USGS Visual Identifier

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GEOLEX database

Geologic Unit: Cook Mountain

Publication:
Barnes, V.E., 1970, Geologic atlas of Texas, Waco Sheet; Lloyd 
   William Stephenson memorial edition: University of Texas-Austin, 
   Bureau of Economic Geology, 1 sheet, scale 1:250,000
Usage in Publication:
Cook Mountain Formation

Modifications: Geologic Province: Dominant Lithology:
 Mapped 1:250k
 Gulf Coast basin
 East Texas basin
 Clay
 Sand
 Marl
 Limestone

Summary:
Is Eocene formation mapped in southeasternmost part of map sheet in northern Madison Co, TX (Gulf Coast basin) and southern Leon Co, TX (East Texas basin). Overlies Sparta Sand (Eocene) west of Carryall Creek in vicinity of Normangee, Leon Co, TX; overlies Stone City Formation (Eocene) northeastward from Carryall Creek; overlain by Yegua Formation (Eocene). Comprised of four members (descending): Mount Tabor, Spiller, Landrum, and Wheelock Members, which are not separately mapped. Mount Tabor Member described as clay and marly sand, gray to brown, marine megafossils, about 50 ft thick; Spiller Member --sand, argillaceous, carbonaceous, about 80 ft thick; Landrum Member --marl and clay, glauconitic, limestone lentils, lower part bentonitic, marine megafossils, about 100 ft thick; Wheelock Member --marly, clay, some glauconitic calcareous ironstone, very abundant marine megafossils, about 70 ft thick. Total formation about 300 ft thick.
Source: GNU records (USGS DDS-6; Denver GNULEX).


Publication:
Barnes, V.E., 1974, Geologic atlas of Texas, Seguin Sheet; Donald 
   Clinton Barton memorial edition: University of Texas-Austin, 
   Bureau of Economic Geology, 1 sheet, scale 1:250,000
Usage in Publication:
Cook Mountain Formation

Modifications: Geologic Province: Dominant Lithology:
 Mapped 1:250k
 Gulf Coast basin
 Clay
 Sandstone

Summary:
Is Eocene formation mapped in southwest to north-central part of map sheet in narrow southwest-northeast trending belt in southeast Wilson, central Gonzales, southwest Fayette, and southeast Bastrop Cos, TX (Gulf Coast basin). Overlies Sparta Sand (Eocene); overlain by Yegua Formation (Eocene). Map unit described as clay and sandstone; clay, gypsiferous, slightly silty and lignitic, minor glauconite, brown to brownish gray, weathers brownish gray to yellowish gray; sandstone, very fine grained, calcareous, glauconitic, gray to yellowish brown; marine megafossils and microfossils abundant; thickness 200-230 ft.
Source: GNU records (USGS DDS-6; Denver GNULEX).


Publication:
Barnes, V.E., 1974, Geologic atlas of Texas, San Antonio Sheet; 
   Robert Hamilton Cuyler memorial edition: University of 
   Texas-Austin, Bureau of Economic Geology, 1 sheet, scale 
   1:250,000
Usage in Publication:
Cook Mountain Formation

Modifications: Geologic Province: Dominant Lithology:
 Mapped 1:250k
 Gulf Coast basin
 Clay
 Sandstone

Summary:
Is Eocene formation mapped in northeast-southwest trending belt in southern Wilson and eastern Atascosa Cos, TX (Gulf Coast basin) in southeasternmost part of map sheet. Overlies Sparta Sand (Eocene); overlain by Yegua Formation (Eocene). Map unit described as clay and sandstone; clay, gypsiferous, slightly silty and lignitic, minor glauconite, brown to brownish gray, weathers brownish gray to yellowish gray; sandstone near top and at base, very fine grained, calcareous, glauconitic, gray to yellowish brown, marine megafossils and microfossils abundant; thickness about 230 ft.
Source: GNU records (USGS DDS-6; Denver GNULEX).


Publication:
Barnes, V.E., 1976, Geologic atlas of Texas, Crystal City-Eagle 
   Pass Sheet; Dolan Hoye Eargle memorial edition: University 
   of Texas-Austin, Bureau of Economic Geology, 1 sheet, scale 
   1:250,000
Usage in Publication:
Cook Mountain Formation

Modifications: Geologic Province: Dominant Lithology:
 Areal limits
 Mapped 1:250k
 Gulf Coast basin
 Clay
 Sandstone

Summary:
Is Eocene formation mapped northeast of Frio River in Frio and Atascosa Cos, TX (Gulf Coast basin). Overlies Sparta Sand (Eocene); overlain by Yegua Formation (Eocene). Is not mapped southwest of Frio River. Correlation of map units shows Cook Mountain correlative with upper part of Laredo Formation, which is mapped southwest of Frio River. Map unit described as clay and sandstone; clay--gypsiferous, slightly silty and lignitic, minor glauconite, brown to brownish gray, weathers brownish gray to yellowish gray; sandstone--near top and base, very fine grained, calcareous, glauconitic, gray to yellowish brown; marine megafossils and microfossils abundant; thickness about 200-350 ft.
Source: GNU records (USGS DDS-6; Denver GNULEX).


Publication:
Merrill, R.K., Sims, J.J., Jr., Gann, D.E., and Liles, K.J., 
   1985, Newton County geology and mineral resources [Mississippi]: 
   Mississippi Office of Geology Bulletin, no. 126, 108 p.
Usage in Publication:
Cook Mountain Formation

Modifications: Geologic Province: Dominant Lithology:
 Overview
 Mid-Gulf Coast basin
 

Summary:
The Cook Mountain Formation is best exposed in Newton Co., MS, on the south side of I-20 at the Newton exit, in NW1/4NE1/4 sec. 26, T6N, R11E. Varies in thickness in the subsurface, from 47 ft to 135 ft. Thickens downdip. Mapped as a single unit, but two members discussed in text: Potterchitto and Gordon Creek Shale. Basal Archusa Marl Member is not recognized in Newton Co., either at the surface or in the subsurface. Disconformably overlies the Kosciusko Formation and conformably underlies the Cockfield Formation. Age is middle Eocene. Geologic map. Measured section. Stratigraphic column.
Source: GNU records (USGS DDS-6; Reston GNULEX).