Clay minerals as indicators for depositional environment in the south Hallettsville Field, Lavaca County, Texas

Conference · Tue Jan 01 04:00:00 EST 1980 · Trans., Gulf Coast Assoc. Geol. Soc.; (United States)

OSTI ID:6372974

Freed, R L

The South Hallettsville Field, Lavaca County, Texas, produces gas and condensate from Lower Wilcox sandstones and shales which have been interpreted as either channel turbidite deposits in outer-shelf to slope locations or as delta to pro-delta sands and muds. Thirteen core samples were analyzed by X-ray diffraction methods to determine whether a semiquantitative estimate of clay mineral content would aid in determining the depositional environment. Discrete illite, kaolinite, and chlorite are of particular interest because the presence of these minerals is interpreted as being due to original deposition. If a turbidity-type event occurred, the weight percents of nondiagenetic clays in this sequence should: (1) decrease significantly as the boundary is crossed between the shale and the overlying sandstone; and (2) gradually increase in progressively shallower samples within the sandstone. However, the weight percents for kaolinite and chlorite do not vary significantly; the illite content gradually decreases with shallower depths. This sequence is more compatible with a deltaic environment of deposition. 10 references.

• OSTI ID: 6372974
• Conference Information: Journal Name: Trans., Gulf Coast Assoc. Geol. Soc.; (United States) Journal Volume: 30
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200* -- Petroleum-- Reserves
Geology
& Exploration
03 NATURAL GAS
030200 -- Natural Gas-- Reserves
Geology
& Exploration
ALUMINIUM COMPOUNDS
ALUMINIUM SILICATES
CHEMICAL ANALYSIS
CHLORITE MINERALS
CLAYS
COHERENT SCATTERING
DEPTH
DIFFRACTION
DIMENSIONS
FEDERAL REGION VI
GEOLOGIC DEPOSITS
GEOLOGIC STRUCTURES
ILLITE
KAOLINITE
MINERAL RESOURCES
MINERALS
NATURAL GAS DEPOSITS
NORTH AMERICA
OXYGEN COMPOUNDS
PETROLEUM DEPOSITS
QUANTITATIVE CHEMICAL ANALYSIS
RESERVOIR ROCK
RESOURCES
ROCKS
SAMPLING
SANDSTONES
SCATTERING
SEDIMENTARY ROCKS
SILICATE MINERALS
SILICATES
SILICON COMPOUNDS
TEXAS
USA
X-RAY DIFFRACTION