Terrestrial palynomorph biostratigraphy of the Cypress Hills, Wood Mountain, and Turtle Mountain areas (Upper Cretaceous - Paleocene) of western Canada

Abstract

Three cored test holes were drilled to study the stratigraphic interval spanning the Cretaceous-Tertiary boundary: one in the western Cypress Hills near Elkwater, Alberta; a second in the eastern portion of the Wood Mountain area near Killdeer, Saskatchewan; and a third on the western edge of Turtle Mountain near Goodlands, Manitoba. The terrestrial elements of the palynological assemblages are discussed. The Maastrichtian assemblages encompassed the Scollardia trapaformis Zone and two new subzones, Myrtipites scabratus - Aquilapollenites delicatus var. collaris and Porosipollis porosus - Aquilapollenites notabile within the Wodehouseia spinata Zone. The Paleocene zones encountered include the Aquilapollenites reticulatus Subzone of the W. spinata Zone, the previously described Wodehouseia fimbriata and Momipites wyomingensis zones, and the newly defined Tricolporopollenites kruschii Zone. These provide a biostratigraphy for the cored intervals which can be related to polarity chrons. The observations made demonstrate that existing zonations are not applicable basin wide, as there are chronologically distinct disconformity-bounded sequences in western and eastern basin sectors. Apparent diachronisms within the preserved assemblages were documented by earlier entry levels within the Momipites lineage and a significant upwards extention in the range of W. fimbriata in the eastern part of the basin.