In situ determination of hafnium isotopes from rutile using LA-MC-ICP-MS  

作　　者：LI Yang YANG YueHeng JIAO ShuJuan WU FuYuan YANG JinHui XIE LieWen HUANG Chao 

机构地区：[1]State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences [2]College of Earth Science, University of Chinese Academy of Sciences

出　　处：《Science China Earth Sciences》2015年第12期2134-2144,共11页中国科学（地球科学英文版）

基　　金：supported by the National Natural Science Foundation of China(Grants Nos.41130313&41525012)

摘　　要：The hafnium isotopic analysis using laser ablation has been widely conducted on Hf-rich minerals （zircon/baddeleyite/ calzirtite/eudialyte）, however, little work has been reported on Hf-poor （〈100 ppm） minerals. This work presents a detailed procedure of in situ hafnium isotopic analysis from ruffle using laser ablation multiple collector inductively coupled plasma mass spectrometry （LA-MC-ICP-MS）. The rutile U-Pb dating reference material JDX shows homogeneous hafnium isotopic ratios, with 176Hf/177Hf=0.281795±0.000015 （2SD, n=33） and176Lu/177Hf=0.000018±0.000004 （2SD, n=17） that suggest the possibility of using JDX as a new reference material hafnium isotopic measurement. We also measure hafnium isotopic compositions of other rutile U-Pb dating reference material （R10, Sugluk-4 and PCA-S207） and the 176Hf/177Hf values are similar to previously reported results, which confirms that we can acquire accurate and precise hafnium isotopic compositions using our developed analytical protocol. We analyzed hafnium isotopic compositions and U-Pb ages of rutile in high-temperature and ultrahigh-temperature granulites from various terrains of the Khondalite Belt from the North China Craton, combined with zircon results in the same area, suggesting that the metamorphic evolution history of the granulite is much more complicated than previously thought.The hafnium isotopic analysis using laser ablation has been widely conducted on Hf-rich minerals(zircon/baddeleyite/ calzirtite/eudialyte), however, little work has been reported on Hf-poor(<100 ppm) minerals. This work presents a detailed procedure of in situ hafnium isotopic analysis from rutile using laser ablation multiple collector inductively coupled plasma mass spectrometry(LA-MC-ICP-MS). The rutile U-Pb dating reference material JDX shows homogeneous hafnium isotopic ratios, with 176Hf/177Hf=0.281795±0.000015(2SD, n=33) and 176Lu/177Hf=0.000018±0.000004(2SD, n=17) that suggest the possibility of using JDX as a new reference material hafnium isotopic measurement. We also measure hafnium isotopic compositions of other rutile U-Pb dating reference material(R10, Sugluk-4 and PCA-S207) and the 176Hf/177 Hf values are similar to previously reported results, which confirms that we can acquire accurate and precise hafnium isotopic compositions using our developed analytical protocol. We analyzed hafnium isotopic compositions and U-Pb ages of rutile in high-temperature and ultrahigh-temperature granulites from various terrains of the Khondalite Belt from the North China Craton, combined with zircon results in the same area, suggesting that the metamorphic evolution history of the granulite is much more complicated than previously thought.

关 键 词：RUTILE hafnium isotope in situ laser ablation MC-ICP-MS KHONDALITE 

分 类 号：P597[天文地球—地球化学]