A re-examination of the type area of the Devono-Mississippian Cariboo Orogeny, central British Columbia

Abstract

Three tectonostratigraphic successions are established from remapping of the area near Barkerville and Cariboo River. The first, of Late Proterozoic to Cambrian sediments, was deposited on the shallow to moderately deep platformal shelf west of and derived from the exposed North American craton. The second is an unconformably overlying Ordovician to Permian sequence of sedimentary and volcanic rocks representing a basinal environment with periodic highs. These packages of sediments were deposited on the North American craton and its western transitional extensions. The third succession, composed of oceanic chert and basalt of the Permo-Pennsylvanian Antler Formation, was thrust eastward over the other two during the early Mesozoic. The three successions were folded, faulted, and metamorphosed during the mid-Mesozoic Columbian Orogeny. The DevonoMississippian Cariboo Orogeny, which was thought to have affected all of the first sequence and part of the second, could not be documented in its type locality. The geology of the Barkerville -Cariboo River area has many similarities with that of Selwyn Basin and Cassiar platform of northern British Columbia and Yukon.Trois successions tectonostratigraphiques sont Ctablies suite a une reprise de la cartographie de la region pr&s de Barkerville et de la riviere Cariboo. La premibre est composCe de sCdiments du ProtCrozoi'que supkrieur a Cambrien et fut dCposCe sur la plateforme peu h modCrCment profonde du plateau continental a l'ouest du craton nord amkricain expos6 et lequel a fourni les sCdiments. La deuxieme est une sCquence discordante sus-jacente ordovicienne B permienne de roches ~Cdimentaires et volcaniques qui reprksentent un environnement de bassin avec des points culminants pkriodiques. Ces ensembles de sCdiments furent dCposks sur le craton nord amkricain et sur les zones de transition se prolongeant vers l'ouest. La troisibme succession est composCe de chert ocCanique et de basalte de la formation Antler d'lge Permo-Pennsylvanien qui a chevauchC vers l'est au-dessus des deux autres durant le MCsozoique infkrieur. Les trois successions ont Ct C plisstes, faillCes et mCtamorphisCes pendant I'orogCnie colombienne au MCsozoi'que rnoyen. L'orogenie Cariboo d'lge DCvono-Mississipien, laquelle semble avoir affect6 la totalit6 de la premikre sCquence et une partie de la deuxibme, ne fournit aucun renseignement reliC B la localit6 type. La gtologie de la rkgion Barkerville -riviere Cariboo prksente plusieurs similitudes avec celle du bassin Selwyn et de la plateforme Cassiar du nord de la Colombie Britannique et au Yukon.

Devonian Antler fold and thrust belt and foreland basin development in the southern Canadian Cordillera: implications for the Western Canada Sedimentary Basin

“…White, 1959;Sutherland Brown, 1963;Struik, 1981;Gordey et al, 1987;Smith and Gehrels, 1992;Smith et al, 1993). Early conclusions that mid-Paleozoic contractional orogenic activity took place in western Canada were based on complex structural, stratigraphic and metamorphic relationships in south-central British Columbia interpreted by Reesor (1957), White (1959), andSutherland Brown (1963).…”

“…These conclusions have been generally discounted in subsequent years (e.g. Struik, 1981) based on later detailed work, and based on interpretations that much of the central and western Canadian Cordillera comprises terranes that are allochthonous with respect to the ancient Cordilleran Passive Margin (e.g. Monger et al, 1991).…”

“…The existence of the Antler Orogeny in Canada has been debated for decades (e.g. Sutherland Brown, 1963;Struik, 1981;Gordey et al, 1987;Smith and Gehrels, 1992;Smith et al, 1993), however, because Mesozoic and Cenozoic deformation, metamorphism, and erosion within the Cordillera have destroyed much of the evidence. The mid-Paleozoic tectonic setting of the continental margin in western Canada has been variously interpreted as one of extensional, strike-slip, or thrust deformation (e.g.…”

“…The mid-Paleozoic tectonic setting of the continental margin in western Canada has been variously interpreted as one of extensional, strike-slip, or thrust deformation (e.g. Gabrielse, 1976;Struik, 1981;Eisbacher, 1983;Gordey et al, 1987;Smith et al, 1993Smith et al, , 1993Berger and Davies, 1999a).…”

Conodonts and stratigraphy of upper Paleozoic limestones in Cariboo gold belt, east-central British Columbia

“…The name Greenberry Formation was first introduced by Johnston and Uglow (1926) to include crinoidal limestone that overlies the Guyet Formation (see Struik 1981). The Greenberry Formation was originally dated as possibly Mississippian from identification of a poorly preserved brachiopod (Spirifer keokuk?)…”