Results 181 to 190 of about 17,328 (228)

Thermodynamics of the Upper Mantle

Geophysical Journal of the Royal Astronomical Society, 2010
Summary An analysis is made of the energy input from the upper mantle to the crust since Palaeozoic times under the Japanese islands. It is argued that significant changes in this rate have occurred. These changes in energy input are interpreted in terms of unsteady mantle convection. The effect of the C layer on convection is discussed.
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Earth’s Structure, Upper Mantle

2011
The upper mantle is defined as that part of the mantle between the crust and the phase transition of γ-olivine to perovskite. The total mass of the upper mantle is 1.06 × 1024 kg, about a quarter of the total mass of the mantle. Its volume, 2.95 × 1011 km3, is a third of the total volume of the mantle. Until the discovery of a major transition near 660-
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The Upper Mantle

Geological Magazine, 1973
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Upper Mantle Project

Eos, Transactions American Geophysical Union, 1964
The Upper Mantle Project was proposed in 1960 as an international scientific program, in which the attention of geophysisists would be directed toward the Earth's interior—in particular toward the outermost 1000 km of the Earth's radius, or that part of the Earth whose processes most influence the development of the Earth's crust.
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Upper mantle mineralogy

Journal of Geodynamics, 1995
The mineralogy of the upper mantle is reviewed in the context of the petrology of xenolith suites entrained in alkali basalts and kimberlites. Low pressure (spinel) and high pressure (garnet) lherzolites (olivine + clinopyroxene + orthopyroxene) are the most abundant fertile (i.e.
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Upper mantle project

Eos, Transactions American Geophysical Union, 1966
The International Upper Mantle Project (UMP) is one of the main programs of the International Council of Scientific Unions (ICSU). The UMP is coordinated by the International Upper Mantle Committee, an IUGG Committee set up jointly by the International Union of Geodesy and Geophysics and the International Union of Geological Sciences, with rules ...
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The nature of the upper mantle

Mineralogical Magazine, 1981
AbstractThe nature of the upper mantle below the ancient cratonic areas can be deduced by study of the xenolith suites in kimberlites. Studies on the proportions of xenoliths, together with their mineralogy and chemistry, suggest an upper mantle containing an upper harzburgite zone and a lower lherzolite zone, with both of these zones containing ...
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Palaeoanisotropy in the upper mantle

Nature, 1977
CARTER1 has reviewed advances in understanding the steady-state flow of rocks with particular reference to the behaviour and anisotropic alignment of rocks in the upper mantle. Some form of high-temperature creep is clearly responsible for the distribution of continents and their first-order structures2. The difficulty is specifying the exact mechanism
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A model for the upper mantle

Journal of Geophysical Research, 1962
The occurrence of a low-velocity zone in the upper mantle has been attributed to the effect of high temperature gradients. If the upper mantle is homogeneous, it is shown that the required temperature gradients would lead to extensive melting. Since this consequence is unacceptable, it appears necessary to consider nonhomogeneous models.
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On the structure of the upper mantle

Bulletin of the Seismological Society of America, 1966
Abstract From apparent velocities of first arrivals across the Tonto Forest array for epicentral distances from 11° to 29° Niazi and Anderson derived a structure of the upper mantle deviating markedly from other structures as determined of late. It is found that on a different interpretation their data are in good accord with the Lehmann
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