The Travis Peak Formation (Hosston Formation in Louisiana) is a basinward-thickening wedge of terrigenous clastics that extends in an arc from eastern Texas across southern Arkansas and northern Louisiana into southern Mississippi. This formation is a large reservoir of natural gas that is contained in sandstones of low permeability that are generally classified as tight gas sands. Because of the stratigraphic complexity and past limited economic interest in this Lower Cretaceous formation, little is known about the distribution or depositional environments of potentially productive sandstones within it. This subsurface study of the Travis Peak (Hosston) and Sligo Formations utilized 1,300 electric logs distributed across an area of approximately 35,000 mi2 covering the east half of the East Texas Basin, the North Louisiana Basin, and part of southern Arkansas.
In addition to the standard isopach and structure maps, several lithofacies maps and six semi-regional stratigraphic cross sections made it possible to recognize the following five depositional systems in the Travis Peak (Hosston) Formation: fluvial-deltaic, delta fringe, restricted marine shelf, shelf margin, and open marine. The most sand-rich systems are the fluvial-deltaic and the shelf-margin systems.
Two major high-constructive delta complexes have been identified in the study area. These deltas were located over the present sites of the Sabine and Monroe Uplifts. The North Louisiana Salt Basin, a marine embayment in Travis Peak (Hosston) time, accumulated a thick section of interbedded shales and limestones in a restricted back-reef or back-bar shelf area. A carbonate or sandstone barrier appears to extend across the central Louisiana Early Cretaceous shelf margin.
The delta-fringe system, although containing less sand, consists of a variety of lithofacies deposited in a transition zone ranging from delta-plain to shallow-marine-shelf environments, and it appears to correlate with the most hydrocarbon-productive part of the Travis Peak (Hosston) Formation. Oil and gas accumulations in the Travis. Peak (Hosston) are closely associated with salt-cored structures in East Texas and North Louisiana. This study should aid in the projection of prospective tight gas trends.