Results 121 to 130 of about 4,715 (162)

The anatectic effect on the zircon Hf isotope composition of migmatites and associated granites

Lithos, 2015
Zircon Hf isotope composition is widely used to trace the growth and evolution of continental crust. However, it is controversial whether the Hf isotope composition of magmatic zircons can faithfully reflect that of their sources, especially for S-type granites.
Yi-Xiang Chen, Peng Gao, Yong-Fei Zheng
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Zircon Hf isotope composition of metamorphic eclogite from Xindian, Dabie Terrain

Science in China Series D: Earth Sciences, 2007
Hf isotope measurement has been carried out for UHP metamorphic eclogite from Xindian by using LA-MC-ICP-MS technique. The result indicates that metamorphic growth zircon has high 176Hf/177Hf (0.282544–0.282612) and low 176Lu/177Hf (0.000004–0.000211) ratio, inherited and recrystallized protolith zircon has low 176Hf/177Hf (0.282266–0.282466) and high ...
DaoGong Chen, Tao Ni, LieWen Xie
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Episodic zircon ages, Hf isotopic composition, and the preservation rate of continental crust

Geological Society of America Bulletin, 2011
U/Pb detrital zircon ages from global modern river sediments define eight peak clusters centered at 2700, 2500, 2010, 1840, 1600, 1150, 600, and 300 Ma. These clusters extend vertically into both positive and negative e Hf (T) space and are similar to those in orogenic granitoids that correlate well with supercontinent formation.
K. C. Condie, M. E. Bickford, R. C. Aster, E. Belousova, D. W. Scholl   +4 more
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Hf isotopic compositions of the standard zircons and baddeleyites used in U–Pb geochronology

Chemical Geology, 2006
Abstract Zircon and baddeleyite U–Pb geochronological dating is widely used in solid Earth sciences and the advent of rapid in-situ methods of analysis, such SIMS and ICP-MS, has re-emphasized the importance of having uniform standards. Recently, it has been shown that Hf isotopic data can provide important information on these minerals since they ...
Fu-Yuan Wu, Yue-Heng Yang, Lie-Wen Xie, Jin-Hui Yang, Ping Xu   +4 more
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The magma source at Mount Etna volcano: Perspectives from the Hf isotope composition of historic and recent lavas

Chemical Geology, 2011
Abstract High-precision Hf isotopic data for selected historic (pre-1971 eruption) and recent (post-1971) Etnean lavas are discussed in light of their covariation with previously reported Sr–Nd–Pb isotope ratios. 176Hf/177Hf ranges between 0.282961 and 0.282989 in the historic lavas, and between 0.282943 and 0.282990 in the recent ones, displaying ...
VICCARO, MARCO, NICOTRA E, MILLAR I. L, CRISTOFOLINI R.   +3 more
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Petrogenesis of Fuzhou composite pluton: Constraint from zircon U-Pb geochronology, geochemistry, and Hf isotopes

Acta Petrologica Sinica, 2021
福州复式岩体I-A型复合花岗岩的岩石成因与源区性质目前尚未得到很好认识。本文对福州复式岩体花岗岩进行了岩石学、锆石U-Pb年代学、主量和微量元素地球化学及锆石Hf同位素研究。该复式岩体花岗岩可分为钙碱性和碱性系列。LA-ICP-MS锆石U-Pb定年结果表明，钙碱性系列花岗岩形成年龄为111~101Ma，是早白垩世多期次岩浆活动作用的产物；碱性系列花岗岩形成的年龄为95~93Ma，是晚白垩世岩浆活动的产物。两类岩石均具有Eu负异常、LREE富集和HREE亏损的特征，并且Rb、Th、U、K、Pb等大离子亲石元素相对富集，Ba、Sr以及高场强元素Nb、Ta、P、Ti相对亏损。其中，钙碱性系列花岗岩的轻重稀土分馏程度较之碱性系列花岗岩明显，而碱性系列花岗岩的负铕异常比钙碱性系列花岗岩明显 ...
ZHU XueLi, YANG JinBao, HOU QingYe, ZHAO ZhiDan   +3 more
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The Sr–Nd–Pb–Hf Isotopic Composition of Late Paleozoic Granitoids in Central Chukotka

Doklady Earth Sciences, 2019
The results of Sr–Nd–Pb–Hf isotope analysis of Late Paleozoic granitoids of Central Chukotka, which are exemplified by the Kibera and Kuekvun plutons, are presented. The ages of these granitic plutons and of granite pebbles from conglomerates at the base of the overlying Lower Carboniferous strata are 351–363 Ma (U–Pb zircon, TIMS, SIMS, LA–ICP–MS ...
M. V. Luchitskaya, B. V. Belyatsky, E. A. Belousova, L. M. Natapov   +3 more
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Zircon age and Nd–Hf isotopic composition of the Yunnan Tethyan belt, southwestern China

International Journal of Earth Sciences, 2006
The Baoshan block of the Tethyan Yunnan, southwestern China, is considered as northern part of the Sibumasu microcontinent. Basement of this block that comprises presumably greenschist-facies Neoproterozoic metamorphic rocks is covered by Paleozoic to Mesozoic low-grade metamorphic sedimentary rocks.
Fukun Chen, Xiang-Hui Li, Xiu-Li Wang, Qiu-Li Li, Wolfgang Siebel   +4 more
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The Lu–Hf Isotope Composition of Zircon from Syenites of the Saharjok Alkaline Massif, Kola Peninsula

Geology of Ore Deposits, 2020
Zircon crystals from the alkaline and nepheline syenites of the Saharjok massif, which were formed during the magmatic (2645 ± 7 Ma), hydrothermal (1832 ± 7 Ma), and metamorphic (1784 ± 22 Ma) crystallization stages, were studied. Zircon from alkaline syenites displays lower eHf and eNd values than zircon from ocean island basalts (OIB); these values ...
V. R. Vetrin, E. A. Belousova
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Lu-Hf Isotopic Compositions of SNC Meteorites: Implications for Martian Mantle Evolution

Mineralogical Magazine, 1998
In contrast to the Earth, garnet is not stable in the lunar mantle and should not appear in the Martian mantle at shallow depth either. Clinopyroxene, however, is expected to be present in different proportions in the mantles of all three planets. The potential of Hf isotope geochemistry lies with a large parent-daughter Lu-Hf fractionation for garnet ...
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