The Edwards Formation, on the downthrown side of Mt. Bonnell fault in the Austin, Texas, area (Hays and Travis Counties), is part of the northeastern extension of the Edwards Underground Reservoir, the primary source of water in numerous counties along the Balcones Fault Zone.

Data collected during the last 5 years on the 15 shallow salt diapirs that extend upward to shallow depths (<4,000 ft, 1,220 m) in the East Texas Basin are presented here in graphical and tabular form. East Texas Basin salt diapirs penetrate and have controlled the deformation of Jurassic and younger units in the central part of the basin.

Post-Aptian strata (younger than 112 ma) in the East Texas Basin were strongly influenced by halokinesis and recorded the evolution associated sate structures.

Thirty-one low-permeability gas-bearing sandstones in 15 sedimentary basins were surveyed to delineate the major depositional systems and associated facies of each stratigraphic unit. The depositional system of each unit provides a basis of comparison between formations of different ages in different structural and sedimentary settings.