Deglacial dynamics of the Foxe–Baffin Ice Sheet, Frobisher Bay, Nunavut, Canada revealed by submarine landform mapping

Abstract

Previous interpretation of the nature and distribution of subaerial glacial landforms established that Frobisher Bay in southeastern Baffin Island was glaciated in the Late Wisconsinan by ice flowing southeast from the Foxe–Baffin Ice Dome. New seafloor mapping within the bay has revealed submarine glacial landforms that are described and interpreted in the context of their subglacial, ice‐marginal, glaciomarine and marine process environments. Interpretation of the evidence confirms that ice occupied Frobisher Bay, flowing from the northwest to southeast, parallel to the orientation of the bay. Relatively rapid ice velocities are indicated by the presence of ice‐moulded bedrock and megaridges flanking a deep trough (>700 m) along the faulted southern flank of Frobisher Bay. In shallower regions, areal scouring and channelisation indicate the widespread presence of glacial ice. As ice retreated to the northwest towards the Foxe Ice Dome, De Geer and recessional moraines were deposited at the ice front. The latter correlate spatially with the extensive Frobisher Bay Moraine System on land. Two iceberg ploughmark populations are evident, with smaller relict features in shallow water in rare locations in the northwest of the bay, and larger relict and modern ploughmarks in deeper water in outer Frobisher Bay.

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