Structural Styles and Seismic Stratigraphy of Pliocene Sediment Gravity Flows at MC-118, Gulf of Mexico
Josgre Salazar¹, James Knapp¹, Camelia Knapp¹, David Pyles², and Christopher Kendall¹
¹ University of South Carolina, Columbia, South Carolina 29208
² Chevron Center of Research Excellence, Colorado School of Mines, Golden, Colorado 80401
OCS Block MC-118 is located 128 miles southeast of New Orleans on the middle slope in ~2600 ft of water. This site is subject of intense study in geology and gas hydrates/ petroleum system. The goal of this study is to do a tectono-stratigraphic interpretation of the Pliocene sedimentary succession. Results from this study can be used by the petroleum industry to have a better understanding of sediment-salt interplay in deepwater environments and to improve prediction of reservoir distributions/quality. Data used to carry out this study are: (1) 130 km2 of 3D seismic and (2) 3 well logs with biostratigraphic data. The area is divided into three structural domains: (1) a western domain consisting of a basinward-dipping normal fault family and associated strata; (2) a central domain composed of a landward-plunging diapiric salt tongue canopy and associated salt welds, two flanking NE-SW trending salt-withdrawal minibasins and a crestal fault family; and (3) an eastern domain comprised of a listric growth and normal basinward/ landward dipping fault families and their associated rollovers. These structural domains are genetically related to each other and extend beyond the limits of the area of study. They are part of the regional salt-stock canopy end-member of Louisiana's continental slope. Seismic stratigraphic analysis of a Pliocene (3.13–4.95 Ma) third-order genetic stratigraphic sequence is up to ~3600 ft in thickness within the mini-basins reveals an alternation of the following facies: mass transport complexes; slope fans; muddy turbidites and condensed sections; and transitional-wedging facies that collectively have ponded and wedged external geometries.
AAPG Search and Discovery Article #90158©2012 GCAGS and GC-SEPM 6nd Annual Convention, Austin, Texas, 21-24 October 2012