成矿地质事件的同位素年代学研究

RESEARCH ON ISOTOPIC GEOCHRONOLOGY OF MINERALIZATION EVENTS

成矿事件同位素地质年代学研究是一项十分重要而复杂的任务。成矿事件时间维的确定，对于矿床成因、成矿作用与其它异常地质事件的耦合关系的认识，以及对于找矿勘探均具有至关重要的理论和实际意义。文中讨论了各种常用测年方法（如ＲｂＳｒ、ＳｍＮｄ等时线法和ＵＰｂ法等）的适用性和局限性，并介绍了测年方法（尤其是与成矿事件年代学研究有关的测年方法）的新进展。结合国内外典型研究事例分析，比较了成矿事件的直接测年和间接测年方法，强调应在扎实的野外地质工作的基础上，综合采用多元同位素体系对成矿事件进行年代学研究。最后讨论了成矿事件与其它异常地质事件的耦合关系，并指出应加强成矿事件与大陆聚散旋回的时间耦合性的研究。

Research on geochronology of mineralization events has l ong been a very important but quite complicated task The determination of the temporal dimension on a mineralization event is of great significance both in theory and in practice, which is helpful to the understanding of the origin of an ore deposit and the coupling relationship between mineralization events and other abnormal geological events and also to the exploration of deposits In this paper, various dating methods (e g Rb Sr, Sm Nd isochron and U Pb methods) are firstly discussed in terms of applicability and limitation, and the advancement in geochronology of mineralization events is also introduced Then combined with analyses of some typical research examples from both at home and abroad, the direct and indirect dating methods of mineralization events are contrasted It is proposed that geochronology of mineralization events be done by means of poly isotopic system methods, based on thorough field work And finally, the relationship between mineralization events and other abnormal geological events is discussed, and the temporal coupling relationship between mineralization events and the assembling and dispersal cycles of super continents is especially highlighted for future study, which is important to our understanding of minerogenesis