Results 191 to 200 of about 77,130 (271)

Palaeoproterozoic S‐type granites from Garhwal Himalaya, NW India: Geochemistry, Sm–Nd isotope systematics and tectonic implications

Geological Journal, 2022
A combined geochemical and Sm–Nd isotopic study on the Palaeoproterozoic (1,845 Ma) granites of the Lesser Himalayan Crystalline Sequence (LHCS) in the Garhwal region of NW India has been done in the present study. These granite samples are characterized
Sumit Mishra, A. Slabunov, H. C. Nainwal, Vinod K. Singh, P. Singh, N. Nesterova, S. Svetov   +6 more
semanticscholar   +1 more source

Sm-Nd Isotopic Data and Earth's Evolution

Science, 1996
Samuel A. Bowring and Todd Housh (1) report Sm/Nd isotopic data giving a wide range of initial ENd values, from +3.5 to -4 at 4.0 billion years ago (Ga) and from +4 to -7 at 3.6 Ga. Their samples were from the Acasta gneisses of northern Canada, which represent the oldest known outcrops of continental crust (2).
S, Moorbath, M J, Whitehouse
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Sm-Nd isotopic evolution of chondrites

Earth and Planetary Science Letters, 1980
The ^(143)Nd/^(144)Nd and ^(147)Sm/^(144)Nd ratios have been measured in five chondrites and the Juvinas achondrite. The range in ^(143)Nd/^(144)Nd for the analyzed meteorite samples is 5.3 e-units (0.511673–0.511944) normalized to ^(150)Nd/^(142)Nd= 0.2096. This is correlated with the variation of 4.2% in ^(147)Sm/^(144)Nd (0.1920–0.2000).
Jacobsen, Stein B., Wasserburg, G. J.
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Sm-Nd isotopic provinces of the Aldan Shield

Doklady Earth Sciences, 2006
The formation of the Early Precambrian continental crust is among the most topical problems of modern geology and petrology and has remained a subject of debate for several decades. The Sm‐Nd isotopic mapping, which occupies an important place among modern methods developed for the solution of this issue, makes it possible to estimate the relative ...
A. B. Kotov, E. B. Sal’nikova, V. A. Glebovitsky, V. P. Kovach, A. M. Larin, S. D. Velikoslavinsky, N. Yu. Zagornaya   +6 more
openaire   +1 more source

Evidence for inherited Sm?Nd isotopes in granitoid zircons

Contributions to Mineralogy and Petrology, 1992
This study presents evidence to show that, in addition to preserving U−Pb isotope systematics, refractory zircons also preserve, at least in part, an inherited Sm−Nd isotope component. The zircons analyzed during this study were taken from the Strontian granitoid (NW Scotland). The inner intrusion of this composite pluton is known from a previous study
Rogers, G., Stephens, W. E., Paterson, B. A.   +2 more
openaire   +1 more source

Sm-Nd isotopic evolution of chondrites and achondrites, II

Earth and Planetary Science Letters, 1984
The ^(147)Sm-^(143)Nd and ^(146)Sm-^(142)Nd isotope systematics have been investigated in five chondrites and the achondrites Moama and Angra dos Reis (ADOR). The new chondrite data and those we have reported before are all consistent with our previously reported reference values for CHUR (“chondritic uniform reservoir”) of (^(143)Nd/^(144)Nd)_(CHUR)^0
Jacobsen, S. B., Wasserburg, G. J.
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SmNd isotopic systematics of a gabbro-eclogite transition

Lithos, 1986
Abstract SmNd isotopic systems have been studied in: (1) a sequence of coronitic olivine gabbros showing different degrees of transition to eclogite; (2) coronitic leuco-gabbro norite; and (3) country-rock eclogite, all from the Nordoyane-Brattvag area, western Norway. Isochrons defined by combinations of whole-rock samples and relict igneous phases
Mai Britt E. Mørk, Euan W. Mearns
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Sm-Nd and Rb-Sr isotopic systematics of ureilites

Geochimica et Cosmochimica Acta, 1991
The present evaluation of Sm-Nd and Rb-Sr isotopic data for seven ureilites establishes their divisions into three groups on the bases of Sm-Nd isotopic systematics. The first group of ureilites is made up of whole-rock samples whose highly depleted assemblages indicate Sm-Nd model ages consistent with 4.55 Ga. The second group of whole-rock samples of
Cyrena Anne Goodrich, P.Jonathan Patchett, Gunter W Lugmair, Michael J Drake   +3 more
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Sm—Nd isotopic age of Precambrian—Cambrian boundary in China

Geological Magazine, 1996
AbstractBy the new method of Sm—Nd isotopic dating on phosphatic small skeletal fossils and collo-phanite minerals, the Zhongyicun Member of the earliest Cambrian Meishucun Stage at Meishucun in Yunnan, southern China, has been dated at 562.8 ± 7.9 Ma and 562.1 ± 5.7 Ma.
Yang Jie-Dong, Sun Wei-Guo, Wang Zong-Zhe, Wang Yin-Xi   +3 more
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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 proposed that ...
S.N. Ehrenberg, P.H. Nadeau
openaire   +1 more source