Seismic Stratigraphy and Salt Tectonics of Upper Continental Slope, East Breaks Flexure Trend, Gulf of Mexico

Wayne B. Gardiner

A study of more than 1,200 mi of 72-fold, migrated, seismic reflection profiles, from the eastern part of the East Breaks flexure trend, Gulf of Mexico, indicates that, although individual seismic reflectors cannot be traced across the entire area, seismic depositional units can be recognized and correlated from basin to basin in most instances. Three tentative conclusions are evident from this study: (1) salt diapirs appear to have grown through a series of intermittent movements to form structurally separate intraslope basins; (2) sedimentation is probably channeled by differential dome growth, which creates local stratigraphic differences between basins; and (3) packages of distinctive seismic depositional units can be successfully used to map sediment cycles between s parate basins.

Fluctuations of Pleistocene sea level appears to be the dominate depositional control on the upper continental slope in this area. During high sea level stands, turbidity currents were confined to depressions between diapirs, whereas pelagic deposition blanketed the slope. But during low sea level stands, sediment bypassed the shelf and deposited directly onto the upper slope, which increased the sediment load and helped initiate diapirism. Repeated sea level fluctuation would then lead to the cyclic pattern of seismic depositional packages that is commonly seen on upper slope seismic records.

AAPG Search and Discovery Article #91043©1986 AAPG Annual Convention, Atlanta, Georgia, June 15-18, 1986.