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Ninemile Formation
The Ninemile Shale is a geologic formation in Nevada. It preserves fossils dating back to the Ordovician period. See also * List of fossiliferous stratigraphic units in Nevada * Paleontology in Nevada Paleontology in Nevada refers to paleontological research occurring within or conducted by people from the U.S. state of Nevada. Nevada has a rich fossil record of plants and animal life spanning the past 650 million years of time. The earliest fo ... References * Ordovician geology of Nevada Ordovician System of North America Geologic formations of Nevada Ordovician southern paleotropical deposits {{Ordovician-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geologic Formation
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 Wer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ordovician
The Ordovician ( ) is a geologic period and System (geology), system, the second of six periods of the Paleozoic Era (geology), Era. The Ordovician spans 41.6 million years from the end of the Cambrian Period million years ago (Mya) to the start of the Silurian Period Mya. The Ordovician, named after the Celtic Britons, Welsh tribe of the Ordovices, was defined by Charles Lapworth in 1879 to resolve a dispute between followers of Adam Sedgwick and Roderick Murchison, who were placing the same Rock (geology), rock beds in North Wales in the Cambrian and Silurian systems, respectively. Lapworth recognized that the fossil fauna in the disputed Stratum, strata were different from those of either the Cambrian or the Silurian systems, and placed them in a system of their own. The Ordovician received international approval in 1960 (forty years after Lapworth's death), when it was adopted as an official period of the Paleozoic Era by the International Union of Geological Sciences, Intern ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shale
Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4) and tiny fragments (silt-sized particles) of other minerals, especially quartz and calcite.Blatt, Harvey and Robert J. Tracy (1996) ''Petrology: Igneous, Sedimentary and Metamorphic'', 2nd ed., Freeman, pp. 281–292 Shale is characterized by its tendency to split into thin layers ( laminae) less than one centimeter in thickness. This property is called '' fissility''. Shale is the most common sedimentary rock. The term ''shale'' is sometimes applied more broadly, as essentially a synonym for mudrock, rather than in the more narrow sense of clay-rich fissile mudrock. Texture Shale typically exhibits varying degrees of fissility. Because of the parallel orientation of clay mineral flakes in shale, it breaks into thin layers, often splintery and usually parallel to the otherwise indistinguishable beddin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nevada
Nevada ( ; ) is a U.S. state, state in the Western United States, Western region of the United States. It is bordered by Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. Nevada is the List of U.S. states and territories by area, 7th-most extensive, the List of U.S. states and territories by population, 32nd-most populous, and the List of U.S. states and territories by population density, 9th-least densely populated of the U.S. states. Nearly three-quarters of Nevada's people live in Clark County, Nevada, Clark County, which contains the Las Vegas–Paradise, NV MSA, Las Vegas–Paradise metropolitan area, including three of the state's four largest incorporated cities. Nevada's capital is Carson City, Nevada, Carson City. Las Vegas is the largest city in the state. Nevada is officially known as the "Silver State" because of the importance of silver to its history and economy. It is also known as the "Battle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pogonip Group
The Pogonip Group is an Ordovician period geologic group located in southern Nevada and in Utah. Geology Its subunits in Nevada, from youngest/later to oldest/earlier, are: * Goodwin Limestone — thick * Ninemile Formation — thick * Antelope Valley Limestone — thick It preserves fossils dating back to the Early Ordovician stage of the Ordovician period. See also * List of fossiliferous stratigraphic units in Nevada * List of fossiliferous stratigraphic units in Utah This article contains a list of fossil-bearing stratigraphic units in the state of Utah, U.S. Sites See also * Paleontology in Utah References * {{DEFAULTSORT:Fossiliferous stratigraphic units in Utah Utah Stratigraphic units A strat ... References Geologic groups of Nevada Geologic groups of Utah Lower Ordovician Series Ordovician geology of Nevada Ordovician geology of Utah Ordovician System of North America {{Ordovician-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antelope Valley Limestone
The Antelope Valley Limestone is a limestone geologic formation of the Pogonip Group in southern Nevada. It is found in the Antelope Valley region of Eureka County and Nye County. It preserves fossils dating back to the Whiterock Stage of the Ordovician period. See also * List of fossiliferous stratigraphic units in Nevada * Paleontology in Nevada Paleontology in Nevada refers to paleontological research occurring within or conducted by people from the U.S. state of Nevada. Nevada has a rich fossil record of plants and animal life spanning the past 650 million years of time. The earliest fo ... References * * Ordovician geology of Nevada Limestone formations of the United States Geography of Eureka County, Nevada Geography of Nye County, Nevada Ordovician System of North America Geologic formations of Nevada Ordovician southern paleotropical deposits {{Ordovician-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Goodwin Limestone
The Goodwin Limestone is a geologic formation of the Pogonip Group in Nevada. It preserves fossils dating back to the Ordovician period. See also * List of fossiliferous stratigraphic units in California * List of fossiliferous stratigraphic units in Nevada This article contains a list of fossil-bearing stratigraphic units in the state of Nevada, U.S. Sites See also * Paleontology in Nevada References * {{DEFAULTSORT:Fossiliferous stratigraphic units in Nevada Nevada Stratigraphic units ... References * Ordovician geology of Nevada Ordovician California Ordovician System of North America Geologic formations of California Geologic formations of Nevada Ordovician southern paleotropical deposits {{Ordovician-stub ... [...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 Wer ... [...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 Nevada
This article contains a list of fossil-bearing stratigraphic units in the state of Nevada, U.S. Sites See also * Paleontology in Nevada References * {{DEFAULTSORT:Fossiliferous stratigraphic units in Nevada Nevada 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 Nevada Nevada geography-related lists United States geology-related lists ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleontology In Nevada
Paleontology in Nevada refers to paleontological research occurring within or conducted by people from the U.S. state of Nevada. Nevada has a rich fossil record of plants and animal life spanning the past 650 million years of time. The earliest fossils from the state are from Esmeralda County, and are Late Proterozoic in age and represent stromatolite reefs of cyanobacteria, amongst these reefs were some of the oldest known shells in the fossil record, the Cloudina-fauna. Much of the Proterozoic and Paleozoic fossil story of Nevada is that of a warm, shallow, tropical sea, with a few exceptions towards the Late Paleozoic. As such many fossils across the state are those of marine animals, such as trilobites, brachiopods, bryozoans, honeycomb corals, archaeocyaths, and horn corals. After the Paleozoic, tectonic activity on the western margin of North America increased. This increase in tectonism forced portions of Nevada formerly below sea level higher. In the Triassic northern and c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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