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Dapingian First Appearances
The Dapingian is the third stage of the Ordovician period and the first stage of the Middle Ordovician series. It is preceded by the Floian and succeeded by the Darriwilian. The top of the Floian is defined as the first appearance of the conodont species ''Baltoniodus triangularis'' which happened about million years ago. The Dapingian lasted for about 2.7 million years until about million years ago.Note: there is an apparent typo in the article referenced; they give the coordinates as "a latitude of 30°51’37.8"N and a longitude of 110°22’26.5"E", but their map and location description better corresponds to 30°51’37.8"N 111°22’26.5"E. History The Ordovician was divided into three series and six global stages in 1995; in 2005, this was amended to seven stages with the formalization of the Hirnantian stage as the last stage in the Late Ordovician. The Dapingian was the last Ordovician stage to be ratified, and was initially referred to as an informal and unnamed "third ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Commission On Stratigraphy
The International Commission on Stratigraphy (ICS), sometimes referred to unofficially as the "International Stratigraphic Commission", is a daughter or major subcommittee grade scientific daughter organization that concerns itself with stratigraphy, stratigraphical, geology, geological, and chronology, geochronological matters on a global scale. It is the largest subordinate body of the International Union of Geological Sciences (IUGS). The ICS is essentially a permanent working committee, working subcommittee, which meets far more regularly than the quadrennial meetings scheduled by the IUGS, when it meets as a congress or committee, membership of the whole. Aims One of its main aims, a project begun in 1974, is to establish a multidisciplinary standard and global geologic time scale that will ease paleontology, paleontological and geobiology, geobiological comparisons region to region by benchmarks with stringent and rigorous strata criteria called Global Boundary Stratotype ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Index Fossils
Biostratigraphy is the branch of stratigraphy which focuses on correlating and assigning relative ages of rock strata by using the fossil assemblages contained within them.Hine, Robert. “Biostratigraphy.” ''Oxford Reference: Dictionary of Biology'', 8th ed., Oxford University Press, 2019. The primary objective of biostratigraphy is ''correlation'', demonstrating that a particular horizon in one geological section represents the same period of time as another horizon at a different section. Fossils within these strata are useful because sediments of the same age can look completely different, due to local variations in the sedimentary environment. For example, one section might have been made up of clays and marls, while another has more chalky limestones. However, if the fossil species recorded are similar, the two sediments are likely to have been laid down around the same time. Ideally these fossils are used to help identify biozones, as they make up the basic biostratigrap ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Whiterockian
The Whiterockian, often referred to simply as the Whiterock, is an earliest or lowermost stage of the Middle Ordovician. Although the Whiterockian or Whiterock Stage refers mainly to the early Middle Ordovician in North America, it is often used in the older literature in a global sense. The Whitetrock Stage was introduced by Cooper and Cooper (in Cooper, 1956, p. 6–7) "as a post-Canadian – pre-Chazyan chrono-stratographic unit" based on strata "in the Monitor and Antelope Ranges, flanking Antelope Valley, and in the Toquima Range of central Nevada", referred to as the Antelope Valley Limestone. The strato-type section in Whiterock Canyon in the northern Monitor Range and reference section at Meiklejohn Peak, Bare Mountain Quad. Nev. both show the boundary between the middle Ordovician Whiterock and underlying (mostly Canadian) Ibex series lies between the conodont ''Oepikodus evae'', below, and ''Tripodus laevis'', above, at the start of the ''Isograptus victoria ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
England
England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe by the North Sea to the east and the English Channel to the south. The country covers five-eighths of the island of Great Britain, which lies in the North Atlantic, and includes over 100 smaller islands, such as the Isles of Scilly and the Isle of Wight. The area now called England was first inhabited by modern humans during the Upper Paleolithic period, but takes its name from the Angles, a Germanic tribe deriving its name from the Anglia peninsula, who settled during the 5th and 6th centuries. England became a unified state in the 10th century and has had a significant cultural and legal impact on the wider world since the Age of Discovery, which began during the 15th century. The English language, the Anglican Church, and Engli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arenig
In geology, the Arenig (or Arenigian) is a time interval during the Ordovician period and also the suite of rocks which were deposited during this interval. History The term was first used by Adam Sedgwick in 1847 with reference to the "Arenig Ashes and Porphyries" in the neighbourhood of Arenig Fawr, in Merioneth, North Wales. The rock-succession in the Arenig district has been recognized by W. G. Fearnsides (“On the Geology of Arenig Fawr and Moel Llanfnant", Q.J.G.S. vol. lxi., 1905, pp. 608–640, with maps). The above succession is divisible into: # A lower series of gritty and calcareous sediments, the "Arenig Series" as it is now understood; # A middle series, mainly volcanic, with shale, the "Llandeilo Series"; and # The shale and limestones of the Bala or Caradoc Stage. It was to the middle series (2) that Sedgwick first applied the term "Arenig". In the typical region and in North Wales generally the Arenig series appears to be unconformable upon the Cambri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dawan Formation
The term Dawan may refer to: Places China Towns * Dawan, Chongqing, in Yubei District * Dawan, Gaoyao, in Gaoyao District, Guangdong * Dawan, Guiping, in Guiping district, Guangxi * Dawan, Guizhou, in Zhongshan District, Liupanshui * Dawan, Jilin, in Meihekou * Dawan, Yunnan, in Zhenxiong County Townships * Dawan Township, Guangxi, in Xingbin District, Laibin * Dawan Township, Ningxia, in Jingyuan County * Dawan Township, Sichuan, in Dechang County * Dawan, Huarong District, former township in Ezhou, Hubei Other places * Dawan District, a subdistrict of Klungkung, Bali, Indonesia * Dawan, a ''barangay'' of Mati, Davao Oriental, Philippines * Dawan, an administrative division of Yongkang District, Taiwan Other uses * Atoni, also known as Dawan, an ethnic group on Timor * Dayuan, a historical people of West China (pinyin spelling) * Dawan language, an Austronesian language spoken by Atoni people of West Timor * a character in the short story ''Sing to the Dawn'' by the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GSSP
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] |
Chenjiahe
Chenjiahe Town () is an urban town in Sangzhi County, Zhangjiajie, Hunan Province, China. Administrative division The town is divided into 20 village A village is a clustered human settlement or community, larger than a hamlet but smaller than a town (although the word is often used to describe both hamlets and smaller towns), with a population typically ranging from a few hundred ...s and 2 communities, the following areas: Qiaotou Community, Huangmutan Community, Caijiaping Village, Maota Village, Zhoujiawan Village, Chenjiawan Village, Yuanjiaping Village, Liujiawan Village, Pengjiata Village, Xinjie Village, Erdongping Village, Poufuxi Village, Tangjiaping Village, Chenjiahe Village, Ganxi Village, Longtangou Village, Changwan Village, Wujiawan Village, Cangguanyu Village, Banxi Village, Xiaojiaping Village, and Sanlanzi Village (桥头社区、黄木潭社区、蔡家坪村、毛塔村、周家弯村、陈家湾村、袁家坪村、刘家湾村、彭家塔 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chitinozoan
Chitinozoa (singular: chitinozoan, plural: chitinozoans) are a group of flask-shaped, organic walled marine microfossils produced by an as yet unknown organism. Common from the Ordovician to Devonian periods (i.e. the mid-Paleozoic), the millimetre-scale organisms are abundant in almost all types of marine sediment across the globe. This wide distribution, and their rapid pace of evolution, makes them valuable biostratigraphic markers. Their bizarre form has made classification and ecological reconstruction difficult. Since their discovery in 1931, suggestions of protist, plant, and fungal affinities have all been entertained. The organisms have been better understood as improvements in microscopy facilitated the study of their fine structure, and it has been suggested that they represent either the eggs or juvenile stage of a marine animal. However, recent research has suggested that they represent the hard shell of a group of protists with uncertain affinities. Chitinozoan eco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protoprioniodus
''Protoprioniodus'' is an extinct genus of conodonts. Use in stratigraphy The Whiterock Stage refers mainly to the early Middle Ordovician in North America. It is often used in the older literature in a global sense. The Whiterock Stage is given a range from 471.8 (ca. 472) to 462 m.y.a., spanning close to 10 million years. Officially its start is defined by the potentially lowest occurrence of the conodonts ''Protoprioniodus aranda'' or '' Baltoniodus triangularis''. References External links * * Prioniodontida genera Ordovician conodonts {{conodont-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Argentina
Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, the fourth-largest country in the Americas, and the eighth-largest country in the world. It shares the bulk of the Southern Cone with Chile to the west, and is also bordered by Bolivia and Paraguay to the north, Brazil to the northeast, Uruguay and the South Atlantic Ocean to the east, and the Drake Passage to the south. Argentina is a federal state subdivided into twenty-three provinces, and one autonomous city, which is the federal capital and largest city of the nation, Buenos Aires. The provinces and the capital have their own constitutions, but exist under a federal system. Argentina claims sovereignty over the Falkland Islands, South Georgia and the South Sandwich Islands, and a part of Antarctica. The earliest recorded human prese ... [...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] |
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