Santa Rosa Formation | |
---|---|
Stratigraphic range: | |
Type | Formation |
Sub-units | Tecolotito Member, Los Esteros Member, Tres Lagunas Member |
Underlies | Garita Creek Formation |
Overlies | Anton Chico Formation |
Thickness | 32 meters (105 ft) |
Lithology | |
Primary | Sandstone, mudstone |
Other | Conglomerate |
Location | |
Coordinates | 34°57′43″N104°41′25″W / 34.9620°N 104.6902°W |
Region | New Mexico, Texas |
Country | United States |
Type section | |
Named for | Santa Rosa, New Mexico |
Named by | N.H. Dalton |
Year defined | 1919 |
The Santa Rosa Formation is a geologic formation exposed in New Mexico that was deposited in the Carnian Age of the late Triassic Period. [1]
The formation consists mostly of white to brown sandstone and mudstone with some interbedded conglomerate. The formation lies on the Anton Chico Formation [1] and is overlain by the Garita Creek Formation. [2] The total thickness of the formation is 32 meters (105 ft). [1]
The formation is divided into (in ascending stratigraphic order) the Tecolotito Member , which is primarily sandstone; the Los Esteros Member, which is primarily mudstone; and the Tres Lagunas Member, which is primarily sandstone. [1]
The sandstone members are interpreted as alluvial sheets deposited by braided streams. The Los Esteros Member is interpreted as a lacustrine deposit in lakes that formed due to local subsidence from dissolution of underlying Permian salt beds. Paleocurrents were primarily to the south in the Tecolotito Member and northeast in the Tres Lagunas Member but are indeterminate in the Los Esteros Member. [3]
The Los Esteros Member has yielded fossils of the fern Cynepteria lasiophora, the cycad Zamites powelli , the conifer Pelourdea pleoensis, the gymnosperm Dinophyton spinusos, and seeds ( Samaropsis ). [4]
This member also includes a microvertebrate site in Santa Fe County, New Mexico that has yielded a diverse fossil assemblage. Fish fossils include lungfish toothplates of Arganodus dorothea, a redfieldiid dermopteric, and scales from Turseodus , including from coprolites. Amphibian fossil fragments are probably from Buttneria perfecta and Apachesaurus gregorii. Reptiles include Trilophosaurus , indeterminate phytosaurs, Desmatosuchus haplocerus, Stagonolepis wellesii, several new aetosaurs, Chatterjeea elegans, Hesperosuchus , and Parrishia mcreai. Synapsids are represented by an indeterminate kannemeyeriiform dicynodont [5] and an unnamed cynodont. [6]
In east-central New Mexico, the Los Esteros Member has also yielded a Otischalkian dinosauromorph assemblage that includes specimens of Silesauridae and Lagerpetidae, including Dromomeron , the latter of unusually large size. [7]
The formation was first named as the Santa Rosa Sandstone by N.H. Darton in July 1919 but the report was not published until 1922. [8] By then the name had already appeared in other publications. [9] [10] A type locality was not formally designated until 1972. [11] In 1987, Spencer G. Lucas and Adrian Hunt removed the lower sandstone beds into the Anton Chico Formation and divided the remaining beds into members. [1] W.I. Finch and coinvestigators redesignated the unit as the Santa Rosa Formation in 1988. [12]
The Entrada Sandstone is a formation in the San Rafael Group found in the U.S. states of Wyoming, Colorado, northwest New Mexico, northeast Arizona, and southeast Utah. Part of the Colorado Plateau, this formation was deposited during the Jurassic Period sometime between 180 and 140 million years ago in various environments, including tidal mudflats, beaches, and sand dunes. The Middle Jurassic San Rafael Group was dominantly deposited as ergs in a desert environment around the shallow Sundance Sea.
The Moenkopi Formation is a geological formation that is spread across the U.S. states of New Mexico, northern Arizona, Nevada, southeastern California, eastern Utah and western Colorado. This unit is considered to be a group in Arizona. Part of the Colorado Plateau and Basin and Range, this red sandstone was laid down in the Lower Triassic and possibly part of the Middle Triassic, around 240 million years ago.
The Chinle Formation is an Upper Triassic continental geological formation of fluvial, lacustrine, and palustrine to eolian deposits spread across the U.S. states of Nevada, Utah, northern Arizona, western New Mexico, and western Colorado. In New Mexico, it is often raised to the status of a geological group, the Chinle Group. Some authors have controversially considered the Chinle to be synonymous to the Dockum Group of eastern Colorado and New Mexico, western Texas, the Oklahoma panhandle, and southwestern Kansas. The Chinle Formation is part of the Colorado Plateau, Basin and Range, and the southern section of the Interior Plains. A probable separate depositional basin within the Chinle is found in northwestern Colorado and northeastern Utah. The southern portion of the Chinle reaches a maximum thickness of a little over 520 meters (1,710 ft). Typically, the Chinle rests unconformably on the Moenkopi Formation.
The Glen Canyon Group is a geologic group of formations that is spread across the U.S. states of Nevada, Utah, northern Arizona, north west New Mexico and western Colorado. It is called the Glen Canyon Sandstone in the Green River Basin of Colorado and Utah.
The Dockum is a Late Triassic geologic group found primarily on the Llano Estacado of western Texas and eastern New Mexico with minor exposures in southwestern Kansas, eastern Colorado, and Oklahoma panhandle. The Dockum reaches a maximum thickness of slightly over 650 m but is usually much thinner. The Dockum rests on an unconformity over the Anisian aged Anton Chico Formation.
The Crevasse Canyon Formation is a coal-bearing Cretaceous geologic formation in New Mexico and Arizona.
The Garita Creek Formation is a geologic formation in New Mexico that contains vertebrate fossils characteristic of the Carnian Age of the late Triassic.
The Moenave Formation is a Mesozoic geologic formation, in the Glen Canyon Group. It is found in Utah and Arizona.
The Shinarump Conglomerate is a geologic formation found in the Four Corners region of the United States. It was deposited in the early part of the Late Triassic period.
The Redonda Formation is a geologic formation exposed in eastern New Mexico. It contains vertebrate fossils of the late Triassic Period. Fossil theropod tracks have been reported from the formation.
The Baldy Hill Formation is a geologic formation in northeastern New Mexico and western Oklahoma. It preserves fossils dating back to the late Triassic period.
The Trujillo Formation is a geologic formation in Texas and New Mexico. It preserves fossils dating back to the upper Triassic period. It is also known as the Trujillo Sandstone.
The San Jose Formation is an Early Eocene geologic formation in the San Juan Basin of New Mexico and Colorado.
The Yeso Group is a group of geologic formations in New Mexico. It contains fossils characteristic of the Kungurian Age of the early Permian Period.
The Petrified Forest Member is a stratigraphic unit of the Chinle Formation in Arizona, Colorado, New Mexico, Nevada, and Utah. It preserves fossils dating back to the Triassic period.
The Salitral Formation is a Late Triassic geologic formation found in north-central New Mexico, primarily the northwestern Jemez Mountains. It is an older subunit of the Chinle Group, overlying the Shinarump Conglomerate and underlying the Poleo Formation.
The San Pedro Arroyo Formation is a geologic formation in south-central New Mexico. It preserves fossils dating back to the late Triassic period.
The Rock Point Formation is a geologic formation in New Mexico, Arizona, and Utah. It preserves fossils dating back to the late Triassic.
The Poleo Formation is a geologic formation in northern New Mexico. Its stratigraphic position corresponds to the late Triassic epoch.
The Anton Chico Formation is a geologic formation exposed in New Mexico that was deposited in the Anisian Age of the middle Triassic Period.