Material properties and microstructure from
... is 25°C at the surface and 1300°C at the bottom of the lithosphere. Radiogenic heat production (Ah) in the Indian crust was constrained by the average 70 mW/m2 surface heat flux of the stable northern Indian crust. Ah in the upper plate was assumed to be 2 µW/m3 throughout and in the mantle 0.01 µW/ ...
... is 25°C at the surface and 1300°C at the bottom of the lithosphere. Radiogenic heat production (Ah) in the Indian crust was constrained by the average 70 mW/m2 surface heat flux of the stable northern Indian crust. Ah in the upper plate was assumed to be 2 µW/m3 throughout and in the mantle 0.01 µW/ ...
High geotherm
... • Low-angle subduction zones, great distance from trench to active arc. • Magmatic events produce large composite batholiths, with superunits and units which individually show mafic to acid (primitive to mature) compositional trends. • Very large volumes of magma are emplaced into the crust, and can ...
... • Low-angle subduction zones, great distance from trench to active arc. • Magmatic events produce large composite batholiths, with superunits and units which individually show mafic to acid (primitive to mature) compositional trends. • Very large volumes of magma are emplaced into the crust, and can ...
Primary magmas and mantle temperatures
... the pressure range of 1 to 5 GPa (~ 30 to 170 km). Within widely accepted models of plate tectonics, including the concept of deep mantle plumes, there is the expectation or hypothesis that melting of subducted oceanic crust will occur under conditions of eclogite stability. Thus eclogite melting wi ...
... the pressure range of 1 to 5 GPa (~ 30 to 170 km). Within widely accepted models of plate tectonics, including the concept of deep mantle plumes, there is the expectation or hypothesis that melting of subducted oceanic crust will occur under conditions of eclogite stability. Thus eclogite melting wi ...
Canada`s craton: A bottoms-up view
... recognized within the cratons of continents today (Bleeker, 2003). The largest mass of lithosphere beneath these cratons underlies the Moho in the mantle. Thus, the long-term strength and stability of a craton must be engendered in the properties of its mantle lithosphere, which may ultimately be ti ...
... recognized within the cratons of continents today (Bleeker, 2003). The largest mass of lithosphere beneath these cratons underlies the Moho in the mantle. Thus, the long-term strength and stability of a craton must be engendered in the properties of its mantle lithosphere, which may ultimately be ti ...
Meteorite Impacts as Triggers to Large Igneous Provinces
... and distance (FIG. 3). Some of this melt will quench, but most will crystallise slowly, taking perhaps tens of thousands of years to solidify (Jones et al. 2005a). Massive reorganisation of the affected upper mantle, driven by largescale physical disturbances such as displaced crust, juxtaposed hot ...
... and distance (FIG. 3). Some of this melt will quench, but most will crystallise slowly, taking perhaps tens of thousands of years to solidify (Jones et al. 2005a). Massive reorganisation of the affected upper mantle, driven by largescale physical disturbances such as displaced crust, juxtaposed hot ...
EAS 102 / BIO G 170 Lecture 10, Page 1 of 6 PLATE TECTONICS
... the product of more complete melting of the mantle beneath midocean ridges, may have been as much as three times thicker, and thus less susceptible to subduction. However, being correspondingly more mantle-like in composition, Archean oceanic crust should have been less buoyant . The opposed effects ...
... the product of more complete melting of the mantle beneath midocean ridges, may have been as much as three times thicker, and thus less susceptible to subduction. However, being correspondingly more mantle-like in composition, Archean oceanic crust should have been less buoyant . The opposed effects ...
Proterozoic subduction-related and continental rift
... magmas vary from highly depleted mid-oceanic ridge basalt (MORB) to enriched OIB compositions6,21 overprinted with subduction fluid/melt related geochemical signatures. Similarly, modern lines of research have recognized that oceanic island basalts are largely derived from sublithospheric mantle sou ...
... magmas vary from highly depleted mid-oceanic ridge basalt (MORB) to enriched OIB compositions6,21 overprinted with subduction fluid/melt related geochemical signatures. Similarly, modern lines of research have recognized that oceanic island basalts are largely derived from sublithospheric mantle sou ...
Plate Tectonics as a Far- From- Equilibrium Self
... End-Member Mechanisms. Some ofthe elements of plate tectonics are continental breakup, triple junctions, volcanic chains and large igneous provinces. There are two endmember hypotheses for explaining these elements, which are sometimes treated as independent from, or external to, the theory of plate ...
... End-Member Mechanisms. Some ofthe elements of plate tectonics are continental breakup, triple junctions, volcanic chains and large igneous provinces. There are two endmember hypotheses for explaining these elements, which are sometimes treated as independent from, or external to, the theory of plate ...
The Subductability of Continental Lithosphere
... oceanic domain is composed of a thin layer of pelagic sediments, a basaltic upper crust, a gabbroic lower crust, a depleted shallow lithospheric mantle, and a deep (less depleted) lithospheric mantle. The reference passive margin includes some layers from the continental and oceanic domains plus two ...
... oceanic domain is composed of a thin layer of pelagic sediments, a basaltic upper crust, a gabbroic lower crust, a depleted shallow lithospheric mantle, and a deep (less depleted) lithospheric mantle. The reference passive margin includes some layers from the continental and oceanic domains plus two ...
40. Regional Problems - Deep Sea Drilling Project
... western Philippine Sea might be underlain by Paleozoic crust. The East Pacific Ridge might have at one time extended round the northern and western margins of the Pacific Basin and given rise to young crust west of the oldest known oceanic area. The abrupt contact of young and old sea floor along th ...
... western Philippine Sea might be underlain by Paleozoic crust. The East Pacific Ridge might have at one time extended round the northern and western margins of the Pacific Basin and given rise to young crust west of the oldest known oceanic area. The abrupt contact of young and old sea floor along th ...
Flow and melting of a heterogeneous mantle
... defined by OIBs globally. Our models not only predict testable variations in trace-element and isotopic ratios with mean extent of partial melting, but also show that pyroxenite can complicate such correlations because it can melt to very high extents, in many cases, completely. If the thickness of ...
... defined by OIBs globally. Our models not only predict testable variations in trace-element and isotopic ratios with mean extent of partial melting, but also show that pyroxenite can complicate such correlations because it can melt to very high extents, in many cases, completely. If the thickness of ...
Zoned mantle convection
... inconsistent with the storage of old plates of ordinary oceanic lithosphere, i.e. with the concept of a plate graveyard. Isotopic inventories indicate that the deep-mantle composition is not correctly accounted for by continental debris, primitive material or subducted slabs containing normal oceani ...
... inconsistent with the storage of old plates of ordinary oceanic lithosphere, i.e. with the concept of a plate graveyard. Isotopic inventories indicate that the deep-mantle composition is not correctly accounted for by continental debris, primitive material or subducted slabs containing normal oceani ...
topic_4_5 - Earth and Environmental Sciences
... is being rapidly transported into the Earth’s interior, with little time to be conductively heated by the surrounding, hotter mantle. We’ve shown several figures – of thermal models for subduction zones, and seismic data – illustrating that this is true. As noted in the previous lecture, there is am ...
... is being rapidly transported into the Earth’s interior, with little time to be conductively heated by the surrounding, hotter mantle. We’ve shown several figures – of thermal models for subduction zones, and seismic data – illustrating that this is true. As noted in the previous lecture, there is am ...
Document
... Los Angeles lies on the Pacific plate. San Jose lies on the North American plate. How will the distance between the two cities change over millions of years? Over millions of years the distance between Los Angeles and San Jose will increase as the Pacific plate moves northwest relative to the North ...
... Los Angeles lies on the Pacific plate. San Jose lies on the North American plate. How will the distance between the two cities change over millions of years? Over millions of years the distance between Los Angeles and San Jose will increase as the Pacific plate moves northwest relative to the North ...
Degree-one mantle convection: Dependence on
... dominates the mantle flow pattern. The viscosity contrast across the system is represented by symbol borders; symbols with 1, 2, and 3 borders represent cases with 103, 104, and 102 viscosity contrasts, respectively. maximum Raeff in our calculations, has an even higher Dhlith than Case 5 yet does n ...
... dominates the mantle flow pattern. The viscosity contrast across the system is represented by symbol borders; symbols with 1, 2, and 3 borders represent cases with 103, 104, and 102 viscosity contrasts, respectively. maximum Raeff in our calculations, has an even higher Dhlith than Case 5 yet does n ...
Dynamic elevation of the Cordillera, western United States
... Mantle magmagenesis entails the preferential melting and separation of Fe and Al silicates in a mantle aggregate. In a mantle partial melt, both the liquid phase and the solid residuum will be less dense than the original aggregate [Jordan, 1978; Fujii and Kushiro, 1977]. Various investigations have ...
... Mantle magmagenesis entails the preferential melting and separation of Fe and Al silicates in a mantle aggregate. In a mantle partial melt, both the liquid phase and the solid residuum will be less dense than the original aggregate [Jordan, 1978; Fujii and Kushiro, 1977]. Various investigations have ...
Plate tectonics and planetary habitability
... tectonics may be paraphrased by the following questions: how did plate tectonics evolve in the past?, why does plate tectonics take place on Earth?, and when did plate tectonics first appear on Earth? Considerable progress has been made on the first question in the last decade, and this progress tur ...
... tectonics may be paraphrased by the following questions: how did plate tectonics evolve in the past?, why does plate tectonics take place on Earth?, and when did plate tectonics first appear on Earth? Considerable progress has been made on the first question in the last decade, and this progress tur ...
Water, Life, and Planetary Geodynamical Evolution
... Keywords Mantle dynamics · Habitability · Magnetic field · Volatiles · Thermal evolution ...
... Keywords Mantle dynamics · Habitability · Magnetic field · Volatiles · Thermal evolution ...
Plate tectonics - Free
... most active and widely known today. These boundaries are discussed in further detail below. Some volcanoes occur in the interiors of plates, and these have been variously attributed to internal plate deformation[8] and to mantle plumes. As explained above, tectonic plates may include continental cru ...
... most active and widely known today. These boundaries are discussed in further detail below. Some volcanoes occur in the interiors of plates, and these have been variously attributed to internal plate deformation[8] and to mantle plumes. As explained above, tectonic plates may include continental cru ...
Mantle plume
A mantle plume is a mechanism proposed in 1971 to explain volcanic regions of the earth that were not thought to be explicable by the then-new theory of plate tectonics. Some such volcanic regions lie far from tectonic plate boundaries, for example, Hawaii. Others represent unusually large-volume volcanism, whether on plate boundaries, e.g. Iceland, or basalt floods such as the Deccan or Siberian traps.A mantle plume is posited to exist where hot rock nucleates at the core-mantle boundary and rises through the Earth's mantle becoming a diapir in the Earth's crust. The currently active volcanic centers are known as ""hot spots"". In particular, the concept that mantle plumes are fixed relative to one another, and anchored at the core-mantle boundary, was thought to provide a natural explanation for the time-progressive chains of older volcanoes seen extending out from some such hot spots, such as the Hawaiian–Emperor seamount chain.The hypothesis of mantle plumes from depth is not universally accepted as explaining all such volcanism. It has required progressive hypothesis-elaboration leading to variant propositions such as mini-plumes and pulsing plumes. Another hypothesis for unusual volcanic regions is the ""Plate model"". This proposes shallower, passive leakage of magma from the mantle onto the Earth's surface where extension of the lithosphere permits it, attributing most volcanism to plate tectonic processes, with volcanoes far from plate boundaries resulting from intraplate extension.