矿物微区Lu-Hf同位素分析技术研究进展  

A Review of Progress in Microbeam Lu-Hf Isotopic Analysis on Minerals

作　　者：王浩 杨岳衡[1,2] 杨进辉 WANG Hao;YANG Yueheng;YANG Jinhui(State Key Laboratory of Lithospheric Evolution,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China;College of Earth and Planetary Sciences,University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院地质与地球物理研究所岩石圈演化国家重点实验室,北京100029 [2]中国科学院大学地球与行星科学学院,北京100049

出　　处：《岩矿测试》2022年第6期881-905,共25页Rock and Mineral Analysis

基　　金：国家自然科学基金面上项目(41973035);中国科学院青年创新促进会人才项目(2020068)。

摘　　要：矿物微区Lu-Hf同位素分析技术为了解岩浆活动和变质反应的微观过程以及示踪沉积物源信息提供了重要手段,极大地促进了岩石地球化学等领域学科发展。本文评价了176Yb和176Lu同质异位素、稀土元素氧化物以及富Ta基体等对微区Hf同位素测量精度和准确度的影响方式、校正策略和应对方案,总结了针对锆石、斜锆石、钙钛锆石、钛锆钍矿、异性石、金红石、锡石和铌铁矿等富铪矿物的微区Lu-Hf同位素分析方法、适用对象以及相关标样特征。富镥矿物的微钻/微锯Lu-Hf同位素等时线定年具有高精度的特点,可精确限定多期造山作用和矿物生长持续时间等。利用激光剥蚀电感耦合等离子体三重四极杆串级质谱(LA-ICP-Q-MS/MS)可以实现对石榴石等富镥矿物微米尺度高空间分辨率的微区Lu-Hf单点/等时线定年。该方法依赖Hf与NH3的碰撞反应实现Lu和Hf的在线分离,达到同步测量176Lu/177Hf和176Hf/177Hf比值的目的。新一代带碰撞/反应池的多接收串级磁式质谱具有高稳定性和高灵敏度特性,可在消除多离子(团)干扰的同时实现高精度Hf同位素分析,是未来微区Lu-Hf同位素分析发展的重要方向。BACKGROUND: Mircobeam Lu-Hf isotopic analysis on minerals provides an important means to understand the microscopic process of magmatic activity and metamorphic reaction and to trace provenance of sediment, which greatly promotes the development of petrogeochemistry. Many methods were provided to obtain accurate and precise microbeam Lu-Hf isotopic data, and many mineral standards for microbeam Lu-Hf isotopic analysis were developed.OBJECTIVES: To review and understand the microbeam methods for Lu-Hf isotopic analysis.METHODS: Systematic compilations of published data of standards and discussion on the different methods for microbeam Lu-Hf isotopic analysis.RESULTS: The development history of microbeam Lu-Hf isotopic analysis in the past 30 years is reviewed, and the influence of176Yb and176Lu isobars, REE oxides, and Ta-rich matrices on the precision and accuracy of Hf isotope measurement is systematically evaluated as well as the different correction strategies and programs provided in previous studies. In addition, a comprehensive compilation of the different Yb and Lu isotopic compositions reported in references and the different methods of microbeam Lu-Hf isotopic analyses on various Hf-rich minerals such as zircon, baddeleyite, zirconolite, zirkelite, calzirtite, eudialyte, rutile, cassiterite, and columbite-group minerals is made. The micro-drill/micro-saw sampling Lu-Hf isotopic analysis of Lu-rich minerals has played an important role in revealing the multi-stage orogenic process and the duration of mineral growth. The advent of laser ablation inductively coupled plasma triple quadrupole mass spectrometry(LA-ICP-Q-MS/MS) has increased the spatial resolution of Lu-Hf single-spot/isochron dating analysis of Lu-rich minerals to the micrometer scale. This method relies on the collision reaction of Hf and NH3to realize the online separation of Hf from Lu, and achieves the purpose of synchronous measurement of176Lu/177Hf and176Hf/177Hf ratios, which is introduced in detail.CONCLUSIONS: The new generation of ta

关 键 词：LU-HF同位素 LA-MC-ICPMS 锆石 石榴石 微区分析 

分 类 号：O657.63[理学—分析化学]