LA-(MC)-ICPMS 和(Nano)SIMS 硫化物微量元素和硫同位素原位分析与矿床形成的精细过程

硫化物微区原位分析技术包括LA-ICPMS定点微量元素分析、LA-ICPMS和(Nano) SIMS微量元素面扫描分析,以及SIMS、Nano SIMS和LA-MC-ICPMS原位硫同位素点分析和面扫描。这些分析方法可以有效地获取不同期次硫化物微量元素含量、丰度分布图像、硫同位素比值和分布特征,结合微区时间分辨信号谱图、微量元素相关性分析等,在矿床学的成矿元素行为与赋存状态、成矿元素置换反应、成矿流体与硫的来源、矿石矿物的化学分带性、矿床成因模型等研究中有着重要的应用前景,以探讨矿床的精细成矿过程。硫化物原位微量元素和同位素LA-(MC)-ICPMS和(Nano) SIMS分析,需要降低仪器和分析方法的系统误差,克服严重的基体效应和同位素分馏效应。

稀土元素在热液中的迁移与沉淀

近年来,高新技术产业的不断发展使得全球稀土资源需求不断上涨,此外稀土元素作为研究地球起源与演化等有关地球科学问题的重要工具也深受地球科学界的重视。而热水溶液体系中稀土元素迁移、富集、沉淀及分馏机制等相关理论知识的不断完善对于理解稀土成矿作用、稀土地球化学特征以及微量元素示踪等方面均具有重要意义。本文总结了近年来有关稀土元素在热液体系中迁移、沉淀以及轻、重稀土分馏的最新研究进展,对不同稀土络合物的稳定性、溶解度以及搬运稀土元素的能干性进行了阐述,最后展望了"稀土元素在热液中迁移与沉淀"研究中仍需完善及拓展的方向。

Mineralizing age of the Rushan lode gold deposit in the Jiaodong Peninsula:SHRIMP U-Pb dating on hydrothermal zircon

Zircons from the auriferous quartz vein in the Rushan gold deposit, Jiaodong Peninsula, have high common Pb contents (206Pbc = 2.00%—15.88%) and Th/U ratios (0.31—1.35), and trap primary CO2-H2O fluid inclusion similar to ore-forming fluids, indicating that they grew from high Th/U ratio ore-forming fluids responsible for gold min- eralization. SHRIMP U-Pb analyses of these zircons gave an age of 117±3 Ma comparable with the ages reported by the former researches in the other areas in the Jiaodong Penin- sula, which is interpreted as the age of gold mineralization at Rushan. The age of SHRIMP zircon U-Pb dating with 160±3 Ma from host rock Kunyushan monzogranite is different from that of the gold mineralization, indicating that there is no genetic relationship between gold mineralization and the granitic magmatism. SHRIMP U-Pb dating on hydrothermal zircons from auriferous quartz veins could be used to con- strain the timing of lode gold mineralization and the rela- tionship to relevant hydrothermal event.