Is Lower Cretaceous formation mapped only in westernmost part of sheet in Terrell Co, TX (Permian basin). Overlies Sue Peaks Formation. Overlain by Del Rio Clay or Buda Limestone. Map unit described as limestone, fine-grained to microgranular, massive, beds up to 10 ft thick, some marl interbeds in upper part, rounded chert nodules and silicified rudistids common in more massive beds, light-gray to white; weathers dark-gray and shades of brown; rudistids and miliolids abundant; forms cliffs; thickness about 350-450+ ft. Is not mapped east of Terrell Co, TX. In map explanation, is schematically depicted to be equivalent to Salmon Peak Limestone, upper part of Devils River Limestone, and upper part of Segovia Member of Edwards Limestone.

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

Santa Elena Limestone. Mapped in Terrell, Brewster, and Presidio Counties, Texas. Mapped (undifferentiated) with Sue Peaks Formation, Del Carmen Limestone, and Telephone Canyon Formation in Terlingua and Christmas-Rosillos Mountain areas, and Tascotal Mesa, Agua Fria, and Santiago Peak quadrangles. Limestone, fine-grained to microgranular, massive, beds up to 10 feet thick, some marl interbeds in upper part, rounded chert nodules and silicified rudistids common in more massive beds, light-gray to white; weathers dark-gray and shades of brown; rudistids and milliolids abundant; forms cliffs. Thickness about 500 feet in Santiago Peak area, 740 feet at mouth of Santa Elena Canyon, 943 feet in Black Gap area. Overlies Sue Peaks Formation. Underlies Del Rio Clay. Age is Early Cretaceous.

Source: Publication; supplemental information from GNU records (USGS DDS-6; Denver GNULEX).