Pg. 2633. Tordilla sandstone bed [informal] in Dubose member of Whitsett formation. Local name applied to a 30-foot silicified fine-grained sandstone bed in Dubose member of the Whitsett. Age is late Eocene.
Exposed in Tordilla Hill, western tip of Karnes Co., south-central TX.

Source: US geologic names lexicon (USGS Bull. 1200, p. 3924)

Tordilla Sandstone Member of Whitsett Formation of Jackson Group. Rocks previously included as uppermost unit of Dubose Member, (Tordilla Sandstone of Eargle, 1959), removed from Dubose, adopted, and raised in rank to Tordilla Sandstone Member of Whitsett Formation. Overlies Dubose Member; underlies Fashing Clay Member; is stratigraphic equivalent of Calliham Sandstone Member. Present in south-central Texas. Age is late Eocene.

Source: Changes in stratigraphic nomenclature, 1972 (USGS Bull. 1394-A, p. A48-A49).

Pg. 29. Tordilla Sandstone Member of Whitsett Formation (upper Eocene). Considered stratigraphic equivalent of Calliham Sandstone Member of Whitsett by Eargle (1972). He used term Tordilla for fine-grained beach sandstone unit in western Karnes County and term Calliham for medium- to coarse-grained sandstone deposited in distributary channels in Atascosa and McMullen Counties to southwest. Studies of new exposures provided by the uranium mining in Karnes County show that the Calliham channels were scoured into the Tordilla beach sand, and though they are deposited physically at about the same horizon, the Calliham deposits are younger. The Calliham is equivalent in age to the Fashing Clay Member, which overlies the Tordilla in Karnes County.

Source: Publication.