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Ouki
Ouki was an ancient lake in the Bolivian Altiplano. Its existence was postulated in 2006 by a group of scientists which had subdivided the Lake Minchin lake cycle in several subcycles. The Lake Minchin cycle had been previously identified in 1904 as a now disappeared lake in the central Altiplano. Sediments attributed to Lake Minchin may be part of Ouki instead. The dating is uncertain, with radiocarbon and uranium-thorium dating yielding different dates spanning the time between 28,200 and 125,990 ± 9,580 years ago. Whether Ouki existed is a subject of controversy. In 2011, scientists claimed that the lake did not exist outside of the Lake Poopo basin. The formation of Ouki is associated with a major glaciation and was probably caused by increased precipitation, which has also been observed elsewhere. General characteristics Ouki reached a water level of approximately with preserved shorelines at Lake Poopó, and it may have covered the Salar de Uyuni, the Salar de Coipasa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lake Tauca
Lake Tauca is a former lake in the Altiplano of Bolivia. It is also known as Lake Pocoyu for its constituent lakes: Lake Poopó, Salar de Coipasa and Salar de Uyuni. The lake covered large parts of the southern Altiplano between the Eastern Cordillera and the Western Cordillera, covering an estimated of the basins of present-day Lake Poopó and the Salars of Uyuni, Coipasa and adjacent basins. Water levels varied, possibly reaching in altitude. The lake was saline. The lake received water from Lake Titicaca, but whether this contributed most of Tauca's water or only a small amount is controversial; the quantity was sufficient to influence the local climate and depress the underlying terrain with its weight. Diatoms, plants and animals developed in the lake, sometimes forming reef knolls. The duration of Lake Tauca's existence is uncertain. Research in 2011 indicated that the rise in lake levels began 18,500 BP, peaking 16,000 and 14,500 years ago. About 14,200 years ago, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lake Minchin
Lake Minchin is a name of an ancient lake in the Altiplano of South America. It existed where today the Salar de Uyuni, Salar de Coipasa and Lake Poopó lie. It was formerly considered the highest lake in the Altiplano but research indicated that the highest shoreline belongs to the later Lake Tauca instead. The concept of a "Lake Minchin" was first coined in 1906 and the name is based on John B. Minchin. The dating of the lake varies but probably lasted until 22,000 – 21,000 BP. A glacier advance was in progress in the Andes during that time period. The name "Minchin" has also been used in other contexts, and it has been proposed that the lake was actually a combination of several different paleolakes. Definition The name "Lake Minchin" has been used inconsistently to refer to either a lake existing 45,000 years ago, the highest lake in the Altiplano, or to sediment formations. This confusion has led to calls to drop the usage of the name "Minchin". An alternative theor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lake Titicaca
Lake Titicaca (; es, Lago Titicaca ; qu, Titiqaqa Qucha) is a large freshwater lake in the Andes mountains on the border of Bolivia and Peru. It is often called the highest navigable lake in the world. By volume of water and by surface area, it is also the largest lake in South America.Grove, M. J., P. A. Baker, S. L. Cross, C. A. Rigsby and G. O. Seltzer 2003 Application of Strontium Isotopes to Understanding the Hydrology and Paleohydrology of the Altiplano, Bolivia-Peru. ''Palaeogeography, Palaeoclimatology, Palaeoecology'' 194:281-297. Lake Titicaca has a surface elevation of . The "highest lake" claim is generally considered to refer to commercial craft. Numerous smaller bodies of water (that are not considered lakes) around the world are at higher elevations. For many years, the largest vessel afloat on the lake was the 2,200-ton (2,425 U.S. tons), SS ''Ollanta''. Today, the largest vessel is most likely the similarly sized train barge/float '' Manco Capac'', operate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lake Poopó
__NOTOC__ Lake Poopó ( es, Lago Poopó ) was a large saline lake in a shallow depression in the Altiplano Mountains in Oruro Department, Bolivia, at an altitude of approximately . Because the lake was long and wide (), it made up the eastern half of the department, known as a mining region in southwest Bolivia. The permanent part of the lake body covered approximately and it was the second-largest lake in the country. The lake received most of its water from the Desaguadero River, which flows from Lake Titicaca at the north end of the Altiplano. Since the lake lacked any major outlet and had a mean depth of less than , the surface area differed greatly seasonally. In 2002 the lake was designated as a site for conservation under the Ramsar Convention. By December 2015, the lake had completely dried up, leaving only a few marshy areas. Although the lake has dried up completely twice in the past, it does not appear that it will recover this time. Suggested causes of the decli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salar De Uyuni
Salar de Uyuni (or "Salar de Tunupa") is the world's largest salt flat, or playa, at over in area. It is in the Daniel Campos Province in Potosí in southwest Bolivia, near the crest of the Andes at an elevation of above sea level. The Salar was formed as a result of transformations between several prehistoric lakes that existed around forty thousand years ago but had all evaporated over time. It is now covered by a few meters of salt crust, which has an extraordinary flatness with the average elevation variations within one meter over the entire area of the Salar. The crust serves as a source of salt and covers a pool of brine, which is exceptionally rich in lithium. The large area, clear skies, and exceptional flatness of the surface make the Salar ideal for calibrating the altimeters of Earth observation satellites. Following rain, a thin layer of dead calm water transforms the flat into the world's largest mirror, across. The Salar serves as the major transport route ac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salar De Coipasa
__NOTOC__ Lago Coipasa or Salar de Coipasa is a lake in Sabaya Province, Oruro Department, Bolivia. At an elevation of 3657 m, its surface area is 806 km². It is on the western part of Altiplano, 20 km north of Salar de Uyuni and south of the main road linking Oruro and Huara (Chile). Lake Coipasa is a tectonic saline lake with a depth of 3.5 metres that is surrounded by the Coipasa salt flat (''Salar de Coipasa''), and the volcanic cone of Wila Pukarani. Thousands of flamingos have settled on the shores of Lake Coipasa. Gallery Coipasa lake map of the shape and depth (bathymetry) 2020.jpg, Map of the shape and depth (bathymetry) of the Coipasa lake, 2020 Lago Uru Uru Chipaya 4.jpg, The lake Poblacion Chipaya.jpg, The village of Chipaya, Oruro, Bolivia, near the lake See also * Chipaya * Ouki Ouki was an ancient lake in the Bolivian Altiplano. Its existence was postulated in 2006 by a group of scientists which had subdivided the Lake Minchin lake cycle in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Altiplano
The Altiplano (Spanish for "high plain"), Collao ( Quechua and Aymara: Qullaw, meaning "place of the Qulla") or Andean Plateau, in west-central South America, is the most extensive high plateau on Earth outside Tibet. The plateau is located at the latitude of the widest part of the north-south-trending Andes. The bulk of the Altiplano lies in Bolivia, but its northern parts lie in Peru, and its southwestern fringes lie in Chile. There are on the plateau several cities in each of these three nations, including El Alto, La Paz, Oruro, and Puno. The northeastern part of the Altiplano is more humid than the southwestern part, which has several salares (salt flats), due to its aridity. At the Bolivia–Peru border lies Lake Titicaca, the largest lake in South America. Farther south, in Bolivia, there was until recently a lake, Lake Poopó, but by December 2015 it had completely dried up, and was declared defunct. It is unclear whether that lake, which had been the second-large ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Smectite
A smectite (from ancient Greek ''σμηκτός'' smektos 'lubricated'; ''σμηκτρίς'' smektris 'walker's earth', 'fuller's earth'; rubbing earth; earth that has the property of cleaning) is a mineral mixtures of various swelling sheet silicates (phyllosilicates), which have a three-layer 2:1 (TOT) structure and belong to the clay minerals. Smectites mainly consist of montmorillonite, but can often contain secondary minerals such as quartz and calcite. Terminology In clay mineralogy, smectite is synonym of montmorillonite (also the name of a pure clay mineral phase) to indicate a class of swelling clays. The term smectite is commonly used in Europe and in the UK while the term montmorillonite is preferred in North America, but both terms are equivalent and can be used interchangeably. For industrial and commercial applications, the term bentonite is mostly used in place of smectite or montmorillonite. Mineralogical structure The 2:1 layer (TOT) structure consists of tw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyroxene
The pyroxenes (commonly abbreviated to ''Px'') are a group of important rock-forming inosilicate minerals found in many igneous and metamorphic rocks. Pyroxenes have the general formula , where X represents calcium (Ca), sodium (Na), iron (Fe II) or magnesium (Mg) and more rarely zinc, manganese or lithium, and Y represents ions of smaller size, such as chromium (Cr), aluminium (Al), magnesium (Mg), cobalt (Co), manganese (Mn), scandium (Sc), titanium (Ti), vanadium (V) or even iron (Fe II) or (Fe III). Although aluminium substitutes extensively for silicon in silicates such as feldspars and amphiboles, the substitution occurs only to a limited extent in most pyroxenes. They share a common structure consisting of single chains of silica tetrahedra. Pyroxenes that crystallize in the monoclinic system are known as clinopyroxenes and those that crystallize in the orthorhombic system are known as orthopyroxenes. The name ''pyroxene'' is derived from the Ancient Greek words for 'fire' ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quartz
Quartz is a hard, crystalline mineral composed of silica ( silicon dioxide). The atoms are linked in a continuous framework of SiO4 silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical formula of SiO2. Quartz is the second most abundant mineral in Earth's continental crust, behind feldspar. Quartz exists in two forms, the normal α-quartz and the high-temperature β-quartz, both of which are chiral. The transformation from α-quartz to β-quartz takes place abruptly at . Since the transformation is accompanied by a significant change in volume, it can easily induce microfracturing of ceramics or rocks passing through this temperature threshold. There are many different varieties of quartz, several of which are classified as gemstones. Since antiquity, varieties of quartz have been the most commonly used minerals in the making of jewelry and hardstone carvings, especially in Eurasia. Quartz is the mineral definin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiometric
Radiometry is a set of techniques for measuring electromagnetic radiation, including visible light. Radiometric techniques in optics characterize the distribution of the radiation's power in space, as opposed to photometric techniques, which characterize the light's interaction with the human eye. The fundamental difference between radiometry and photometry is that radiometry gives the entire optical radiation spectrum, while photometry is limited to the visible spectrum. Radiometry is distinct from quantum techniques such as photon counting. The use of radiometers to determine the temperature of objects and gasses by measuring radiation flux is called pyrometry. Handheld pyrometer devices are often marketed as infrared thermometers. Radiometry is important in astronomy, especially radio astronomy, and plays a significant role in Earth remote sensing. The measurement techniques categorized as ''radiometry'' in optics are called ''photometry'' in some astronomical applicat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bulimulidae
Bulimulidae is a taxonomic family of medium-sized to large, air-breathing, tropical and sub-tropical land snails, terrestrial pulmonate gastropod molluscs in the superfamily Orthalicoidea.MolluscaBase eds. (2020). MolluscaBase. Bulimulidae Tryon, 1867. Accessed through: World Register of Marine Species at: http://www.marinespecies.org/aphia.php?p=taxdetails&id=549409 on 2020-06-27 Distribution Distribution of species in the family Bulimulidae includes Ecuador (9 genera) and other South American countries. Some species also occur in North America. Fossil record The family's oldest fossil record dates from the late Cretaceous of Brazil (Itaboraí Basin). Anatomy Members of this family have a haploid chromosome number between 26 and 30 (according to the values in this table).Barker G. M.: Gastropods on Land: ''Phylogeny, Diversity and Adaptive Morphology''. in Barker G. M. (ed.): The biology of terrestrial molluscs'. CABI Publishing, Oxon, UK, 2001, . 1-146, cited pages: 139 an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
