Mahone Bay is located on the Atlantic coast of Nova Scotia. It is an exhumed Carboniferous basin, overdeepened by glacial erosion, with widespread late Wisconsinan sheet and drumlin tills. Subglacial channels that cut both till and bedrock were formed when the ice sheet stagnated after marine incursion into the Bay of Fundy. Seismic reflection profiling and piston cores show up to 75 m of proglacial lake silts ponded behind a bedrock sill at the entrance to the bay. These are overlain by a thin lagoonal sequence, and then by marine sediments accumulated over the last 6000 years, reflecting the gradual Holocene transgression.