Sheep Pen Sandstone Stratigraphic range: | |
---|---|
Type | Formation |
Unit of | Dockum Group |
Underlies | Exeter Sandstone |
Overlies | Sloan Canyon Formation |
Thickness | 33 meters (108 ft) |
Lithology | |
Primary | Sandstone |
Location | |
Coordinates | 36°58′17″N103°10′27″W / 36.9714°N 103.1743°W |
Region | Colorado New Mexico Oklahoma |
Country | United States |
Type section | |
Named for | Sheep Pen Canyon |
Named by | B.H. Parker |
Year defined | 1930 |
The Sheep Pen Sandstone is a late Triassic geologic formation exposed in northeastern New Mexico. [1] Fossil theropod tracks have been reported from the formation. [2]
The formation consists of up to 33 meters (108 ft) of thinly bedded light brown sandstone. It with a slight angular unconformity on the Sloan Canyon Formation and is overlain unconformably by the Exeter Sandstone. [3]
The formation is usually assigned to the Dockum Group. [1] [3] The proposal of Spencer G. Lucas and his collaborators to abandon the Dockum Group, possibly in favor of the Chinle Group, is highly controversial. [4]
Ichnofossils (track fossils) have been found in thee different locations 10 kilometres (6.2 mi) north of Kenton, Oklahoma. The lower site includes the invertebrates Scoyenia and the dinosauroid Grallator on a scour surface. The traces are numerous but of low diversity. The middle site has at least ten distinct trackways, eight of Grallator and two of Brachychirotherium . The upper site has well-preserved tracks of Grallator and some poorly preserved tracks, possibly of Brachychirotherium. The tracks suggest a stable ecosystem with low diversity, which may be typical of the middle Norian. [5]
The formation has some copper mineralization around the western Oklahoma panhandle. Some 200 mines were in operation from 1884 to 1925. but these likely produced less than 10,000 tons of ore. The ore took the form of chalcocite, malachite, and azurite, deposited both in lenticular beds and in clastic plugs. [6]
The formation was first named by B.H. Parker in 1930. [7]
The Morrison Formation is a distinctive sequence of Upper Jurassic sedimentary rock found in the western United States which has been the most fertile source of dinosaur fossils in North America. It is composed of mudstone, sandstone, siltstone, and limestone and is light gray, greenish gray, or red. Most of the fossils occur in the green siltstone beds and lower sandstones, relics of the rivers and floodplains of the Jurassic period.
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. The Chinle is controversially considered to be synonymous to the Dockum Group of eastern Colorado and New Mexico, western Texas, the Oklahoma panhandle, and southwestern Kansas. The Chinle is sometimes colloquially named as a formation within the Dockum Group in New Mexico and in Texas. The Chinle Formation is part of the Colorado Plateau, Basin and Range, and the southern section of the Interior Plains.
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 Garita Creek Formation is a geologic formation in New Mexico that contains vertebrate fossils characteristic of the Carnian Age of the late Triassic.
The Point Lookout Sandstone is a Cretaceous bedrock formation occurring in New Mexico and Colorado.
The Tres Hermanos Formation is a geologic formation in central and west-central New Mexico. It contains fossils characteristic of the Turonian Age of the late Cretaceous.
The Pajarito Formation is a geologic formation in eastern New Mexico and west Texas. It preserves fossils dating back to the Albian Age of the Cretaceous Period.
Paleontology in Virginia refers to paleontological research occurring within or conducted by people from the U.S. state of Virginia. The geologic column in Virginia spans from the Cambrian to the Quaternary. During the early part of the Paleozoic, Virginia was covered by a warm shallow sea. This sea would come to be inhabited by creatures like brachiopods, bryozoans, corals, and nautiloids. The state was briefly out of the sea during the Ordovician, but by the Silurian it was once again submerged. During this second period of inundation the state was home to brachiopods, trilobites and entire reef systems. During the mid-to-late Carboniferous the state gradually became a swampy environment.
Paleontology in Oklahoma refers to paleontological research occurring within or conducted by people from the U.S. state of Oklahoma. Oklahoma has a rich fossil record spanning all three eras of the Phanerozoic Eon. Oklahoma is the best source of Pennsylvanian fossils in the United States due to having an exceptionally complete geologic record of the epoch. From the Cambrian to the Devonian, all of Oklahoma was covered by a sea that would come to be home to creatures like brachiopods, bryozoans, graptolites and trilobites. During the Carboniferous, an expanse of coastal deltaic swamps formed in areas of the state where early tetrapods would leave behind footprints that would later fossilize. The sea withdrew altogether during the Permian period. Oklahoma was home a variety of insects as well as early amphibians and reptiles. Oklahoma stayed dry for most of the Mesozoic. During the Late Triassic, carnivorous dinosaurs left behind footprints that would later fossilize. During the Cretaceous, however, the state was mostly covered by the Western Interior Seaway, which was home to huge ammonites and other marine invertebrates. During the Cenozoic, Oklahoma became home to creatures like bison, camels, creodonts, and horses. During the Ice Age, the state was home to mammoths and mastodons. Local Native Americans are known to have used fossils for medicinal purposes. The Jurassic dinosaur Saurophaganax maximus is the Oklahoma state fossil.
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 Bell Ranch Formation is a Late Jurassic (Kimmeridgian) geologic formation in eastern and northeastern New Mexico and the western Oklahoma panhandle. Fossil theropod tracks have been reported from the formation.
The Nugget Sandstone is a Late Triassic to Early Jurassic geologic formation that outcrops in Colorado, Idaho and Utah, western United States. Fossil theropod tracks have been reported from the formation.
The Sloan Canyon Formation is a late Triassic geologic formation exposed in northeastern New Mexico. 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 Sandia Formation is a geologic formation in New Mexico. Its fossil assemblage is characteristic of the early Pennsylvanian.
The Travesser Formation is a geologic formation in northeastern New Mexico, southeastern Colorado, westernmost Oklahoma, and northwestern Texas, particularly in the Dry Cimarron valley. It preserves fossils dating back to the late Triassic period.
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 Exeter Sandstone is a geologic formation exposed in northeastern New Mexico. Its age is poorly controlled, but it is thought to have been deposited during the middle Jurassic.
The Glencairn Formation is a geologic formation found in Colorado and New Mexico. It preserves fossils characteristic of the Albian Age of the Cretaceous Period.