Whole-rock major and trace elements data, and whole-rock and carbonate isotope data, for the potassic and ultrapotassic rocks from Nangqian basin (Eastern Tibet)

Whole-rock major and trace elements data, and whole-rock and carbonate isotope data, for the Nangqian potassic and ultrapotassic rocks. Whole-rock major and trace elements were measured at ISTerre, University Grenoble Alpes. For major elements, 50 mg of rock powder were digested in HF/HNO3 mixture at 90 during five days. Excess HF was neutralized using boric acid and solutions were diluted with 250 mL of Milli-Q water. Major element contents were measured by Inductively Coupled Plasma - Atomic Spectrometry (ICP-AES) in Grenoble using the method given in Chauvel et al. (2011, doi:10.1111/j.1751-908X.2010.00086.x). For trace elements, 100mg of rock powder were digested with a mixture of concentrated HF and HNO3 at 150 for at least two weeks in steer Spar bombs. Excess Hf was neutralized with HNO3, using cycles of acid addition/evaporation. 300 mg of a spike containing Be, Ge, In, Tm and Bi were added to an aliquot of the rock solution corresponding to 8 mg of the initial powder. The solutions were then evaporated, diluted with 2% HNO3 (+ 1 drop of HF), and analysed by Inductively Coupled Plasma - Mass Spectrometry. During measurement, the signal was calibrated using the reference material BR24 (Chauvel et al., 2011, doi:10.1111/j.1751-908X.2010.00086.x), which was run every 4 or 5 analyses. Quality of the analytical procedure was checked by analysing blanks, international reference materials (BHVO2, BEN, BCR2), duplicate solutions and multiple runs of solutions. Only elements with external reproducibility < 15% are given. The SARM-CRPG in Nancy and SEDISOR in Brest performed the whole-rock Sr and Nd isotope analyses. Results were normalized to values of 143Nd/144Nd = 0.512110 for JNd-I reference material and 0.511850 for LaJolla, and to 87Sr/86Sr = 0.710250 for the reference material NIST SRM 987. Blanks were 74 pg for Nd and 137 pg for Sr. ε-Nd(T) ratios were calculated using the CHUR isotopic composition of Bouvier et al. (2008, doi:10.1016/j.epsl.2008.06.010). Stable isotope analysis of carbonates was carried out in the stable isotope laboratory of Geoscience Rennes, CNRS-University of Rennes I. Carbonates in whole-rock powders were selectively dissolved at 50 with anhydrous phosphoric acid H3PO4. The released CO2 gases were collected using a cryogenic extraction line, and their isotopic compositions were analyzed by a VG Optima triple collector mass spectrometer. […]

本数据集涵盖囊谦钾质及超钾质岩石的全岩主量元素、微量元素数据，以及全岩与碳酸盐同位素数据。全岩主量元素与微量元素的测试工作在格勒诺布尔阿尔卑斯大学ISTerre实验室完成。
对于主量元素分析：称取50 mg岩石粉末，置于HF/HNO3混合溶剂中，于90℃下消解五日。过量的HF采用硼酸中和，随后用250 mL Milli-Q超纯水稀释溶液。主量元素含量通过电感耦合等离子体原子发射光谱法（Inductively Coupled Plasma - Atomic Spectrometry, ICP-AES）在格勒诺布尔测定，测试方法参照Chauvel等人（2011，doi:10.1111/j.1751-908X.2010.00086.x）的实验方案。
对于微量元素分析：称取100 mg岩石粉末，以浓HF与HNO3混合溶剂在Steer型高压消解弹中于150℃下消解至少两周。通过多次加酸-蒸发循环，用HNO3中和过量的HF。移取对应初始粉末8 mg的岩石溶液分样，加入含Be、Ge、In、Tm和Bi的混合内标300 mg。随后将溶液蒸发，用2% HNO3（添加1滴HF）稀释，通过电感耦合等离子体质谱法（Inductively Coupled Plasma - Mass Spectrometry, ICP-MS）完成分析。测试期间，每4~5次分析即插入BR24标准参考物质（Chauvel等，2011，doi:10.1111/j.1751-908X.2010.00086.x）进行信号校准。
分析流程的质量控制通过空白样测试、国际参考物质（BHVO2、BEN、BCR2）分析、平行消解溶液制备以及多次重复测定来完成。仅给出外部重现性优于15%的元素数据。
全岩Sr、Nd同位素分析由南希的SARM-CRPG实验室与布雷斯特的SEDISOR实验室完成。同位素结果的标准化参数设置如下：JNd-I参考物质的143Nd/144Nd比值为0.512110，LaJolla标准的143Nd/144Nd比值为0.511850，NIST SRM 987参考物质的87Sr/86Sr比值为0.710250。本底空白为Nd 74 pg、Sr 137 pg。ε-Nd(T)比值采用Bouvier等人（2008，doi:10.1016/j.epsl.2008.06.010）提出的球粒陨石均一库（CHUR）同位素组成计算得到。
碳酸盐稳定同位素分析在法国国家科研中心雷恩第一大学地球科学研究所（Geoscience Rennes, CNRS-University of Rennes I）的稳定同位素实验室开展。将全岩粉末中的碳酸盐组分在50℃下用无水磷酸H3PO4选择性溶解，释放的CO2气体通过低温萃取系统收集，随后采用VG Optima型三接收器质谱仪分析其同位素组成。[...]