Named as the basal sandstone tongue of five newly named tongues assigned to the newly named Terryville Sandstone of the Cotton Valley Group. Type section designated as the interval between 9,100 and 9,430 ft in the California Co. Colvin No. 1, SE NW sec 14, T19N, R4W in Lincoln Parish, LA in the Arkla basin. Consists of white quartzose sandstone about 50 ft thick. Considered to be a blanket sandstone that overlies and underlies unnamed gray shale of the Hico Shale (new) of Cotton Valley Group. Cross sections. Pinches out northward into the Hico Shale. Distal edge present into southernmost AR. Late Jurassic age.

Source: GNU records (USGS DDS-6; Denver GNULEX).