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Frasnian Stage
The Frasnian is one of two faunal stages in the Late Devonian Period. It lasted from million years ago to million years ago. It was preceded by the Givetian Stage and followed by the Famennian Stage. Major reef-building was under way during the Frasnian Stage, particularly in western Canada and Australia. On land, the first forests were taking shape. In North America, the Antler orogeny peaked, which were contemporary with the Bretonic phase of the Variscan orogeny in Europe. The Frasnian coincides with the second half of the "charcoal gap" in the fossil record, a time when atmospheric oxygen levels were below 13 percent, the minimum necessary to sustain wildfires. North American subdivisions of the Frasnian include * West Falls Group * Sonyea Group * Genesee Group Name and definition The Frasnian Stage was proposed in 1879 by French geologist Jules Gosselet and was accepted for the lower stage of the Upper Devonian by the Subcommission on Devonian Stratigraphy in 19 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Commission On Stratigraphy
The International Commission on Stratigraphy (ICS), sometimes unofficially referred to as the International Stratigraphic Commission, is a daughter or major subcommittee grade scientific organization that concerns itself with stratigraphy, stratigraphical, geology, geological, and chronology, geochronological matters, worldwide. 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 Section and Points ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Famennian
The Famennian is the later of two faunal stages in the Late Devonian epoch. The most recent estimate for its duration is that it lasted from around 371.1 to 359.3 million years ago. An earlier 2012 estimate, still used by the International Commission on Stratigraphy, is that it lasted from million years ago to million years ago. It was preceded by the Frasnian stage and followed by the Tournaisian stage. Major events In the seas, a novel major group of ammonoid cephalopods called clymeniids appeared, underwent tremendous diversification and spread worldwide, then just as suddenly went extinct. The beginning of the Famennian is marked by the final stages of a major extinction event, the Kellwasser Event, which is the largest component of the Late Devonian mass extinction. The end of the Famennian experiences a smaller but still quite severe extinction event, the Hangenberg Event. A brief episode of glaciation, possibly linked to the Hangenberg event, occurred during the l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Couvin
Couvin (; ) is a municipality and city of Wallonia located in the province of Namur, Belgium. On 1 January 2018 the municipality had 13,782 inhabitants. Couvin is the second largest municipality of Belgium by surface area, after Tournai. The total area is , giving a population density of . The municipality consists of the following districts: Aublain, Boussu-en-Fagne, Brûly, Brûly-de-Pesche, Couvin, Cul-des-Sarts, Dailly, Frasnes-lez-Couvin, Gonrieux, Mariembourg, Pesche, Petigny, Petite-Chapelle, and Presgaux. Transport Couvin railway station provides the town with a rail link direct to Charleroi. The line terminates here; the next station is Mariembourg. Tourism There are a number of sites of interest to tourists in the municipality. One end of the Chemin de Fer à vapeur des Trois Vallées heritage railway is at Mariembourg. The ''Brasserie des Fagnes'' brewery is also situated there. Caves in the area include the Trou de l’Abîme and the Neptune Ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jules Gosselet
Jules-Auguste Gosselet (19 April 1832 – 20 March 1916) was a French geologist born in Cambrai, France.Prix Gosselet - Société géologique de France (biography) Following unsuccessful studies of , and a stint as a teacher at the Lycée du Quesnoy, he pursued a career in . In 1853 he became a preparateur of [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genesee Group
The Genesee Formation (Group) is a geologic formation in New York. It is equivalent the Harrell Shale in Pennsylvania. It dates back to the Upper Devonian period. It is the basal unit of the Frasnian and Upper Devonian period. The Genesee Formation was defined by de Witt and Colton, 1959 as all strata between the Middlesex Unit of the Sonyea Group and the Tully Formation, where present or the Moscow Formation where the Tully is not present. Description The Genesee includes several members. Moving westward towards the Findley and Cincinnati Archs the formation thins to less than 9 feet. To the east it feathers in with coarser grained formations. Stratigraphy The Genesee has several members. With coarser clastic material coming mostly from the east there are several members that are feathered to the West River and Penn Yann on the eastern flanks. Below are listed the units found within the Genesee. West River Shale Member Clarke and Luther (1904, p. 28) coined ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sonyea Group
The Sonyea Group is a geologic group in the northern part of the Appalachian Basin. It preserves fossils dating back to the Devonian period. In the western part, it is divided into the Cashaqua Shale at the top, and the Middlesex Shale at the bottom. In the east, various shale formations are included between the Cashaqua and Middlesex members, including Rye Point Shale, Rock Stream Formation ("Enfield Formation The Enfield Formation is a Formation (stratigraphy), geologic formation in New York (state), New York. It preserves fossils dating back to the Devonian Period (geology), period. See also * List of fossiliferous stratigraphic units in New York R ...") Siltstone, Pulteney shale, Sawmill Creek Shale, Johns Creek Shale and Montour Shale. See also * List of fossiliferous stratigraphic units in Pennsylvania * Paleontology in Pennsylvania References * * Geologic groups of Pennsylvania Devonian Pennsylvania Devonian geology of New York (state) Shale form ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
West Falls Group
The West Falls Group is a geologic group in the Appalachian Basin. It dates back to the Devonian period. Also stratigraphically equivalent to the Portage Group. Description Stratigraphy The West Falls Group is a geologic group in New York. It dates back to the Devonian period. Also stratigraphically equivalent to the Portage Group. The West Falls formation is bounded above by the Java Formation and below by the Sonyea Formation. It comprises the Angola Shale and Rhinestreet Shale Members. It was deposited during the Acadian Orogeny and is part of the Salina thrust sheet. Also known as the West Falls Formation in New York. Geographic distribution The West Falls is recognized in the subsurface from western New York to eastern Tennessee. Lithology The predominant lithology of the West Falls Group is shale. The Rhinestreet Member can be further subdivided into two shale types: a thick, fissile black shale underlies a gray to greenish-gray shale that likely indicates a transi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Europe
Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east. Europe shares the landmass of Eurasia with Asia, and of Afro-Eurasia with both Africa and Asia. Europe is commonly considered to be Boundaries between the continents#Asia and Europe, separated from Asia by the Drainage divide, watershed of the Ural Mountains, the Ural (river), Ural River, the Caspian Sea, the Greater Caucasus, the Black Sea, and the waterway of the Bosporus, Bosporus Strait. "Europe" (pp. 68–69); "Asia" (pp. 90–91): "A commonly accepted division between Asia and Europe ... is formed by the Ural Mountains, Ural River, Caspian Sea, Caucasus Mountains, and the Black Sea with its outlets, the Bosporus and Dardanelles." Europe covers approx. , or 2% of Earth#Surface, Earth's surface (6.8% of Earth's land area), making it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 ''Variscan'' comes from the Medieval Latin name for the district '' Variscia'', the home of a Germanic tribe, the Varisci; Eduard Suess, professor of geology at the University of Vienna, coined the term in 1880. ( Variscite, a rare green mineral first discovered in the Vogtland district of Saxony in Germany, which is in the Variscan belt, has the same etymology.) ''Hercynian'', on the other hand, derives from the Hercynian Forest. Both words were descriptive terms of strike directions observed by geologists in the field, ''variscan'' for southwest to northeast, ''hercynian'' for northwest to southeast. The ''variscan'' direction reflected the direction of ancient fold belts cropping out throughout Germany and adjacent countries and the meanin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
North America
North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Caribbean Sea, and to the south and west by the Pacific Ocean. The region includes Middle America (Americas), Middle America (comprising the Caribbean, Central America, and Mexico) and Northern America. North America covers an area of about , representing approximately 16.5% of Earth's land area and 4.8% of its total surface area. It is the third-largest continent by size after Asia and Africa, and the list of continents and continental subregions by population, fourth-largest continent by population after Asia, Africa, and Europe. , North America's population was estimated as over 592 million people in list of sovereign states and dependent territories in North America, 23 independent states, or about 7.5% of the world's popula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
