Named as lowermost of three newly named members of Word Formation (revised) in the Glass Mountains, west TX--these are (ascending): China Tank, Willis Ranch, and Apple Ranch [spelled Appel Ranch in subsequent reports] Members. Type section designated on west side of hill 5611, just east of the fault that bounds Hess Ranch horst in west-central Hess Canyon quad, Brewster Co, TX. Named for China Tank, a cattle tank on Hess Ranch, that takes its name from a nearby grove of Chinaberry trees. This unit was formerly designated the "Second Limestone" member of Word (King, 1931). China Tank Member is siliceous, brownish-gray to yellowish-gray limestone, 113 ft thick; contains abundant silicified fossils. Well displayed on the bluffs on the east side of Hess Canyon about 1.5 mi south of the head of the southwest branch of the canyon, due west of the Old Word Ranch. Merges into main mass of Word Formation east of Old Word Ranch. Member has been mapped westward (by King, 1931) only in vicinity of its type locality near the head of Hess Canyon; member is not extensive. Of Permian (Guadalupian) age.

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