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Lebo Formation
The Lebo Member is a geologic member of the Fort Union Formation in Montana and Wyoming. It preserves fossils dating back to the Paleogene period. See also * List of fossiliferous stratigraphic units in Montana This article contains a list of fossil-bearing stratigraphic units in the state of Montana, U.S. Sites See also * Paleontology in Montana References * {{DEFAULTSORT:Fossiliferous stratigraphic units in Montana Montana Stratigraphic u ... * Paleontology in Montana References Paleogene Montana Paleogene geology of Wyoming {{Paleogene-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Member (stratigraphy)
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 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 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 lithostratigraphic units are assigned by geological surveys. Units of formation or hi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleogene
The Paleogene ( ; British English, also spelled Palaeogene or Palæogene; informally Lower Tertiary or Early Tertiary) is a geologic period, geologic period and system that spans 43 million years from the end of the Cretaceous Period million years ago (annum, Mya) to the beginning of the Neogene Period Mya. It is the beginning of the Cenozoic Era of the present Phanerozoic Eon. The earlier term Tertiary Period was used to define the span of time now covered by the Paleogene Period and subsequent Neogene Period; despite no longer being recognised as a formal stratigraphy, stratigraphic term, 'Tertiary' is still widely found in earth science literature and remains in informal use. Paleogene is often abbreviated "Pg" (but the United States Geological Survey uses the abbreviation PE for the Paleogene on the Survey's geologic maps). During the Paleogene, evolution of mammals, mammals diversified from relatively small, simple forms into a large group of diverse animals in the wake of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Montana
Montana () is a state in the Mountain West division of the Western United States. It is bordered by Idaho to the west, North Dakota and South Dakota to the east, Wyoming to the south, and the Canadian provinces of Alberta, British Columbia, and Saskatchewan to the north. It is the fourth-largest state by area, the eighth-least populous state, and the third-least densely populated state. Its state capital is Helena. The western half of Montana contains numerous mountain ranges, while the eastern half is characterized by western prairie terrain and badlands, with smaller mountain ranges found throughout the state. Montana has no official nickname but several unofficial ones, most notably "Big Sky Country", "The Treasure State", "Land of the Shining Mountains", and " The Last Best Place". The economy is primarily based on agriculture, including ranching and cereal grain farming. Other significant economic resources include oil, gas, coal, mining, and lumber. The health ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wyoming
Wyoming () is a U.S. state, state in the Mountain states, Mountain West subregion of the Western United States. It is bordered by 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 a population of 576,851 in the 2020 United States census, 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, with the List of U.S. states by population density, second-lowest population density after Alaska. The state capital and List of municipalities in Wyoming, most populous city is Cheyenne, Wyoming, Cheyenne, which had an estimated population of 63,957 in 2018. Wyoming's western half is covered mostly by the ranges and rangelands of the Rocky Mountains, while the eastern half of the state is high-elevation prairie called the High Plains (United States), High Plains. It is drier ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territories, nine Minor Outlying Islands, and 326 Indian reservations. The United States is also in free association with three Pacific Island sovereign states: the Federated States of Micronesia, the Marshall Islands, and the Republic of Palau. It is the world's third-largest country by both land and total area. It shares land borders with Canada to its north and with Mexico to its south and has maritime borders with the Bahamas, Cuba, Russia, and other nations. With a population of over 333 million, it is the most populous country in the Americas and the third most populous in the world. The national capital of the United States is Washington, D.C. and its most populous city and principal financial center is New York City. Paleo-Americ ... [...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] |
Tongue River Member
The Tongue River Member is the uppermost geologic member of the Fort Union Formation in Montana, North Dakota, Wyoming. The strata are yellow or light-colored massive sandstones and numerous thick coal beds. The vertebrate fossil fauna includes fishes, turtles, crocodiles, and mammals. Mammalian genera known from rocks of both the Torrejonian and the Tiffanian land mammal ages (middle and late Paleocene) are present. See also * List of fossiliferous stratigraphic units in North Dakota * Paleontology in North Dakota * Paleontology in Wyoming Paleontology in Wyoming includes research into the prehistoric life of the U.S. state of Wyoming as well as investigations conducted by Wyomingite researchers and institutions into ancient life occurring elsewhere. The fossil record of the US sta ... References Paleogene Montana Paleogene geology of North Dakota {{Paleogene-stub Mudstones and sandstone, Tongue River Member, exposed in a roadcut, US Highway 87 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Member (geology)
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 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 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 lithostratigraphic units are assigned by geological surveys. Units of formation or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fossils
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in amber, hair, petrified wood and DNA remnants. The totality of fossils is known as the ''fossil record''. Paleontology is the study of fossils: their age, method of formation, and evolutionary significance. Specimens are usually considered to be fossils if they are over 10,000 years old. The oldest fossils are around 3.48 billion years old to 4.1 billion years old. Early edition, published online before print. The observation in the 19th century that certain fossils were associated with certain rock strata led to the recognition of a geological timescale and the relative ages of different fossils. The development of radiometric dating techniques in the early 20th century allowed scientists to quantitatively measure the absolute ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Period (geology)
The geologic time scale, or geological time scale, (GTS) is a representation of time based on the rock record of Earth. It is a system of chronological dating that uses chronostratigraphy (the process of relating strata to time) and geochronology (scientific branch of geology that aims to determine the age of rocks). It is used primarily by Earth scientists (including geologists, paleontologists, geophysicists, geochemists, and paleoclimatologists) to describe the timing and relationships of events in geologic history. The time scale has been developed through the study of rock layers and the observation of their relationships and identifying features such as lithologies, paleomagnetic properties, and fossils. The definition of standardized international units of geologic time is the responsibility of the International Commission on Stratigraphy (ICS), a constituent body of the International Union of Geological Sciences (IUGS), whose primary objective is to precisely define ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Fossiliferous Stratigraphic Units In Montana
This article contains a list of fossil-bearing stratigraphic units in the state of Montana, U.S. Sites See also * Paleontology in Montana References * {{DEFAULTSORT:Fossiliferous stratigraphic units in Montana Montana 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 Montana Montana geography-related lists United States geology-related lists ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleontology In Montana
Paleontology in Montana refers to paleontological research occurring within or conducted by people from the U.S. state of Montana. The fossil record in Montana stretches all the way back to the Precambrian. During the Late Precambrian, western Montana was covered by a warm, shallow sea where local bacteria formed stromatolites and bottom-dwelling marine life left tracks on the sediment that would later fossilize. This sea remained in place during the early Paleozoic, although withdrew during the Silurian and Early Devonian, leaving a gap in the local rock record until its return. This sea was home to creatures including brachiopods, conodonts, crinoids, fish, and trilobites. During the Carboniferous the state was home to an unusual cartilaginous fish fauna. Later in the Paleozoic the sea began to withdraw, but with a brief return during the Permian. During the Triassic Montana was again covered in a sea whose inhabitants are the state's only known fossils from this time. Much of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
