BEAUBOUEF, R. T., and C. ROSSEN
Exxon Production Research Company, Houston, Texas

Abstract: Reconstructing Slope to Basin Floor Depositional Systems From Outcrop and Subsurface Data Sets; Examples of Sand Rich, Canyon-Fed Submarine Fan Complexes

This study compares sand-rich, canyon-fed submarine fan complexes, from the Permian Brushy Canyon Formation of the Guadalupe and Delaware Mts., West Texas and Miocene of offshore West Africa. Although these deposits are of different ages, and occur in dissimilar basins they exhibit many common characteristics and are considered highly analogous to one another. By comparing and combining these high resolution data sets depositional models can be built that provide insights into the controls and processes involved in constructing these submarine fan complexes. The 3D seismic data set for the West African example allows detailed analysis of the spatial and temporal relationships between shelf, slope and basin floor depositional systems and high resolution seismic characterization of the geometry and architecture of the deposits. These images provide a template within which selected outcrop observations can be placed. In turn, the outcrop data provide information for the building blocks of these systems including the variations in channel dimensions, bedding styles and lithofacies along the depositional profile. From this comparison we conclude the evolution of these depositional systems includes: 1) delivery of sand to the upper reaches of canyons during lowstands of relative sea level, and initiation of sand-rich sediment gravity flows, 3) erosion, mass wasting, and sand bypass on the slope with concurrent delivery of sand-rich flows to basin floor fans, 4) progressive backfilling of feeder channels with variable fill during waning stages of deposition, and 5) cessation of sand delivery to the basin and progressive fan abandonment.

AAPG Search and Discovery Article #90928©1999 AAPG Annual Convention, San Antonio, Texas