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Skullrockian
Stage 10 of the Cambrian is the still unnamed third and final stage of the Furongian series. It follows the Jiangshanian and precedes the Ordovician Tremadocian Stage. The proposed lower boundary is the first appearance of the trilobite ''Lotagnostus americanus'' around million years ago, but other fossils are also being discussed (Cambrian Stage 10#Stratotype, see below). The upper boundary is defined as the appearance of the conodont ''Iapetognathus fluctivagus'' which marks the beginning of the Tremadocian and is radiometrically dated as million years ago. Naming The 10th stage of the Cambrian has not been formally named by the International Commission on Stratigraphy, ICS yet, although a number of Cambrian#Subdivisions, local names exist. Several authors favor the name "Lawsonian" after Lawson Cove, in the Wah Wah Mountains of Utah. The lower part of the North American Skullrockian Stage corresponds roughly to the Cambrian Stage 10. The name "Nelegerian", after the Neleger ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cambrian Stage 10
Stage 10 of the Cambrian is the still unnamed third and final stage of the Furongian series. It follows the Jiangshanian and precedes the Ordovician Tremadocian Stage. The proposed lower boundary is the first appearance of the trilobite '' Lotagnostus americanus'' around million years ago, but other fossils are also being discussed ( see below). The upper boundary is defined as the appearance of the conodont ''Iapetognathus fluctivagus'' which marks the beginning of the Tremadocian and is radiometrically dated as million years ago. Naming The 10th stage of the Cambrian has not been formally named by the ICS yet, although a number of local names exist. Several authors favor the name "Lawsonian" after Lawson Cove, in the Wah Wah Mountains of Utah. The lower part of the North American Skullrockian Stage corresponds roughly to the Cambrian Stage 10. The name "Nelegerian", after the Neleger River in Yakutia, was also proposed in 2011. Stratotype The ICS is still discussing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cambrian Utah
The Cambrian ( ) is the first geological period of the Paleozoic Era, and the Phanerozoic Eon. The Cambrian lasted 51.95 million years from the end of the preceding Ediacaran period 538.8 Ma (million years ago) to the beginning of the Ordovician Period 486.85 Ma. Most of the continents lay in the southern hemisphere surrounded by the vast Panthalassa Ocean. The assembly of Gondwana during the Ediacaran and early Cambrian led to the development of new convergent plate boundaries and continental-margin arc magmatism along its margins that helped drive up global temperatures. Laurentia lay across the equator, separated from Gondwana by the opening Iapetus Ocean. The Cambrian marked a profound change in life on Earth; prior to the Period, the majority of living organisms were small, unicellular and poorly preserved. Complex, multicellular organisms gradually became more common during the Ediacaran, but it was not until the Cambrian that fossil diversity seems to rapidly increase ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cambrian
The Cambrian ( ) is the first geological period of the Paleozoic Era, and the Phanerozoic Eon. The Cambrian lasted 51.95 million years from the end of the preceding Ediacaran period 538.8 Ma (million years ago) to the beginning of the Ordovician Period 486.85 Ma. Most of the continents lay in the southern hemisphere surrounded by the vast Panthalassa Ocean. The assembly of Gondwana during the Ediacaran and early Cambrian led to the development of new convergent plate boundaries and continental-margin arc magmatism along its margins that helped drive up global temperatures. Laurentia lay across the equator, separated from Gondwana by the opening Iapetus Ocean. The Cambrian marked a profound change in life on Earth; prior to the Period, the majority of living organisms were small, unicellular and poorly preserved. Complex, multicellular organisms gradually became more common during the Ediacaran, but it was not until the Cambrian that fossil diversity seems to rapidly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zhejiang
) , translit_lang1_type2 = , translit_lang1_info2 = ( Hangzhounese) ( Ningbonese) (Wenzhounese) , image_skyline = 玉甑峰全貌 - panoramio.jpg , image_caption = View of the Yandang Mountains , image_map = Zhejiang in China (+all claims hatched).svg , mapsize = 275px , map_caption = Location of Zhejiang in China , coordinates = , subdivision_type = Country , subdivision_name = China , named_for = Old name of Qiantang River , seat_type = Capital and largest city , seat = Hangzhou , established_title = Annexation by the Qin dynasty , established_date = 222 BC , established_title2 = Jiangnandong Circuit , established_date2 = 626 , established_title3 = Liangzhe Circuit , established_date3 = 997 , established_title4 = Zhejiang Province formed , established_date4 = 1368 , established_title5 = Republican Period , established_date5 = 1 January 1912 , established_title6 ... [...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] |
Geological Ages
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 (a 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 standardised international units of geological 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 de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lotagnostus
''Lotagnostus'' is a genus of very small trilobites in the order Agnostida, which lived on the outer continental shelves worldwide, during the late Upper Cambrian. It was described by Whitehouse in 1936, and the type species is ''Lotagnostus trisectus'', which was originally described as a species of ''Agnostus'' by Salter in 1864. Taxonomy The Treatise on Invertebrate Paleontology divides ''Lotagnostus'' into three subgenera that differ in the degree of effacement: ''L. (Lotagnostus)'' Whitehouse, 1936 (neither cephalon nor pygidium strongly effaced), ''L. (Distagnostus)'' Shergold, 1972 (strongly effaced on the outer/dorsal surface, but with clear furrows on the inner/ventral surface and ''L. (Eolotagnostus)'' Zhou ''in'' Zhiqiang Zhou, li & Qu, 1982 (with even the inner/ventral surface strongly effaced). Later authors however consider it likely that creating these subgenera would render the nominate subgenus paraphyletic. Biostratographic significance The first appearance ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Facies
In geology, a facies ( , ; same pronunciation and spelling in the plural) is a body of rock with distinctive characteristics. The characteristics can be any observable attribute of rocks (such as their overall appearance, composition, or condition of formation) and the changes that may occur in those attributes over a geographic area. A facies encompasses all the characteristics of a rock including its chemical, physical, and biological features that distinguish it from adjacent rock. The term "facies" was introduced by the Swiss geologist Amanz Gressly in 1838 and was part of his significant contribution to the foundations of modern stratigraphy, which replaced the earlier notions of '' Neptunism''. Walther's law Walther's law of facies, or simply Walther's law, named after the geologist Johannes Walther, states that the vertical succession of facies reflects lateral changes in environment. Conversely, it states that when a depositional environment "migrates" laterally, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eoconodontus Notchpeakensis
''Eoconodontus'' is an extinct genus of conodonts of the Late Cambrian. It is a two-elements (rounded and compressed) genus from the ''Proconodontus'' lineage. Use in stratigraphy It is suggested that ''Eoconodontus notchpeakensis'' can be a marker of the Stage 10 of the Furongian the fourth and final series of the Cambrian. In 2006, a working group proposed the first appearance of '' Cordylodus andresi''. Currently the first appearance of ''E. notchpeakensis'' is favored by many authors because it is globally widespread and is independent of facies In geology, a facies ( , ; same pronunciation and spelling in the plural) is a body of rock with distinctive characteristics. The characteristics can be any observable attribute of rocks (such as their overall appearance, composition, or con ... (known from continental rise to peritidal environments).Landing, E.; Westrop, S.R.; Adrain, J.M. (19 September 2011). "The Lawsonian Stage - the Eoconodontus notchpeakensis FAD and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palaeoworld
''Palaeoworld'' is a peer-reviewed academic journal with a focus on palaeontology and stratigraphy research in and around China. It was founded in 1991 by the Nanjing Institute of Geology and Palaeontology at the Chinese Academy of Sciences (NIGPAS). The journal has been published quarterly since 2006; prior to 2006, it did not adhere to a fixed publication schedule. The journal publishes articles from several specialised fields pertaining to palaeobiology and earth science, such as: fossil taxonomy; biostratigraphy, chemostratigraphy, and chronostratigraphy; evolutionary biology; evolutionary ecology; palaeoecology; palaeoclimatology; and molecular palaeontology. Its editors-in-chief are Shuzhong Shen of the State Key Laboratory of Palaeobiology and Stratigraphy at NIGPAS, and Norman MacLeod of the Natural History Museum, London. See also * ''Paleontological Journal'' * List of fossil sites References External links * (Elsevier.com) * (ScienceDirect ScienceDirect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cordylodus Andresi
''Cordylodus'' is an extinct genus of conodonts in the family Cordylodontidae. Use in stratigraphy It is suggested that ''Cordylodus andresi'' can be a marker of the Cambrian Stage 10. Distribution Fossils of ''Cordylodus'' have been found in Argentina, Australia, Canada (Quebec), China, Colombia (Tarqui, Huila),Moreno et al., 2008, p.10 Kazakhstan, Malaysia, Mexico, Norway, the Russian Federation, Sweden, and the United States, in the states of Alaska, Minnesota, Nevada, New York, Oklahoma (Bromide Formation The Bromide Formation is a formation (stratigraphy), geological formation in Oklahoma, USA. It is well known for its diverse echinoderm and trilobite fossil fauna. Location The Bromide Formation crops out in the Arbuckle Mountains, Arbuckle a ...), Vermont and Wyoming. ''C. horridus'' has been recovered from the Blakely Sandstone and ''C. angulatus'' from the Collier Shale, Ordovician geologic formations in the Ouachita Mountains of Arkansas and Oklahoma. R ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
