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Pajarito Formation
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. Description In Quay County, New Mexico, where the unit was first described, it consists of poorly cemented brown sandstone and gray shale and is thick. It overlies the Mesa Rica Formation and underlies the Graneros Shale, and is assigned to the Purgatoire Group. Further north, in the valley of the Dry Cimarron, the formation consists of medium gray shale and is thick. The formation was deposited in a shallow marine. or delta plain environment. This marked the onset of the Greenhorn marine cycle in northeastern New Mexico. Fossils The formation contains abundant fossil remains of the oyster '' Ostrea quadriplicata'', a fossil of early Cretaceous age. Dinosaur trackways are preserved in the sandstone and silty sandstone horizons of the formation, which is part of the "dinosaur freeway" megatracksite of New Mexic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Formation (geology)
A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics (lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exposed in a geographical region (the stratigraphic column). It is the fundamental unit of lithostratigraphy, the study of strata or rock layers. A formation must be large enough that it can be mapped at the surface or traced in the subsurface. Formations are otherwise not defined by the thickness of their rock strata, which can vary widely. They are usually, but not universally, tabular in form. They may consist of a single lithology (rock type), or of alternating beds of two or more lithologies, or even a heterogeneous mixture of lithologies, so long as this distinguishes them from adjacent bodies of rock. The concept of a geologic formation goes back to the beginnings of modern scientific geology. The term was used by Abraham Gottlob W ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quay County, New Mexico
Quay County () is a county in the state of New Mexico. As of the 2010 census, the population was 9,041. Its county seat is Tucumcari. The county was named for Pennsylvania senator Matthew Quay, who supported statehood for New Mexico. Its eastern border is the Texas state line, approximately 103.04 degrees west longitude. Geography According to the U.S. Census Bureau, the county has a total area of , of which is land and (0.3%) is water. Adjacent counties * Union County - north * Harding County - northwest * San Miguel County - west * Guadalupe County - west * De Baca County - southwest * Roosevelt County - south * Curry County - south * Deaf Smith County, Texas - southeast * Oldham County, Texas - east * Hartley County, Texas - northeast Demographics 2000 census As of the 2000 census, there were 10,155 people, 4,201 households, and 2,844 families living in the county. The population density was 4 people per square mile (1/km2). There were 5,664 housing units ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Purgatoire Formation
The Purgatoire Formation is an abandoned (1987) Cretaceous period geologic formation classification. The classification was used in Colorado, New Mexico, and Oklahoma, with mentions in older geologic literature in neighboring states.Griggs and Read, 1959. Units previously classified as members of the abandoned formation, including Lytle, Mesa Rica, Pajarito, Romeroville, and Glencairn, have been generally elevated to formation rank. Particularly, significant divisions of the Purgatoire classification, Lytle and Glencairn, were realized as having characteristics of formations in their own right as well as representing the greatest disconformity in the Lower Cretaceous sediments of the Western Interior Seaway. Rather than including these promoted formations in an elevated Purgatoire Group, the Mesa Rica, Pajarito, and Romeroville were placed in a definition of the Dakota Group local to the Dry Cimarron. See also * List of fossiliferous stratigraphic units in Colorado * Pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caririchnium
''Caririchnium'' is an ichnogenus of ornithopod dinosaur footprint, belonging to either derived iguanodonts or basal hadrosauroids. It includes the species ''Caririchnium lotus'' from Lower Cretaceous Jiaguan Formation and ''C''. ''protohadrosaurichnos'' from Upper Cretaceous Woodbine Formation.Yuong-Nam Lee, 1997, "Bird and dinosaur footprints in the Woodbine Formation (Cenomanian), Texas", ''Cretaceous Research'' (1997) 18: 849-864 Specimens are also known from the Lower Cretaceous El Castellar Formation and Camarillas Formations. The trackmacker was probably a large styracosterna Ankylopollexia is an extinct clade of ornithischian dinosaurs that lived from the Late Jurassic to the Late Cretaceous. It is a derived clade of iguanodontian ornithopods and contains the subgroup Styracosterna. The name stems from the Greek word ...n related to '' Iguanodon''. See also * List of dinosaur ichnogenera References Dinosaur trace fossils Ornithopods {{Ornithopo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clayton Lake State Park
Clayton Lake State Park is a state park of New Mexico, United States, featuring a recreational reservoir and a fossil trackway of dinosaur footprints. It is located north of Clayton, close to New Mexico's border with Colorado, Oklahoma, and Texas. The park is accessed via New Mexico State Road 455. The landscape is characterized by rolling grasslands, volcanic rocks, and sandstone bluffs, set on the western edge of the Great Plains. The park area was a stopover point for travelers along the Cimarron Cutoff of the Santa Fe Trail. Visitor activities include picnicking, camping, and fishing at the lake, as well as viewing one of the most extensive dinosaur trackways in North America. Clayton Lake was created by the New Mexico Department of Game and Fish in 1955 as a fishing lake and winter waterfowl resting area. A dam was constructed across Seneca Creek, which is actually a series of seeps except after heavy rains. During the fishing season, which usually runs from March t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fossil Track
A fossil track or ichnite (Greek "''ιχνιον''" (''ichnion'') – a track, trace or footstep) is a fossilized footprint. This is a type of trace fossil. A fossil trackway is a sequence of fossil tracks left by a single organism. Over the years, many ichnites have been found, around the world, giving important clues about the behaviour (and foot structure and stride) of the animals that made them. For instance, multiple ichnites of a single species, close together, suggest 'herd' or 'pack' behaviour of that species. Combinations of footprints of different species provide clues about the interactions of those species. Even a set of footprints of a single animal gives important clues, as to whether it was bipedal or quadrupedal. In this way, it has been suggested that some pterosaurs, when on the ground, used their forelimbs in an unexpected quadrupedal action. Special conditions are required, in order to preserve a footprint made in soft ground (such as an alluvial plain or a f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Early Cretaceous
The Early Cretaceous (geochronological name) or the Lower Cretaceous ( chronostratigraphic name), is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 145 Ma to 100.5 Ma. Geology Proposals for the exact age of the Barremian-Aptian boundary ranged from 126 to 117 Ma until recently (as of 2019), but based on drillholes in Svalbard the defining early Aptian Oceanic Anoxic Event 1a (OAE1a) was carbon isotope dated to 123.1±0.3 Ma, limiting the possible range for the boundary to c. 122–121 Ma. There is a possible link between this anoxic event and a series of Early Cretaceous large igneous provinces (LIP). The Ontong Java- Manihiki- Hikurangi large igneous province, emplaced in the South Pacific at c. 120 Ma, is by far the largest LIP in Earth's history. The Ontong Java Plateau today covers an area of 1,860,000 km2. In the Indian Ocean another LIP began to form at c. 120 Ma, the Kergue ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ostrea
''Ostrea'' is a genus of edible oysters, marine bivalve mollusks in the family Ostreidae, the oysters. Fossil records This genus is very ancient. It is known in the fossil records from the Permian to the Quaternary (age range: from 259 to 0.0 million years ago). Fossil shells of these molluscs can be found all over the world. Genus ''Ostrea'' includes about 150 extinct species. History At least one species within this genus, '' Ostrea lurida'', has been recovered in archaeological excavations along the Central California coast of the Pacific Ocean, demonstrating it was a marine taxon exploited by the Native American Chumash people as a food source. Species Species in the genus ''Ostrea'' include: * † '' Ostrea albertensis'' Russell & Landes, 1937 * '' Ostrea algoensis'' G. B. Sowerby II, 1871 *''Ostrea angasi'' G.B. Sowerby II, 1871 * '' Ostrea angelica'' Rochebrune, 1895 * † '' Ostrea angusta'' Deshayes, 1824 * † '' Ostrea anomialis'' Lamarck, 1819 * † '' Ost ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Greenhorn Limestone
The Greenhorn Limestone or Greenhorn Formation is a geologic formation in the Great Plains Region of the United States, dating to the Cenomanian and Turonian ages of the Late Cretaceous period. The formation gives its name to the Greenhorn cycle of the Western Interior Seaway. Description The formation was named for the Greenhorn Station on Greenhorn Creek in Colorado in 1896 by Grove Karl Gilbert; and it is the namesake of the Greenhorn Marine Cycle of the Cretaceous Western Interior Seaway. With the underlying Graneros Shale and Dakota Formation, it records the progressive stage of Greenhorn Marine Cycle while the overlying Carlile Shale records the regressive stage. The Greenhorn unit name is recognized in the Great Plains Region from Minnesota and Iowa to New Mexico to Montana and the Dakotas. In much of Alberta and Saskatchewan, the "Second White-Specked Shale" contains limy equivalents of the Greenhorn. In Kansas, the Greenhorn Formation is divided into t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Delta (river)
A river delta is a landform shaped like a triangle, created by deposition of sediment that is carried by a river and enters slower-moving or stagnant water. This occurs where a river enters an ocean, sea, estuary, lake, reservoir, or (more rarely) another river that cannot carry away the supplied sediment. It is so named because its triangle shape resembles the Greek letter Delta. The size and shape of a delta is controlled by the balance between watershed processes that supply sediment, and receiving basin processes that redistribute, sequester, and export that sediment. The size, geometry, and location of the receiving basin also plays an important role in delta evolution. River deltas are important in human civilization, as they are major agricultural production centers and population centers. They can provide coastline defense and can impact drinking water supply. They are also ecologically important, with different species' assemblages depending on their landscape position ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cimarron River (Arkansas River Tributary)
The Cimarron River ( ; iow, Ñíxgu, script=Latn or , meaning 'Salt River'; chy, Hotóao'hé'e) extends across New Mexico, Oklahoma, Colorado, and Kansas. The headwaters flow from Johnson Mesa west of Folsom in northeastern New Mexico. Much of the river's length lies in Oklahoma, where it either borders or passes through eleven counties. There are no major cities along its route. The river enters the Oklahoma Panhandle near Kenton, Oklahoma, crosses the southeastern corner of Colorado into Kansas, reenters the Oklahoma Panhandle, reenters Kansas, and finally returns to Oklahoma where it joins the Arkansas River at Keystone Reservoir west of Tulsa, Oklahoma, its only impoundment. The Cimarron drains a basin that encompasses about .Larry O'Dell, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Purgatoire Group
The Purgatoire Formation is an abandoned (1987) Cretaceous period geologic formation classification. The classification was used in Colorado, New Mexico, and Oklahoma, with mentions in older geologic literature in neighboring states.Griggs and Read, 1959. Units previously classified as members of the abandoned formation, including Lytle, Mesa Rica, Pajarito, Romeroville, and Glencairn, have been generally elevated to formation rank. Particularly, significant divisions of the Purgatoire classification, Lytle and Glencairn, were realized as having characteristics of formations in their own right as well as representing the greatest disconformity in the Lower Cretaceous sediments of the Western Interior Seaway. Rather than including these promoted formations in an elevated Purgatoire Group, the Mesa Rica, Pajarito, and Romeroville were placed in a definition of the Dakota Group local to the Dry Cimarron. See also * List of fossiliferous stratigraphic units in Colorado ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
