Part 4 - Berg - Hughes Center

order. According to Granata (1963), the end of Comanchean time was characterized by
uplift and erosion across east Texas, southern Arkansas, north Louisiana and across into
west central portions of Mississippi. With the retreat of the seas in this region, workers
estimate that up to 10,000 ft of sediments were removed by erosion in southwest
Arkansas alone.
Minor hydrocarbon production occurs in Washita-Fredericksburg reservoirs. Depth
to top of the pay ranges from 2,300 to 9,800 ft. The net pay of mostly gas prone
carbonates is 10 to 30 ft thick. Although porosity can range from 10 to 30%, permeability
tends to be low.
Upper Cretaceous Gulf Series (Tuscaloosa, Austin, Taylor, Navarro)
Tuscaloosa Group
Producing Parishes
Bienville, Webster, Red River, Natchitoches,
Bossier, De Soto, Richland, Franklin,
Tensas, Concordia
According to Granata (1963), deposition of Woodbine in Texas and Tuscaloosa in
Louisiana began with the advance of the Gulfian seas over Lower Cretaceous
Comanchean formations. From northwestern Louisiana and eastward, the Tuscaloosa
thickens from 100 to almost 1,000 ft at the Mississippi border (Cullom et al., 1962). In
northern Louisiana, the Upper Cretaceous consists of the Eagle Ford and Tuscaloosa
Group, including Upper, Middle and Lower Tuscaloosa formations. The sequence
consists mostly of red and gray shales, red and gray mudstones, gray siltstones, and fine-
to medium-grained sandstones, that contain silt, ash, glauconite, mica and/or calcite.
Conglomerates and/or pebbly sandstones and occasional thin, tan to gray fossiliferous
limestones are also present.
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