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Stephanian (stage)
The Stephanian is a Stage (stratigraphy), stage in the regional stratigraphy of northwest Europe with an age between roughly 307.5 and 299 Megaannum, Ma (million years ago). It is a subdivision of the Carboniferous system (stratigraphy), system or period (geology), period and the regional Silesian (series), Silesian series (stratigraphy), series. The uppermost units of the Coal Measures of England and Wales are probably of Stephanian age, though the larger part of this formation is referred to the earlier Westphalian (stage), Westphalian. The stage derives its name from the city of Saint-Étienne for its Loire coal mining basin, coal mining basin in eastern central France (which itself derives from associations with Saint Stephen) where strata of this age occur. In the official geologic timescale of the International Commission on Stratigraphy, ICS, the Stephanian is placed within the Pennsylvanian (geology), Pennsylvanian epoch (323-299 Ma). The (regionally defined) Stephanian sta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stage (stratigraphy)
In chronostratigraphy, a stage is a succession of rock strata laid down in a single age on the geologic timescale, which usually represents millions of years of deposition. A given stage of rock and the corresponding age of time will by convention have the same name, and the same boundaries. Rock series are divided into stages, just as geological epochs are divided into ages. Stages are divided into smaller stratigraphic units called chronozones or substages, and added together into superstages. The term faunal stage is sometimes used, referring to the fact that the same fauna (animals) are found throughout the layer (by definition). Definition Stages are primarily defined by a consistent set of fossils ( biostratigraphy) or a consistent magnetic polarity (see paleomagnetism) in the rock. Usually one or more index fossils that are common, found worldwide, easily recognized, and limited to a single, or at most a few, stages are used to define the stage's bottom. Thus, f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geologic Timescale
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 precise ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pennsylvanian Geochronology
Pennsylvanian may refer to: * A person or thing from Pennsylvania * Pennsylvanian (geology) The Pennsylvanian ( , also known as Upper Carboniferous or Late Carboniferous) is, on the International Commission on Stratigraphy, ICS geologic timescale, the younger of two period (geology), subperiods of the Carboniferous Period (or the uppe ..., a geological subperiod of the Carboniferous Period * ''Pennsylvanian'' (train), an Amtrak train {{disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carboniferous Geochronology
The Carboniferous ( ) is a geologic period and system of the Paleozoic era that spans 60 million years, from the end of the Devonian Period Ma (million years ago) to the beginning of the Permian Period, Ma. It is the fifth and penultimate period of the Paleozoic era and the fifth period of the Phanerozoic eon (geology), eon. In North America, the Carboniferous is often treated as two separate geological periods, the earlier Mississippian (geology), Mississippian and the later Pennsylvanian (geology), Pennsylvanian. The name ''Carboniferous'' means "coal-bearing", from the Latin ("coal") and ("bear, carry"), and refers to the many coal beds formed globally during that time. The first of the modern "system" names, it was coined by geologists William Conybeare (geologist), William Conybeare and William Phillips (geologist), William Phillips in 1822, based on a study of the British rock succession. Carboniferous is the period during which both terrestrial animal and Embryophyte, l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cantabria
Cantabria (, ; ) is an autonomous community and Provinces of Spain, province in northern Spain with Santander, Cantabria, Santander as its capital city. It is called a , a Nationalities and regions of Spain, historic community, in its current Statute of Autonomy. It is bordered on the east by the Basque Country (autonomous community), Basque autonomous community (Biscay, province of Biscay), on the south by Castile and León (Province of León, provinces of León, Palencia (province), Palencia and Province of Burgos, Burgos), on the west by the Asturias, Principality of Asturias, and on the north by the Cantabrian Sea, which forms part of the Bay of Biscay. Cantabria belongs to ''Green Spain'', the name given to the strip of land between the Bay of Biscay and the Cantabrian Mountains, so called because of its particularly lush vegetation, due to the wet and temperate oceanic climate. The climate is strongly influenced by Atlantic Ocean winds trapped by the mountains; the averag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asturias
Asturias (; ; ) officially the Principality of Asturias, is an autonomous communities of Spain, autonomous community in northwest Spain. It is coextensive with the provinces of Spain, province of Asturias and contains some of the territory that was part of the larger Kingdom of Asturias in the Middle Ages. Divided into eight Comarcas of Asturias, ''comarcas'' (counties), the autonomous community of Asturias is bordered by Cantabria to the east, by Province of León, León (Castile and León) to the south, by Province of Lugo, Lugo (Galicia (Spain), Galicia) to the west, and by the Cantabrian Sea to the north. Asturias is situated in a mountainous setting with vast greenery and lush vegetation, making it part of Green Spain. The region has a oceanic climate, maritime climate. It receives plenty of annual rainfall and little sunshine by Spanish standards and has very moderate seasons, most often averaging in the lower 20s Celsius. Heat waves are rare due to mountains blocking s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saar–Nahe Basin
Saar–Nahe Basin is a molasse basin in southwest Germany. The basin is located south of the Hunsrück mountains between the rivers Nahe and the Saar. The aggregation of sediments in the basin started in the late Carboniferous and Early Permian as part of the Variscan orogeny The Variscan orogeny, or Hercynian orogeny, was a geologic mountain-building event caused by Late Paleozoic continental collision between Euramerica (Laurussia) and Gondwana to form the supercontinent of Pangaea. Nomenclature The name ''Varis .... See also * Saar-Nahe Hills Further reading * * * * * * * * * * * * * * * {{DEFAULTSORT:Saar-Nahe Basin Structural geology Sedimentology Geology of Germany Basins of Europe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Red Beds
Red beds (or redbeds) are sedimentary rocks, typically consisting of sandstone, siltstone, and shale, that are predominantly red in color due to the presence of ferric oxides. Frequently, these red-colored sedimentary strata locally contain thin beds of Conglomerate (geology), conglomerate, marl, limestone, or some combination of these sedimentary rocks. The ferric oxides, which are responsible for the red color of red beds, typically occur as a coating on the grains of sediments comprising red beds. Classic examples of red beds are the Permian and Triassic strata of the western United States and the Devonian Old Red Sandstone facies of Europe. Primary red beds Primary red beds may be formed by the erosion and redeposition of red soils or older red beds, but a fundamental problem with this hypothesis is the relative scarcity of red-colored source sediments of suitable age close to an area of red-bed sediments in Geology of Cheshire, Cheshire, England. Primary red beds may al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unconformity
An unconformity is a buried erosional or non-depositional surface separating two rock masses or strata of different ages, indicating that sediment deposition was not continuous. In general, the older layer was exposed to erosion for an interval of time before deposition of the younger layer, but the term is used to describe any break in the sedimentary geologic record. The significance of angular unconformity (see below) was shown by James Hutton, who found examples of Hutton's Unconformity at Jedburgh in 1787 and at Siccar Point in Berwickshire in 1788, both in Scotland. The rocks above an unconformity are younger than the rocks beneath (unless the sequence has been overturned). An unconformity represents time during which no sediments were preserved in a region or were subsequently eroded before the next deposition. The local record for that time interval is missing and geologists must use other clues to discover that part of the geologic history of that area. The interval ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gzhelian
The Gzhelian ( ) is an age in the ICS geologic time scale or a stage in the stratigraphic column. It is the youngest stage of the Pennsylvanian, the youngest subsystem of the Carboniferous. The Gzhelian lasted from to Ma. It follows the Kasimovian age/stage and is followed by the Asselian age/stage, the oldest subdivision of the Permian system. The Gzhelian is more or less coeval with the Stephanian Stage of the regional stratigraphy of Europe. Name and definition The Gzhelian is named after the Russian village of Gzhel (), nearby Ramenskoye, not far from Moscow. The name and type locality were defined by Sergei Nikitin (1851–1909) in 1890. The base of the Gzhelian is at the first appearance of the Fusulinida genera '' Daixina'', '' Jigulites'' and '' Rugosofusulina'', or at the first appearance of the conodont ''Streptognathodus zethus''. The top of the stage (the base of the Permian system) is at the first appearance of the conodont ''Streptognathodus isolat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kasimovian
The Kasimovian is a geochronologic age or chronostratigraphic stage in the ICS geologic timescale. It is the third stage in the Pennsylvanian (late Carboniferous), lasting from to Ma.; 2004: ''A Geologic Time Scale 2004'', Cambridge University Press. The Kasimovian Stage follows the Moscovian and is followed by the Gzhelian. The Kasimovian saw an extinction event which occurred around 305 mya, referred to as the Carboniferous Rainforest Collapse. It roughly corresponds to the Missourian in North American geochronology and the Stephanian in western European geochronology. Name and definition The Kasimovian is named after the Russian city of Kasimov. The stage was split from the Moscovian in 1926 by Boris Dan'shin (1891-1941), who gave it the name ''Teguliferina horizon''. The name was posthumously changed to ''Kasimov horizon'' by Dan'shin in 1947. The name Kasimovian was introduced by Georgy Teodorovich in 1949. The base of the Kasimovian Stage is at the base of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
