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Vicuña Mackenna Batholith
The Vicuña Mackenna Batholith () is a group of plutons in the Chilean Coast Range of Norte Grande, northern Chile. The plutons of the batholith formed (cooled from magma to rock) between the Early Jurassic and the Late Cretaceous (192–98 million years ago, Ma). The magmas that formed the batholith originated in mantle (geology), Earth's mantle and have not suffered any significant crustal contamination. A group of Early Cretaceous plutons were intruded methods of pluton emplacement, 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 and monzogabbronorite. * Ventarrones Unit (149-138 Ma) * Remiendos Unit (133-128 Ma) * Herradura Unit (108-98 Ma) See also * Coastal Batholith of Peru Referen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Batholith
A batholith () is a large mass of intrusive rock, intrusive igneous rock (also called plutonic rock), larger than in area, that forms from cooled magma deep in the Earth's crust. Batholiths are almost always made mostly of felsic or intermediate composition, 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 relative ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atacama Fault
The Atacama Fault Zone (AFZ) is an extensive system of faults cutting across the Chilean Coastal Cordillera in Northern Chile between the Andean Mountain range and the Pacific Ocean. The fault system is north–south striking and runs for more than 1100 km North and up to 50 km in width through the Andean forearc region. The zone is a direct result of the ongoing subduction of the Eastward moving Nazca plate beneath the South American plate and is believed to have formed in the Early Jurassic during the beginnings of the Andean orogeny. The zone can be split into 3 regions: the North, Central and South. Tectonic history and formation The AFZ has gone through periods of inactivity and reactivation since its inception in the Cretaceous. The fault series was formed through a complex series of tectonic regimes dating back to the Early Jurassic, when the Andean back-arc basin separated from the Pacific Ocean. Intra-arc ductile deformation occurred in the Late Jurassic, cr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jurassic Chile
The Jurassic ( ) is a geologic period and stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately 143.1 Mya. The Jurassic constitutes the second and middle period of the Mesozoic Era as well as the eighth period of the Phanerozoic Eon 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 (CAMP). The beginning of the Toarcian Age started around 183 million years ago and is marked by the Toarcian Oceanic Anoxic Event, a global episode of oceanic anoxia, ocean acidification, and elevated global temperatures associated with extinctions, likely caused by the eruption of the Karoo-Ferrar large igneous provinces. The end of the Jurassic, however, has no clear, definitive boundary with the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geology Of The Chilean Coast Range
Geology (). is a branch of natural science concerned with the Earth and other astronomical objects, the rocks of which they are composed, and the processes by which they change over time. Modern geology significantly overlaps all other Earth sciences, including hydrology. It is integrated with Earth system science and planetary science. Geology describes the structure of the Earth on and beneath its surface and the processes that have shaped that structure. Geologists study the mineralogical composition of rocks in order to get insight into their history of formation. Geology determines the relative ages of rocks found at a given location; geochemistry (a branch of geology) determines their absolute ages. By combining various petrological, crystallographic, and paleontological tools, geologists are able to chronicle the geological history of the Earth as a whole. One aspect is to demonstrate the age of the Earth. Geology provides evidence for plate tectonics, the evolutionary ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Batholiths Of South America
A batholith () is a large mass of intrusive rock, intrusive igneous rock (also called plutonic rock), larger than in area, that forms from cooled magma deep in the Earth's crust. Batholiths are almost always made mostly of felsic or intermediate composition, 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 relative ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coastal Batholith Of Peru
The Coastal Batholith of Peru () 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 basin. The magma that formed the batholith's plutons is thought to have originated from the partial melting of hydrated basaltic rocks at the base of the crust during rifting (extension). Subsequently, the rift basin was inverted. During the ascent the magma followed vertical pathways but emplacement was mostly in the form of tabular bodies. Plutons of the batholith intrude both the deformed strata of Marañón fold and thrust belt and the Casma Group. See also *Casma Group * Cordillera Blanca Batholith *Vicuña Mackenna Batholith The Vicuña Mackenna Batholith () is a group of plutons in the Chilean Coast Range of Norte Grande, northern Chile. The plutons of the batholith formed (cooled from magm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 makes up 0% to 5% of the QAPF mineral fraction, plagioclase Plagioclase ( ) is a series of Silicate minerals#Tectosilicates, tectosilicate (framework silicate) minerals within the feldspar group. Rather than referring to a particular mineral with a specific chemical composition, plagioclase is a continu ... makes up 65% to 90% of the total feldspar content, and the plagioclase is calcium-rich (% An > 50). References Plutonic rocks {{igneous-rock-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monzodiorite
Monzodiorite is an intrusive rock with a composition intermediate between diorite and monzonite. It is defined in the QAPF classification as coarse-grained igneous rock in which quartz makes up 0% to 5% of the QAPF mineral fraction, plagioclase Plagioclase ( ) is a series of Silicate minerals#Tectosilicates, tectosilicate (framework silicate) minerals within the feldspar group. Rather than referring to a particular mineral with a specific chemical composition, plagioclase is a continu ... makes up 65% to 90% of the total feldspar content, and the plagioclase is sodium-rich (% An < 50). References Plutonic rocks {{igneous-rock-stub ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diorite
Diorite ( ) is an intrusive rock, intrusive igneous rock formed by the slow cooling underground of magma (molten rock) that has a moderate content of silica and a relatively low content of alkali metals. It is Intermediate composition, intermediate in composition between low-silica (mafic) gabbro and high-silica (felsic) granite. Diorite is found in mountain-building belts (''orogens'') on the margins of continents. It has the same composition as the fine-grained volcanic rock, andesite, which is also common in orogens. Diorite has been used since prehistoric times as decorative stone. It was used by the Akkadian Empire of Sargon of Akkad for funerary sculptures, and by many later civilizations for sculptures and building stone. Description Diorite is an intrusive rock, intrusive igneous rock composed principally of the silicate minerals plagioclase feldspar (typically andesine), biotite, hornblende, and sometimes pyroxene. The chemical composition of diorite is Intermedia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
