PROXIMAL-DISTAL RELATIONSHIPS OF DEEP-WATER DEPOSITS, PERMIAN BRUSHY CANYON FORMATION, WEST TEXAS

Deep-water sediment gravity-flow deposits of the Permian Brushy Canyon Formation are exposed in a continuous 45 km outcrop belt in the Guadalupe and Delaware Mountains of West Texas. These exposures, along with gravity maps and nearby subsurface well logs provide insight regarding regional shelf-to-basin correlation and resulting proximal-distal facies relationships. Determination of point-sourced submarine fan complexes replicate shelf margin trend and reconstruct the paleogeography of the Permian Brushy Canyon Formation.

Tertiary Basin-and-Range extensional tectonism created the down-dropped Salt Basin Graben while uplifting and exposing Permian sediments in the Guadalupe, Delaware, Sierra Diablo, and Apache Mountains. The Salt Basin Graben, however, overlaps the western margin of the Permian Delaware Basin introducing uncertainty regarding carbonate shelf margin configuration and location of Brushy Canyon sediment point sources.

Fairways of sandstone-rich channels and channel complexes have been mapped in the outcrop belt and extended up and down depositional dip. Scintillometer (outcrop gamma-ray) profiles and rock properties derived from core plugs allow proper calibration and comparison of subsurface data to the outcrop belt. Subsurface-outcrop-subsurface cross-sections parallel the principal directions of sediment transport and subsequent isopach maps illustrate the distribution of sediment dispersal along the western margin of the basin. Variations in sedimentologic facies and architectural style along a depositional profile reflect changes in gradient and inherited paleotopography of a deep-water system.