SULLIVAN, N. M., Earth Science and Resources Institute, University of South Carolina, Columbia, SC, A. LOWRIE Consultant, Picayune, MS, C. J. KROTZER, Metairie, LA, J. CARTER, Shreveport, LA, and I. LERCHE and K. PETERSEN, University of South Carolina, Columbia, SC

ABSTRACT: Tectonic and Depositional Model of the North Louisiana-South Arkansas Basin

A tectonic and depositional model is presented for the North Louisiana-South Arkansas (NL-SA) basin. This area is defined as extending from the updip sedimentary outcrop limit of the Mississippi Embayment, to the Sabine uplift and its possible eastward extension to the Wiggens arch in the south, and lying between the Sabine and Monroe uplifts. Included in this designation is the North Louisiana Salt basin.

Geohistory modeling of basin subsidence with time has been correlated to sediment deposition, as well as to regional climatic and oceanographic information. In each instance, quantification and/or ranges of the natural processes are provided. The objective is to develop a dynamic model framework accurate enough to underpin individual prospects with regional understanding.

The tectonic chronology begins with (1) subduction in the lower Paleozoic, followed by (2) incipient and interrupted rifting that is possibly part of mantle plume rising in the upper Paleozoic. A second episode of magmatic intrusion associated with Upper Jurassic sea-floor spreading south of the Sabine uplift. Regional subsidence occurred from the edge of the Mississippi Embayment through the North Louisiana Salt basin, including the proto-Sabine uplift. Lower Cretaceous cessation of the central Gulf of Mexico spreading was accompanied by initiation of tectonic subsidence and the beginning of the South Louisiana Salt basin. A continued regional downdip existed from the edge of the Mississippi Embayment through the proto-Sabine uplift region. Middle Cretaceous initiation of the Sabine nd Monroe uplifts, with a reduction of subsidence rate in the NL-SA area, also impacted the evolution of sedimentary fill and associated structural evolution.

AAPG Search and Discovery Article #90989©1993 GCAGS and Gulf Coast SEPM 43rd Annual Meeting, Shreveport, Louisiana, October 20-22, 1993.