The Sabine uplift of northwestern Louisiana and northeastern Texas is reflected on the surface by a large inlier of Midway, Wilcox, and lower Claiborne sediments. Surface work in this area revealed the presence of three Midway and four Wilcox formations. The formations consist typically of a basal sandy member, a middle lignitic and carbonaceous shale member, and an upper calcareous silt and shale member. The following nomenclature is proposed for these sediments.

Wilcox group
Carrizo formation
Sabinetown formation
Pendleton formation
High Bluff member
Slaughter Creek member
Bayou Lenann member
Marthaville formation

Midway group
Hall Summit formation
Bistineau member
Grand Bayou member
Loggy Bayou member
Logansport formation
Lime Hill member
Cow Bayou member
Dolet Hills member
Naborton formation (base not exposed)

The Midway and Wilcox beds are largely deltaic and barren of fossils, but marine faunas are present therein around the southern flank of the uplift. These faunas permit correlation with the type Midway and Wilcox sediments of Alabama and Mississippi. The mapping methods employed revealed surface indications of nearly all the known oil and gas fields of the area.