The southernmost peninsula of Baffin Island is a tilted peneplane, with an escarpment along Frobisher Bay. During most of the Wisconsin age, precipitation in the area must have been low, and there is evidence that the higher parts of the escarpment remained above the ice. Cirques with submerged floors show that during a considerable part of the glacial ages sea level was lower than today. Strand lines up to 1425 feet A.T. indicate very great depression of the land in the late Wisconsin, possibly connected with an increase of ice in the Hudson Strait area as precipitation increased after the disappearance of the topographic barrier of the main Laurentide Ice Sheet. When the sea level was between 210 and 180 feet the overflow from an ice-dammed lake cut two great gorges and formed a large bay-head delta. The dam may have been the northern margin of an ice sheet centered in the Quebec-Labrador Peninsula. There is evidence of a warmer period in the recent past, and the present small icecaps are probably the rejuvenated relics of a larger icecap.