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Rio Grande Rise
The Rio Grande Rise, also called the Rio Grande Elevation or Bromley Plateau, is an aseismic ocean ridge in the southern Atlantic Ocean off the coast of Brazil. Together with the Walvis Ridge off Africa, the Rio Grande Rise forms a V-shaped structure of mirrored hotspot tracks or seamount chains across the northern South Atlantic. In 2013, Brazilian scientists announced that they found granite boulders on the Rio Grande Rise and speculated that it could be the remains of a submerged continent, which they called the "Brazilian Atlantis". Other researchers, however, noted that such boulders can end-up on the ocean floor by less speculative means. Brazil proposes the area as part of its continental shelf since December 2018, but it has yet to be approved by the Commission on the Limits of the Continental Shelf. It is far beyond the country's exclusive economic zone and would thus be part of its extended continental shelf. Geology The Rio Grande Rise separates the Santos and Campo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rio Grande Rise NOAA
Rio or Río is the Portuguese and Spanish word for "river". The word also exists in Italian, but is largely obsolete and used in a poetical or literary context to mean "stream". Rio, RIO or Río may also refer to: Places United States * Rio, Florida, a census-designated place * Rio, Georgia, an unincorporated community * Rio, Illinois, a village * Rio, a location in Deerpark, New York * Rio, Virginia, a community * Rio, West Virginia, a village * Rio, Wisconsin, a village * El Río, Las Piedras, Puerto Rico, a barrio Elsewhere * Rio de Janeiro, Brazil, often referred to as simply Rio * Rio, Italy, a municipality on the island of Elba in Tuscany * Rio, Greece, a community in suburban Patras People * Rio (given name) * Rio (surname) * Tina Yuzuki (born 1986), also known as Rio, Japanese AV idol Arts and entertainment Films * ''Rio'' (1939 film), starring Basil Rathbone * ''Rio'' (franchise), a film series and related media * ''Rio'' (2011 film), an animated film from 20t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Early Cretaceous
The Early Cretaceous (geochronology, geochronological name) or the Lower Cretaceous (chronostratigraphy, chronostratigraphic name) is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 143.1 Megaannum#SI prefix multipliers, Ma to 100.5 Ma. Geology Proposals for the exact age of the Barremian–Aptian boundary ranged from 126 to 117 Ma until recently (as of 2019), but based on drillholes in Svalbard the defining Anoxic event#Cretaceous, early Aptian Oceanic Anoxic Event 1a (OAE1a) was dated to 123.1±0.3 Ma, limiting the possible range for the boundary to c. 122–121 Ma. There is a possible link between this anoxic event and a series of Early Cretaceous large igneous provinces (LIP). The Ontong Java Plateau, Ontong Java-Manihiki Plateau, Manihiki-Hikurangi Plateau, Hikurangi large igneous province, emplaced in the South Pacific at c. 120 Ma, is by far the largest LIP in Earth's history. The Onto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lavocatavis
''Lavocatavis'' is an extinct genus of prehistoric bird from the Eocene of Algeria. A fossilized femur was described from the Glib Zegdou Formation in 2011 and is the only known specimen of ''Lavocatavis''. The species was designated ''L. africana''. Discovery and naming The holotype of ''Lavocatavis'', UM HGL 51-55, consists of an almost complete right femur. It is reasonably well preserved in the middle, but fragmentary at both ends. It originates from layer HGL 51 of the Glib Zegdou Formation of Algeria. The generic epithet (meaning "Lavocat's bird") was named in honor of René Lavocat, the person who first reported the earth layer of the holotype. Paleobiogeography The oldest phorusrhacids are from South America and Antarctica, so if this genus were indeed a phorusrhacid, the ancestors of ''Lavocatavis'' might have migrated into Africa from the west. During the Eocene, the Atlantic Ocean separated South America from Africa by at least , ruling out a land migration. For a f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jan Mayen
Jan Mayen () is a Norway, Norwegian volcanic island in the Arctic Ocean with no permanent population. It is long (southwest-northeast) and in area, partly covered by glaciers (an area of around the Beerenberg volcano). It has two parts: larger northeast Nord-Jan and smaller Sør-Jan, linked by a wide isthmus. It lies northeast of Iceland (495 km [305 mi] NE of Kolbeinsey), east of central Greenland, and northwest of Vesterålen, Norway. The island is mountainous, the highest summit being the Beerenberg volcano in the north. The isthmus is the location of the two largest lakes of the island, Sørlaguna (South Lagoon) and Nordlaguna (North Lagoon). A third lake is called Ullerenglaguna (Ullereng Lagoon). Jan Mayen was formed by the Jan Mayen hotspot and is defined by geologists as a Continental fragment, microcontinent. Although administered separately, in the ISO 3166-1 standard, Jan Mayen and Svalbard are collectively designated as ''Svalbard and Jan Mayen'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kerguelen
The Kerguelen Islands ( or ; in French commonly ' but officially ', ), also known as the Desolation Islands (' in French), are a group of islands in the sub-Antarctic region. They are among the most isolated places on Earth, with the closest territory being the Heard Island and McDonald Islands territory of Australia located at roughly , and the nearest inhabited territory being Madagascar at more than in distance. The islands, along with Adélie Land, the Crozet Islands, Amsterdam and Saint Paul islands, and France's Scattered Islands in the Indian Ocean, are part of the French Southern and Antarctic Lands and are administered as a separate district. The islands constitute one of the two exposed parts of the Kerguelen Plateau (the other being Heard Island and the McDonald islands), a large igneous province mostly submerged in the southern Indian Ocean. The main island, Grande Terre, is in area, about three-quarters of the size of Corsica, and is surrounded by a further 300 s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Micro-continent
Continental crustal fragments, partly synonymous with microcontinents, are pieces of continents that have broken off from main continental masses to form distinct islands that are often several hundred kilometers from their place of origin. Causes Continental fragments and microcontinent crustal compositions are very similar to those of regular continental crust. The rifting process that caused the continental fragments to form most likely impacts their layers and overall thickness along with the addition of mafic intrusions to the crust. Studies have determined that the average crustal thickness of continental fragments is approximately . The sedimentary layer of continental fragments can be up to thick and can overlay two to three crustal layers. Continental fragments have an average crustal density of which is very similar to that of typical continental crust. Strike-slip fault zones cause the fragmentation of microcontinents. The zones link the extensional zones where co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maastrichtian
The Maastrichtian ( ) is, in the International Commission on Stratigraphy (ICS) geologic timescale, the latest age (geology), age (uppermost stage (stratigraphy), stage) of the Late Cretaceous epoch (geology), Epoch or Upper Cretaceous series (stratigraphy), Series, the Cretaceous geologic period, Period or system (stratigraphy), System, and of the Mesozoic geologic era, Era or Erathem. It spanned the interval from . The Maastrichtian was preceded by the Campanian and succeeded by the Danian (part of the Paleogene and Paleocene). It is named after the city of Maastricht, the capital and largest city of the Limburg (Netherlands), Limburg province in the Netherlands. The Cretaceous–Paleogene extinction event (formerly known as the Cretaceous–Tertiary period, Tertiary extinction event) occurred at the end of this age. In this extinction event, mass extinction, many commonly recognized groups such as non-avian dinosaurs, plesiosaurs and mosasaurs, as well as many other lesser-kn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gough Island
Gough Island ( ), also known historically as Gonçalo Álvares, is a rugged volcanic island in the South Atlantic Ocean. It is a dependency of Tristan da Cunha and part of the British overseas territory of Saint Helena, Ascension and Tristan da Cunha. It is approximately south-east of the Tristan da Cunha archipelago (which includes Nightingale Island and Inaccessible Island), north-east from South Georgia Island, west from Cape Town, and over from the nearest point of South America. Gough Island is uninhabited, except for the personnel of a weather station (usually six people) that the South African National Antarctic Programme has maintained, with British permission, continually on the island since 1956. It is one of the most remote places with a constant human presence. It is part of the UNESCO World Heritage Site of "Gough and Inaccessible Island". It is one of the most important seabird colonies in the world. Name The island was first named ''Ilha de Gonçalo Álv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tristan Da Cunha
Tristan da Cunha (), colloquially Tristan, is a remote group of volcano, volcanic islands in the South Atlantic Ocean. It is one of three constituent parts of the British Overseas Territories, British Overseas Territory of Saint Helena, Ascension and Tristan da Cunha, with its own constitution. The territory consists of the inhabited island Tristan da Cunha, which has a diameter of roughly and an area of ; the wildlife reserves of Gough Island and Inaccessible Island; and the smaller, uninhabited Nightingale Islands. , the main island had 250 permanent inhabitants, who all carry British Overseas Territories citizenship. The other islands are uninhabited, except for the South African personnel of a weather station on Gough Island. As there is no airstrip on the island, the only way of travelling to or from Tristan is by ship. There are six-day journeys from Cape Town, South Africa, and some cruises offered departing from Ushuaia, Argentina. History Discovery The islan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mid-Atlantic Ridge
The Mid-Atlantic Ridge is a mid-ocean ridge (a Divergent boundary, divergent or constructive Plate tectonics, plate boundary) located along the floor of the Atlantic Ocean, and part of the List of longest mountain chains on Earth, longest mountain range in the world. In the North Atlantic, the ridge separates the North American plate, North American from the Eurasian plate and the African plate, north and south of the Azores triple junction. In the South Atlantic, it separates the African plate, African and South American plate, South American plates. The ridge extends from a junction with the Gakkel Ridge (Mid-Arctic Ridge) northeast of Greenland southward to the Bouvet triple junction in the South Atlantic. Although the Mid-Atlantic Ridge is mostly an underwater feature, portions of it have enough elevation to extend above sea level, for example in Iceland. The ridge has an average spreading rate of about per year. Discovery A ridge under the northern Atlantic Ocean was first ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tristan Hotspot
The Tristan hotspot is a volcanic hotspot which is responsible for the volcanic activity which forms the volcanoes in the southern Atlantic Ocean. It is thought to have formed the island of Tristan da Cunha and the Walvis Ridge on the African Plate. Geology It is also believed to be closely connected with the Paraná and Etendeka flood basalt provinces, which formed over the hotspot during the opening of the South Atlantic Ocean. The Tristan and Gough hotspots are widely spaced end-members of the volcanic system that generated the Walvis Ridge on the African plate and the Rio Grande Rise on the South American plate beginning at when the Paraná and Etendeka traps formed. Whether or not Tristan and Gough represent two distinct volcanic centers is still debated. argued that the Walvis Ridge is not the product of a deep mantle plume or the Tristan hotspot, but that changes in the internal stress in the spreading African and South American plates trigger changes in the magm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Namibia
Namibia, officially the Republic of Namibia, is a country on the west coast of Southern Africa. Its borders include the Atlantic Ocean to the west, Angola and Zambia to the north, Botswana to the east and South Africa to the south; in the northeast, approximating a quadripoint, Zimbabwe lies less than 200 metres (660 feet) away along the Zambezi, Zambezi River near Kazungula, Zambia. Namibia's capital and largest city is Windhoek. Namibia is the driest country in sub-Saharan Africa, and has been inhabited since prehistoric times by the Khoekhoe, Khoi, San people, San, Damara people, Damara and Nama people. Around the 14th century, immigration, immigrating Bantu peoples arrived as part of the Bantu expansion. From 1600 the Ovambo people#History, Ovambo formed kingdoms, such as Ondonga and Oukwanyama. In 1884, the German Empire established rule over most of the territory, forming a colony known as German South West Africa. Between 1904 and 1908, German troops waged a punitive ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
