Geologic Unit: Trinity

Usage:

Trinity Group (AR*,LA*,MS*,NM,OK*,TX*)
Trinity Sand (LA*,OK*,TX*)
Trinity Formation (AR,LA,TX)

Subunits:

GROUP STATUS (alphabetical): Antlers Formation (NM,OK,TX) or Antlers Sand (TX) or Antlers Sandstone (OK), Bluff Dale Sand (TX), Bluff Mesa Formation (TX*) or Bluff Mesa Limestone (TX*), Cossatot Formation (AR), Cow Creek Limestone (TX*), Cox Sandstone (TX*), Cuchillo Formation (TX), De Queen Limestone (AR*,OK*), Delight Sand (AR*), Dierks Limestone (AR*), Ferry Lake Anhydrite (AR*,LA*,MS*,TX*) or Ferry Lake Formation (MS), Glen Rose Formation (TX*) or Glen Rose Limestone (TX*), Holly Creek Formation (AR*,OK*), Hosston Formation (LA,TX), James Limestone (AR*,LA*,MS*,TX*), Maxon Formation (TX*), Mooringsport Formation (AR*,LA*,MS*,TX*), Paluxy Formation (AR*,LA*,MS*,TX*) or Paluxy Sand (OK*,TX*), Pearsall Formation (TX*), Pike Gravel (AR*), Pine Island Formation (LA,TX) or Pine Island Shale (AR*,LA*,TX*), Presidio Formation (TX*), Quitman Formation (TX), Rodessa Formation (AR*,LA*,MS*,TX*), Rusk Formation (LA,TX), Shafter Limestone (TX*), Shingle Hills Formation (TX), Sligo Formation (TX), Travis Peak Formation (TX*), Twin Mountains Formation (TX), Yucca Formation (TX).

FORMATION STATUS --all in AR: De Queen Limestone Member, Dierks Limestone Member, Pike Gravel Member.

Geologic age:

Early Cretaceous*

Type section, locality, area and/or origin of name:

Named from exposures on the Trinity Rivers of TX (Hill, 1888).
Reference section (Trinity division): Hayes-Travis Cos. area, central eastern TX. Measured at localities in order of geologic sequence (ascending) Hammet Crossing section, Hamilton Pool, Craft Ranch, Murrah Ranch, and Shingle Hills (Lozo and Stricklin, 1956).

AAPG geologic province:

Ouachita folded belt*
Arkla basin*
East Texas basin*