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List Of Fossiliferous Stratigraphic Units In South Dakota
This article contains a list of fossil-bearing stratigraphic units in the state of South Dakota, U.S. Sites See also * Paleontology in South Dakota References * {{DEFAULTSORT:Fossiliferous stratigraphic units in South Dakota South Dakota Stratigraphic units A stratigraphic unit is a volume of rock of identifiable origin and relative age range that is defined by the distinctive and dominant, easily mapped and recognizable petrographic, lithologic or paleontologic features (facies) that characterize ... Stratigraphy of South Dakota South Dakota geography-related lists United States geology-related lists ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stratigraphic Units
A stratigraphic unit is a volume of Rock (geology), rock of identifiable origin and relative age range that is defined by the distinctive and dominant, easily mapped and recognizable petrology, petrographic, lithology, lithologic or paleontology, paleontologic features (facies) that characterize it. Units must be ''mappable'' and ''distinct'' from one another, but the contact need not be particularly distinct. For instance, a unit may be defined by terms such as "when the sandstone component exceeds 75%". Lithostratigraphic units Sequences of sedimentary rock, sedimentary and volcanic rocks are subdivided the basis of their shared or associated lithology. Formally identified lithostratigraphic units are structured in a hierarchy of lithostratigraphic rank, higher rank units generally comprising two or more units of lower rank. Going from smaller to larger in rank, the main lithostratigraphic ranks are Bed, Member, Formation, Group and Supergroup. Formal names of lithostratigraph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Niobrara Formation
The Niobrara Formation , also called the Niobrara Chalk, is a geologic formation in North America that was deposited between 87 and 82 million years ago during the Coniacian, Santonian, and Campanian stages of the Late Cretaceous. It is composed of two structural units, the Smoky Hill Chalk Member overlying the Fort Hays Limestone Member. The chalk formed from the accumulation of coccoliths from microorganisms living in what was once the Western Interior Seaway, an inland sea that divided the continent of North America during much of the Cretaceous. It underlies much of the Great Plains of the US and Canada. Evidence of vertebrate life is common throughout the formation and includes specimens of plesiosaurs, mosasaurs, and pterosaurs as well as several primitive aquatic birds. The type locality for the Niobrara Chalk is the Niobrara River in Knox County in northeastern Nebraska. The formation gives its name to the Niobrara cycle of the Western Interior Seaway. History of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lance Formation
The Lance (Creek) Formation is a division of Late Cretaceous (dating to about 69 - 66 Ma) rocks in the western United States. Named after Lance Creek, Wyoming, the microvertebrate fossils and dinosaurs represent important components of the latest Mesozoic vertebrate faunas. The Lance Formation is Late Maastrichtian in age (Lancian land mammal age), and shares much fauna with the Hell Creek Formation of Montana and North Dakota, the Frenchman Formation of southwest Saskatchewan, and the lower part of the Scollard Formation of Alberta. The Lance Formation occurs above the ''Baculites clinolobatus'' ammonite marine zone in Wyoming, the top of which has been dated to about 69 million years ago, and extends to the K-Pg boundary, 66 million years ago. However, the characteristic land vertebrate fauna of the Lancian age (which take its name from this formation) is only found in the upper strata of the Lance, roughly corresponding to the thinner equivalent formations such as the Hell C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Judith River Formation
The Judith River Formation is a fossil-bearing geologic formation in Montana, and is part of the Judith River Group. It dates to the Late Cretaceous, between 79 and 75.3 million years ago, corresponding to the "Judithian" land vertebrate age. It was laid down during the same time period as portions of the Two Medicine Formation of MontanaSullivan, R.M. and Lucas, S. G. (2006). "The Kirtlandian land-vertebrate "age"–faunal composition, temporal position and biostratigraphic correlation in the nonmarine Upper Cretaceous of western North America." Pp. 7-29 in Lucas, S. G. and Sullivan, R.M. (eds.), ''Late Cretaceous vertebrates from the Western Interior. New Mexico Museum of Natural History and Science Bulletin 35''. and the Oldman Formation of Alberta. It is an historically important formation, explored by early American paleontologists such as Edward Drinker Cope, who named several dinosaurs from scrappy remains found here on his 1876 expedition (such as ''Monoclonius''). Modern ... [...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 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 In the geologic timescale, the Valanginian is an age or stage of the Early or Lower Cretaceous. It spans between 139.8 ± 3.0 Ma and 132.9 ± 2.0 Ma (million years ago). The Valanginian Stage succeeds the Berriasian Stage of the Lower Cretaceou ... age for the Chilson Member has been extrapolated by means of ostracods and charophytes. Vertebrate paleofauna Dinosaurs Mammals Turtles References Geologic formations of South Dakota Cretaceous geology of South Dakota Cretaceous Manitoba Cretaceous geology of Nebraska Berriasian Stage Valanginian Sta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inyan Kara Group
The Inyan Kara Group is a geologic group classification applied in South Dakota and adopted in portions of Wyoming and Montana. It preserves fossils of the mid-Cretaceous period. Of late Albian age, this classification correlates with the lower Dakota Formation (Nishnabotna member) known in the southwest corner of the State. The South Dakota Geological Survey has also extended the Graneros to group other formations into a unit that correlates with the upper Dakota Formation ''(Note: This definition is widely different than the generally consistent definitions of Graneros/Belle Fourche.'''')''. These state definitions of the Inyan Kara and Graneros Groups thereby cover the first two sequences of the Western Interior Seaway recorded by the Dakota Formation. North Dakota also classifies the same strata as Inyan Kara, but only of formation rank without recognizing further formal subdivision, and assigns this Inyan Kara Formation as the lowest member of the Dakota Group. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hell Creek Formation
The Hell Creek Formation is an intensively studied division of mostly Upper Cretaceous and some lower Paleocene rocks in North America, named for exposures studied along Hell Creek, near Jordan, Montana. The formation stretches over portions of Montana, North Dakota, South Dakota, and Wyoming. In Montana, the Hell Creek Formation overlies the Fox Hills Formation. The site of Pompeys Pillar National Monument is a small isolated section of the Hell Creek Formation. In 1966, the Hell Creek Fossil Area was designated as a National Natural Landmark by the National Park Service. It is a series of fresh and brackish-water clays, mudstones, and sandstones deposited during the Maastrichtian and Danian (respectively, the end of the Cretaceous period and the beginning of the Paleogene) by fluvial activity in fluctuating river channels and deltas and very occasional peaty swamp deposits along the low-lying eastern continental margin fronting the late Cretaceous Western Interior Seaway. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Miocene
The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recent" because it has 18% fewer modern marine invertebrates than the Pliocene has. The Miocene is preceded by the Oligocene and is followed by the Pliocene. As Earth went from the Oligocene through the Miocene and into the Pliocene, the climate slowly cooled towards a series of ice ages. The Miocene boundaries are not marked by a single distinct global event but consist rather of regionally defined boundaries between the warmer Oligocene and the cooler Pliocene Epoch. During the Early Miocene, the Arabian Peninsula collided with Eurasia, severing the connection between the Mediterranean and Indian Ocean, and allowing a faunal interchange to occur between Eurasia and Africa, including the dispersal of proboscideans into Eurasia. During the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Harrison Formation
The Harrison Formation is a geologic group in South Dakota and Nebraska. It preserves fossils from the Miocene. See also * List of fossiliferous stratigraphic units in South Dakota * Paleontology in South Dakota Paleontology in South Dakota refers to paleontological research occurring within or conducted by people from the U.S. state of South Dakota. South Dakota is an excellent source of fossils as finds have been widespread throughout the state. During ... References * Geology of South Dakota Neogene geology of Nebraska Neogene geology of Wyoming {{Cretaceous-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Greenhorn Formation
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 the (lowest) Li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fox Hills Formation
The Fox Hills Formation is a Cretaceous geologic Formation (geology), formation in the northwestern Great Plains of North America. It is present from Alberta on the north to Colorado in the south. Fossil remains of dinosaurs, including tyrannosaurs, as well as large marine reptiles, such as mosasaurs, have been recovered from the formation. Lithology The Fox Hills Formation consists of marginal marine yellow to grey sandstone with shale interbeds. It was deposited as a regressive sequence of barrier islands during the retreat of the Western Interior Seaway in Late Cretaceous time. In its eastern extents, the formation is underlain by the marine Pierre Shale in the United States and by the equivalent Bearpaw Formation in Canada, while in western ranges in Montana and Wyoming it overlies the Lewis Shale. The Fox Hills is overlain by continental sediments of the Laramie Formation in Colorado and the Lance Formation in Wyoming, the later being the equivalent of the overlying Hell ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fort Union Formation
The Fort Union Formation is a geologic unit containing sandstones, shales, and coal beds in Wyoming, Montana, and parts of adjacent states. In the Powder River Basin, it contains important economic deposits of coal, uranium, and coalbed methane. Description The Fort Union is mostly of Paleocene age and represents a time of extensive swamps as well as fluvial and lacustrine conditions. The rocks are more sandy in southwestern Wyoming and more coal-bearing in northeast Wyoming and southeast Montana, reflecting a general change from rivers and lakes in the west to swamps in the east, but all three environments were present at various times in most locations. Coal in the Fort Union in the Powder River Basin occurs mainly in the Tongue River Member, where as many as 32 coal seams total more than 300 feet in thickness. One such bed, the Wyodak Coal near Gillette, Wyoming, is as much as thick. Most of the coals in the Fort Union Formation are ranked subbituminous.''Cretaceous and Ter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
