LA-(MC)-ICP-MS锡石U-Pb定年研究进展

The Reseach Advances in LA-(MC)-ICP-MS U-Pb Dating of Cassiterite

随着锡石U-Pb定年方法的不断进步,利用锡石微区原位U-Pb定年直接测定锡多金属矿床的成矿(锡矿化)时代已经具备了相对成熟的技术条件,成为锡矿床成矿年代学研究最直接和最有效的途径之一。本文结合近几年本实验室开展的相关研究工作,总结了LA-(MC)-ICP-MS锡石U-Pb定年方法的研究进展,简要评述了多接收器LA-MC-ICP-MS和单接收器LA-ICP-MS两种方法的优缺点。此外,文章还介绍利用LA-(MC)-ICP-MS锡石U-Pb定年方法在湖南芙蓉、云南个旧和广西大厂等超大型锡矿成矿年代学研究中取得的重要进展,指出这一方法目前存在的主要问题和技术难点在于普通铅的准确校正和理想标样的研制,选择合理的普通铅扣除方法和实验外标,有利于提高测定结果的精确度和准确性。同时本文提出通过进一步优化这一测年技术,可以获得锡多金属矿床准确的成矿年代学信息,为全面认识相关矿床的生成和演化历史提供技术支持。

With the increasing improvement of cassiterite U Pb dating method, using cassiterite in site U Pb dating for tin polymetallic deposits has been of relatively mature technical conditions and will be one of the most direct and effective approach in study of the metallogenic time of tin deposits. Based on our lab research in the past several years, this study summarized the progress of LA （MC） ICP MS cassiterite U Pb dating method and the advantages and disadvantages of LA MC ICP MS and LA ICP MS. In addition, the application results of this method in super large tin deposits in Furong, Gejiu and Dachang are described. This study also presents the existing problems and technical difficulties of the method, which are common lead correction and ideal sample production, only through which can the precision and accuracy of dating results be improved. Meanwhile we further optimized in situ cassiterite U Pb dating technique, which can not only obtain accurate metallogenic chronology information but also provide technical support for understanding the formation and evolution of relevant deposits.