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Hf isotopic compositions of the standard zircons for U-Pb dating 总被引:48,自引:4,他引:48
XU Ping WU Fuyuan XIE Liewen & YANG Yueheng Institute of Geology Geophysics Chinese Academy of Sciences Beijing China Correspondence should be addressed to Wu Fuyuan 《科学通报(英文版)》2004,49(15):1642-1648
Zircon, a common accessory mineral in various kindsof rocks, is an important subject for U-Pb isotopic dating.With requirements for high spatial resolution with highprecision and accuracy, SHRIMP (Sensitive High Resolu-tion Ion Micro Probe) and LA-ICPMS (Laser AblationInductively Coupled Plasma Mass Spectrometry) nowserve as the important tools in zircon U-Pb dating. Sinceboth methods need standard zircon for external age cali-bration, an ideal standard zircon is critical for obtai… 相似文献
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《科学通报(英文版)》2008,(7)
Using newly determined Sm isotopic abundances for correcting the isobaric interference of 144Sm on 144Nd and the established mass bias relationship between Sm and Nd, a series of in situ Nd isotopic measurements were conducted for relatively high Nd concentrations of natural geological materials, including apatite, titanite, monazite and perovskite on a Neptune multi-collector inductively coupled plasma mass spectrometry (MC-ICPMS), coupled to a 193 nm ArF excimer laser ablation system. The results show that Ce has no significant influence on the precision and accuracy of Nd isotopic analyses for LREE-enriched geological minerals and that our approach is efficient in obtaining reliable 143Nd/144Nd and 147Sm/144Nd ratios for those materials with Sm/Nd<1 (147Sm/144Nd<0.6). When combined with trace element and U-Pb isotope data, the in situ Nd isotopic data can provide important information on geological processes. 相似文献
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LA-MC-ICPMS U-Pb dating has been performed on detrital zircons from the Upper Carboniferous Tai-yuan Formation (N-8) in the Ningwu-Jingle Basin, west of the North China Craton (NCC). The ages of 72 detrital zircon grains are divided into three groups: 303―320 Ma (6 grains), 1631―2194 Ma (37 grains, peaked at 1850 Ma), 2318―2646 Ma (29 grains, peaked at 2500 Ma). Detrital zircons of Group 2 and Group 3 were likely derived from the basement of the NCC. Group 1 zircons exhibit 176Hf/177Hf ratios ranging from 0... 相似文献
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Qinghu zircon: A working reference for microbeam analysis of U-Pb age and Hf and O isotopes 总被引:13,自引:0,他引:13
LI XianHua TANG GuoQiang GONG Bing YANG YueHeng HOU KeJun HU ZhaoChu LI QiuLi LIU Yu LI WuXian 《科学通报(英文版)》2013,58(36):4647-4654
Zircon is the most useful mineral for studies in U-Pb geochronology and Hf and O isotope geochemistry. Matrix effect is a major problem of the microbeam techniques such as SIMS and LA-(MC)-ICPMS. Therefore, external standardization using well-characterized natural zircon standards is fundamental for accurate microbeam measurements. While the isotopic geochro- nology and geochemistry laboratories equipped with microbeam analytical facilities have been increasingly established in China during the past decade, applications of the isotopic microanalysis are still limited due to shortage of available standards. We report here the Qinghu zircon as a potential new working reference for microbeam analysis of zircon U-Pb age and O-Hf isotopes. This zircon was separated from the Qinghu quartz monzonite from the western Nanling Range, Southeast China. It is fairly homoge- neous in U-Pb age and Hf and O isotopes in terms of large amounts of mircobeam measurements by LA-MC-ICPMS and SIMS at the scales of 20-60 ~tm. SIMS measurements yield consistent 2~6pb/238U age within analytical uncertainties with that obtained by ID-TIMS. Precise determinations of O isotopes by IRMS and Hf isotopes by solution MC-ICPMS are in good agreement with the statistical mean of microbeam measurements. We recommend U-Pb age of = 159.5 ± 0.2 Ma (2SE), δ^18O = 5.4‰ ± 0.2%0 (2SD) and 176Hf/177Hf = 0.283002 ± 0.000004 (2SD) as the best reference values for the Qinghu zircon. 相似文献
5.
Using newly determined Sm isotopic abundances for correcting the isobaric interference of ^144Sm on ^144Nd and the established mass bias relationship between Sm and Nd, a series of in situ Nd isotopic measurements were conducted for relatively high Nd concentrations of natural geological materials, including apatite, titanite, monazite and perovskite on a Neptune multi-collector inductively coupled plasma mass spectrometry (MC-ICPMS), coupled to a 193 nm ArF excimer laser ablation system. The results show that Ce has no significant influence on the precision and accuracy of Nd isotopic analyses for LREE-enriched geological minerals and that our approach is efficient in obtaining reliable ^143Nd/^144Nd and ^147Sm/^144Nd ratios for those materials with Sm/Nd〈1(^147Sm/^144Nd〈0.6). When combined with trace element and U-Pb isotope data, the in situ Nd isotopic data can provide important information on geological processes. 相似文献
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