About This Item

Share This Item

The AAPG/Datapages Combined Publications Database

GCAGS Transactions

Abstract


Gulf Coast Association of Geological Societies Transactions
Volume 54 (2004)

EXTENDED ABSTRACT: Seismic and Sequence Stratigraphy of Upper Cretaceous Strata, Offshore Alabama and Mississippi Area

Liu, Kaiyu1

ABSTRACT

Upper Cretaceous (Cenomanian to Maastrichtian) strata in the offshore Alabama and Mississippi area consist of a thick section of siliciclastic and carbonate sediments of about 1000 meters. These sediments were deposited on a broad shelf and coastal plain where eustasy had significant impacts on sedimentation patterns. An integrated seismic and sequence stratigraphic approach improves the understanding of Late Cretaceous paleoenvironments, sea level fluctuations and depositional patterns.

202 lines of high quality, two dimensional, multi-channel seismic reflection data (approximately 3,500 kilometers in total length) were studied to decipher the geometry and architecture of Upper Cretaceous strata in the study area. The stratal patterns as interpreted from seismic reflector configurations are distinct for different positions on the continental shelf. Four major sequence boundaries and two maximum flooding surfaces were identified from seismic reflector configurations and traced across the shelf. The four sequence boundaries correspond to major regional unconformities as recognized from outcrop and core studies. These include a mid-Cenomanian unconformity, a Turonian-Coniacian unconformity, a Campanian-Maastrichtian unconformity, and a Maastrichtian-Paleocene unconformity and two maximum flooding surfaces that occur in the Tuscaloosa Marine Shale (Late Cenomanian to Early Turonian) and middle Mooreville Chalk (Early Campanian) intervals. The maximum flooding surface for the upper-most sequence was not recognized from seismic data.

Well log information was integrated with seismic reflection data through the use of synthetic seismograms and check shot surveys to establish an integrated seismic and sequence stratigraphic framework. Facies architecture from middle shelf to outer shelf areas is interpreted from seismic facies analysis and well log correlations.

Pay-Per-View Purchase Options

The article is available through a document delivery service. Explain these Purchase Options.

Watermarked PDF Document: $14
Open PDF Document: $24