The Physiography and Engineering Constraints of the Continental Slope in the Northwestern Gulf of Mexico

Bryant, William R.; Simmons, Gregory R.; ,

The Physiography and Engineering Constraints of the Continental Slope in the Northwestern Gulf of Mexico

by William R. Bryant, Texas A&M Univ, College Station, United States,
Gregory R. Simmons, Texas A&M Univ, College Station, United States,

Document Type: Proceeding Paper

Part of: Civil Engineering in the Oceans V

Abstract:

The emplacement of structures on the seafloor has always been difficult but until recently, few knew just how difficult possible construction on the Northwestern Gulf of Mexico Continental Slope really was. Newly constructed bathymetric maps (TAMU) and recent multibeam swath mapping surveys by NOAA of the continental slope of the Northwestern Gulf of Mexico reveal the presence of over 90 intraslope basins with relief in excess of 150 meters. It was found that bathymetry in conjunction with multichannel seismic data is extremely valuable for studying the halokinetic style of the slope and the interaction between salt and physiography. It was found that the evolution and the general configuration of the basins on the continental slope off Texas and Louisiana are a function of the halokinesis of allocthonous salt. Intraslope-interlobal and intraslope -supralobal basins occupy the upper/middle, and lower continental slope respectively. The intraslope-interlobal basins of the upper continental slope are commonly elongate in shape with a northwest to southeast orientation. Intraslope-interlobal basins are located in areas where salt is more deeply rooted than in the lower slope. The intraslope-supralobal basins of the lower slope have a more circular geometry and are located in the Sigsbee Salt Nappe complex, the Sigsbee Escarpment being the southern boundary of the nappe.

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