Results 231 to 240 of about 17,487 (279)
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Structure of melt flow channels in the mantle
Geotectonics, 2008Structural events during the formation of the mantle peridotite section in the Voikar-Syn’ya massif of the Polar Urals are considered. The structural units of the mantle section were formed during several deformation stages. Dunite bodies in restitic peridotites were formed in the course of deformation that completed the formation of large-scale folds ...
Savelieva, G. +4 more
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Nature, 1995
OCEANIC ridges are the dominant sites of energy and mass transfer from the Earth's interior to the crust, hydrosphere and atmosphere, but many key processes beneath ridges remain poorly understood. One outstanding problem is how partial melts in the asthenosphere concentrate into channels - initially, melts must leave their source by intergranular ...
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OCEANIC ridges are the dominant sites of energy and mass transfer from the Earth's interior to the crust, hydrosphere and atmosphere, but many key processes beneath ridges remain poorly understood. One outstanding problem is how partial melts in the asthenosphere concentrate into channels - initially, melts must leave their source by intergranular ...
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Transcrystalline Melt Migration and Earth's Mantle
Science, 2006Plate tectonics and volcanism involve the formation, migration, and interaction of magma and gas. Experiments show that melt inclusions subjected to a thermal gradient migrate through olivine crystals, under the kinetic control of crystal-melt interface mechanisms.
Pierre, Schiano +3 more
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Science, 2007
GEOCHEMISTRY During Earth's history, heavy metals gradually decoupled from silicate rocks and sank toward the core, which became differentiated from the overlying mantle. Signatures of this process can be traced in the distribution of highly siderophile elements (Re and the platinum group elements Os, Ir, Ru, Pt, and Pd) that are chemically associated ...
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GEOCHEMISTRY During Earth's history, heavy metals gradually decoupled from silicate rocks and sank toward the core, which became differentiated from the overlying mantle. Signatures of this process can be traced in the distribution of highly siderophile elements (Re and the platinum group elements Os, Ir, Ru, Pt, and Pd) that are chemically associated ...
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Platinum group elements in mantle melts and mantle samples
Lithos, 2015Abstract A large data compilation has been assembled of platinum group element (PGE) analyses in mantle melts and mantle rocks, the latter including an assortment of xenoliths and obducted mantle massifs. The degree of correlation has been investigated among the PGEs and with other major element variables such as Al2O3, TiO2 and Mg number, and the ...
Stephen J. Barnes +2 more
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Melting Temperatures in the Earth's Mantle
Tectonophysics, 1972Abstract In common with most recent investigators, we assume that olivine in the upper mantle goes through a phase change to spinel. Spinel at higher pressures breaks down to a post-spinel phase, possibly a mixture of the oxides, periclase and stishovite.
George C. Kennedy, Gary H. Higgins
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Earth and Planetary Science Letters, 1989
Abstract The attainment of equilibrium between basalt and residual peridotite depends on the relative magnitudes of melt segregation rate and solid residue re-equilibration rate. Garnets and pyroxenes (and perhaps spinels) require at least 103 years to equilibrate with melt by volume inter-diffusion.
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Abstract The attainment of equilibrium between basalt and residual peridotite depends on the relative magnitudes of melt segregation rate and solid residue re-equilibration rate. Garnets and pyroxenes (and perhaps spinels) require at least 103 years to equilibrate with melt by volume inter-diffusion.
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Science, 1999
Most of Earth9s volume is silicate mantle, hidden from view by a layer of surface crust. A large geophysical experimental collaboration called MELT (mantle electromagnetic and tomography) has in recent years sought to detect and map a region of mantle partial melting to better understand its behavior. As Buck discusses in his Perspective,
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Most of Earth9s volume is silicate mantle, hidden from view by a layer of surface crust. A large geophysical experimental collaboration called MELT (mantle electromagnetic and tomography) has in recent years sought to detect and map a region of mantle partial melting to better understand its behavior. As Buck discusses in his Perspective,
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Olivine flotation in mantle melt
Earth and Planetary Science Letters, 1993Abstract Molten komatiite and peridotite have been compressed in an octahedral multi-anvil device up to 10 GPa. Densities of the melts were measured at pressure intervals in the range 7 to 10 GPa by observing sinking and floating San Carlos olivines and synthetic forsterite marker spheres.
Carl B. Agee, David Walker
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Partial melting in the upper mantle
Physics of the Earth and Planetary Interiors, 1970The low velocity zone in tectonic and oceanic regions is too pronounced to be the effect of high temperature gradients alone. Partial melting is consistent with the low velocity, low Q and abrupt boundaries of this region of the upper mantle and is also consistent with measured heat flow values.
Anderson, Don L., Sammis, Charles
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