Preliminary Map 53 portrays the geology of the Barriere River-Clearwater area (82M/4, 5, 12; 92P/1, 8, 9) in south central British Columbia. The 1:50 000 scale geology map includes a legend, 8 geological cross sections, and a table of mineral occurrences.
The parautochthonous Eagle Bay Formation is Mississippian and perhaps older. Units within the Formation are: dominantly chloritic phyllite, schist, and schistose volcanic breccia with lesser carbonates, quartzite and phyllite and includes white crystalline limestone and white quartzite interlayers; quartz phyllite and muscovite-quartz schist with lesser dark grey phyllite, chloritic phyllite, and schistose volcanic breccia, and local feldspar porphyry, feldspathic schist, pyritic sericite-quartz schist, and metavolcanic breccia; feldspathic phyllite and phyllitic volcanic breccia with local ‘cherty quartzite (siliceous exhalites?); and dark grey slate and phyllite with interbedded siltstone, sandstone, and grit, and lesser conglomerate, limestone, metatuff and metavolcanic breccia. Rocks of the Devonian to Permian Fennel Formation comprise an allochthonous, internally imbricated oceanic terrane. The units of the ‘lower structural division’ are: intraformational conglomerate; limestone and marble; sandstone, siltstone, slate, phyllite and quartzite and local metatuff; quartz feldspar porphyry; gabbro, diorite and diabase; mainly chert, cherty argillite; and massive and pillowed metabasalt and local tuff. The ‘upper structural division’ contains a bedded chert unit, and a pillowed and massive metabasalt unit with local breccia, tuff, diabase, gabbro and chert. Younger rocks include granite and granodiorite of the Cretaceous Baldy batholith, rocks of the Eocene Kamloops Group and Miocene or younger olivine basalt flows. The Kamloops Group consists of the lower, Chu Chua Formation, which contains sandstone, shale, conglomerate and minor coal, and the Skull Hill Formation with vesicular and amygdaloidal andesite flows.
Major faults in the area underlie valleys that strike north east-northeast and southeast. Thrust faults with general northerly trends imbricate rocks of the allochthonous Fennel Formation. More than one generation of thrust faults occur and older thrust are folded. The folds they define have one limb with a low dip angle, and one that is upright or slightly overturned toward the west.
Mineral occurrences in the area include Cyprus massive sulphide Cu (Zn) deposits, like Chu Chua, and Noranda/Kuroko massive sulphide Cu-Pb-Zn deposits, like Homestake and Harper Creek. There are also polymetallic vein occurrences, volcanic hosted uranium deposits, like Rexspar, auriferous quartz veins, and potential for skarn and epithermal deposits.