Sedimentology and Lithostratigraphy of a Late Wisconsinan Outer Shelf Delta, Research Consortium Boring in Main Pass Block 303, Mississippi Delta Area

ROBERTS, H. H., A. H. BOUMA, and J. M. COLEMAN, Louisiana State University, Baton Rouge, LA, R. H. FILLON, Texaco, New Orleans, LA, B. KOHL and R. E. CONSTANS, Chevron, New Orleans, LA, and R. D. WINN, Marathon Oil, Littleton, CO

A 92 m continuous boring was collected in Main Pass Area, Block 303, to better understand shelf-edge deltaic sedimentation and facies architecture in relationship to glacio-eustatic cycles. The boring was also used to calibrate sequence stratigraphy with lithology and chronostratigraphy.

The boring spans six isotope stages, covering parts of the last three sea-level cycles. The basal part (92-81 m; glacial isotope Stage 6) is interpreted as a mudflow composed of a rapidly deposited shale with distorted bedding, gas-related structures, and C-13 depleted diagenetic carbonates. This glacial stage is overlain by transgressive systems tract shelf shales capped by a 4-m-thick nodular calcareous shale/shelly limestone, representing the interglacial isotope Stage 5 condensed section.

AAPG Search and Discovery Article #91004 © 1991 AAPG Annual Convention Dallas, Texas, April 7-10, 1991 (2009)