Glacial and nonglacial events in the eastern James Bay lowlands, Canada
Marine and continental records indicate that the Laurentide Ice Sheet (LIS) was highly dynamic throughout the last glacial cycle, with significant reorganizations of its ice divide system. The extensive depositional record of the Hudson Bay lowlands (HBL) is particularly important for the study of ice sheet dynamics because this region was once located near two important ice domes of the LIS. However, important stratigraphic issues remain in the HBL, notably regarding the chronology of nonglacial units and the direction and extent of the ice-flow events recognized. Here we focus on the northeastern sector of the LIS by documenting the provenance of tills and dating nonglacial deposits in sedimentary sequences east of James Bay. Our investigations indicate that the regional stratigraphy comprises at least five distinct tills and an important unit of glaciolacustrine rhythmites. This glacial sequence lies on massive lacustrine clay and fluvial sand containing abundant organic debris and wood fragments. The ...