Foraminiferal zonation of the Viking interval in the Hasler Shale (Albian), northeastern British Columbia
A dominantly arenaceous foraminiferal fauna of over 33 genera and 65 species was recovered from silty shales in the mid-portion of the Hasler Formation in the upper Albian part of the Fort St. John Group. The assemblages lie stratigraphically below occurrences of Neogastroplites and below the Miliammina manitobensis Zone. The foraminifera come from above the occurrence of Haplophragmoides gigas gigas, although assignment of the beds is to the upper part of the H. gigas Zone.The upper part of the Haplophragmoides gigas Zone may be divided into several subzones above the H. gigas gigas Sub-zone in ascending order, viz., H. gigas ssp A Subzone, Reophax tundraensis Subzone, Trochammina depressa Subzone, Trochammina umiatensis Subzone, and Reophax troyeri Subzone.The assemblages have close affinities with the faunas of both the overlying and underlying shales, and are an expression of a late shallowing–deepening cycle within the Skull Creek – Joli Fou seaway. They were penecontemporaneous with Viking Sandstone...