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Paibi
Paibi (), a village in Paibi Township (), Huayuan County, Xiangxi Tujia and Miao Autonomous Prefecture Hunan, China, is the location of the Global Boundary Stratotype Section and Point (GSSP) which marks the boundary between the third and Furongian epochs of the Cambrian Period on the geologic time scale. Paibi was selected over the Kyrshabakty River section, Malyi Karatau, Kazakhstan, and the GSSP was ratified by the International Union of Geological Sciences in late 2003. It established the first formally agreed upon subdivision of the Cambrian. The village gives its name to the Paibian Age in the Cambrian Period. The Paibi section occurs within the Huaqiao Formation, which consists of a thick succession of carbonate beds deposited in the outer part of the Jiangnan Slope Belt, and extends from the middle Cambrian through the Lower Ordovician. It satisfies all the geological and biostratigraphic requirements for a GSSP, is readily accessible, and includes chemostratigraphic, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Furongian
The Furongian is the fourth and final epoch and series of the Cambrian. It lasted from to million years ago. It succeeds the Miaolingian series of the Cambrian and precedes the Lower Ordovician Tremadocian Stage. It is subdivided into three stages: the Paibian, Jiangshanian and the unnamed 10th stage of the Cambrian. Naming The Furongian was also known as the Cambrian Series 4, and the name replaced the older term Upper Cambrian and equivalent to the local term Hunanian. The present name was ratified by the International Commission on Stratigraphy in 2003. () means ' lotus' in Mandarin and refers to Hunan which is known as the "lotus state". Definition The lower boundary is defined in the same way as the GSSP of the Paibian Stage. Both begin with the first appearance of the trilobite ''Glyptagnostus reticulatus'' around million years ago. The upper boundary is the lower boundary and GSSP of the Tremadocian Stage which is the first appearance of the conodont ''Iapetognathus f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paibian
The Paibian is the lowest stage of Furongian series of the Cambrian. It follows the Guzhangian ( 3rd series of the Cambrian) and is succeeded by the Jiangshanian Stage. The base is defined as the first appearance of the trilobite ''Glyptagnostus reticulatus'' around million years ago. The top, or the base of the Jiangshanian is defined as the first appearance of the trilobite ''Agnostotes orientalis'' around million years ago. The name is derived from Paibi, a village in Hunan, China. The GSSP is defined in the "Paibi section" (Wuling Mountains, Huayuan County), an outcrop of the Huaqiao Formation(花桥组). The base is the first occurrence of ''Glyptagnostus reticulatus'' which is 396 m above the base of the Huaqiao Formation Huaqiao may refer to: *Overseas Chinese (华侨), or Huaqiao in pinyin *Huaqiao University (华侨大学), in Quanzhou, Fujian *Huaqiao railway station (花桥站), station of the Shanghai-Nanjing Intercity High-Speed Railway in Shanghai *Huaqiao s ... at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paibi Township
Paibi (), a village in Paibi Township (), Huayuan County, Xiangxi Tujia and Miao Autonomous Prefecture Hunan, China, is the location of the Global Boundary Stratotype Section and Point (GSSP) which marks the boundary between the third and Furongian epochs of the Cambrian Period on the geologic time scale. Paibi was selected over the Kyrshabakty River section, Malyi Karatau, Kazakhstan, and the GSSP was ratified by the International Union of Geological Sciences in late 2003. It established the first formally agreed upon subdivision of the Cambrian. The village gives its name to the Paibian Age in the Cambrian Period. The Paibi section occurs within the Huaqiao Formation, which consists of a thick succession of carbonate beds deposited in the outer part of the Jiangnan Slope Belt, and extends from the middle Cambrian through the Lower Ordovician. It satisfies all the geological and biostratigraphic requirements for a GSSP, is readily accessible, and includes chemostratigraphi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glyptagnostus Reticulatus
''Glyptagnostus reticulatus'' is a species of agnostid trilobite belonging to the genus '' Glyptagnostus''. It existed during the Paibian Age ( million years ago) of the Cambrian. It has a cosmopolitan distribution and is an important index fossil in biostratigraphy. It was characterized by an unusual net-like pattern of furrows on both the cephalon and the pygidium. Description Like all members of the suborder Agnostida, ''Glyptagnostus reticulatus'' is completely blind and only has two thoracic segments. The cephalon and pygidium are more or less the same size and shape ( isopygous). The glabella of the cephalon has two lobes. The front lobe is roughly squarish in shape, while the rear lobe is elongated and split along the middle. The cephalon has a narrow well-defined border. The pygidium has a long tapering central axis which can be divided into three lobes. The axis is connected to the rear margin by a central furrow. At both sides of the axis are a row of four or more pi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geologic Time Scale
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] |
Westergaardodina Proligula
''Westergaardodina'' is a species-rich genus of spine, U or W-shaped paraconodont known from Middle Cambrian to Lower Ordovician strata. Use in stratigraphy Paibi, a village in Hunan, China, is the location of the Global Boundary Stratotype Section and Point (GSSP) which marks the boundary between the Miaolingian and Furongian epochs of the Cambrian Period on the geologic time scale. The GSSP was ratified by the International Union of Geological Sciences in late 2003. It established the first formally agreed upon subdivision of the Cambrian. Markers which occur near the boundary include the first appearance of ''Westergaardodina proligula'' and the Steptoean positive carbon isotope excursion, a large positive shift in carbon-13 isotope Isotopes are two or more types of atoms that have the same atomic number (number of protons in their nuclei) and position in the periodic table (and hence belong to the same chemical element), and that differ in nucleon numbers ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hunan
Hunan (, ; ) is a landlocked province of the People's Republic of China, part of the South Central China region. Located in the middle reaches of the Yangtze watershed, it borders the province-level divisions of Hubei to the north, Jiangxi to the east, Guangdong and Guangxi to the south, Guizhou to the west and Chongqing to the northwest. Its capital and largest city is Changsha, which also abuts the Xiang River. Hengyang, Zhuzhou, and Yueyang are among its most populous urban cities. With a population of just over 66 million residing in an area of approximately , it is China's 7th most populous province, the fourth most populous among landlocked provinces, the second most populous in South Central China after Guangdong and the most populous province in Central China. It is the largest province in South-Central China and the fourth largest among landlocked provinces and the 10th most extensive province by area. Hunan's nominal GDP was US$ 724 billion (CNY 4.6 trillion) a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Global Boundary Stratotype Section And Point
A Global Boundary Stratotype Section and Point (GSSP) is an internationally agreed upon reference point on a stratigraphic section which defines the lower boundary of a stage on the geologic time scale. The effort to define GSSPs is conducted by the International Commission on Stratigraphy, a part of the International Union of Geological Sciences. Most, but not all, GSSPs are based on paleontological changes. Hence GSSPs are usually described in terms of transitions between different faunal stages, though far more faunal stages have been described than GSSPs. The GSSP definition effort commenced in 1977. As of 2022, 77 of the 101 stages that need a GSSP have a ratified GSSP. Rules A geologic section has to fulfill a set of criteria to be adapted as a GSSP by the ICS. The following list summarizes the criteria: * A GSSP has to define the lower boundary of a geologic stage. * The lower boundary has to be defined using a primary marker (usually first appearance datum of a fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Huayuan County
Huayuan County () is a county of Hunan Province, China, it is under the administration of Xiangxi Autonomous Prefecture. Located on the western margin of the province and the south western Xiangxi, it is immediately adjacent to the borders of Guizhou Province and Chongqing Municipality. The county is bordered to the north and the northeast by Baojing County, to the southeast by Jishou City, to the south by Fenghuang County, to the west by Songtao County of Guizhou and Xiushan County of Chongqing. Huayuan County covers , as of 2015, It had a registered population of 312,800 and a resident population of 300,800.the population of Huayuan County in 2015, according to the Statistical Communiqué of Huayuan County on the 2015 National Economic and Social Development - (2015年花垣县国民经济和社会发展统计公报)biancheng.gov.cn o/ref> The county has 9 towns and 3 townships under its jurisdiction, the county seat is Huayuan Town ().the divisions of Huayuan County in 2015, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Township (PRC)
Townships (), formally township-level divisions (), are the basic level (fourth-level administrative units) of political divisions in China. They are similar to municipalities and communes in other countries and in turn may contain village committees and villages. In 1995 there were 29,502 townships and 17,532 towns (a total of 47,034 township-level divisions) in China. Much like other levels of government in mainland China, the township's governance is divided between the Communist Party Township Secretary, and the "county magistrate" (). The township party secretary, along with the township's party committee, determines policy. The magistrate is in charge of administering the daily affairs of government and executing policies as determined by the party committee. A township official is the lowest-level ranked official in the civil service hierarchy; in practice, however, the township party secretary and magistrate can amass high levels of personal power. A township government ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geology
Geology () is a branch of natural science concerned with Earth and other astronomical objects, the features or rocks of which it is composed, and the processes by which they change over time. Modern geology significantly overlaps all other Earth sciences, including hydrology, and so is treated as one major aspect of integrated Earth system science and planetary science. Geology describes the structure of the Earth on and beneath its surface, and the processes that have shaped that structure. It also provides tools to determine the relative and absolute ages of rocks found in a given location, and also to describe the histories of those rocks. By combining these tools, geologists are able to chronicle the geological history of the Earth as a whole, and also to demonstrate the age of the Earth. Geology provides the primary evidence for plate tectonics, the evolutionary history of life, and the Earth's past climates. Geologists broadly study the properties and processes of E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basal (phylogenetics)
In phylogenetics, basal is the direction of the ''base'' (or root) of a phylogenetic tree#Rooted tree, rooted phylogenetic tree or cladogram. The term may be more strictly applied only to nodes adjacent to the root, or more loosely applied to nodes regarded as being close to the root. Note that extant taxa that lie on branches connecting directly to the root are not more closely related to the root than any other extant taxa. While there must always be two or more equally "basal" clades sprouting from the root of every cladogram, those clades may differ widely in taxonomic rank, Phylogenetic diversity, species diversity, or both. If ''C'' is a basal clade within ''D'' that has the lowest rank of all basal clades within ''D'', ''C'' may be described as ''the'' basal taxon of that rank within ''D''. The concept of a 'key innovation' implies some degree of correlation between evolutionary innovation and cladogenesis, diversification. However, such a correlation does not make a given ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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