CLINTON- Predominantly orange-brown, fine-grained sandstone, the "Whitehorse Group" is mapped as Pwh where separate formations have not been distinguished and as the "Rush Springs Formation" and the "Marlow Formation" where identified. "Rush Springs Formation," Pr, orange-brown, cross-bedded, fine-grained sandstone with some dolomite and gypsum beds. Thickness, about 300 feet, thinning northward to about 186 feet. The "Weatherford Gypsum Bed," Prw, is about 30 to 60 feet below the top (mapped in southeastern part only). "Marlow Formation," Pm, orange-brown, fine-grained sandstone and siltstone, about 100 to 130 feet thick, thinning northward. This formation has 2 gypsum and (or) dolomite beds in upper 20 feet--the "Emanuel Bed" (at top) and the "Relay Creek Bed" (20 feet below top). Two thin, pale shales occur; the first is 1 foot below the top ("Gracemont") and the second is 55 feet above the base (unnamed). The "Verden Sandstone Lentil," Pmv, is a coarse-grained, calcareous, fossiliferous sandstone (2 to 10 feet thick) that occurs in the middle of the Marlow, about 25 feet below the Relay Creek Bed and 85 to 95 feet above the base. LAWTON- Predominantly orange-brown, fine-grained sandstone, the "Whitehorse Group" is mapped as Pwh where separate formations have not been distinguished and as the "Rush Springs Formation" and the "Marlow Formation" where identified. "Whitehorse Group undifferentiated," Pwh, fine-grained sandstone and siltstone as much as 100 feet (30 m) thick in western part of quadrangle, interbedded with gypsum beds 3 to 10 feet (1 to 3 m) thick.