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

Abstract

Interpretation of Deep Sea Drilling Project results and air-gun seismic profiles suggests that about 10⁶ km³ 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 Bulletin83, 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.