|
Coastal Batholith Of Peru
The Coastal Batholith of Peru ( es, Batolito costero peruano) is a group of hundreds, if not thousands, of individual plutons that crop out near or at the coast of Peru. The batholith runs a length of ca. 1600 km. Most of the plutons of the batholith were intruded in an elongated coast-parallel extensional tectonics, extensional sedimentary basin, basin. The magma that formed the batholith's plutons is thought to have originated from the partial melting of hydrogen, hydrated mafic, basaltic rocks at the base of the continental crust, crust during rifting (extension). Subsequently, the rift basin was basin inversion, inverted. During the ascent the magma followed vertical pathways but methods of pluton emplacement, emplacement was mostly in the form of Sheet intrusion, tabular bodies. Plutons of the batholith intrude both the deformed strata of Marañón fold and thrust belt and the Casma Group. References See also *Casma Group *Cordillera Blanca Batholith *Vicuña Mackenn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pluton
In geology, an igneous intrusion (or intrusive body or simply intrusion) is a body of intrusive igneous rock that forms by crystallization of magma slowly cooling below the surface of the Earth. Intrusions have a wide variety of forms and compositions, illustrated by examples like the Palisades Sill of New York and New Jersey; the Henry Mountains of Utah; the Bushveld Igneous Complex of South Africa; Shiprock in New Mexico; the Ardnamurchan intrusion in Scotland; and the Sierra Nevada Batholith of California. Because the solid country rock into which magma intrudes is an excellent insulator, cooling of the magma is extremely slow, and intrusive igneous rock is coarse-grained (phaneritic). Intrusive igneous rocks are classified separately from extrusive igneous rocks, generally on the basis of their mineral content. The relative amounts of quartz, alkali feldspar, plagioclase, and feldspathoid is particularly important in classifying intrusive igneous rocks. Intrusions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methods Of Pluton Emplacement
The methods of pluton emplacement are the ways magma is accommodated in a host rock where the final result is a pluton. The methods of pluton emplacement are not yet fully understood, but there are many different proposed pluton emplacement mechanisms. Stoping, diapirism and ballooning are the widely accepted mechanisms. There is now evidence of incremental emplacement of plutons. Stoping Vertical migration of magma is driven by gravity. Stoping occurs when blocks of wall rock material are transferred downward through a pluton. Stoping is an important emplacement mechanism in a variety of tectonic settings and has been widely used to explain discordant pluton contacts. The most common signatures of stoping are sharp discordant contacts between plutons and wall rocks and a lack of ductile deformation of the wall rocks. Other characteristics of stoping include the presence of xenoliths in the plutons, evidence for the rotation of xenoliths and geochemical evidence of magma contami ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vicuña Mackenna Batholith
The Vicuña Mackenna Batholith ( es, Batolito Vicuña Mackenna) is a group of plutons in the Chilean Coast Range of northern Chile. The plutons of the batholith formed (cooled from magma to rock) between the Early Jurassic and the Late Cretaceous (192–98 Ma). The magmas that formed the batholith originated in Earth's mantle and have not suffered any significant crustal contamination. A group of Early Cretaceous plutons were intruded syn-tectonically on the Atacama Fault. Subdivision Geologists Miguel Hervé and Nicolás Marinivic identify six major units. From the oldest to the youngest these are: * Barazate Unit (192-181 Ma) * Paranal Unit (ca. 170 Ma). This unit has the largest areal extent. It is composed of gabbronorite, gabbro, diorite, monzodiorite, monzogabbro Monzogabbro is an intrusive rock with a composition intermediate between gabbro and monzonite. It is defined in the QAPF classification as coarse-grained igneous rock in which quartz Quartz is a hard, crys ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cordillera Blanca Batholith
The Cordillera Blanca Batholith ( es, Batolito de la Cordillera Blanca) is an extensive group of individual plutons that crop out near or at Cordillera Blanca, Peru. The batholith intrudes the Jurassic Chicama Formation. To the west the Cordillera Blanca Fault makes up the border of the batholith. It has been suggested that the magma that originated the batholith was the product of partial melting of underplated basaltic crust. References See also * Casma Group *Coastal Batholith of Peru The Coastal Batholith of Peru ( es, Batolito costero peruano) is a group of hundreds, if not thousands, of individual plutons that crop out near or at the coast of Peru. The batholith runs a length of ca. 1600 km. Most of the plutons of the bat ... Batholiths of South America Geology of Peru {{geology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Casma Group
The Casma Group ( es, Grupo Casma) is a stratigraphic group of Cretaceous (Albian to Cenomanian) sedimentary formations exposed along the coast and within the Cordillera Occidental near Casma, Peru. Description The sediments of the Casma Group reflect deposition in two distinct environments of the West Peruvian Basin. Some sediments were deposited near the Casma Volcanic Arc in an intra-cratonic sedimentary basin that was occasionally connected to the ocean. Other sediments were deposited in what was once a continental platform bounded by reefs and with anoxic pockets.Compare et al, 1983 Together with the Morro Solar and Imperial Groups, the Casma Group contains clastic volcanosedimentary material derivative of the Mesozoic Casma Volcanic Arc.Pfiffner & González, 2013 The folding of the Casma Group sediments is the result of the Cretaceous Mochica Phase of the Andean orogeny. The group is intruded by plutons of the Coastal Batholith of Peru. The Casma Group include th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marañón Fold And Thrust Belt
The Marañón fold and thrust belt ( es, faja corrida y plegada del Marañón) is a long, northwest–southeast trending belt of deformed rocks located in the Andes of central Peru. The formation of the belt defines the Incaic Phase of the Andean orogeny. Prior to the deformation and uplift the rocks forming the Marañón fold and thrust belt constituted the fill of a marine back-arc basin that existed in the Mesozoic and was parallel to the present-day coast. The west-dipping Chonta Fault existed as a normal fault within this basin and allowed continued basin subsidence and sediment accumulation in the Mesozoic. The onset of Andean orogeny first caused the basin to rise and dry up with red beds being deposited in its eastern part. Then the sedimentary basin was subject of a complete basin inversion. During deformation Chonta Fault acted as a barrier "damming-up" folded and thrust strata west of it. This makes the fault define the limits of two different styles of thin-skinned ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Strata
In geology and related fields, a stratum ( : strata) is a layer of rock or sediment characterized by certain lithologic properties or attributes that distinguish it from adjacent layers from which it is separated by visible surfaces known as either '' bedding surfaces'' or ''bedding planes''.Salvador, A. ed., 1994. ''International stratigraphic guide: a guide to stratigraphic classification, terminology, and procedure. 2nd ed.'' Boulder, Colorado, The Geological Society of America, Inc., 215 pp. . Prior to the publication of the International Stratigraphic Guide, older publications have defined a stratum as either being either equivalent to a single bed or composed of a number of beds; as a layer greater than 1 cm in thickness and constituting a part of a bed; or a general term that includes both ''bed'' and ''lamina''.Neuendorf, K.K.E., Mehl, Jr., J.P., and Jackson, J.A. , eds., 2005. ''Glossary of Geology'' 5th ed. Alexandria, Virginia, American Geological Institute. 779 pp. . ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tectonophysics (journal)
''Tectonophysics, The International Journal of Geotectonics and the Geology and Physics of the Interior of the Earth'' is a weekly peer-reviewed scientific journal published by Elsevier. It was established in 1964 and covers the field of tectonophysics, including kinematics, structure, composition, and dynamics of the solid Earth at all scales. Organization The editors-in-chief are Philippe Agard (Pierre and Marie Curie University), Jean-Philippe Avouac (California Institute of Technology), Ramon Carbonell (Spanish National Research Council), Rob Govers (Utrecht University), Zheng Xiang Li (Curtin University), and Kelin Wang (Geological Survey of Canada). Abstracting and indexing This journal is abstracted and indexed in over fifty databases, including Current Contents, GeoRef, Inspec, Scopus and Web of Science. Notable articles According to the ''Journal Citation Reports'', ''Tectonophysics'' has a 2011 impact factor The impact factor (IF) or journal impact factor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sheet Intrusion
A sheet intrusion, or tabular intrusion, is a planar sheet of roughly the same thickness, that forms inside a pre-existing rock.Essentials of Geology, 3rd Ed, Stephen Marshak When it cuts into another unlayered mass, or across layers, it is called a " dike". When it is formed between layers in a layered rock mass, it is called a "sill". An igneous sheet intrusion is formed where a mass of molten magma takes advantage of a pre-existing linear feature in a host rock, such as a long rupture or fault, and forces its way into these spaces. Thus the magma, intruded between existing rocks, solidifies into large thin sheets of igneous rock. They are among the most extensive igneous features on Earth, in the form of dikes, laccolith A laccolith is a body of intrusive rock with a dome-shaped upper surface and a level base, fed by a conduit from below. A laccolith forms when magma (molten rock) rising through the Earth's crust begins to spread out horizontally, prying apar ...s, cone ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basin Inversion
In structural geology inversion or basin inversion relates to the relative uplift of a sedimentary basin or similar structure as a result of crustal shortening. This normally excludes uplift developed in the footwalls of later extensional faults, or uplift caused by mantle plumes. "Inversion" can also refer to individual faults, where an extensional fault is reactivated in the opposite direction to its original movement. The term ''negative inversion'' is also occasionally used to describe the reactivation of reverse faults and thrusts during extension. The term "inversion" simply refers to the fact that a relatively low-lying area is uplifted – the rock sequence itself is not normally inverted. Formation Many inversion structures are caused by the direct reactivation of pre-existing extensional faults. In some cases only the deeper parts of the fault are reactivated and the shortening is accommodated over a much broader area in the shallow part of the section. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peru
, image_flag = Flag of Peru.svg , image_coat = Escudo nacional del Perú.svg , other_symbol = Great Seal of the State , other_symbol_type = Seal (emblem), National seal , national_motto = "Firm and Happy for the Union" , national_anthem = "National Anthem of Peru" , march = "March of Flags" , image_map = PER orthographic.svg , map_caption = , image_map2 = , capital = Lima , coordinates = , largest_city = capital , official_languages = Peruvian Spanish, Spanish , languages_type = Co-official languages , languages = , ethnic_groups = , ethnic_groups_year = 2017 , demonym = Peruvians, Peruvian , government_type = Unitary state, Unitary Semi-presidential system, semi-presidential republic , leader_title1 = President of Peru, President ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rift
In geology, a rift is a linear zone where the lithosphere is being pulled apart and is an example of extensional tectonics. Typical rift features are a central linear downfaulted depression, called a graben, or more commonly a half-graben with normal faulting and rift-flank uplifts mainly on one side. Where rifts remain above sea level they form a rift valley, which may be filled by water forming a rift lake. The axis of the rift area may contain volcanic rocks, and active volcanism is a part of many, but not all, active rift systems. Major rifts occur along the central axis of most mid-ocean ridges, where new oceanic crust and lithosphere is created along a divergent boundary between two tectonic plates. ''Failed rifts'' are the result of continental rifting that failed to continue to the point of break-up. Typically the transition from rifting to spreading develops at a triple junction where three converging rifts meet over a hotspot. Two of these evolve to the poi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
