To meet the rapid development of zircon U-Pb geochronology and Hf-O isotope geochemistry,it is imperative to develop well-characterized zircon reference materials for microbeam analysis.Here,zircon KV01 separated from...To meet the rapid development of zircon U-Pb geochronology and Hf-O isotope geochemistry,it is imperative to develop well-characterized zircon reference materials for microbeam analysis.Here,zircon KV01 separated from the Kaap Valley pluton,South Africa is introduced as a potential Archean reference material for microbeam U-Pb age and Hf-O isotope determination.SIMS and LA-ICP-MS U-Pb isotopic measurements gave grand mean 207Pb/206Pb ages of 3233±16 Ma(2 s,n=90)and 3230±26 Ma(2 s,n=52),which are consistent with reported CA-ID-TIMS results.Slight heterogeneity of oxygen isotopes is revealed by SIMS analyses that yielded a relatively largeδ18O range of 4.61–6.51‰.Among them,the zircon grains with clear oscillatory zones give a grand meanδ18O value of 6.17±0.33‰(2 s),which is suggested to record the primary O isotopic compositions.The homogeneity in the Hf isotopic compositions of KV01 zircon was checked by the laser ablation and solution MC-ICP-MS methods.They yielded consistent results with a recommended 176Hf/177Hf ratio of 0.280810±0.000013(2 s).The results reported here demonstrate that KV01 zircon could be a reliable reference material for microbeam 207Pb/206Pb age and Hf isotope determinations of ancient zircons,and be suitable as a quality monitor for SIMS oxygen isotopic analysis.展开更多
基金supported by the National Key R&D Program of China(Grant No.2016YFC0600109)the B-type Strategic Priority Program of the Chinese Academy of Sciences(Grant No.XDB41000000)+2 种基金the National Natural Science Foundation of China(Grant Nos.41973035&41688103)the Youth Innovation Promotion Association of the Chinese Academy of Sciences(Grant No.2020068)the State Key Laboratory of Lithospheric Evolution(Grant No.SKL-Z201901-YT)。
文摘To meet the rapid development of zircon U-Pb geochronology and Hf-O isotope geochemistry,it is imperative to develop well-characterized zircon reference materials for microbeam analysis.Here,zircon KV01 separated from the Kaap Valley pluton,South Africa is introduced as a potential Archean reference material for microbeam U-Pb age and Hf-O isotope determination.SIMS and LA-ICP-MS U-Pb isotopic measurements gave grand mean 207Pb/206Pb ages of 3233±16 Ma(2 s,n=90)and 3230±26 Ma(2 s,n=52),which are consistent with reported CA-ID-TIMS results.Slight heterogeneity of oxygen isotopes is revealed by SIMS analyses that yielded a relatively largeδ18O range of 4.61–6.51‰.Among them,the zircon grains with clear oscillatory zones give a grand meanδ18O value of 6.17±0.33‰(2 s),which is suggested to record the primary O isotopic compositions.The homogeneity in the Hf isotopic compositions of KV01 zircon was checked by the laser ablation and solution MC-ICP-MS methods.They yielded consistent results with a recommended 176Hf/177Hf ratio of 0.280810±0.000013(2 s).The results reported here demonstrate that KV01 zircon could be a reliable reference material for microbeam 207Pb/206Pb age and Hf isotope determinations of ancient zircons,and be suitable as a quality monitor for SIMS oxygen isotopic analysis.
