Atarque Sandstone | |
---|---|
Stratigraphic range: | |
Type | Formation |
Underlies | Moreno Hill Formation |
Overlies | Rio Salado Tongue, Mancos Shale |
Thickness | 100 feet (30 m) |
Lithology | |
Primary | Sandstone |
Other | Shale |
Location | |
Coordinates | 35°07′54″N108°39′07″W / 35.131797°N 108.651864°W |
Region | New Mexico |
Country | United States |
Type section | |
Named for | Atarque settlement |
Named by | W.S. Pike, Jr. |
Year defined | 1947 |
The Atarque Sandstone is a geologic formation in New Mexico. It preserves fossils dating back to the late Cretaceous period. [1]
The formation consists of very fine to fine buff fossiliferous sandstone with a maximum thickness of 100 feet (30 m). The beds are flat, massive and have low-angle crossbedding. The formation intertongues with the underlying Rio Salado Tongue of the Mancos Shale and is overlain by either the Carthage Member of the Tres Hermanos Formation or the Moreno Hill Formation. It was deposited during the early to middle Turonian Age of the late Cretaceous. [2]
The formation is interpreted as a coastal barrier sandstone deposited by a regression of the Western Interior Seaway to the northeast. [2]
The formation contains fossil pelecypods and plesiosaur vertebra. [3] It also contains fossils of the ammonite Spathites rioensis characteristic of the middle Turonian. [4]
The unit was first defined as the Atarque Member of the Mesaverde Formation by W.S. Pike in 1947. Pike assigned the lowermost 127 feet (39 m) of the Mesaverde in the San Juan Basin to the unit. [1] S.C. Hook and coinvestigators revised the Cretaceous stratigraphy of the San Juan and Zuni basins in 1983 and assigned both Pike's Atarque Member and beds in the Zuni Basin assigned to the lower Gallup Sandstone to the Tres Hermanos Formation. The Atarque Member was redefined as the lower sandstone beds of the Tres Hermanos Formation. [2] Simultaneously, M.W. McLellan and coinvestigators raised the Atarque to formation rank as the Atarque Sandstone in the Salt Lake coal field of west-central New Mexico. [3]
Placenticeras is a genus of ammonites from the Late Cretaceous. Its fossils have been found in Asia, Europe, North and South America.
The Moreno Hill Formation is a geological formation in western New Mexico whose strata were deposited in the Late Cretaceous. Dinosaur remains are among the fossils that have been recovered from the formation.
The McRae Group is a geological group exposed in southern New Mexico whose strata, including layers of the Hall Lake Formation and Jose Creek Formation, date to the Late Cretaceous. Dinosaur remains are among the fossils that have been recovered from this unit.
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 Straight Cliffs Formation is a stratigraphic unit in the Kaiparowits Plateau of south central Utah. It is Late Cretaceous in age and contains fluvial, paralic, and marginal marine (shoreline) siliciclastic strata. It is well exposed around the margin of the Kaiparowits Plateau in the Grand Staircase – Escalante National Monument in south central Utah. The formation is named after the Straight Cliffs, a long band of cliffs creating the topographic feature Fiftymile Mountain.
The Carlile Shale is a Turonian age Upper/Late Cretaceous series shale geologic formation in the central-western United States, including in the Great Plains region of Colorado, Kansas, Nebraska, New Mexico, North Dakota, South Dakota, and Wyoming.
The genus Cibolaites is a strongly ribbed and nodose ammonoid cephalopod from the middle Cretaceous of western New Mexico, included in the taxonomic family Collignoniceratidae. A single species Cibolaites molenaari is known.
Collignociceras is a strongly ribbed and tuberculate, evolute ammonite from the Turonian of the western U.S. and Europe belonging to the ammonitid family Collignoniceratidae. The genus is named after the French paleontologist Maurice Collignon. The type is Collignoniceras woollgari, named by Mantell in 1822 for specimens from Sussex, England.
Neoptychites is an extinct ammonoid cephalopod genus from the Turonian stage of the Upper Cretaceous, with a worldwide distribution.
Morrowites, named by Cobban and Hook, 1983, is a moderate to large-sized ammonite with quadrangular to depressed whorls, broadly rounded to depressed venter, low ribs, umbilical and inner and outer ventrolateral tubercles and smooth early whorls except for occasional ribs along weak constrictions. The suture is moderately simple and has an unusually broad bifid first lateral lobe. It is so far restricted to the Lower Turonian stage, in the mid Cretaceous.
The Mancos Shale or Mancos Group is a Late Cretaceous geologic formation of the Western United States.
The Cliff House Sandstone is a late Campanian stratigraphic unit comprising sandstones in the western United States.
The Graneros Shale is a geologic formation in the United States identified in the Great Plains as well as New Mexico that dates to the Cenomanian Age of the Cretaceous Period. It is defined as the finely sandy argillaceous or clayey near-shore/marginal-marine shale that lies above the older, non-marine Dakota sand and mud, but below the younger, chalky open-marine shale of the Greenhorn. This definition was made in Colorado by G. K. Gilbert and has been adopted in other states that use Gilbert's division of the Benton's shales into Carlile, Greenhorn, and Graneros. These states include Kansas, Texas, Oklahoma, Nebraska, and New Mexico as well as corners of Minnesota and Iowa. North Dakota, South Dakota, Wyoming, and Montana have somewhat different usages — in particular, north and west of the Black Hills, the same rock and fossil layer is named Belle Fourche Shale.
The Lewis Shale is a geologic formation in the Western United States. It preserves fossils dating back to the Campanian to Maastrichtian stages of the late Cretaceous period.
The Gallup Sandstone is a geologic formation in the Gallup-Zuni basin of New Mexico. It preserves fossils dating back to the late Cretaceous period.
The Baca Formation is a geologic formation in southern New Mexico and Arizona. It preserves fossils dating back to the Eocene period.
The Cub Mountain Formation is a geologic formation in southern New Mexico. It preserves fossils dating back to the Eocene epoch. The formation also records the progressive unroofing of nearby mountainous uplifts during the Laramide orogeny.
Juana Lopez refers to both the uppermost member of the Carlile Shale formation and to the environment that caused it to form. The Juana Lopez Member is calcareous sandstone dated to the Turonian age of the Upper Cretaceous and is exposed in the southern and western Colorado, northern and central New Mexico, and northeastern Utah. The unit has been described as "the most enigmatic" member of the Carlile Shale.