Domes of East Texas: ABSTRACT

Abstract

Data have been collected in the last 5 yr on the 15 salt diapirs that extend upward to shallow depths (4,000 ft or 1,220 m) in the East Texas basin. These salt diapirs penetrate Jurassic and younger units and have controlled their deformation in the central part of the basin. Both primary and secondary data have been gathered. Primary data are observations of dome shape, depth, structure, and resources. Examples of primary data are depths to cap rock and salt, cross-sectional area, axial ratio, crestal area and percentage of planar crest, axial plunge, tilt azimuth and distance, structural symmetry, side convergence, and overhang azimuth and percentage, as well as a new quantitative classification of dome shape. The structural styles of strata around each dome can be desc ibed in terms of the size of the rim syncline and drag zone around the diapir, angular relations between the strata and the salt, and style of faulting. Secondary data include deductions and inferences based on the primary data. The growth evolution developed from the pillow stage, through the diapir stage, to the post-diapir stage. Unconformities resulted from erosional breaching of the dome in the past. The structural stability and hydrologic integrity of each dome have been assessed in terms of the age of the most recent deformation. Geomorphic and hydrologic evidence for dome uplift, subsidence, or brine leakage are included in a new classification of drainage patterns above domes. End_of_Article - Last_Page 1213------------