Bulletin 006

Bulletin 006

BUL 006

Upper Cretaceous Foraminifera from the Smoky River Area, Alberta

Author(s) Wall, J.H. Date 1960-01-01

Nineteen species and subspecies of foraminifera are figured and described. One of which is proposed as new from the upper part of the Kaskapau shale and the lower part of the Puskwaskau shale in the Smoky River area of Alberta, Western Canada. The problem of stratigraphic nomenclature within the Smoky River group is reviewed and a new formation name, Puskwaskau, introduced to designate the shales lying between the Bad Heart sandstone and the Wapiti formation in the Smoky River area. Brief descriptions of the lithology encountered at the two collecting localities on the Smoky and Bad Heart Rivers are given.

Although little change in the general aspect of the microfauna from the Kaskapau and Puskwaskau shales is noted, a few apparently diagnostic species from each shale unit are listed. The microfauna are dated Coniacian-Santonian by their association with ammonites of the Scaphites Ventricosus, Scaphites depressus and Clioscaphites Vermiformis zones. The white-speckled calcareous shale �zone� in the Puskwaskau shale is considered the partial equivalent of the first or upper white-speckled shale �zone� occurring at or near the top of the Colorado shale in other areas of Alberta and northern Montana. The microfauna associated with this �zone� carries elements common to both the Boyne member of the Vermillion River formation of Manitoba and the Niobrara Formation of the Central Plains region of the United States.

The Foraminiferal assemblages are dominantly arenaceous. The depth of the water appears to have been quite shallow, but deepened considerably at the time of the deposition of the white-speckled shale as revealed by the associated calcareous, pelagic Foraminifera.

Wall, J.H. (1960): Upper Cretaceous Foraminifera from the Smoky River area, Alberta; Research Council of Alberta, RCA/AGS Bulletin 06, 45 p.