Magnetostratigraphy of late neogene glacial, interglacial, and preglacial sediments in the Saskatoon and Regina areas, Saskatchewan, Canada

Two new records of glacial stratigraphy obtained from borecores collected in southcentral Saskatchewan are compared to previously published records from Wellsch Valley and Swift Current Creek in southern Saskatchewan. The comparisons are based on magnetostratigraphy and tephrochronology, and describe preglacial, glacial, and interglacial deposits. The new stratigraphy is compared to the composite global marine oxygen isotope record. Although the ages and extents of late Pleistocene continental glaciations are relatively well constrained, they are less well defined for the middle and early Pleistocene. Data presented here highlight recent studies carried out from borecores and outcrops of extensive pre-Illinoian (pre-Saalian) glacial deposits. Based on this new data, at least seven Laurentide (continental) glaciations are recognized in Saskatchewan, and these records are the most extensive to date in the Northern Interior Plains of Canada. The magnetostratigraphic records from the Sutherland Overpass and Wascana Creek sites provide the first evidence of reversely magnetized glacial deposits in the Canadian Prairies. These deposits can be assigned to the latest Matuyama (MIS 20) and indicate that Laurentide (continental) glaciations did not impact southern Saskatchewan until the late Early Pleistocene.