ABSTRACT: Salt Tectonism, Growth Faulting, and Sedimentation of Central Offshore Louisiana, Gulf of Mexico

ZHANG JIE, and JOEL S. WATKINS, Texas A&M University, College Station, TX

The geologic setting of central offshore Louisiana, Gulf of Mexico, shows close relationships between salt tectonics, growth faulting, and sedimentation. The distribution of salt falls into three structural provinces. Province I is characterized by broad intradomal basins isolated mainly by salt domes and ridges. Province II is characterized by narrow intradomal basins isolated mainly by salt ridges and closely spaced salt rollers. Province III is characterized by supralobal and interlobal basins that form on or between salt sheets. Long, widely spaced salt withdrawal faults are characteristic of the inner shelf, whereas closely spaced, interconnected arcuate salt detachment faults are characteristic of the outer shelf. Both groups of faults exhibit a complex growth fault pattern. Fau ts in the inner shelf flatten with depth to form a master detachment. In the outer shelf, salt rollers evident in footwalls of major faults suggest downdip movement of salt. Updip of the salt rollers, sediments touch down onto the master detachment surface and weld discordantly to subsalt sediments. The slope segment may consist of counter-regional growth faults. Our data suggest that salt withdrawal was due to sediment loading, which in turn caused the growth faulting. That is, progradational loading initiates salt withdrawal, gravity sliding, and progressive seaward development of growth faults.

AAPG Search and Discovery Article #91012©1992 AAPG Annual Meeting, Calgary, Alberta, Canada, June 22-25, 1992 (2009)