34-9 Origin and significance of ice-rafted Carbonate Diamict Beds in Pleistocene strata of western Baffin Bay and the Labrador Sea

Session: High latitude paleoceanographic discoveries from Scientific Ocean Drilling (IODP, ODP, DSDP). (Posters)

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In Baffin Bay and the Labrador Sea, dozens of prominent, sharp-based beds of detrital carbonate mud and outsized clasts (diamict) occur in Pleistocene strata recovered by various drilling projects. These beds are interpreted as deposits of ice-rafted debris derived from regions with exposed carbonate bedrock, providing a unique signature of sediment transportation and depositional processes associated with Pleistocene glaciation in the Baffin Bay region. However, the spatiotemporal distribution of the beds and their significance with respect to regional ice sheet dynamics is poorly constrained. To develop a framework that provides insight into the distribution, significance, and origin of the carbonate-dominated deposits, carbonate diamict beds in Pleistocene strata recovered at ODP Sites 645-647 were documented, described, and placed into a chronostratigraphic framework. Data were collected using high-resolution core photographs and other data archived in the online IODP JOIDES Resolution Science Operator. This framework provides spatiotemporal constraints on the distribution of the beds in western Baffin Bay and the Labrador Sea that can be compared to other nearby sites. Results reveal temporal variability in ice-rafting events associated with ice streams specifically from regions of the Canadian Arctic Archipelago underlain by carbonate bedrock. Improved understanding of these unique deposits contributes to reconstructions of high-latitude Pleistocene ice dynamics and how ice sheets respond to climatic change. Such insights are increasingly relevant as modern climatic changes are projected to increase the rate of melting in the Greenland Ice Sheet, potentially increasing global mean sea level by up to 7 meters.

Geological Society of America Abstracts with Programs. Vol. 58, No. 2, 2026

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