MASS MOVEMENT OF SEDIMENT ON THE CONTINENTAL-SLOPE AND RISE SEAWARD OF THE BALTIMORE CANYON TROUGH

Sediment instability has produced large submarine slides on the continental slope and rise seaward of the coast of New Jersey and the Baltimore Canyon Trough. Sediment failure is confined to Quaternary material over a continuous mid-Pliocene unconformity. The thickness of Pleistocene sediment is greatest in proximity to Wilmington and Spencer Canyons, indicating that the canyons influence the amount of sediment on the lower slope and rise. Differences in thickness of sediment between both canyons suggest variations in the amount of sediment each transported. Sediment failure is ubiquitous in this area. Instability appears to be related to sediment thickness rather than to other trigger mechanisms. Rapid sediment accumulation and the probable low shear strength-under-consolidated condition of Pleistocene deposits on the mid-Pliocene unconformity are believed to be major factors controlling sediment instability in this area. © 1979.