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Salta Basin
Salta Basin or Salta Rift Basin is a sedimentary basin located in the Argentine Northwest. The basin started to accumulate sediments in the Early Cretaceous (Neocomian) and at present it has sedimentary deposits reaching thicknesses of . The basin contains seven sub-basins: Tres Cruces, Lomas de Olmedo, Metán, Alemanía, Salfity, El Rey, Sey and Brealito. The basin environment has variously been described as a " foreland rift" and an "intra-continental rift". The basin developed under conditions of extensional tectonics and rift-associated volcanism. Description The basin basement is composed of rocks belonging to the Puncoviscana Formation.Grier et al., 1991 The volcanism that began in the Late Jurassic was initially of subalkaline character (low sodium and potassium content), but turned increasingly alkaline in the Early Cretaceous.Marquillas et al., 2005 The rifts of Salta Basin developed in a time of generalized extensional tectonics along western South America.Ramos, 2009 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salta Province
Salta () is a province of Argentina, located in the northwest of the country. Neighboring provinces are from the east clockwise Formosa, Chaco, Santiago del Estero, Tucumán and Catamarca. It also surrounds Jujuy. To the north it borders Bolivia and Paraguay and to the west lies Chile. History Before the Spanish conquest, numerous native peoples (now called Diaguitas and Calchaquíes) lived in the valleys of what is now Salta Province; they formed many different tribes, the Quilmes and Humahuacas among them, which all shared the Cacán language. The Atacamas lived in the Puna, and the Wichís (Matacos), in the Chaco region. The first conquistador to venture into the area was Diego de Almagro in 1535; he was followed by Diego de Rojas. Hernando de Lerma founded San Felipe de Lerma in 1582, following orders of the viceroy Francisco de Toledo, Count of Oropesa; the name of the city was soon changed to "San Felipe de Salta". By 1650, the city had around five hundred inhabitan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of the entire Phanerozoic. The name is derived from the Latin ''creta'', "chalk", which is abundant in the latter half of the period. It is usually abbreviated K, for its German translation ''Kreide''. The Cretaceous was a period with a relatively warm climate, resulting in high eustatic sea levels that created numerous shallow inland seas. These oceans and seas were populated with now- extinct marine reptiles, ammonites, and rudists, while dinosaurs continued to dominate on land. The world was ice free, and forests extended to the poles. During this time, new groups of mammals and birds appeared. During the Early Cretaceous, flowering plants appeared and began to rapidly diversify, becoming the dominant group of plants across the Earth b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pliocene
The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58See the 2014 version of the ICS geologic time scale million years ago. It is the second and most recent epoch of the Neogene Period in the . The Pliocene follows the Epoch and is followed by the Epoch. Prior to the 2009 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salar De Atacama
Salar de Atacama is the largest salt flat in Chile. It is located south of San Pedro de Atacama, is surrounded by mountains, and has no drainage outlets. In the east it is enclosed by the main chain of the Andes, while to the west lies a secondary mountain range of the Andes called Cordillera de Domeyko. Large volcanoes dominate the landscape, including the Licancabur, Acamarachi, Aguas Calientes and the Láscar. The last is one of the most active volcanoes in Chile. All of them are located along the eastern side of the Salar de Atacama, forming a generally north-south trending line of volcanoes that separate it from smaller endorheic basins. Features The salt flat encompasses , is about long and wide, which makes it the third largest in the world, after Salar de Uyuni in Bolivia (). and Salinas Grandes in Argentina (). Its average elevation is about 2,300 m above sea level. The topography of the core portion of the ''salar'' exhibits a high level of roughness, the result of e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potassium
Potassium is the chemical element with the symbol K (from Neo-Latin ''kalium'') and atomic number19. Potassium is a silvery-white metal that is soft enough to be cut with a knife with little force. Potassium metal reacts rapidly with atmospheric oxygen to form flaky white potassium peroxide in only seconds of exposure. It was first isolated from potash, the ashes of plants, from which its name derives. In the periodic table, potassium is one of the alkali metals, all of which have a single valence electron in the outer electron shell, that is easily removed to create an ion with a positive charge – a cation, that combines with anions to form salts. Potassium in nature occurs only in ionic salts. Elemental potassium reacts vigorously with water, generating sufficient heat to ignite hydrogen emitted in the reaction, and burning with a lilac- colored flame. It is found dissolved in sea water (which is 0.04% potassium by weight), and occurs in many minerals such as orthoclase, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sodium
Sodium is a chemical element with the symbol Na (from Latin ''natrium'') and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 of the periodic table. Its only stable isotope is 23Na. The free metal does not occur in nature, and must be prepared from compounds. Sodium is the sixth most abundant element in the Earth's crust and exists in numerous minerals such as feldspars, sodalite, and halite (NaCl). Many salts of sodium are highly water-soluble: sodium ions have been leached by the action of water from the Earth's minerals over eons, and thus sodium and chlorine are the most common dissolved elements by weight in the oceans. Sodium was first isolated by Humphry Davy in 1807 by the electrolysis of sodium hydroxide. Among many other useful sodium compounds, sodium hydroxide (lye) is used in soap manufacture, and sodium chloride (edible salt) is a de-icing agent and a nutrient for animals including h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jurassic
The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The Jurassic constitutes the middle period of the Mesozoic, Mesozoic Era and is named after the Jura Mountains, where limestone strata from the period were first identified. The start of the Jurassic was marked by the major Triassic–Jurassic extinction event, associated with the eruption of the Central Atlantic magmatic province, Central Atlantic Magmatic Province. The beginning of the Toarcian Stage started around 183 million years ago and is marked by an extinction event associated with widespread Anoxic event, oceanic anoxia, ocean acidification, and elevated temperatures likely caused by the eruption of the Karoo-Ferrar, Karoo-Ferrar large igneous provinces. The end of the Jurassic, however, has no clear boundary with the Cretaceous and i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Puncoviscana Formation
Puncoviscana Formation ( es, Formación Puncoviscana) is a formation of sedimentary and metasedimentary rocks Late Ediacaran and Lower Cambrian age, estimated at between 700 and 535 Ma, that crop out in the Argentine Northwest. Most of the formation lies in Jujuy, Salta and Tucumán Province albeit some authors extend the formation further south to the Sierras Pampeanas near Córdoba. There are various tectonic interpretations on the origin and type of sedimentary basin that accumulated Puncoviscana Formations sediments. An early interpretation was that the sediments originated from a passive marginal basin of the ancient continent Gondwana. Others suggested an intra-cratonic rift or aulacogen basin between Río de la Plata-Pampia Craton and Arequipa Massif. Yet other hypotheses revolve around the idea that the Puncoviscana Formation is related to a terrane called Pampia that accreted to Gondwana causing the closure of a sea in the way. Stratigraphy, lithology and fossils ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanism
Volcanism, vulcanism or volcanicity is the phenomenon of eruption of molten rock (magma) onto the surface of the Earth or a solid-surface planet or moon, where lava, pyroclastics, and volcanic gases erupt through a break in the surface called a vent. It includes all phenomena resulting from and causing magma within the crust or mantle of the body, to rise through the crust and form volcanic rocks on the surface. Magmas, that reach the surface and solidify, form extrusive landforms. Volcanic processes Magma from the mantle or lower crust rises through the crust towards the surface. If magma reaches the surface, its behavior depends on the viscosity of the molten constituent rock. Viscous (thick) magma produces volcanoes characterised by explosive eruptions, while non-viscous (runny) magma produce volcanoes characterised by effusive eruptions pouring large amounts of lava onto the surface. In some cases, rising magma can cool and solidify without reaching the surface. Inste ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extensional Tectonics
Extensional tectonics is concerned with the structures formed by, and the tectonic processes associated with, the stretching of a planetary body's crust or lithosphere. Deformation styles The types of structure and the geometries formed depend on the amount of stretching involved. Stretching is generally measured using the parameter ''β'', known as the ''beta factor'', where : \beta = \frac \,, ''t''0 is the initial crustal thickness and ''t''1 is the final crustal thickness. It is also the equivalent of the strain parameter ''stretch''. Low beta factor In areas of relatively low crustal stretching, the dominant structures are high to moderate angle normal faults, with associated half grabens and tilted fault blocks. High beta factor In areas of high crustal stretching, individual extensional faults may become rotated to too low a dip to remain active and a new set of faults may be generated. Large displacements may juxtapose syntectonic sediments against metamorphic roc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
