Hudson Bay river sediments and regional glaciation: III. Implications of mineralogical studies for Wisconsinan and earlier ice-flow patterns
Mineralogical studies of river sediments from the Hudson Bay and James Bay Lowlands suggest that the glacial erosion of pre-Devonian Paleozoic carbonate rocks played an important role in the production of calcite-enriched debris in the Cape Henrietta Maria watershed. Ice flowing southwesterly across Devonian basins in western Hudson Bay and the James Bay Lowlands would largely bypass the intervening cape area.Enrichment of iron in river sands of the cape watershed is attributed to Proterozoic ferruginous sources now largely submerged under the waters of eastern Hudson Bay. Distributional patterns of carbonates and iron indicate that the dominant flow of ice from eastern Hudson Bay was southwesterly toward Cape Henrietta Maria, without major flow from the area of Proterozoic bedrock into the Nelson River watershed. In the cape area, iron enrichment due to Proterozoic sources significantly overshadows possible contributions from siderite-bearing Devonian bedrock.The fluvial sediment data are consistent with...