Conodont biostratigraphy of the Lower to Middle Devonian Deserters Formation (new), Road River Group, northeastern British Columbia

Abstract

A new Lower to Middle Devonian basinal unit of the Road River Group, herein formally named the Deserters Formation, contains argillaceous, crinoidal limestone and black shale deposited in a linear sub-basin of the Ospika Embayment, southern Kechika Trough. The abrupt lateral facies changes in the region, facies thickness, and occurrence of volcanics indicate a period of extensional tectonism. A total of 53 (4–5 kg each) samples from the Deserters Formation yielded 7766 conodont elements assigned to 14 genera representing 33 species. The formation ranges from the Lochkovian (eleanorae Zone, or lower part of the delta Zone of the Cordilleran Region) to Eifelian (australis Zone). The temporal constraints established by conodont biostratigraphy allow correlation to the Grizzly Bear Formation, a regionally restricted Lower to Middle Devonian unit in the Selwyn Basin to the north.

Emsian (Lower Devonian) conodont stratigraphy and correlation of the Anti-Atlas (Southern Morocco)

“…The eastern Anti-Atlas laticostatus Zone correlates straight forward with the top lower Emsian laticostatus Zone of Alaska (Lane & Ormiston 1979), British Columbia (Pyle et al 2002), Nevada (Klapper & Johnson 1975), Armorican Massif (NW France, Bultynck 1989), Montagne Noire (southern France, Feist et al 1985), the Central Pyrenees (Martínez-Pérez et al 2011), central Spain , Moroccan Meseta (Benfrika et al 2007), the Rhenish Massif (e.g., Weddige & Ziegler 1977), Harz Mountains (Germany, Luppold 1984), Bohemia (Klapper et al 1978), Bulgaria (Boncheva 1991), eastern Urals (Snigireva & Nasedkina 1995, Yurtische section), Uzbekistan (Yolkin et al 1994, Mawson 1995, Tadzhikistan (Bardashev & Ziegler 1992), Guangxi, South China (Ziegler & Wang 1985), and Russian Far East (Gagiev 2000).…”

“…This applies also to the Fergana Valley of central Asia (Kim et al 1988), South China (Ziegler & Wang 1985, Bai & Bai 1988, and Queensland (Mawson & Talent 1989). In Nevada (Johnson et al 1980, table 15), British Columbia (Pyle et al 2002), and New South Wales , L. serotinus enters slightly before L. bultyncki. The "Tafilalt pattern", with L. bultyncki as the only polygnathid at the base of the serotinus Zone, was also observed in the Istanbul region (Saydam-Demiray & Capkinoglu 2012).…”

Sucesión de Polygnátidos (Conodontos) del Emsiense (Devónico Inferior) en los Pirineos Centrales Españoles

“…The specimens studied have a completely inverted basal cavity with a relatively large, asymmetrical basal pit (with a more developed outer lip) located just before the inward deflection of the keel. This species is close in shape and (Bultynck and Morzadec, 1979); in the Barrandian area in the Czech Republic (Klapper et al, 1978;Weddige and Ziegler, 1977); in Tajikistan (Bardashev and Ziegler, 1992) in central Asia; in Nevada (Klapper and Johnson, 1975;Johnson et al, 1980;Klapper and Johnson, 1980) in the USA; and in British Columbia (Pyle et al, 2003) in Canada. Carls and Gandl, 1969 MGUV-20.889;a1, lower view;a2, upper view; Baliera 6 section Bed 49. b1-b2) Polygnathus gronbergi Klapper and Johnson, 1975 MGUV-20.920; b1, lower view; b2, upper view; Baliera 6 section Bed 49. c1-c2) Polygnathus laticostatus Klapper and Johnson, 1975 MGUV-20.931;c1, lower view;c2, upper view; LGA section Bed 28. d1-d2) Polygnathus nothoperbonus Mawson, 1987 MGUV-20.968;d1, upper view;d2, lower view; LGA section Bed 18. e1-e2) Polygnathus nothoperbonus Mawson, 1987 MGUV-20.966; e1, lower view; e2, upper view; CP-I top section Bed 210. f1-f2) Polygnathus nothoperbonus Mawson, 1987 MGUV-20.972.…”