Results 201 to 210 of about 77,130 (271)
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Complex isotopic-geochemical (Sm-Nd, U-Pb) study of Salma eclogites
Doklady Earth Sciences, 2010Salma eclogites distinguished in the northwestern part of the Belomorian mobile belt (BMB) is one of the key objects supporting the application of the plate tectonics mechanism to the Early Precambrian [1]. In this connection, age dating of eclogite metamorphism acquires principal importance and requires a complex approach.
S. G. Skublov +7 more
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Sm-Nd isotopic study of garnets and their metamorphic host rocks
Transactions of the Royal Society of Edinburgh: Earth Sciences, 1980ABSTRACTIn this feasibility study, Sm/Nd and 143Nd/144Nd ratios have been determined on garnets and coexisting mineral and whole-rock phases from a selection of amphibolite facies rocks, granulite facies rocks and an eclogite. In two micaceous schists and an eclogite the distribution coefficient of the Sm/Nd ratio in garnet relative to other phases is ...
O. van Breemen, C. J. Hawkesworth
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The theoretical effect of metasomatism on Sm-Nd isotopic systems
Geochimica et Cosmochimica Acta, 1990Abstract If Sm and Nd are mobilized during fluid-rock interaction, fractionation of the ratio between Sm and Nd in geological units may take place. The fractionation can be characterized by a fractionation factor F , which can attain any value between D Sm /D Nd and 1 /( D Sm /D Nd ) depending on the fluid/rock ratio ...
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Isotopic evidence for chondritic Lu/Hf and Sm/Nd of the Moon
Earth and Planetary Science Letters, 2013Abstract Refractory lithophile elements are generally considered to occur in chondritic relative abundances in terrestrial planets. This assumption forms the basis for using isotope systems such as 176Lu–176Hf and 146, 147Sm–142, 143Nd as tracers of planetary evolution.
Sprung Peter +2 more
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Sm-Nd Isotopic Studies of Proterozoic Anorthosites: Systematics and Implications
1985Sm-Nd isotopic studies of anorthosites can be used to provide information on their ages of crystallization and metamorphism, contamination history, and mantle sources. Proterozoic anorthosites in the Grenville and Nain Provinces of eastern North America crystallized between about 1100 and 1600 Ma, and some were metamorphosed at about 1000 Ma. Grenville
Lewis D. Ashwal, Joseph L. Wooden
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SM–ND isotopic investigations of Isua supracrustals and implications for mantle evolution
Nature, 1978THE 147Sm–143 Nd system has been successfully exploited for the dating of lunar rocks and meteorites1–3 and has yielded results of comparable precision to those obtained from the 87Rb–87Sr system. Furthermore, recent studies of the Angra dos Reis achondrite3,4,30 have shown that the age obtained by the Sm–Nd method is in excellent agreement with ages ...
P. J. HAMILTON +4 more
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Evaluation of sample dissolution method for Sm-Nd isotopic analysis of scheelite
Journal of Analytical Atomic Spectrometry, 2012Sm-Nd isotope systematics of scheelite is becoming a powerful geochronometer for dating the Au and W ore deposits. However, Sm-Nd isotopic analysis of scheelite is relatively difficult due to the formation of large amounts of tungstic acid (H2WO4) precipitates during the conventional acid decomposition of scheelite.
Zhu-Yin Chu +6 more
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Sm-Nd Isotopic Data from Archean Metavolcanic Rocks at Holenarsipur, South India
The Journal of Geology, 1987Results of a Sm-Nd isotopic analysis of Archean metavolcanics in the Holenarsipur greenstone belt, Karnataka, South India, give a whole-rock isochron age of 2.62 Ga for lightly deformed metabasaltic amphibolites in the northern part of the belt. This is within error of the age of high-grade metamorphism and crustal thickening which affected areas ...
S. A. Drury +2 more
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Origin of eclogites from South Brittany, France: A SmNd isotopic and REE study
Chemical Geology: Isotope Geoscience section, 1985Abstract Rare-earth element (REE) distribution patterns and Sr and Nd isotopic compositions have been obtained on 10 whole-rock samples (5 eclogites, 2 garnet-pyroxenites, 3 metagabbros) from the Armorican massif in the Hercynian fold-belt of western France. The REE distribution patterns suggest that: (1) the protoliths of the eclogites originated in
Bernard-Griffiths, J., Cornichet, J.
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Rb–Sr, Sm–Nd and Ar–Ar isotopic systematics of Martian dunite Chassigny
Earth and Planetary Science Letters, 2006Abstract Isotopic analysis of the Martian meteorite Chassigny yields a Rb–Sr age of 1406 ± 14 Ma with an initial 87 Sr/ 86 Sr ratio of 0.702251 ± 0.000034, a Sm–Nd age of 1386 ± 28 Ma with an initial e 143Nd -value of + 16.9 ± 0.3 and an 39 Ar– 40 Ar age of 1360 + 40 − 20 Ma.
K MISAWA +4 more
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