SUBGLACIAL RECHARGE INTO THE WESTERN CANADA SEDIMENTARY BASIN - IMPACT OF PLEISTOCENE GLACIATION ON BASIN HYDRODYNAMICS

Brine springs discharging from Devonian carbonates of the Western Canada Sedimentary Basin have distinct water chemistry from brines in laterally equivalent units deeper in the basin. Stable isotope data suggests that the brine springs originated as Pleistocene melt water. These waters are interpreted to originate as an influx of subglacial meltwater related to a reversal of the basin-scale flow-system, caused by the overriding ice sheet. Esker distribution shows a notable relationship between shield and sedimentary rocks. An integrated sedimentary basin/ice sheet model supports the interpretation that high permeability carbonate units acted as preferential subglacial drains that in turn affected esker development. The fluid flow history of the Western Canada Sedimentary Basin is characterized by back-and-forth movement through geological time in response to changing boundary conditions. Modern day flow systems may not then be indicative of historic movement of economic fluids through the basin.