Morphology of Sea Floor in Gulf of Mexico

B. A. McGregor, D. C. Twichell, N. H. Kenyon, R. G. Rothwell, L. M. Parson

Approximately 120,000 nmi² of sea floor was mapped in the northern Gulf of Mexico using the GLORIA (Geologic Long-Range Inclined Asdic) system. The digital side-scan sonar data have been radiometrically and geometrically corrected and enhanced using image processing techniques. The extensive deformation of the continental slope seaward of Texas and Louisiana by salt tectonics has resulted in a complex morphology. Salt pinnacles 1 km in diameter and salt domes and basins up to 40 km across can be mapped using the imagery. The seaward edge of the salt front is marked by the Sigsbee Escarpment. Three reentrants in the salt front are the locations of canyon systems that provided pathways for sediment transport from the Texas-Louisiana shelf edge to the deep water o the Gulf. Remnants of these pathways are visible on the imagery traversing the slope from the shelf edge to the escarpment. Three other discontinuous channel systems can be identified in the northern Gulf of Mexico contributing sediments to the deep water of the gulf. Fans related to these channel systems are present seaward of the Rio Grande, the Mississippi Canyon, and De Soto Canyon areas. Each of these fans has a different surface morphology and reflects a varied combination of channelized flow and mass wasting processes in fan construction.

AAPG Search and Discovery Article #91038©1987 AAPG Annual Convention, Los Angeles, California, June 7-10, 1987.