Results 201 to 210 of about 40,674 (250)
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Halogen geochemistry of mantle fluids in diamond
AIP Conference Proceedings, 1995Argon and halogens (Cl, Br and I) have been measured, using 40Ar‐39 Ar stepped heating method, in diamonds from Jwaneng, Orapa (both in Botswana) and Zaire. The samples analysed included cubic (coated) stones and polycrystalline diamonds of eclogitic association. Both these types of diamond contain H2O, CO2, carbonate and silicate inclusions.
R. Burgess, G. Turner
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Mantle geochemistry: Insights from ocean island basalts
Science China Earth Sciences, 2017The geochemical study of the Earth’s mantle provides important constraints on our understanding of the formation and evolution of Earth, its internal structure, and the mantle dynamics. The bulk Earth composition is inferred by comparing terrestrial mantle rocks with chondrites, which leads to the chondritic Earth model.
ShiChun Huang, YongFei Zheng
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Geochemistry of Chromium in the Earth’s Mantle
2020A huge amount of data has been accumulated in the field of high-pressure mineralogy to date (Agee 1998; Stachel 2001; Akaogi 2007; Irifune and Tsuchiya 2007; Kaminsky 2012; and others). Direct study of the substance of the Earth’s mantle using data on the minerals of mantle xenolith and inclusions in natural diamonds is significantly restricted ...
Ekaterina A. Matrosova +2 more
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The geochemistry of carbon in mantle peridotites
Geochimica et Cosmochimica Acta, 1984Abstract Carbon abundances have been determined in mantle xenoliths from alkalic basalts and kimberlites and interpreted in terms of the nature and distribution of the C-rich phases. Anhydrous Cr-diopside Group I spinel lherzolites from basalts typically contain 15–50 ppm C, and amphibole-bearing ones have only marginally higher concentrations (40 ...
E.A. Mathez, V.J. Dietrich, A.J. Irving
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Geochemistry and models of mantle circulation
Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences, 1989Geochemical data help to constrain the sizes of identifiable reservoirs within the framework of models of layered or whole-mantle circulation, and they identify the sources of the circulating heterogeneities as mainly crustal and/or lithospheric, but they do not decisively distinguish between different types of circulation.
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Geochemistry and petrology of Victorian mantle xenoliths
2021This thesis was scanned from the print manuscript for digital preservation and is copyright the author. Researchers can access this thesis by asking their local university, institution or public library to make a request on their behalf. Monash staff and postgraduate students can use the link in the References field.
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The geochemistry and evolution of early precambrian mantle
Contributions to Mineralogy and Petrology, 1977Seven high-purity cumulate clinopyroxenes from 2.7 b.y. maficultramafic rock associations from the Abitibi belt, Superior Province, Canada, have been analyzed for major elements and K, Rb, Cs, Ba, Sr and 87Sr/86Sr ratio. Attempts to reconstruct the trace element patterns of the original parent magmas were partially successful; Sr contents (140 ppm), K ...
Stanley R. Hart, Christopher Brooks
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The carbon isotope geochemistry of mantle xenoliths
Earth-Science Reviews, 2002Abstract Carbon occurs in mantle samples in several chemical, mineralogical and morphological forms. It has been observed as CO 2 , CH 4 and CO in fluid inclusions, as carbonate, graphite, diamond, moissanite, solid solution in silicates, and organic compounds.
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Geochemistry of Dharwar ultramafics and the Archaean mantle
Lithos, 1975Abstract Geochemical and petrological studies on serpentinised ultramafics of Kadakola, Mysore State, India, indicate that the Archaean mantle beneath the Indian Shield was of peridotitic in nature. This protomantle in the Archaean period was undifferentiated with higher concentrations of siderophile and transitional elements.
V. Divakara Rao +3 more
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1979
The degree to which the mantle can be considered chemically uniform depends partly on the scales at which phenomena are analyzed. Many key geophysical observations (e.g., seismic velocities) relate to scales of 10–100 km. A key result discussed in Chapter 1 is that at these scales, the overall pyrolite composition derived for the upper mantle is ...
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The degree to which the mantle can be considered chemically uniform depends partly on the scales at which phenomena are analyzed. Many key geophysical observations (e.g., seismic velocities) relate to scales of 10–100 km. A key result discussed in Chapter 1 is that at these scales, the overall pyrolite composition derived for the upper mantle is ...
openaire +1 more source