No Abstract Avaliable

This study is based on seismic reflection profiles and correlation with data from offshore wells and dredge hauls. Regional unconformities have been mapped. Two styles of sedimentary accumulation have been active: (1) platform upbuilding and (2) platform outbuilding or progradation of the shelf. In post-Albian time, the area became a marine province, and sediment accumulated on a level platform. During the Santonian-Coniacian a shelf prograded seaward across this platform, but during the Campanian, Maestrichtian, and Paleocene, deposition on a level plateau resumed. Paleocene strata are deeply eroded in the subsurface, and this may mark the initial appearance of the Gulf Stream. During the Eocene and Oligocene, another wedge of shelf sediments prograded across the plateau but was interrupted at the end of the Oligocene by erosion. A progradational wedge of Miocene to Holocene age covers the unconformity at the base of the Miocene. Accumulation of post-Paleocene sediment at the foot of the Florida-Hatteras Slope and seaward on the Blake Plateau has been very slow, owing to a reduction in sediment supply and erosion by the Gulf Stream. Tertiary isopach maps suggest a triangular depocenter under the Florida-Georgia Shelf. The margins coincide with magnetic anomalies, and it is suggested that the basin is related to differential subsidence across older crustal structures during the Tertiary.