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Geology Of Andorra
Andorra is located in the ''Axial Zone'' of the central Pyrenees mountain range in southwestern Europe, which means that it has intensely folded and thrust rocks formed when the Iberian peninsula was rotated onto the European continent. Overview Rocks from the Cambrian or Ordovician occur in the form of conglomerate, limestone, phyllite, quartzite, and slate. Diapirs of slate from the Silurian Period are found in the Llavirsi syncline near Bixessarri in the south west. Gneiss and schist are found in the cores of anticlines in the north east of the country. This gneiss contains muscovite. The antiforms are connected with near horizontal shear zones, containing nappes of metamorphosed sediments. Younger overlying Paleozoic metamorphosed sediments found over most of Andorra have also been steeply folded. In the south east of the country is an alkaline granite from a batholith called Mt-Louis-Andorra Batholith. It extends into Spain and covers an area of . Different rock compositi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Andorra Geology
, image_flag = Flag of Andorra.svg , image_coat = Coat of arms of Andorra.svg , symbol_type = Coat of arms , national_motto = la, Virtus Unita Fortior, label=none (Latin)"United virtue is stronger" , national_anthem = "The Great Charlemagne" , image_map = Location Andorra Europe.png , map_caption = , image_map2 = , capital = Andorra la Vella , coordinates = , largest_city = capital , official_languages = Catalan , ethnic_groups = , ethnic_groups_year = 2017 , religion = Christianity (Catholicism) , religion_ref = , demonym = Andorran , government_type = constitutional elective diarchy , leader_title1 = Co-Princes , leader_name1 = , leader_title2 = Representatives , leader_name2 = , leader_title3 = Prime Minister ... [...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 defining the val ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monzogranite
Monzogranites are biotite granite rocks that are considered to be the final fractionation product of magma. Monzogranites are characteristically felsic (SiO2 > 73%, and FeO + MgO + TiO2 < 2.4), weakly (Al2O3/ (CaO + Na2O + K2O) = 0.98–1.11), and contain , , and as accessory |
Spain
, image_flag = Bandera de España.svg , image_coat = Escudo de España (mazonado).svg , national_motto = ''Plus ultra'' (Latin)(English: "Further Beyond") , national_anthem = (English: "Royal March") , image_map = , map_caption = , image_map2 = , capital = Madrid , coordinates = , largest_city = Madrid , languages_type = Official language , languages = Spanish language, Spanish , ethnic_groups = , ethnic_groups_year = , ethnic_groups_ref = , religion = , religion_ref = , religion_year = 2020 , demonym = , government_type = Unitary state, Unitary Parliamentary system, parliamentary constitutional monarchy , leader_title1 = Monarchy of Spain, Monarch , leader_name1 = Felipe VI , leader_title2 = Prime Minister of Spain ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Batholith
A batholith () is a large mass of intrusive igneous rock (also called plutonic rock), larger than in area, that forms from cooled magma deep in Earth's crust. Batholiths are almost always made mostly of felsic or intermediate rock types, such as granite, quartz monzonite, or diorite (see also ''granite dome''). Formation Although they may appear uniform, batholiths are in fact structures with complex histories and compositions. They are composed of multiple masses, or ''plutons'', bodies of igneous rock of irregular dimensions (typically at least several kilometers) that can be distinguished from adjacent igneous rock by some combination of criteria including age, composition, texture, or mappable structures. Individual plutons are solidified from magma that traveled toward the surface from a zone of partial melting near the base of the Earth's crust. Traditionally, these plutons have been considered to form by ascent of relatively buoyant magma in large masses called ''p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Granite
Granite () is a coarse-grained (phaneritic) intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase. It forms from magma with a high content of silica and alkali metal oxides that slowly cools and solidifies underground. It is common in the continental crust of Earth, where it is found in igneous intrusions. These range in size from dikes only a few centimeters across to batholiths exposed over hundreds of square kilometers. Granite is typical of a larger family of ''granitic rocks'', or ''granitoids'', that are composed mostly of coarse-grained quartz and feldspars in varying proportions. These rocks are classified by the relative percentages of quartz, alkali feldspar, and plagioclase (the QAPF classification), with true granite representing granitic rocks rich in quartz and alkali feldspar. Most granitic rocks also contain mica or amphibole minerals, though a few (known as leucogranites) contain almost no dark minerals. Granite is nearly alway ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleozoic
The Paleozoic (or Palaeozoic) Era is the earliest of three geologic eras of the Phanerozoic Eon. The name ''Paleozoic'' ( ;) was coined by the British geologist Adam Sedgwick in 1838 by combining the Greek words ''palaiós'' (, "old") and ''zōḗ'' (), "life", meaning "ancient life" ). It is the longest of the Phanerozoic eras, lasting from , and is subdivided into six geologic periods (from oldest to youngest): # Cambrian # Ordovician # Silurian # Devonian # Carboniferous # Permian The Paleozoic comes after the Neoproterozoic Era of the Proterozoic Eon and is followed by the Mesozoic Era. The Paleozoic was a time of dramatic geological, climatic, and evolutionary change. The Cambrian witnessed the most rapid and widespread diversification of life in Earth's history, known as the Cambrian explosion, in which most modern phyla first appeared. Arthropods, molluscs, fish, amphibians, reptiles, and synapsids all evolved during the Paleozoic. Life began in the ocean ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metamorphism
Metamorphism is the transformation of existing rock (the protolith) to rock with a different mineral composition or texture. Metamorphism takes place at temperatures in excess of , and often also at elevated pressure or in the presence of chemically active fluids, but the rock remains mostly solid during the transformation. Metamorphism is distinct from weathering or diagenesis, which are changes that take place at or just beneath Earth's surface. Various forms of metamorphism exist, including regional, contact, hydrothermal, shock, and dynamic metamorphism. These differ in the characteristic temperatures, pressures, and rate at which they take place and in the extent to which reactive fluids are involved. Metamorphism occurring at increasing pressure and temperature conditions is known as ''prograde metamorphism'', while decreasing temperature and pressure characterize ''retrograde metamorphism''. Metamorphic petrology is the study of metamorphism. Metamorphic petrologists re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nappe
In geology, a nappe or thrust sheet is a large sheetlike body of rock (geology), rock that has been moved more than or above a thrust fault from its original position. Nappes form in compressional tectonic settings like continental collision zones or on the overriding plate in active subduction zones. Nappes form when a mass of rock is forced (or thrust fault, "thrust") over another rock mass, typically on a low angle fault plane. The resulting structure may include large-scale recumbent Fold (geology), folds, shearing along the fault plane,Twiss, Robert J. and Eldridge M. Moores, ''Structural Geology,'' W. H. Freeman, 1992, p. 236 Thrust fault#Thrust duplex, imbricate thrust stacks, Window (geology), fensters and klippes. The term stems from the French word for ''tablecloth'' in allusion to a rumpled tablecloth being pushed across a table. History Nappes or nappe belts are a major feature of the European Geology of the Alps, Alps, Dinaric Alps, Dinarides, Carpathians and S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shear Zone
In geology, a shear zone is a thin zone within the Earth's crust or upper mantle that has been strongly deformed, due to the walls of rock on either side of the zone slipping past each other. In the upper crust, where rock is brittle, the shear zone takes the form of a fracture called a Fault (geology), fault. In the lower crust and mantle, the extreme conditions of pressure and temperature make the rock ductile. That is, the rock is capable of slowly deforming without fracture, like hot metal being worked by a blacksmith. Here the shear zone is a wider zone, in which the ductile rock has slowly flowed to accommodate the relative motion of the rock walls on either side. Because shear zones are found across a wide depth-range, a great variety of different rock types with their characteristic structures are associated with shear zones. General introduction A shear zone is a zone of strong deformation (with a high strain rate) surrounded by rocks with a lower state of Deforma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Muscovite
Muscovite (also known as common mica, isinglass, or potash mica) is a hydrated phyllosilicate mineral of aluminium and potassium with formula K Al2(Al Si3 O10)( F,O H)2, or ( KF)2( Al2O3)3( SiO2)6( H2O). It has a highly perfect basal cleavage yielding remarkably thin laminae (sheets) which are often highly elastic. Sheets of muscovite 5 meters × 3 meters (16.5 feet × 10 feet) have been found in Nellore, India. Muscovite has a Mohs hardness of 2–2.25 parallel to the 01face, 4 perpendicular to the 01and a specific gravity of 2.76–3. It can be colorless or tinted through grays, browns, greens, yellows, or (rarely) violet or red, and can be transparent or translucent. It is anisotropic and has high birefringence. Its crystal system is monoclinic. The green, chromium-rich variety is called fuchsite; mariposite is also a chromium-rich type of muscovite. Muscovite is the most common mica, found in granites, pegmatites, gneisses, and schists, and as a contact metamorphic ro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
