Evaporite karst in the rolling plains and High Plains of Texas--Process and petrographic evidence

Conference · Mon Feb 01 04:00:00 EST 1993 · Geological Society of America, Abstracts with Programs; (United States)

OSTI ID:6002624

Hovorka, S D ^[1]

---

1. Univ of Texas, Austin, TX (United States). Bureau of Economic Geology

Permian halite and anhydrite have been extensively dissolved by ground water in the shallow subsurface of the Texas Panhandle. Large caves in halite have collapsed, producing breccia chimneys. In contrast, stratiform halite dissolution has resulted in passive letdown of overlying beds. Residues left after halite dissolution can be identified by wavy lamination formed by top-to-bottom accretion and by distinctive limpid, multifaceted dolomite. In the deeper, more saline parts of the dissolution zone, anhydrite has been replaced volume-for-volume by gypsum, causing large amounts of calcium sulfate to be released. This regime is dominated by gypsum precipitation forming pore-filling cements and fibrous veins along fractures caused by salt dissolution. In the more flushed parts of the dissolution zone, gypsum is dissolved, further enhancing permeability. Paleo-dissolution horizons can be identified because (1) they are discordant with the active dissolution zone, demonstrating that they formed at times of lower topographic relief and (2) they are marked by silicification and calcitization of gypsum. Evaporite dissolution has a negative impact on water quality, and better understanding of dissolution processes has implications for design of remediation projects to decrease natural brine discharge into ground-water supplies.

• OSTI ID: 6002624
• Report Number(s): CONF-9303212--
• Conference Information: Journal Name: Geological Society of America, Abstracts with Programs; (United States) Journal Volume: 25:1
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000* -- Geosciences
ANHYDRITE
BRINES
CAVES
CAVITIES
DEVELOPED COUNTRIES
DISSOLUTION
EVAPORITES
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GROUND SUBSIDENCE
GROUND WATER
GYPSUM
HALIDE MINERALS
HALITE
HYDROGEN COMPOUNDS
MINERALS
NORTH AMERICA
OXYGEN COMPOUNDS
PALEOZOIC ERA
PERMIAN PERIOD
POLLUTION
POLLUTION ABATEMENT
ROCKS
SEDIMENTARY ROCKS
SULFATE MINERALS
TEXAS
USA
WATER
WATER POLLUTION
WATER POLLUTION ABATEMENT