Late Quaternary Sedimentology of Continental Slope (Longitude 94° to 95°30^prime), Northwestern Gulf of Mexico

Will M. Satterfield, E. William Behrens

Recent analysis of high-resolution seismic (3.5 kHz), piston core, multichannel seismic, and side-scan sonar data from the continental slope has been used to determine the distribution of acoustic facies and sediment types and to interpret the depositional processes and their controls. Although hemipelagic drape is aerially the most extensive sediment, much thicker sequences of slumps, slides, debris flows, and turbidites are concentrated in intraslope basins and troughs created by salt/shale tectonics.

Sedimentation concentrated by tectonics also affects diapir tectonism, producing a cyclic feedback of sediments. This tectono-sedimentary cyclicity is superimposed on and interrelated to larger scale sequences resulting from glacio-eustatic cycles.

A recently discovered interbasin channel shows a pathway through which sand has been transported to a midslope basin where the channel ends. This pathway crosses two "filled" upper slope basins, showing a succession of downslope basin-filling. Enigmatically, basins farther downslope contain sands indicating other, unknown channels or quite rapid destruction of downslope sediment conduits by salt tectonism.

AAPG Search and Discovery Article #91036©1988 GCAGS and SEPM Gulf Coast Section Meeting; New Orleans, Louisiana, 19-21 October 1988.