upper mantle


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Related to upper mantle: lower mantle

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 ?
Vertical segregation of the lithosphere is as follows: high-resistivity upper crust; low-resistivity middle--lower crusts; top of the upper mantle, which has weak characteristics of high resistivity; and bottom boundary of the lithosphere at 130 km depth, where resistivity becomes low again.
The study area is known as a super fast spreading segment of the EPR, and the experiment focused on revealing the upper mantle structure below the very young oceanic crust within an age of roughly 1.
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).
The JTGM is a tectonic klippe mainly composed of a refractory upper mantle section; here called foliated peridotites that occupy an area of about 150 km2.
The idea is to use seismic waves from quakes and other sources to make images of Earth's crust and upper mantle beneath North America -- "similar to how X-rays are used to make CT scans of the human body," the university says.
In particular we aim to study the influence of viscosity stratification, as well as the influence of the initial thermal regime, as controlled by crustal radiogenic heat production, on the resulting upper mantle structure.
The application of the method to earthquake data follows in order to image reflectors in the earth's crust and upper mantle and to demonstrate the feasibility of the method for estimating subsurface structure.
The geochemistry of volcanic rocks from the NE Pacific demonstrates that enriched components (veins, blobs, mantle plumes) in the upper mantle are a major contributor to intraplate, near-ridge, and ocean ridge volcanism to a degree not commonly seen in other seafloor regions.
8]) is kept or it will increase as the boundary with the upper mantle is approached.
the group velocity is less than the shear wave velocity in the upper mantle.
Topics include wind erosion in deserts, groundwater age dating, diffusion in solid silicates, crinoid ecological morphology, the Southern Dead Sea Fault, the redox state of Earth's mantle, coastal impacts due to sea-level rise, and the rheology of the lower crust and upper mantle.