ABSTRACT: Biostratigraphic Resolution in the Frasnian (Upper Devonian) of Western Canada

MARCHANT, T. R., and R. A. MCLEAN, Amoco Canada Petroleum Company Limited, Calgary, Alberta, Canada

Conodonts, foraminifera, and rugose corals have been used to develop an integrated biostratigraphic faunal succession for the Frasnian cratonic carbonate sequences in the Western Canada sedimentary basin. This biostratigraphic scheme allows detailed time stratigraphic correlations within the basin and provides a framework for time control of sequence stratigraphic interpretations of basin fill.

Frasnian outcrops in the Northwest Territories, northern Alberta, and the Rocky Mountains of Alberta and British Columbia represent a suite of depositional environments from shallow water carbonate shelves to off-shelf, deeper water carbonates and clastics. Detailed collections from numerous measured sections in a variety of lithofacies yielded abundant samples of the three fossil groups.

Eight informal zones and faunal units have been established for the western Canadian Frasnian conodont sequence. This sequence combines elements of both the deeper water palmatolepid biofacies in the early Frasnian and shallower water polygnathid biofacies in the later Frasnian. The eight foraminiferal faunas are based on evolution of the tikhinellid-eonodosarid lineage. Like the foraminifera, the rugose corals increase in diversity, abundance, and biostratigraphic utility upward through the Frasnian, and at present 11 coral faunal assemblages are recognized.

AAPG Search and Discovery Article #91012©1992 AAPG Annual Meeting, Calgary, Alberta, Canada, June 22-25, 1992 (2009)