upper mantle


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upper mantle

[′əp·ər ′mant·əl]
(geology)
The portion of the mantle lying above a depth of about 600 miles (1000 kilometers). Also known as outer mantle; peridotite shell.
References in periodicals archive ?
The high density of eclogite together with the relatively cooler, denser peridotite in the rigid upper mantle causes the oceanic lithosphere to have negative buoyancy compared to the asthenosphere, so that it sinks into the mantle and pulls the tectonic plate along behind it.
The microscopic cracks that we think are in the upper mantle of the plate can partly cancel out the anisotropy of the crystal fabric from mantle flow.
This material accumulated was has been circulated along a northeast orientation, reaching vertically upwards from the upper mantle to the lower crust and forming an open density gradient zone with the high-density Yangzi block in the eastern section.
The researchers propose that upper mantle fluids flow into the fault and provide a source of high pressure that extends the depth of seismic activity.
This is necessary recording length to obtain MT impedance estimates at periods up to 1 day with error level of a few % of the off-diagonal and 5-10% of the diagonal elements for reliable 3-D inversion of the upper mantle structure.
Thus, one can speculate that plate tectonic processes have played a role in controlling magma ascent ascent and arrest from both the fixed mantle plume (seamounts and islands along the main JFR corridor) and perhaps the upper mantle (peripheral and/or isolated seamounts or intracrustal intrusions).
Previous works have reported that these rocks were originated from various kinds of upper mantle to crustal sections of ocean basin (OB) (i.e., MORB origin), intra-oceanic island-arc (intra-OIA), and back-arc basin (BAB) [5, 6].
This section represents the upper mantle segment of oceanic lithosphere and is found in both the massifs of the ophiolite.
The same holds true for Earth's continents and mountain ranges, which maintain their loftiness by having deep, buoyant "roots" that extend into the upper mantle.
3 In science, which is nearest the earth's crust: the outer core or the upper mantle? 4 Yiddish is a language spoken by people of which religion?
"The information from the new images confirms the idea that there needs to be some amount of melt in the upper mantle and that's really what's creating this ductile behaviour for plates to slide.'