Abstract: Plio-Pleistocene Lowstand Systems Tract, Central Offshore Louisiana, Gulf of Mexico

Fangjian Xue, Joel S. Watkins

Interpretation of 5000 miles seismic data and logs from 50 wells from central offshore Louisiana outer continental shelf made it possible to investigate the lowstand systems tract(LST) in the Plio-Pleistocene section. Evolutionary patterns of the Plio-Pleistocene LST are controlled by the changing balance of intrabasinal salt and growth fault activities, eustatic sea level fluctuations, sediment yields, river mouth switching, and eastward shifting of the lower Mississippi River system. A prominent feature in the seismic data is a set of widely and deeply incised valley fills. These fairways are deepest near the shelf edge and tend to die out or amalgamate shelfward position. Their lithofacies patterns indicate that these valleys are commonly filled with fluvial to estuari e sand. Understanding the incised valley system provides a powerful way for predicting sand occurrence in that environment as well as farther downslope.

AAPG Search and Discovery Article #90955©1995 GCAGS 45th Annual Meeting and Gulf Section SEPM, Baton Rouge, Louisiana