Biostratigraphic and biogeographic constraints on the Carboniferous to Jurassic Cache Creek Terrane in central British Columbia

Conodonts, radiolarians, foraminiferids, and corals provide constraints on the geology and tectonics of the Nechako region. They also support the noti on that the Cache Creek Terrane is allochthonous with respect to the North American craton. The 177 conodont collections, assigned to 20 faunas, range in age from Bashkirian (Late Carboniferous) to Norian (Late Triassic); 70 radiolarian collections representing 12 zones range from Gzhelian (Late Car boniferous) to Toarcian (Early Jurassic); 335 collections assigned to 11 fu sulinacean assemblages (with associated foram-algal associations) range fro m Bashkirian to Wordian (Middle Permian); and two coral faunas are of Bashk irian and Wordian age. The fossils document a long but sporadic history of sedimentary events within the Cache Creek Complex that included two major c arbonate buildups in the Late Carboniferous (Pope limestone) and Middle Per mian (Copley limestone), punctuated by intervening Early Permian deepening; basaltic eruptions during the mid Carboniferous and mid Permian; the onset of oceanic chert sedimentation close to the Carboniferous-Permian boundary and its persistence through the Late Triassic (Sowchea succession); latest Permian and Early Triassic mixed clastics and volcanics (Kloch Lake succes sion); Middle and Late Triassic reworking of carbonates (Whitefish limeston e), including cavity fill in older limestones (Necoslie breccia), and fine- grained clastic sedimentation extending into the Early Jurassic (Tezzeron s uccession). Tethyan, eastern Pacific, and (or) low-latitude biogeographic a ttributes of the faunas are noted in the Gzhelian (fusulines), Artinskian ( conodonts, fusulines), Wordian (fusulines, corals, conodonts), and Ladinian (conodonts, radiolarians). The Cache Creek Terrane lay far to the west of the North American continent during these times.