Results 141 to 150 of about 2,514 (184)

Postdepositional Sm/Nd Fractionation in Sandstones: Implications for Neodymium-Isotope Stratigraphy

Journal of Sedimentary Research, 2002
Abstract Sandstone reservoirs from the Norwegian continental shelf commonly show varying degrees of postdepositional fractionation of Sm/Nd ratio, apparently due to preferential incorporation of Sm in the crystal lattice of diagenetic apatite. Based on data from leaching experiments, an apatite mineral separate, and petrography, it is
S.N. Ehrenberg, P.H. Nadeau
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Hydrothermal Remobilisation of Sm-Nd Isotopes at the Mineral Scale in Granites

Mineralogical Magazine, 1994
Very little is known about the behaviour of isotopic systems at the mineral scale during fluidrock interactions (Halliday et al., 1991). In order to investigate this, we have made a Sm-Nd isotope mineralogical study of two examples of granites. It appears that although some minerals retain their magmatic signature, others can be severely affected by ...
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Sm-Nd Isotopic Studies of Proterozoic Anorthosites: Systematics and Implications

1985
Sm-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, 1978
THE 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, R. K. O'NIONS, N. M. EVENSEN, D. BRIDGWATER, J. H. ALLAART   +4 more
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Comparative Sm-Nd isotope behavior of accessory minerals: Reconstructing the Sm-Nd isotope evolution of early Archean rocks

Geochimica et Cosmochimica Acta, 2022
Da Wang, Steven B. Shirey, Richard W. Carlson, Christopher M. Fisher, Anthony I.S. Kemp, Marion E. Bickford   +5 more
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Sm‐Nd isotopic evidence on the age of eclogitization in the Zermatt‐Saas ophiolite

Journal of Metamorphic Geology, 1994
ABSTRACTRocks within the Zermatt‐Saas ophiolite of the western Alps have undergone eclogite facies metamorphism during subduction prior to the Alpine collision. The metamorphic history of these rocks is well defined, with eclogitic assemblages being followed by the limited growth of blueschist assemblages of glaucophane and paragonite.
S. A. BOWTELL, R. A. CLIFF, A. C. BARNICOAT   +2 more
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Combined La–Ce and Sm–Nd isotope systematics in petrogenetic studies

Nature, 1987
A theoretical model is presented for the coupled evolution of cerium and neodymium isotopes in terrestrial rocks. Data presented for samples ranging from mid-ocean-ridge basalts to continental metamorphic rocks show that, while mantle-derived rocks are dispersed on a Ce-Nd diagram, continental crustal rocks form a clearly defined 'mantle array'.
T. Tanaka, H. Shimizu, Y. Kawata, A. Masuda   +3 more
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Evaluation of sample dissolution method for Sm-Nd isotopic analysis of scheelite

Journal of Analytical Atomic Spectrometry, 2012
Sm-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, Jing-Hui Guo, Yue-Heng Yang, Liang Qi, Lei Chen, Xiao-Chun Li, Jian-Feng Gao   +6 more
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Modification of the Sm–Nd isotopic system in garnet induced by retrogressive fluids

Journal of Metamorphic Geology, 2018
AbstractGarnet, as a major constitutive mineral of eclogite, is important for Sm–Nd dating of eclogite due to its high Sm/Nd ratio and its stability during retrogression. However, a comprehensive study of the petrography, mineral chemistry, garnet water content, and Sm–Nd isotopic composition of eclogites from the Bixiling massif, Central Dabie Zone ...
Shi‐Chao An, Shu‐Guang Li, Zhen Liu
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Origin of eclogites from South Brittany, France: A SmNd isotopic and REE study

Chemical Geology: Isotope Geoscience section, 1985
Abstract 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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