Data_Sheet_1_Natural Clinopyroxene Reference Materials for in situ Sr Isotopic Analysis via LA-MC-ICP-MS.XLS

Clinopyroxene is a major host mineral for lithophile elements in the mantle lithosphere, and therefore, its origin is vital for constraints on mantle evolution and melt generation. In situ Sr isotopic measurement of clinopyroxene has been available since the recent development of laser ablation multicollector inductively coupled plasma mass spectrometry (LA-MC-ICP-MS) in the 2000s. Therefore, there is an increasing demand for natural clinopyroxene reference materials for Sr isotope microanalysis. In this contribution, we present six natural clinopyroxene reference materials from South Africa (JJG1424) and China (YY09-47, YY09-04, YY09-24, YY12-01, and YY12-02) for Sr isotope microanalysis. The Sr content of these clinopyroxenes ranges from 50 to 340 μg g−1, which covers most natural clinopyroxene compositions. Homogeneity of these potential reference materials were investigated and evaluated in detail over a 2-year period using 193-nm nanosecond and 257-nm femtosecond laser systems coupled to either a Neptune or Neptune Plus MC-ICP-MS. Additionally, the major and trace element of these clinopyroxenes were examined by electron probe microanalyzer (EPMA) as well as solution and laser ICP-MS. The in situ87Sr/86Sr values obtained for the six natural clinopyroxene reference materials agree well with data obtained using the thermal ionization mass spectrometer (TIMS) method. The Sr isotopic stability and homogeneity of these clinopyroxenes make them potential reference materials for in situ Sr microanalysis to correct instrumental fractionation or as quality control materials for analytical sessions. The new Sr isotope data provided here might be beneficial for microbeam analysis in the geochemical community.

单斜辉石（Clinopyroxene）是岩石圈地幔中亲石元素的主要赋存矿物，其成因对于限定地幔演化与熔体生成过程具有关键意义。自21世纪初激光剥蚀多接收杯电感耦合等离子体质谱仪（LA-MC-ICP-MS）技术发展以来，单斜辉石的原位Sr同位素测试已得以实现。因此，用于Sr同位素微区分析的天然单斜辉石标准参考物质的需求日益攀升。
本项工作中，我们提供了6种适用于Sr同位素微区分析的天然单斜辉石标准参考物质，其中1种产自南非（编号JJG1424），其余5种产自中国（编号分别为YY09-47、YY09-04、YY09-24、YY12-01及YY12-02）。这些单斜辉石的Sr含量介于50至340 μg·g⁻¹之间，覆盖了绝大多数天然单斜辉石的组成范围。
研究团队在为期2年的周期内，分别采用耦合于Neptune或Neptune Plus型多接收杯电感耦合等离子体质谱仪的193纳米纳秒及257纳米飞秒激光系统，对这些候选参考物质的同位素均一性进行了详尽的考察与评估。此外，本研究还通过电子探针显微分析仪（EPMA）、溶液法与激光剥蚀电感耦合等离子体质谱法，对这些单斜辉石的主量与微量元素组成开展了测定。
本次测得的6种天然单斜辉石标准参考物质的原位⁸⁷Sr/⁸⁶Sr比值，与热电离质谱仪（TIMS）法获得的测试结果吻合度极高。这些单斜辉石的Sr同位素稳定性与均一性，使其可作为原位Sr同位素微区分析中用于校正仪器分馏的标准物质，亦或是分析批次的质量控制样品。
本文提供的全新Sr同位素数据，或将为地球化学学界的微束分析研究提供有益参考。