The Atlantic Continental Margin

Turbidity currents, surface, and subsurface currents carry detritus from the land across the continental shelf to the adjacent continental slope where slumps and turbidity currents transport the sediment downslope for hundreds of miles to greater depths, and deep geostrophic contour currents transport it thousands of miles down-current in a direction parallel to the bathymetric contours. The combined effect of these processes has been to create a wide, thick, geosynclinal apron of sediment at the base of the continental slope. Subsidence of the continental shelf has continued since mid-Mesozoic, carrying down Lower Cretaceous reefal limestones to depths of 5,000 meters off Florida. The subsidence of the Atlantic continental margin and the basement of the continental rise geosyncline apparently commenced in mid-Mesozoic time with the creation of abyssal depths in the steadily expanding Atlantic