The Smackover and lower part of the Buckner Formations (Oxfordian) comprise a thick regressive sedimentary sequence deposited on a Jurassic carbonate ramp. Four major depositional systems are recognized: (1) basinal, (2) low-energy open shelf, (3) high-energy shoal, and (4) sabkha. Lithofacies boundaries within each system and between systems follow paleobathymetrical contours. High-energy grainstone facies were concentrated landward; muddy low-energy facies were deposited seaward.
Regional cross sections of Middle and Upper Permian rocks in the Texas Panhandle illustrate the lithology, depositional systems, and structure of these salt-bearing strata. This report explains the interpretative techniques used in preparation of the cross sections that accompany the text, and highlights significant geologic relationships displayed on the cross sections.
Geological investigations in the Texas Panhandle and eastern New Mexico indicate that regional subsurface dissolution of Permian evaporites has occurred and is an ongoing process. Evidence of removal of large volumes of evaporites (mainly halite) and collapse of overlying beds is demonstrated by cross sections constructed from gamma-ray logs.
Jurassic, Cretaceous, and Tertiary sediments in the East Texas Basin have been structurally modified by movement of Middle Jurassic Louann Salt. Important structural elements in the basin include salt diapirs, deep salt anticlines and turtle-structure anticlines as well as prominent fault systems. This set of eight regional structural cross sections shows the general stratigraphy and structure of the basin and illustrates the effect of salt movement. Accompanying the cross sections is a brief discussion of the regional structure and stratigraphy.
Upper Miocene, Pliocene, and Pleistocene deposits in the subsurface of the central Coastal Plain of Texas were subdivided into six operational units comprising the surface-defined Fleming, Goliad, Willis, Lissie, and Beaumont Formations. These sedimentary units constitute the last major depositional episodes in the northwestern Gulf Coast Basin. Late Miocene deposition is represented by transgressive shelf and shallow-marine shales overlain by progradational clastics of the upper part of the Lower Fleming, Upper Fleming, and Lower Goliad-Willis units.