ABSTRACT

Carboniferous and uppermost Devonian strata are mapped from southwestern Manitoba into southwestern District of Mackenzie. Carboniferous tectonic elements included the Prophet Trough, Peace River Embayment, cratonic platform, and the intracratonic Williston Basin. Transgressive basal deposits in the southwestward-thickening package (over 1850 m thick in the west) disconformably overlie Famennian strata, and are overlain by a progradational sequence containing second- and third-order, transgressive/regressive cycles corresponding largely to the units mapped. Late Carboniferous and subsequent erosion removed much of the succession. Remaining deposits, bevelled northeastward below Permian and Mesozoic strata, range from uppermost Famennian to Moscovian in the west and uppermost Famennian to Visean elsewhere.

The succession is divided into three principal map units that are separated locally by unconformities and consist of basin-to-supratidal deposits. From east-central British Columbia into southeastern Yukon, these three map units overlie and pass southwestward into basinal shale of the Besa River Formation. Siliciclastics and ramp-to-platform carbonates of the Bakken, Exshaw, Lodgepole, and Banff formations constitute the lower map unit. The middle map unit comprises ramp and platform carbonates (Mission Canyon and Charles formations, most of the Rundle Group). The middle unit contains a lower subdivision (mainly Pekisko, Shunda and lower Mission Canyon formations) and an overlying subdivision (Turner Valley, Mount Head, Flett, Debolt, upper Mission Canyon, and upper Charles formations). The cyclic, sandstone-dominated, marine and continental deposits of the upper map unit (Kibbey, Etherington, Golata, Kiskatinaw, Taylor Flat, and Mattson formations; Spray Lakes Group) overlie the middle map unit and Besa River Formation. Cross-sections and structure and isopach maps of the succession show extensive syndepositional and post-depositional blockfaulting.

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