BOLCHERT, GRETCHEN, and PAUL WEIMER, University of Colorado, Boulder, CO; and BARRY McBRIDE, HS Resources, Denver, CO

Numerous seeps and chemosynthetic communities are present on the modern slope in the Gulf of Mexico. These features are associated with faults and salt highs and serve as indicators of recent petroleum migration and migration pathways.

Locations of twenty-seven known seep occurrences were superposed on several maps (including present-day salt, bathymetry, present-day migration, reconstructed migration and minibasin classification) and a regional 2-D seismic grid in Green Canyon and Ewing Bank. Maps and seismic data were used to evaluate stratigraphic and structural controls, analyze surface expression of these features, and classify petroleum migration pathways. Five classifications of migration pathways were determined based on salt, salt weld, and fault geometry. These include seeps and chemosynthetic communities associated with: 1) ramp faults from salt stock collapse, possessing landward rotation; 2) roho systems, consisting of south dipping arcuate faults; 3) stepped counter regional systems, consisting of north dipping salt welds; 4) counter regional systems from salt stock collapse, with basinward rotation; and 5) complex salt systems.

These structural models combined, with evidence of seeps andor chemosynthetic communities, allow for the prediction of petroleum migration pathways, which may help better understand the charge potential for prospects.

BOLCHERT, GRETCHEN, PAUL WEIMER, and BARRY McBRIDE

AAPG Search and Discovery Article #90908©2000 GCAGS, Houston, Texas