Lateral Salt Movement and Associated Traps on the Continental Slope, Gulf of Mexico

Pulak K. Ray

Updip sediment loading on the continental shelf of the northern Gulf of Mexico produces lateral movement of the Jurassic salt at its frontal edge under the continental slope. Numerous salt tongues, salt scarps, and extensive concordant and discordant salt layers result from such movement of salt. Salt scarps bulge out seaward, ahead of the depocenter. In response to lateral shifting of the depocenter, the arcuate bulge changes position while the older scarp is deactivated. New bulges form contiguously with old ones or in a new place. The Sigsbee Scarp represents a composite bulge formed when depocenters shifted during the middle Miocene-Pleistocene.

Several types of traps suitable for hydrocarbon accumulation form as a consequence of lateral salt movement. The genesis of the following types of traps is discussed with examples from the continental slope of the northern Gulf of Mexico: (1) stratigraphic traps associated with scarp margin basins, (2) truncation traps and other structural traps below salt tongues, (3) fault and faulted anticlinal traps near the frontal edge, and (4) thrust-faulted anticlinal traps between salt lobes.

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