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Jiangshanian
The Jiangshanian is the middle stage of the Furongian series. It follows the Paibian Stage and is succeeded by the still unnamed Stage 10 of the Cambrian. The base is defined as the first appearance of the trilobite '' Agnostotes orientalis'' which is estimated to be million years ago. The Jiangshanian lasted until approximately million years ago. The Jiangshanian stage was named after Jiangshan, a city in China's Zhejiang province, where its GSSP was defined. Stratigraphy The Global boundary Stratotype Section and Point (GSSP) of the Jiangshanian is the "Duibian B Section" (), west of the village of Duibian (碓边), and 10 km north of Jiangshan. The outcrop belongs to the Huayansi Formation (华严寺组). The upper boundary (the base of the Stage 10) is not formally defined by ICS, but there is a proposal to set the first appearance of an agnostoid '' Lotagnostus americanus'' as its marker. In 2012, international research group proposed the Kyrshabakty s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Furongian
The Furongian is the fourth and final epoch and series of the 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 Ordov .... 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 Cambrian Stage 10, 10th stage of the Cambrian. History and 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 (genus), lotus' in Mandarin and refers to Hunan which is known as the "lotus state". Definition The lower boundary is defi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paibian
The Paibian is the lowest stage of the Furongian Series of the Cambrian System. The Paibian is also the first age of the Furongian Epoch of the Cambrian Period. It follows the Guzhangian ( Miaolingian 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. GSSP 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 at the type locality (). Major events At the turn of the Guzhangian and Paibian ages, an extinction event occurred that reduced ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Agnostotes Orientalis
''Agnostotes orientalis'' is a species of agnostid trilobite belonging to the genus '' Agnostotes''. It existed during the Jiangshanian Age ( million years ago) of the Cambrian. It is an important index fossil in biostratigraphy. Description ''Agnostotes orientalis'', like all members of the suborder Agnostina, possesses two thoracic segments, has a cephalon and pygidium that are more or less the same size and shape ( isopygous), and is completely blind. The axial lobe of the cephalon is narrow. At the front of the glabella is a notch (frontal sulcus), a characteristic unique to the species, making it easy to distinguish from other members of the genus. The posterior end of the axial lobe of the pygidium also widens significantly, another distinct characteristic of the species. Along the margins of the pygidium are a pair of very small backward-pointing spines. Both the pygidium and the cephalon are ornamented with small pits (scrobicules) and wrinkles, extending mostly inwa ... [...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] |
Jiangshan
Jiangshan () is a county-level city located in Quzhou prefecture-level city, in the southwest of Zhejiang Province, China, bordering Jiangxi province to the west. Located about 250 kilometers southwest of Hangzhou, the provincial capital, it is the only county-level city in Quzhou. In 1999, Jiangshan's population stood at 563,196. The city is named aptly: Jiang means river and Shan means mountain; a river runs through the city and scenic Mt. Jianglang sits on its border. ''USA Today'' described Jiangshan as a "fairly prosperous city in one of China's most developed provinces".''Global TEFL'' network The program sends native English-speakers to their network schools to teach English for periods of 2–4 weeks. Aside from these teachers, Jiangshan sees few Westerners because of its relative geographical obscurity. Jiangshan High School is also in Jiangshan. Transportation The area is served by Jiangshan railway station. References {{Authority control Quzhou Cities ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guzhangian
The Guzhangian is an uppermost stage of the Miaolingian Series of the Cambrian. It follows the Drumian Stage and precedes the Paibian Stage of the Furongian Series. The base is defined as the first appearance of the trilobite '' Lejopyge laevigata'' around million years ago. The Guzhangian-Paibian boundary is marked by the first appearance of the trilobite '' Glyptagnostus reticulatus'' around million years ago. The name Guzhangian is derived from Guzhang County, Hunan Province, China. GSSP The GSSP is defined in the Huaqiao Formation in Hunan. The precise base of the Guzhangian is a limestone layer 121.3 m above the base Huaqiao Formation (花桥组) at the Louyixi section (), where '' Lejopyge laevigata'' has its first appearance. Paleogeography It is assumed that in the Guzhangian the distance between the Earth and the Moon was 370,180 ± 1220 km (today, for comparison, it is 384,000 km). The length of an earthly day at that time was about 21.58 hours. Major events ... [...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] |
Global Boundary Stratotype Section And Point
A Global Boundary Stratotype Section and Point (GSSP), sometimes referred to as a golden spike, 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 2024, 79 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 mar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sandu Formation
Sandu may refer to: People Surname *Adrian Sandu (born 1966), Romanian gymnast * Bianca Sandu (born 1992), Romanian footballer * Constantin Sandu (born 1993), Moldovan footballer * Corina Sandu, Romanian-American mechanical engineer * Cristina Sandu (born 1990), Romanian long jumper and triple jumper * Florin Sandu (born 1987), Romanian footballer * Florin Sandu (lawyer) (born 1949), Romanian lawyer and academic and former chief of the Romanian Police * Gabriel Sandu (born 1963), Romanian economist and politician * Gabriel Sandu (footballer) (1952–1998), Romanian football defender * Iddris Sandu (born 1997), Ghanaian-American software engineer * Ion Sandu (born 1993), Moldovan footballer *Maia Sandu (born 1972), Moldovan politician and president of the country * Marian Sandu (born 1972), Romanian Greco-Roman wrestler * Mihaela Sandu (born 1977), Romanian chess player * Mihai Gruia Sandu (born 1956), Romanian actor, playwright, and director * Mircea Sandu (born 1952), Romanian footb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guangxi
Guangxi,; officially the Guangxi Zhuang Autonomous Region, is an Autonomous regions of China, autonomous region of the China, People's Republic of China, located in South China and bordering Vietnam (Hà Giang Province, Hà Giang, Cao Bằng Province, Cao Bằng, Lạng Sơn Province, Lạng Sơn, and Quảng Ninh Provinces) and the Gulf of Tonkin. Formerly a Provinces of China, province, Guangxi became an autonomous region in 1958. Its current capital is Nanning. Guangxi's location, in mountainous terrain in the far south of China, has placed it on the frontier of Chinese civilization throughout much of History of China, Chinese history. The current name "Guang" means "expanse" and has been associated with the region since the creation of Guang Prefecture in 226 AD. It was given Administrative divisions of the Yuan dynasty, provincial level status during the Yuan dynasty, but even into the 20th century, it was considered an open, wild territory. The abbreviation of the regi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Algae
Algae ( , ; : alga ) is an informal term for any organisms of a large and diverse group of photosynthesis, photosynthetic organisms that are not plants, and includes species from multiple distinct clades. Such organisms range from unicellular microalgae, such as cyanobacteria, ''Chlorella'', and diatoms, to multicellular macroalgae such as kelp or brown algae which may grow up to in length. Most algae are aquatic organisms and lack many of the distinct cell and tissue types, such as stomata, xylem, and phloem that are found in embryophyte, land plants. The largest and most complex marine algae are called seaweeds. In contrast, the most complex freshwater forms are the Charophyta, a Division (taxonomy), division of green algae which includes, for example, ''Spirogyra'' and stoneworts. Algae that are carried passively by water are plankton, specifically phytoplankton. Algae constitute a Polyphyly, polyphyletic group because they do not include a common ancestor, and although Eu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
