Trinity Group (geologic group)

Trinity Group
Stratigraphic range: late Aptian-early Albian, 115–106 Ma
TypeGroup
Sub-units
UnderliesFredericksburg sands, Goodland Formation
OverliesCotton Valley Formation
Location
RegionTexas, Arkansas
CountryUnited States
Type section
Named forTrinity Rivers, Texas
Named byRobert Thomas Hill[1]
Trinity Group stratigraphic column in Texas

The Trinity Group is a group (sequence of rock strata) in the Lower Cretaceous lithostratigraphy of Texas, Arkansas, Mississippi, Louisiana and Oklahoma.[2][3][4] It is named for the Trinity River of Texas.

A stratigraphic column at the Mount Bonnell Fault location starts with the Lower Cretaceous Trinity Group overlain by the Edwards Group. Upper Cretaceous formations follow, starting with the Del Rio Clay, Buda Limestone, and then the Eagle Ford Group. Formations within the Trinity Group include the Hammett Formation, Cow Creek Formation, Hensel Formation, and Lower and Upper Glen Rose Formation. The Hammett and the lower portion of the Upper Glen Rose act as confining units (or aquitard) for the Middle Trinity Aquifer. The Upper Glen Rose contains the Upper Trinity Aquifer, which appears to have intra-aquifer groundwater flow with the Edwards Aquifer as water levels are at the same elevation.[5]

  1. ^ Hill, R.T. (1888). "The Trinity formation of Arkansas, Indian Territory, and Texas". Science. 11 (258): 21. doi:10.1126/science.ns-11.258.21. PMID 17742326.
  2. ^ "Geologic Unit: Trinity". National Geologic Map Database. USGS. Retrieved 31 May 2014.
  3. ^ Suarez, Celina A.; Frederickson, Joseph; Cifelli, Richard L.; Pittman, Jeffrey G.; Nydam, Randall L.; Hunt-Foster, ReBecca K.; Morgan, Kirsty (2021-10-21). "A new vertebrate fauna from the Lower Cretaceous Holly Creek Formation of the Trinity Group, southwest Arkansas, USA". PeerJ. 9: e12242. doi:10.7717/peerj.12242. ISSN 2167-8359. PMC 8542373.
  4. ^ "Paleontologists Find Fossils of New Lizard and Fish Species in Arkansas | Sci-News.com". Breaking Science News | Sci-News.com. Retrieved 2021-11-21.
  5. ^ Saribudak, Mustafa (September 2016). "Geophysical mapping of Mount Bonnell fault of Balcones fault zone and its implications on Trinity-Edwards Aquifer interconnection, central Texas, USA". The Leading Edge. 35 (9). Society of Exploration Geophysicists: 752–758. doi:10.1190/tle35090752.1. Retrieved 12 September 2016.