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Morrison Formation
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. It is centered in Wyoming and Colorado, with outcrops in Montana, North Dakota, South Dakota, Nebraska, Kansas, the panhandles of Oklahoma and Texas, New Mexico, Arizona, Utah, and Idaho. Equivalent rocks under different names are found in Canada. It covers an area of 1.5 million square kilometers (600,000 square miles), although only a tiny fraction is exposed and accessible to geologists and paleontologists. Over 75% is still buried under the prairie to the east, and much of its western paleogeographic extent was eroded during exhuma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dinosaur National Monument
Dinosaur National Monument is an American national monument located on the southeast flank of the Uinta Mountains on the border between Colorado and Utah at the confluence of the Green River (Colorado River tributary), Green and Yampa River, Yampa rivers. Although most of the monument area is in Moffat County, Colorado, the Dinosaur Quarry is located in Utah, north of the town of Jensen, Utah. The nearest Colorado town is Dinosaur, Colorado, Dinosaur while the nearest city is Vernal, Utah. Originally preserved in 1915 to protect its famous Dinosaur Quarry, the monument was greatly expanded in 1938 to include its wealth of natural history. The park's wild landscapes, topography, geology, paleontology, and history make it a unique resource for both science and recreation. The park contains over 800 paleontological sites and has fossils of dinosaurs including ''Allosaurus'', ''Deinonychus'', ''Abydosaurus'', and various Sauropoda, sauropods. The ''Abydosaurus'' consists of a nearl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
North Dakota
North Dakota ( ) is a U.S. state in the Upper Midwest, named after the indigenous Dakota people, Dakota and Sioux peoples. It is bordered by the Canadian provinces of Saskatchewan and Manitoba to the north and by the U.S. states of Minnesota to the east, South Dakota to the south, and Montana to the west. North Dakota is part of the Great Plains region, characterized by broad prairies, steppe, temperate savanna, badlands, and farmland. North Dakota is the List of U.S. states and territories by area, 19th-largest state by area, but with a population of just under 800,000, the List of U.S. states and territories by population, fourth-least populous and List of U.S. states by population density, fourth-least densely populated. The List of capitals in the United States, state capital is Bismarck, North Dakota, Bismarck and the List of cities in North Dakota, most populous city is Fargo, North Dakota, Fargo, which accounts for nearly a fifth of the state's population; both cities ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Curtis Formation
The Curtis Formation is a geologic formation in Utah. It preserves fossils dating back to the Callovian age of the Jurassic period. Description The Curtis Formation is composed of shallow marine sandstone, with thin beds of mudstone and minor limestone and gypsum. The sandstone is grayish-green in color and flat bedded or cross bedded. The presence of glauconite and marine invertebrate fossils indicates it was laid down in a shallow marine environment that became hypersaline towards the end of deposition. It represents a high stand of the Sundance Sea in the Callovian.Lucas and Anderson 1992 History of investigation The formation was first described by Gilluly and Reeside in 1928 and named for exposures in the northeast San Rafael Reef at Curtis Point (). Pipiringos and Imlay reassigned the Curtis as a member of the Stump Formation in 1979,Pipiringos and Imlay 1979 but this was rejected by Peterson in 1988.Peterson 1988 Footnotes See also * List of fossiliferous strat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beclabito Formation
The Beclabito Formation is a late Jurassic sedimentary geologic formation, found in northwestern New Mexico and northeastern Arizona. Description The formation is composed mostly of thinly bedded sandstone, siltstone, and mudstone which is reddish-orange to reddish-brown in color. The sandstone is very fine to medium grained and displays ripple crossbedding, trough crossbedding, and horizontal laminations. The siltstones are reddish-brown and show wavy laminations. The formation is thick. The formation conformably overlies the Todilto Formation and conformably underlies the Bluff Formation. The formation is interpreted as having been deposited in a marginal marine or coastal sabkha A sabkha () is a predominately coastal, supratidal mudflat or sandflat in which evaporite-saline minerals accumulate as the result of a semiarid to arid climate. Sabkhas are gradational between land and intertidal zone within restricted coast ... environment. Investigative history The forma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Summerville Formation
The Summerville Formation is a geological formation in New Mexico, Colorado, and Utah of the Southwestern United States. It dates back to the Oxfordian stage of the Late Jurassic.Wilcox 2007 Description The formation consists of up to of red mudstone, with thin interbeds of green and red sandstone. The lower portion of the formation shows polygonal desiccation cracks and localized salt-hopper casts while the upper portion contains considerable gypsum, consistent with deposition in a sabkha on the margin of the Sundance Sea.It is exposed in the San Rafael Reef, the Waterpocket Fold, in the Henry Mountains, with additional exposures scattered across the region from the San Rafael Reef to the Paradox Basin, and in north-central New Mexico. The thin bedding is characteristic throughout the formation, but gypsum is not found in the San Juan Basin and some conglomerate is found on the south and southwestern margins of the formation.Lucas and Anderson 1992, p.81 The correlation of la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Burro Canyon Formation
The Burro Canyon Formation is an Early Cretaceous Period sedimentary geologic formation, found in western Colorado, the Chama Basin and eastern San Juan Basin of northern New Mexico, and in eastern Utah, US. Description The lithology of the Burro Canyon Formation is dominated by medium- to fine-grained sandstone, much of which has rounded chert and quartz pebbles above scour surfaces. The Burro Canyon Formation was deposited in a braided-stream system. The formation overlies the Morrison Formation, with the boundary placed at the first conglomeratic sandstone bed. It underlies the Dakota Formation, from which it is distinguished by the presence of green mudstone and the absence of carbonaceous material. It is similar to the Cedar Mountain Formation on the west side of the Colorado River and the two formations have been interpreted as interfingering alluvial fans from separate source regions. The Jackpile Member of the Morrison Formation may be its lateral equivalent. Foss ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lakota Formation
The Lakota Formation is a sequence of rocks of early Cretaceous (Berriasian to Barremian) age from Western North America. Located in South Dakota, the name of the formation is derived from the Lakota people, Lakota Native Americans in the United States, Native American tribe. There are two units of the Lakota Formation, the Chilson Member (upper Berriasian to Valanginian) and the underlying Fuson Member (upper Valanginian to early Barremian). A Berriasian-Valanginian age for the Chilson Member has been extrapolated by means of ostracods and charophytes. The Fuson Member takes its name from rock exposures in Fuson Canyon, a valley on the eastern side of the Black Hills. Vertebrate paleofauna Dinosaurs Mammals Turtles Other vertebrate remains found within the Lakota Formation include a fish scale from the gar ''Lepisosteus'' and a crocodile tooth References Geologic formations of South Dakota Cretaceous geology of South Dakota Cretaceous Manitoba Cretaceous ge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cloverly Formation
The Cloverly Formation is a formation (geology), geological formation of Early Cretaceous, Early and Late Cretaceous age (Valanginian to Cenomanian stage) that is present in parts of Montana, Wyoming, Colorado and Utah in the western United States. It was named for a post office on the eastern side of the Bighorn Basin in Wyoming by N.H. Darton in 1904. The sedimentary rocks of formation were deposited in floodplain environments and contain vertebrate fossils, including a diverse assemblage of dinosaur remains. In 1973, the Cloverly Formation Site was designated as a National Natural Landmark by the National Park Service. Stratigraphy The Cloverly Formation rests unconformity, disconformably on the Morrison Formation and is conformably overlain by the Thermopolis Shale. It is subdivided into a variety of members, depending on the location.Moberly, R.M., Jr., 1960, Morrison, Cloverly, and Sykes Mountain formations, northern Bighorn basin, Wyoming and Montana: Geological Society of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cedar Mountain Formation
The Cedar Mountain Formation is the name given to a distinctive sedimentary geologic formation in eastern Utah, spanning most of the early and mid-Cretaceous. The formation was named for Cedar Mountain (Utah), Cedar Mountain in northern Emery County, Utah, where William Lee Stokes first studied the exposures in 1944. Geology The formation occurs between the underlying Morrison Formation and overlying Naturita Formation (sometimes formerly called the Dakota Formation). It is composed of non-marine sediments, that is, sediments deposited in rivers, lakes and on flood plains. Based on various fossils and radiometric dating, radiometric dates, the Cedar Mountain Formation was deposited during the last half of the Early Cretaceous Epoch, about 127 - 98 million years ago (mya). It has lithography similar to the Burro Canyon Formation in the region. Dinosaur fossils occur throughout the formation, but their study has only occurred since the early 1990s. The dinosaurs in the lower par ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States
The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 contiguous states border Canada to the north and Mexico to the south, with the semi-exclave of Alaska in the northwest and the archipelago of Hawaii in the Pacific Ocean. The United States asserts sovereignty over five Territories of the United States, major island territories and United States Minor Outlying Islands, various uninhabited islands in Oceania and the Caribbean. It is a megadiverse country, with the world's List of countries and dependencies by area, third-largest land area and List of countries and dependencies by population, third-largest population, exceeding 340 million. Its three Metropolitan statistical areas by population, largest metropolitan areas are New York metropolitan area, New York, Greater Los Angeles, Los Angel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wyoming
Wyoming ( ) is a landlocked U.S. state, state in the Mountain states, Mountain West subregion of the Western United States, Western United States. It borders Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho to the west, Utah to the southwest, and Colorado to the south. With an estimated population of 587,618 as of 2024, Wyoming is the List of U.S. states and territories by population, least populous state despite being the List of U.S. states and territories by area, 10th largest by area, and it has the List of U.S. states by population density, second-lowest population density after Alaska. The List of capitals in the United States, state capital and List of municipalities in Wyoming, most populous city is Cheyenne, Wyoming, Cheyenne, which had a population of 65,132 in 2020. Wyoming's western half consists mostly of the ranges and rangelands of the Rocky Mountains; its eastern half consists of high-elevation prairie, and is referred to as th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Utah
Utah is a landlocked state in the Mountain states, Mountain West subregion of the Western United States. It is one of the Four Corners states, sharing a border with Arizona, Colorado, and New Mexico. It also borders Wyoming to the northeast, Idaho to the north, and Nevada to the west. In comparison to all the U.S. states and territories, Utah, with a population of just over three million, is the List of U.S. states and territories by area, 13th largest by area, the List of U.S. states and territories by population, 30th most populous, and the List of U.S. states by population density, 11th least densely populated. Urban development is mostly concentrated in two regions: the Wasatch Front in the north-central part of the state, which includes the state capital, Salt Lake City, and is home to roughly two-thirds of the population; and Washington County, Utah, Washington County in the southwest, which has approximately 180,000 residents. Most of the western half of Utah lies in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
