Late Wisconsinan ice retreat from the Scotian Shelf

The late middle to late Wisconsinan Laurentide ice sheet terminated at the edge of the Scotian Shelf ca. 21 ka, in close temporal agreement with the H-2 Heinrich event of the North Atlantic stratigraphy. The ice began its recession along the western edge of the shelf prior to 20 ka. By 15 ka, the ice front had retreated in a northeastward direction, exposing much of the western half of the shelf, although ice appears to have remained on the inner shelf north of a morainal system for another 2 k.y. The retreat was probably controlled by an ice divide along the axis of the mainland until after 16 ka, at which time an ice-flow pattern began to emanate from local remnant ice centers on the mainland. Late Wisconsinan ice seems to have remained on much of the eastern portion of the shelf as late as 12–14.5 ka, and probably deposited several outer bank moraines. Younger Dryas ice probably was present at isolated land and coastal areas for a short period ca. 10.5 ka, but its offshore influence appears to have been restricted to floating ice and storm-related events.