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Sakmarian Genera
In the geologic timescale, the Sakmarian is an age or stage of the Permian. It is a subdivision of the Cisuralian Epoch or Series. The Sakmarian lasted between 293.52 and million years ago (Ma). It was preceded by the Asselian and followed by the Artinskian.; 2004: ''A Geologic Time Scale 2004'', Cambridge University Press Stratigraphy The Sakmarian Stage is named after the Sakmara River in the Ural Mountains, a tributary to the Ural River. The stage was introduced into scientific literature by Alexander Karpinsky in 1874. In Russian stratigraphy, it originally formed a substage of the Artinskian Stage. Currently, the ICS uses it as an independent stage in its international geologic timescale. The base of the Sakmarian Stage is laid with the first appearance of conodont species ''Streptognathodus postfusus'' in the fossil record. A global reference profile for the base (a GSSP), located in the southern Ural Mountains, Russia, was ratified in 2018. The top of the Sakma ... [...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] |
Megaannum
A year or annus is the orbital period of a planetary body, for example, the Earth, moving in its orbit around the Sun. Due to the Earth's axial tilt, the course of a year sees the passing of the seasons, marked by change in weather, the hours of daylight, and, consequently, vegetation and soil fertility. In temperate and subpolar regions around the planet, four seasons are generally recognized: spring, summer, autumn and winter. In tropical and subtropical regions, several geographical sectors do not present defined seasons; but in the seasonal tropics, the annual wet and dry seasons are recognized and tracked. A calendar year is an approximation of the number of days of the Earth's orbital period, as counted in a given calendar. The Gregorian calendar, or modern calendar, presents its calendar year to be either a common year of 365 days or a leap year of 366 days, as do the Julian calendars. For the Gregorian calendar, the average length of the calendar year (the mean yea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Permian Geochronology
The Permian ( ) is a geologic period and stratigraphic system which spans 47 million years from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.9 Mya. It is the last period of the Paleozoic Era; the following Triassic Period belongs to the Mesozoic Era. The concept of the Permian was introduced in 1841 by geologist Sir Roderick Murchison, who named it after the region of Perm in Russia. The Permian witnessed the diversification of the two groups of amniotes, the synapsids and the sauropsids (reptiles). The world at the time was dominated by the supercontinent Pangaea, which had formed due to the collision of Euramerica and Gondwana during the Carboniferous. Pangaea was surrounded by the superocean Panthalassa. The Carboniferous rainforest collapse left behind vast regions of desert within the continental interior. Amniotes, which could better cope with these drier conditions, rose to dominance in place of their amphibian ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mesogondolella
''Mesogondolella'' is an extinct genus of conodonts. The species ''M. daheshenensis'' and ''M. subgracilis'' are from the Permian (probably Wordian) of the Daheshen Formation in China.The age of the Daheshen Formation in Jilin Province based on conodonts. Xiao-dong Zhou, Dong-jin Li, Guang-qi Wang, Xi-qing Sun and Cheng-yuan Wang, Acta Palaeontologica Sinica, 2013, volume 52, issue 3, pages 294–308 The top of the Sakmarian stage (the base of the Artinskian) is defined as the place in the stratigraphic record where fossils of conodont species ''Sweetognathus whitei'' and ''Mesogondolella bisselli'' first appear. References External links * Ozarkodinida genera Permian conodonts {{Conodont-stub ... [...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] |
Streptognathodus
''Streptognathodus'' is an extinct genus of conodonts from the Late Carboniferous to Early Permian. Use in stratigraphy Late Carboniferous The top of the Kasimovian stage is close to the first appearance of ''Streptognathodus zethus''. The golden spike for the Kasimovian stage has not yet been assigned (in 2008). The Kasimovian is subdivided into three conodont biozones: *''Idiognathodus toretzianus'' Zone *''Idiognathodus sagittatus'' Zone *''Streptognathodus excelsus'' and ''Streptognathodus makhlinae'' Zone The base of the Gzhelian is at the first appearance of ''Streptognathodus zethus''. The top of the stage (also the top base of the Silesian and the base of the Permian system) is at the first appearance of ''Streptognathodus isolatus'' within the ''Streptognathus "wabaunsensis"'' chronocline. The Gzhelian stage is subdivided into five biozones, based on the conodont genus ''Streptognathodus'': * ''Streptognathodus wabaunsensis'' and ''Streptognathodus bellus'' Zone ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alexander Karpinsky
Alexander Petrovich Karpinsky (russian: Александр Петрович Карпинский, trl. Aljeksandr Pjetrovič Karpinskij; 7 January 1847 ( NS) – 15 July 1936) was a prominent Russian and Soviet geologist and mineralogist, and the president of the Russian Academy of Sciences, and later Academy of Sciences of the USSR, in 1917–1936. Biography Karpinsky was born in Turyinskiye Rudniki, Perm Governorate (now Krasnoturyinsk, Sverdlovsk Oblast), in the Ural Mountains, into a family of mining engineers. From 1857 to 1866 he studied at the mining school in St. Petersburg, and in 1863-1866 he also attended the Mineralogical Institute. From 1866 to 1869 he worked in his home area in the Urals as a mining engineer. He was invited to the Mining Institute, St. Petersburg in 1869 as an Assistant Professor, whilst also doing further studies and research. He was given full professorship in 1877. He stayed there until 1885. He was the imperial director of mining ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ural River
The Ural (russian: Урал, ), known before 1775 as Yaik (russian: Яик, ba, Яйыҡ, translit=Yayıq, ; kk, Жайық, translit=Jaiyq, ), is a river flowing through Russia and Kazakhstan in the continental border between Europe and Asia. It originates in the southern Ural Mountains and discharges into the Caspian Sea. At , it is the third-longest river in Europe after the Volga and the Danube, and the 18th-longest river in Asia. The Ural is conventionally considered part of the boundary between the continents of Europe and Asia. The Ural arises near Mount Kruglaya in the Ural Mountains, flows south parallel and west of the north-flowing Tobol, through Magnitogorsk, and around the southern end of the Urals, through Orsk where it turns west for about , to Orenburg, where the river Sakmara joins. From Orenburg it continues west, passing into Kazakhstan, then turning south again at Oral, and meandering through a broad flat plain until it reaches the Caspian a few miles be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tributary
A tributary, or affluent, is a stream or river that flows into a larger stream or main stem (or parent) river or a lake. A tributary does not flow directly into a sea or ocean. Tributaries and the main stem river drain the surrounding drainage basin of its surface water and groundwater, leading the water out into an ocean. The Irtysh is a chief tributary of the Ob river and is also the longest tributary river in the world with a length of . The Madeira River is the largest tributary river by volume in the world with an average discharge of . A confluence, where two or more bodies of water meet, usually refers to the joining of tributaries. The opposite to a tributary is a distributary, a river or stream that branches off from and flows away from the main stream. PhysicalGeography.net, Michael Pidwirny & S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ural Mountains
The Ural Mountains ( ; rus, Ура́льские го́ры, r=Uralskiye gory, p=ʊˈralʲskʲɪjə ˈɡorɨ; ba, Урал тауҙары) or simply the Urals, are a mountain range that runs approximately from north to south through western Russia, from the coast of the Arctic Ocean to the river Ural and northwestern Kazakhstan.Ural Mountains Encyclopædia Britannica on-line The mountain range forms part of the conventional boundary between the regions of and |
Sakmara River
The Sakmara (russian: Сакмара; ba, Һаҡмар, Haqmar) is a river in Russia that drains the southern tip of the Ural Mountains south into the river Ural. It is long, and has a drainage basin of . It is a right tributary of the Ural, which it meets in Orenburg. The source of the Sakmara is in the Republic of Bashkortostan. Other towns along the Sakmara are Yuldybayevo (Bashkortostan), Kuvandyk, and railway station Saraktash close to the Wozdwizhenskaya Fortress (Orenburg Oblast). It rises in the southern Ural Mountains about west-southwest of Magnitogorsk and flows south through a valley with some canyon development. At Kuvandyk it swings west, leaves the mountains and flows west parallel to the Ural River with many meanders for about (straight-line distance) before turning south to meet the Ural. Major tributaries are the Salmysh and the Bolshoy Ik, both from the north. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cambridge University
, mottoeng = Literal: From here, light and sacred draughts. Non literal: From this place, we gain enlightenment and precious knowledge. , established = , other_name = The Chancellor, Masters and Scholars of the University of Cambridge , type = Public research university , endowment = £7.121 billion (including colleges) , budget = £2.308 billion (excluding colleges) , chancellor = The Lord Sainsbury of Turville , vice_chancellor = Anthony Freeling , students = 24,450 (2020) , undergrad = 12,850 (2020) , postgrad = 11,600 (2020) , city = Cambridge , country = England , campus_type = , sporting_affiliations = The Sporting Blue , colours = Cambridge Blue , website = , logo = University of Cambridge logo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
