Source-to-Sink Linkages Between Clinoform Architecture and Deepwater Deposits, Eastern Mexico Margin, Southern Gulf of Mexico

Lesli Wood¹, Lorena Moscardelli¹, Juan Bermudez², C. Caraveo³, William Ambrose¹, and G. López-Leyva^3
1Bureau of Economic Geology, Jackson School of Geosciences University of Texas at Austin, Austin, TX
²Intituto Mexicanos del Petroleo, Mexico City, Mexico
³PEMEX, Veracruz, Mexico

Clinoform architecture represents the staging area for deepwater sediments, and their nature provides clues to these downslope deposits. Several enormous Tertiary-age deltaic clinoform packages were examined along the eastern Mexico margin of the southern Gulf of Mexico in an attempt to scrutinize these packages as to how they might relate to reservoirs downslope. The shelf edge is characterized by a period of progradation and late-stage sediment bypass along a lowstand horizon, followed by aggradation and limited downslope sedimentation, retrogradational filling of upper-slope sediment troughs, and, finally, oversteepening and significant destabilization. Four primary surfaces—the 350, 400, 450, and 500—were mapped across the area to separate major clinoform packages (each containing multiple clinoforming events) and carried over the shelf break and slope region. Seismic geomorphology of the intervening deepwater packages was then examined, revealing that shelf-edge faults strongly influence the location of deepwater fans. In addition, a deep-seated structural high in the easternmost region of the study area influenced gravity deposits, forcing them to the north until the feature was buried, sometime after 400 time. Amplitude extractions through the lowermost fan interval (350 to 400 time) show a series of fans issuing from normal fault ramps. Smaller (~200-m) channels can be seen, as well as larger lobe developments that crosscut one another. These deposits are overlain by the oversteepened clinoform package, which is dominated downslope by movement of attached mass transport deposits, anticipated to be sandy.

AAPG Search and Discover Article #90078©2008 AAPG Annual Convention, San Antonio, Texas