Geology of the Nelson Map Area, Southeastern British ColumbiaBCMEMPR Open File 1989-11
View Open File (PDF, 2.96 MB)
Open File 1989-11 describes the geology and mineral occurrences of the Nelson map-area (82F/06) in southern British Columbia. The Open File consists of two maps. The first presents geology at 1:50 000 scale and a legend. The second has a series of cross sections, a table of mineral occurrences and references.
The oldest rocks in the area Precambrian, possibly Windermere, age rocks of the Three Sisters Formation, which consists mainly of grit and quartzite with minor schist and limestone. Quartzites of the Quartzite Range Formation, argillaceous quartzite, argillite and schist of the Reno Formation, phyllite, argillite, schist, micaceous quartzite and minor limestone of the Laib Formation, and a sequence of quartzite, schist, argillite, slate and limestone with minor igneous members are all of Lower Cambrian age. Middle Cambrian black limestone, calcareous argillite, slate and phyllite comprise the Nelway Formation. Lower and Middle (?) Ordovician black argillite, slate and quartzite make up the Active Formation. Stratified Mesozoic rocks comprise the Ymir and Rossland Groups. Ymir Group consists mainly of argillite, siltstone, grit and impure limestone. Rossland Formation consists of the Archibald, Elise and Hall Formations. The Archibald Formation contains siltstone, sandstone and argillite. Lower Elise Formation rocks are dominantly augite with or without plagioclase phyric flows, flow breccias and subvolcanic intrusions. Pyroclastic units are basaltic lapilli, crystal and fine-grained tuffs. Upper Elise Formation consists of basaltic and rhyolite to dacite flows, andesitic tuffs, basaltic tuff, tuffaceous siltstone and sandstone, and tuffaceous conglomerate. Hall Formation strata are siltstone, sandstone, conglomerate and argillite with minor limey units.
Intrusive rocks in the area are Lower and Middle (?) Jurassic diorite, porphyritic diorite, and plagioclase porphyry that is locally sheared. Jurassic intrusions include pseudodiorite and pyroxenite, as well as granodiorite, quartz monzonite, diorite porphyry and breccia of the Nelson intrusions.
Mineral occurrence types in the area include: porphyry copper-molybdenum deposits; skarns with gold-copper, copper-gold, or molybdenum-tungsten mineralization; veins with gold-silver-copper, silver-gold, lead-zinc, or gold-silver values; stratiform sulphides with lead-zinc and silver; and conformable gold mineralization with plagioclase porphyry intrusions.
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