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Miliamellus
''Miliamellus'' is a genus of Cenozoic benthic foraminifera with tests made of imperforate opaline silica. It is the only genus in the order Silicoloculinida and the family Silicoloculinidae. It is sometimes referred to by the junior synonym ''Silicoloculina''. The family Silicoloculinidae, named by Resig, ''et al.'', 1980, is characterized by tests that resemble those of the imperforate calcareous Miliolidae, or the finely agglutinated Rzehakinidae in which chambers are about half a coil in length and arranged in various planes. Resig et al. named the genus ''Silicoloculina'' for specimens recovered from below the carbonate compensation depth in the Scotia Sea and the Peru-Chile Trench. Loeblich and Tappan synonymised this genus with ''Miliamellus'' in 1987. ''Miliammellus'', named by Saidova and Burmistrova, 1978, has a small ovoid test, up to 0.5 mm long with chambers arranged as in the miliolid '' Quinqueloculina''. Chambers are slightly more than half a coil in l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Miocene
The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recent" because it has 18% fewer modern marine invertebrates than the Pliocene has. The Miocene is preceded by the Oligocene and is followed by the Pliocene. As Earth went from the Oligocene through the Miocene and into the Pliocene, the climate slowly cooled towards a series of ice ages. The Miocene boundaries are not marked by a single distinct global event but consist rather of regionally defined boundaries between the warmer Oligocene and the cooler Pliocene Epoch. During the Early Miocene, the Arabian Peninsula collided with Eurasia, severing the connection between the Mediterranean and Indian Ocean, and allowing a faunal interchange to occur between Eurasia and Africa, including the dispersal of proboscideans into Eurasia. During the la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scotia Sea
The Scotia Sea is a sea located at the northern edge of the Southern Ocean at its boundary with the South Atlantic Ocean. It is bounded on the west by the Drake Passage and on the north, east, and south by the Scotia Arc, an undersea ridge and island arc system supporting various islands. The sea sits atop the Scotia Plate. It is named after the expedition ship Scotia (barque), ''Scotia''. Many icebergs melt there. Location and description The Scotia Sea is the area of water between the Drake Passage, Tierra del Fuego, South Georgia Island, South Georgia, the South Sandwich Islands, the South Orkney Islands, and the Antarctic Peninsula. These island groups all sit atop the Scotia Arc, which frames the sea on the north, east, and south. The Scotia Sea covers an area around . About half of the sea stands above the continental shelf. History The sea was named about 1932 after the ''Scotia (barque), Scotia'', the expedition ship used in these waters by the Scottish National Antarcti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Foraminifera Orders
Foraminifera (; Latin for "hole bearers"; informally called "forams") are single-celled organisms, members of a phylum or class of amoeboid protists characterized by streaming granular ectoplasm for catching food and other uses; and commonly an external shell (called a "test") of diverse forms and materials. Tests of chitin (found in some simple genera, and Textularia in particular) are believed to be the most primitive type. Most foraminifera are marine, the majority of which live on or within the seafloor sediment (i.e., are benthic), while a smaller number float in the water column at various depths (i.e., are planktonic), which belong to the suborder Globigerinina. Fewer are known from freshwater or brackish conditions, and some very few (nonaquatic) soil species have been identified through molecular analysis of small subunit ribosomal DNA. Foraminifera typically produce a test, or shell, which can have either one or multiple chambers, some becoming quite elaborate in struc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Miocene Life
The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recent" because it has 18% fewer modern marine invertebrates than the Pliocene has. The Miocene is preceded by the Oligocene and is followed by the Pliocene. As Earth went from the Oligocene through the Miocene and into the Pliocene, the climate slowly cooled towards a series of ice ages. The Miocene boundaries are not marked by a single distinct global event but consist rather of regionally defined boundaries between the warmer Oligocene and the cooler Pliocene Epoch. During the Early Miocene, the Arabian Peninsula collided with Eurasia, severing the connection between the Mediterranean and Indian Ocean, and allowing a faunal interchange to occur between Eurasia and Africa, including the dispersal of proboscideans into Eurasia. During the late ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helen Niña Tappan Loeblich
Helen Niña Tappan Loeblich (October 12, 1917 – August 18, 2004) was an American micropaleontologist who was a professor of geology at the University of California, Los Angeles, a United States Geological Survey (USGS) biostratigrapher, and a scientific illustrator whose micropaleontology specialty was research on Cretaceous foraminifera. Early life Dr Helen Nina Tappan Leoblich was born on October 12, 1917, in Norman, Oklahoma. She came from a well-educated background. Her mother Mary Pearl Jenks Tappan was a math teacher at Cornell, and her father, Frank Girard Tappan, was a Dean of Electrical Engineering at the University of Oklahoma. Education Tappan Loeblich earned her BS in 1937 and her Master's in 1939, both in geology from the University of Oklahoma. Her master's thesis was on mid-Cretaceous foraminifera of Oklahoma and Texas. At the University of Oklahoma, she met her future husband and long time scientific collaborator, Alfred R. Loeblich Jr, in c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calcite
Calcite is a carbonate mineral and the most stable polymorph of calcium carbonate (CaCO3). It is a very common mineral, particularly as a component of limestone. Calcite defines hardness 3 on the Mohs scale of mineral hardness, based on scratch hardness comparison. Large calcite crystals are used in optical equipment, and limestone composed mostly of calcite has numerous uses. Other polymorphs of calcium carbonate are the minerals aragonite and vaterite. Aragonite will change to calcite over timescales of days or less at temperatures exceeding 300 °C, and vaterite is even less stable. Etymology Calcite is derived from the German ''Calcit'', a term from the 19th century that came from the Latin word for lime, ''calx'' (genitive calcis) with the suffix "-ite" used to name minerals. It is thus etymologically related to chalk. When applied by archaeologists and stone trade professionals, the term alabaster is used not just as in geology and mineralogy, where it is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Miliolida
The Miliolida are an order of foraminifera with calcareous, porcelacous tests that are imperforate and commonly have a pseudochitinous lining. Tests are composed of randomly oriented calcite needles that have a high proportion of magnesium along with organic material. Tests lack pores and generally have multiple chambers. Miliolids, which range from the Carboniferous to recent, are benthic Foraminifera abundant in shallow waters such as in estuaries An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environme ... and along coastlines, though they also include deepwater oceanic forms. The order Miliolida, sometimes referred to as a suborder, the Miliolina, is divided on the basis of differences in test morphology into five recognized superfamilies. References * External links * Tubot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quinqueloculina
''Quinqueloculina'' is a genus of foraminifera in the family Miliolidae. As with all miliolids the test of ''Quinqueloculina'' is composed of imperforate, porcelaneous calcite, often giving them a yellowish tint. As with the Miliolidae, the chambers are arranged in various planes, with two chambers per whorl. In ''Quinqueloculins'' the chambers are in planes set 72 degrees apart, but successive chambers are in planes separated by 144 degrees. The name ''Quinqueloculina'' comes from ''quinque'', the Latin for five. In ''Quinqueloculina'' five chambers are exposed to view on the outside, although the earlier three are sandwiched between the later two, one on one side, two on the other. Chambers are generally long and tubular, normally without integral floors, that function made by the underlying chamber. Some 30 or more species of ''Quinqueloculina'' have been named. ''Quinqueloculina'' is found in abundance around the coasts of the UK. High concentrations of one species of ''Qu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helen Tappan
Helen may refer to: People * Helen of Troy, in Greek mythology, the most beautiful woman in the world * Helen (actress) (born 1938), Indian actress * Helen (given name), a given name (including a list of people with the name) Places * Helen, Georgia, United States, a small city * Helen, Maryland, United States, an unincorporated place * Helen, Washington, an unincorporated community in Washington state, US * Helen, West Virginia, a census-designated place in Raleigh County * Helen Falls, a waterfall in Ontario, Canada * Lake Helen (other), several places called Helen Lake or Lake Helen * Helen, an ancient name of Makronisos island, Greece * The Hellenic Republic, Greece Arts, entertainment, and media * ''Helen'' (album), a 1981 Grammy-nominated album by Helen Humes * ''Helen'' (2008 film), a British drama starring Annie Townsend * ''Helen'' (2009 film), an American drama film starring Ashley Judd * ''Helen'' (2017 film), an Iranian drama film * ''Helen'' (2019 fi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alfred R
Alfred may refer to: Arts and entertainment *'' Alfred J. Kwak'', Dutch-German-Japanese anime television series * ''Alfred'' (Arne opera), a 1740 masque by Thomas Arne * ''Alfred'' (Dvořák), an 1870 opera by Antonín Dvořák *"Alfred (Interlude)" and "Alfred (Outro)", songs by Eminem from the 2020 album '' Music to Be Murdered By'' Business and organisations * Alfred, a radio station in Shaftesbury, England * Alfred Music, an American music publisher * Alfred University, New York, U.S. * The Alfred Hospital, a hospital in Melbourne, Australia People * Alfred (name) includes a list of people and fictional characters called Alfred * Alfred the Great (848/49 – 899), or Alfred I, a king of the West Saxons and of the Anglo-Saxons Places Antarctica * Mount Alfred (Antarctica) Australia * Alfredtown, New South Wales * County of Alfred, South Australia Canada * Alfred and Plantagenet, Ontario * Alfred Island, Nunavut * Mount Alfred, British Columbia United States * A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peru–Chile Trench
The Peru–Chile Trench, also known as the Atacama Trench, is an oceanic trench in the eastern Pacific Ocean, about off the coast of Peru and Chile. It reaches a maximum depth of below sea level in Richards Deep () and is approximately long; its mean width is and it covers an expanse of some . The trench delineates the boundary between the subducting Nazca Plate and the overriding South American Plate. Geology The trench is a result of a convergent plate boundary, where the eastern edge of the oceanic Nazca Plate is being subducted beneath the continental South American Plate. The trench is also a part of the Chile Triple Junction, an unusual junction that consists of a mid-oceanic ridge and the Chile Rise being subducted under the South American plate at the Peru-Chile Trench. Two seamount ridges within the Nazca Plate enter the subduction zone along this trench: the Nazca Ridge and the Juan Fernández Ridge. From the Chile Triple Junction to Juan Fernández R ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbonate Compensation Depth
Carbonate compensation depth (CCD) is the depth in the oceans below which the rate of supply of calcite ( calcium carbonate) lags behind the rate of solvation, such that no calcite is preserved. Shells of animals therefore dissolve and carbonate particles may not accumulate in the sediments on the sea floor below this depth. Aragonite compensation depth (hence ACD) describes the same behaviour in reference to aragonitic carbonates. Aragonite is more soluble than calcite, so the aragonite compensation depth is generally shallower than the calcite compensation depth. Overview As shown in the diagram, biogenic calcium carbonate (CaCO3) tests are produced in the photic zone of the oceans (green circles). Upon death, those tests escaping dissolution near the surface, settle along with clays materials. In seawater, a dissolution boundary is formed as a result of temperature, pressure, and depth, and is known as the ''saturation horizon''. Above the saturation horizon, waters are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
