碳酸盐岩钙同位素化学分离方法改进及其在青藏高原地质样品中的应用前景  

Improvement of Chemical Separation Method of Calcium Isotopes in Carbonate Rocks and Its Application Prospect in Geological Samples of the Qinghai-Tibet Plateau

作　　者：李柯然 杨迪 夏舜 宋金民 刘芳[3] 杨雄 LI Keran;YANG Di;XIA Shun;SONG Jinmin;LIU Fang;YANG Xiong(State Key Laboratory of Oil and Gas Reservoir Geology,Chengdu,Sichuan 610059,China;College of Energy Resources,Chengdu University of Technology,Chengdu,Sichuan 610059,China;College of Geoscience,Chengdu University of Technology,Chengdu,Sichuan 610059,China)

机构地区：[1]油气藏地质及开发工程国家重点实验室,成都610059 [2]成都理工大学能源学院,成都610059 [3]成都理工大学地球科学学院,成都610059

出　　处：《中国无机分析化学》2023年第1期44-53,共10页Chinese Journal of Inorganic Analytical Chemistry

基　　金：国家自然科学基金资助项目(41872150)。

摘　　要：为获得更高的测试精度,在前人基础上改进了碳酸盐岩(白云石-方解石)地质样品钙同位素化学分离方案。通过对比云南永善桧溪剖面白云岩-灰岩过渡岩性在不同HCl浓度下淋洗结果,确定了5 mol/L的HCl能有效富集白云石-方解石体系中的钙元素,且热电离质谱(TIMS)测试结果显示4 mol/L的HCl与1.6 mol/L的HCl淋洗方案处理后钙同位素测试结果一致,表明在相同测试精度的情况下,针对白云石-方解石体系下碳酸盐岩地质样品化学分离方案能提高化学分离效率。进一步结合青藏高原研究热点问题,对钙同位素在青藏高原地质样品的应用前景进行了分析,分析表明,钙同位素在青藏高原隆升前古海洋环境重建、隆升期构造活动恢复及隆升后火成岩来源示踪上具有广泛应用前景。In order to obtain higher test accuracy,the chemical separation scheme of calcium isotopes in carbonate rock(dolomite-calcite)geological samples was improved on the basis of predecessors in this paper.By comparing the leaching results of dolomite limestone transition lithology under different HCl concentrations in Huixi section,Yongshan,Yunnan,it was determined that 5 mol/L HCl effectively enriched calcium in dolomite calcite system.In addition,the thermal ionization mass spectrometry(TIMS)test results showed that the calcium isotope test results were consistent after pretreated by 4 mol/L and 1.6 mol/L HCl leaching scheme.This indicated that under the same test accuracy,the chemical separation scheme for carbonate geological samples in dolomite calcite system can improve the chemical separation efficiency.This paper further analyzed the application prospects of calcium isotopes in the geological samples of the Qinghai Tibet Plateau in combination with the hot issues in the study of the Qinghai Tibet Plateau.The analysis showed that calcium isotopes have broad application prospects in the reconstruction of the paleomarine environment before the uplift of the Qinghai Tibet Plateau,the restoration of tectonic activity during the uplift,and the tracing of the source of igneous rocks after the uplift.

关 键 词：碳酸盐岩 钙同位素 化学分离 青藏高原 热电离质谱 古海拔重建 古海洋重建 同位素示踪 

分 类 号：O657.63[理学—分析化学] TH843[理学—化学]