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Arroyo Formation
The Arroyo Formation is a geologic formation in Texas.Arroyo Formation at .org It preserves dating back to the stage of the . It ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Formation (stratigraphy)
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 (geology), 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Richards Spur
Richards Spur is a Permian fossil locality located at the Dolese Brothers Limestone Quarry north of Lawton, Oklahoma. The locality preserves clay and mudstone fissure fills of a karst system eroded out of Ordovician limestone and dolomite, with the infilling dating to the Artinskian stage of the early Permian (Cisuralian), around 289 to 286 million years ago. Fossils of terrestrial animals are abundant and well-preserved, representing one of the most diverse Paleozoic tetrapod communities known. A common historical name for the site is Fort Sill, in reference to the nearby military base. Fossils were first reported at the quarry by workers in 1932, spurring a wave of collecting by local and international geologists. Early taxa of interest included the abundant reptile ''Captorhinus'' and microsaurs such as ''Cardiocephalus'' and ''Euryodus''. Later notable discoveries include ''Doleserpeton'' (one of the most lissamphibian-like Paleozoic tetrapods), the most diverse assortment of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dimetrodon
''Dimetrodon'' ( or ,) meaning "two measures of teeth,” is an extinct genus of non-mammalian synapsid that lived during the Cisuralian (Early Permian), around 295–272 million years ago (Mya). It is a member of the family Sphenacodontidae. The most prominent feature of ''Dimetrodon'' is the large neural spine sail on its back formed by elongated spines extending from the vertebrae. It walked on four legs and had a tall, curved skull with large teeth of different sizes set along the jaws. Most fossils have been found in the Southwestern United States, the majority coming from a geological deposit called the Red Beds of Texas and Oklahoma. More recently, its fossils have been found in Germany. Over a dozen species have been named since the genus was first erected in 1878. ''Dimetrodon'' is often mistaken for a dinosaur or as a contemporary of dinosaurs in popular culture, but it became extinct some 40 million years before the first appearance of dinosaurs. Reptile-li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bivalvia
Bivalvia (), in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of marine and freshwater molluscs Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is estim ... that have laterally compressed bodies enclosed by a shell consisting of two hinged parts. As a group, bivalves have no head and they lack some usual molluscan organs, like the radula and the odontophore. They include the clams, oysters, Cockle (bivalve), cockles, mussels, scallops, and numerous other family (biology), families that live in saltwater, as well as a number of families that live in freshwater. The majority are filter feeders. The gills have evolved into Ctenidium (mollusc), ctenidia, specialised organs for feeding and breathing. Most bivalves bury themselves in sediment, where they a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palaeonisciformes
The Palaeonisciformes (Palaeoniscida) are an extinct order of early ray-finned fishes ( Actinopterygii). Palaeonisciformes ''sensu lato'' first appeared in the fossil record in the Late Silurian and last appeared in the Late Cretaceous. The name is derived from the Ancient Greek words παλαιός (''palaiós'', ancient) and ὀνίσκος (''oniskos'', 'cod-fish' or woodlouse), probably pertaining to the organization of the fishes' scales, similar to the exoskeletal plating of woodlice. In an early interpretation of the group, the Palaeonisciformes are divided in two suborders: Palaeoniscoidei (includes '' Palaeoniscum'' and fossil taxa with a broadly similar appearance) and Platysomoidei (includes '' Platysomus'' and other deep-bodied early actinopterygians). These groupings are considered paraphyletic today. In the cladistic sense, Palaeonisciformes '' sensu stricto'' should only refer to the Permian ''Palaeoniscum'', the name giving taxon, and all other taxa that fall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Abilene, Texas
Abilene ( ) is a city in Taylor and Jones Counties in Texas, United States. Its population was 125,182 at the 2020 census, making it the 27th-most populous city in the state of Texas. It is the principal city of the Abilene metropolitan statistical area, which had an estimated population of 169,893, as of 2016. It is the county seat of Taylor County. Dyess Air Force Base is located on the west side of the city. Abilene is located off Interstate 20, between exits 279 on its western edge and 292 on the east. It is west of Fort Worth. The city is looped by I-20 to the north, US 83/84 on the west, and Loop 322 to the east. A railroad divides the city down the center into north and south. The historic downtown area is on the north side of the railroad. History Established by cattlemen as a stock shipping point on the Texas and Pacific Railway in 1881, the city was named after Abilene, Kansas, the original endpoint for the Chisholm Trail. The T&P had bypassed the town of Buffal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salt Fork Brazos River
The Salt Fork Brazos River is a braided, highly intermittent stream about long, heading along the edge of the Llano Estacado about east-southeast of Lubbock, Texas. From its source, it flows generally east-southeastward to join the Double Mountain Fork to form the Brazos River about west-northwest of Haskell, Texas.United States Board on Geographical Names. 1964. Decisions on Geographical Names in the United States, Decision list no. 6402, United States Department of the Interior, Washington DC, p. 53. The Salt Fork stretches across portions of Crosby, Garza, Kent, and Stonewall counties of West Texas. Geography The Salt Fork Brazos River begins as a dry channel (draw) near the edge of the Llano Estacado in Crosby County, about southwest of the cotton gin in the small farming community of Cap Rock, Texas. From the edge of the Caprock Escarpment, the stream channel generally runs southeastward across southern Crosby County, passing to the east of Courthouse Mountain an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wichita Group
The Wichita Group is a geologic group in the Texas Red Beds. It preserves fossils dating back to the Permian period. See also * List of fossiliferous stratigraphic units in Texas * Paleontology in Texas Paleontology in Texas refers to paleontological research occurring within or conducted by people from the U.S. state of Texas. Author Marian Murray has remarked that "Texas is as big for fossils as it is for everything else." Some of the most imp ... References * Geologic groups of Texas Permian System of North America {{Permian-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taylor County, Texas
Taylor County is a county located in the U.S. state of Texas. As of the 2020 census, its population was 143,208. Its county seat is Abilene. The county was created in 1858 and later organized in 1878. It is named for Edward Taylor, George Taylor, and James Taylor, three brothers who died at the Battle of the Alamo. Taylor County is included in the Abilene, TX metropolitan statistical area, and is considered part of West Texas. History Among first inhabitants of the area were the Penteka. In 1849, Capt. Randolph Marcy, a U. S. Army engineer, passed through, scouting out West Texas-to-California routes. The Texas legislature established Taylor County in 1858 from Bexar and Travis Counties. The county is named for Alamo defenders Edward, James, and George Taylor. The Butterfield Overland Mail established the Mountain Pass Station at Merkel; it was in continual use until 1861. By 1872, the first cattlemen had ventured into present Taylor County. Six years later, Tayl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ballinger, Texas
Ballinger ( ) is a city in Runnels County, Texas, United States. The population was 3,767 at the 2010 census. It is the county seat of Runnels County. Downtown Ballinger features historic 1800s buildings with shops and restaurants. Geography Ballinger is located at (31.7409, –99.9538). It is located in the transition zone from the Edwards Plateu to the Texas Southern Plains region of West Texas. According to the United States Census Bureau, the city has a total area of , of which , or 0.06%, is covered by water. Ballinger is about south of Abilene.Glenn, Mike.Fort Bend publisher dies of cancer at 72" ''Houston Chronicle''. July 8, 2013. Retrieved on April 7, 2014. Demographics 2020 census As of the 2020 United States census, there were 3,619 people, 1,449 households, and 860 families residing in the city. 2000 census As of the census of 2000, 4,243 people, 1,578 households, and 1,093 families resided the city. The population density was 1,266.7 people per square mile ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arroyo (creek)
An arroyo (; from Spanish arroyo , "brook"), also called a wash, is a dry stream, creek, stream bed or gulch that temporarily or seasonally fills and flows after sufficient rain. Flash floods are common in arroyos following thunderstorms. ''Wadi'' (Arabic) is used in North Africa and Western Asia for similar landforms. The desert dry wash biome is restricted to the arroyos of the southwestern United States. Arroyos provide a water source to desert animals. Types and processes Arroyos can be natural fluvial landforms or constructed flood control channels. The term usually applies to a Grade (slope), sloped or mountainous terrain in xeric and desert climates. In addition: in many rural communities arroyos are also the principal transportation routes; and in many urban communities arroyos are also parks and recreational locations, often with linear multi-use bicycle, pedestrian, and equestrian trails. Flash flooding can cause the deep arroyos or deposition of sediment on flo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gypsum
Gypsum is a soft sulfate mineral composed of calcium sulfate dihydrate, with the chemical formula . It is widely mined and is used as a fertilizer and as the main constituent in many forms of plaster, blackboard or sidewalk chalk, and drywall. Alabaster, a fine-grained white or lightly tinted variety of gypsum, has been used for sculpture by many cultures including Ancient Egypt, Mesopotamia, Ancient Rome, the Byzantine Empire, and the Nottingham alabasters of Medieval England. Gypsum also crystallizes as translucent crystals of selenite. It forms as an evaporite mineral and as a hydration product of anhydrite. The Mohs scale of mineral hardness defines gypsum as hardness value 2 based on scratch hardness comparison. Etymology and history The word ''gypsum'' is derived from the Greek word (), "plaster". Because the quarries of the Montmartre district of Paris have long furnished burnt gypsum (calcined gypsum) used for various purposes, this dehydrated gypsum became known ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
