Part 4 - Berg - Hughes Center

Sabine, Franklin, Tensas
Shallow water platform Fredericksburg deposition occurred over most of east Texas,
but farther to the east in northern Louisiana the section is partially truncated (Granata,
1963). In northern Louisiana the Middle-Upper Albian Paluxy, Walnut and Goodland
formations are considered part of the Fredericksburg Group. The younger Upper Albian–
Lower Cenomanian Washita Group is truncated and, in some cases, cannot be
differentiated from the Fredericksburg Group in areas of Louisiana. Early workers like
Spofford (1945), placed the Paluxy at the base of Fredericksburg (Walnut clays) and
observed from well study that the Paluxy trended northwest and southeast through Caddo
Parish and northern De Soto Parish. To the west, the Goodland limestone, and the
overlying Washita limestones and shales were also recognized in wells. Cullom et al.
(1962) divided the Washita-Fredericksburg section into a lower Walnut Formation and an
upper Goodland Formation. The former consists of dark shales and dense gray crystalline
to earthy limestones found above the top of the Trinity and the latter unit consists of
porous and non-porous light gray to tan crystalline, fossiliferous shallow water
limestones and interbedded dark marine shales. The top of the Goodland is marked by the
unconformity between beds of Comanchean and those of Gulfian age. According to these
authors, post-Comanchean truncation on the south flank of the South Arkansas Uplift was
cited as being responsible for the erosion of the beds of Washita age. Across the southern
platform area, between 700 and 1,200 ft of Comanchean section is missing due to the
uplift and truncation that accompanied the South Arkansas Uplift. Granata (1963)
reported that the entire Washita Group is only present in a narrow band in east Texas that
trends north into Arkansas but thins east and is no longer present at the north Louisiana
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