Geoscience Map 1993-10: Geology of the Warner Pass Map Area
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Geoscience Map 1003-10 describes the geology of the Warner Pass map area (92O/3) in southern British Columbia.
The map-area includes rocks of the Methow terrane, the Cadwallader terrane, the Relay mountain terrane, the Relay Mountain-Bridge River overlap assemblage, and Tertiary strata. Methow terrane rocks are Lower Cretaceous sandstone, conglomerate, siltstone and shale of the Jackass Mountain Group. Cadwallader terrane is represented by the Late Triassic Tyaughton Group and the Lower to Middle Jurassic Last Creek Formation. The Tyaughton Group has a lower conglomerate, conglomeratic sandstone, and red to brown sandstone unit, and a unit with limestone conglomerate overlain by green sandstone intercalated with conglomerate, overlain by brown sandstone that is overlain by green sandstone with thin conglomerate interbeds. Last Creek Formation contains brown calcareous sandstone, siltstone and conglomerate that are overlain by dark calcareous shale. Relay Mountain terrane strata are of Middle Jurassic to Lower Cretaceous age. The older Relay Mountain Group has three units. The lowest consists of dark siliceous shale intercalated with siltstone and sandstone; the middle unit has fossiliferous sandstone and siltstone; and the upper unit is mainly dark shale and siltstone. The younger Tosh Creek unit is mainly volcanic conglomerate and breccia, and dark shale but has intercalations of siltstone, sandstone and intermediate volcanic rocks. The Overlap assemblage consists of the Lower and perhaps Upper Cretaceous Taylor Creek Group, and the Upper Cretaceous Powell Creek Formation. The Taylor Creek contains sandstone, shale and conglomerate of the Elbow Pass Formation; shale, sandstone, and some conglomerate of the Paradise Formation; chert pebble conglomerate, sandstone, shale and siltstone of the Dash Formation, micaceous sandstone and shale of the Lizard Formation, an intermediate, felsic and mafic flow, tuff and breccia unit with conglomerate, sandstone and shale; and sandstone, siltstone, shale, conglomerate, calcareous sandstone and shale, and ash and crystal tuff. Powell Creek Formation strata include a lower unit of conglomerate, sandstone and shale, a middle unit of andesitic volcanic breccia, lapilli and ash tuff, mafic to intermediate flows, sandstone and conglomerate; and an upper unit of lapilli tuff, volcanic breccia, lahar, conglomerate and sandstone. Tertiary strata include the Paleocene and/or Eocene Mount Sheba volcanics, with intermediate to felsic flows, tuffs and breccias, conglomerate and mudstone of the Cluckata Ridge succession, an intermediate to felsic volcanic flow unit; and basalt flows and flow breccia. Olivine basalt flows comprise the Miocene and perhaps Pliocene Chilcotin Group.
Intrusive rocks in the area include Late Cretaceous granodiorite; Late Cretaceous and/or Early Tertiary diorite and gabbro, and hornblende-feldspar porphyry bodies; Paleocene and/or Eocene hornblende-biotite-quartz-feldspar porphyry; Eocene quartz monzonite and granodiorite; and Oligocene hornblende porphyry.
The structural elements are similar to those to the south with northwest trending, southwest-directed thrusting and north or northwest striking high angle faults with undefined but presumably transcurrent and vertical offsets.
The map area lies northwest of the Bridge River mining camp, which is British Columbia’s foremost historical gold producer from low sulphide mesothermal quartz veins. Other known and potential deposit types in the area are copper-molybdenum porphyries, pluton-associated high sulphide auriferous veins, skarns, scheelite-stibnite or stibnite-only veins, gold-silver polymetallic veins, epithermal gold-silver veins and cinnabar veins and disseminations.
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