Palynostratigraphic zonation of Paleocene strata in the central and south-central Alberta Plains

Abstract

Paleocene strata of the Scollard and Paskapoo formations in the central and south-central Alberta Plains can be subdivided into five formal biostratigraphic zones, based in part on a Momipites–Caryapollenites palynofloral lineage. A similar zonation previously identified from strata of the Wind River basin in Wyoming displays similar palynomorph occurrences. However, differences that are present are likely a result of latitudinal climatic zonation between Alberta and Wyoming during Paleocene time.Lowermost Paleocene strata of Alberta (Wodehouseia fimbriata Zone) are barren of Momipites species, which subsequently first appear in the Momipites wyomingensis Zone. These two zones include strata from the Cretaceous–Tertiary boundary (Nevis coal seam) to the top of the Scollard Formation. A diverse assemblage of Momipites spp. plus Aquilapollenites spinulosus, Caryapollenites prodromus, and Tiliaepollenites danei are present in the Aquilapollenites spinulosus Zone within the lowermost Paskapoo Formation. Two more species of Caryapollenites appear in the Caryapollenites wodehousei Zone. The Pistillipollenites mcgregorii Zone is characterized by the presence of Pistillipollenites mcgregorii, Insulapollenites rugulatus, and Caryapollenites inelegans. Momipites leffingwellii is absent from the lower portion of this zone, with Momipites waltmanensis, Momipites actinus, and Momipites triorbicularis absent from the upper portion. Lower P. mcgregorii Zone strata are the youngest strata encountered in the vicinity of the Red Deer River valley. Upper P. mcgregorii Zone strata include strata of the Obed–Marsh coal zone within the uppermost part of the Paskapoo Formation adjacent to the Alberta Foothills.