Price (1981) and McMechan (2012) as the surface expression of the Vulcan low (Fig. 5). Abrupt changes in thickness and facies in Proterozoic to early Paleozoic strata across 160 b) 151 northeast-trending structures along this trend suggest periodic 140 138 reactivation of basement structures. In the West Kootenays, the 129 126 125 southwestward shift in trend at the south end of the Kootenay 120 114 110 Arc, and other structures indicate a deep structural infl uence 100 that is also on trend with the basement Vulcan Low. 80 Although generally deeply buried, crystalline basement 66 is locally exposed in structural culminations such as the 60 55 Thousands of metres Thousands of 43 Shuswap-Monashee complex (Figs. 4, 5). Located west of 40 the east-dipping Columbia River fault (Fig. 4), the complex 20 is bounded by early Tertiary normal faults, and was exhumed 0 during Tertiary extension (Monger, 1999). Paleoproterozoic granitic and granodiorite gneisses are unconformably overlain by a Neoproterozoic to Paleozoic platformal paragneiss Fig. 2. a) Exploration spending and b) drilling in the Kootenay- assemblage of calc-silicate gneiss, pelitic gneiss, psammitic Boundary Region, 2014. gneiss, quartzite and marble. This paragneiss assemblage hosts stratabound lead-zinc deposits, including Ruddock Creek, Jordan River, and Big Ledge (Fyles, 1970; Höy 1982b), and fl ake graphite deposits. Grassroots 2.1.2. Proterozoic basins on the western margin of ancestral 1% North America Following the Hudsonian orogeny (2.0-1.8 Ga), but before EarlyStage 12% the breakup of ancestral North America (780-570 Ma), sedimentary successions accumulated in the Canadian Cordillera (Nelson et al., 2013). In the Kootenay-Boundary region, the Belt-Purcell basin (1.47-1.4 Ga), was a north- Mine Lease Advanced northwest trending intracratonic rift that extended into northern 40% 18% Idaho and Montana (Fig. 6). In Canada, the basin includes a 10-12 km section of turbiditic rocks (Aldridge Formation), and tholeiitic sills (Moyie sills; Lydon, 2007). Isopach variations along northeast-striking synsedimentary faults suggest that the basin was also affected by movement along transverse Mine Evaluation basement structures associated with the Vulcan low. The Belt- 29% Purcell Supergroup hosts the Sullivan Pb-Zn-Ag SEDEX deposit (see Lydon, 2007). By the end of the Mesoproterozoic (ca. 1.0 Ga), Laurentia was part of the supercontinent Rodinia. Rifting of this supercontinent occurred in at least two main episodes (Colpron