New Evidence from Beneath the Western North Atlantic for the Depth of Glacial Erosion in Greenland and North America

Interpretation of Deep Sea Drilling Project results and air-gun seismic profiles suggests that about 10 6 km 3 of sediment have been eroded from eastern North America and southern Greenland and deposited in the adjacent North Atlantic since the beginning of continental glaciation. This volume is a minimum estimate which does not account for sediment beneath the continental shelf nor that portion carried south of the Blake-Bahama Outer Ridge by the Western Boundary Undercurrent. It represents erosion of about 100 m of solid rock and indicates that more than 90% of the sediment eroded from these areas was deposited as sands, silts, and clays in the adjacent western North Atlantic. Glaciation accounts for between 55 and 95 m of this average 100 m, and fluvial processes account for the remainder. The documented erosion in part substantiates W. A. White's (1972, Geological Society of America Bulletin 83 , 1037–1056) hypothesis of deep erosion and exhumation of shield regions, but is not in agreement with the entire volume of erosion implied by his model.