成矿过程多元同位素体系的时代信息

AGE CONSTRAINTS ON MINERALIZATION PROCESS IN POLY-ISOTOPIC-SYSTEMS

成矿过程时间维的确定是一项重要而复杂的研究任务。尽管我国好多矿床已经测得了大量同位素年龄资料，但这决不等于这些年龄数据均能标定成矿过程中某一地质事件发生的时代。作者通过实例分析指出，矿床同位素地质年代学的研究必须建立在扎实的野外地质背景研究基础之上；在测年方法上，应采用多元同位素体系，但要更多地关注单矿物、乃至矿物微区的、Ａｒ－Ａｒ和Ｒｅ－Ｏｓ测年方法；在使用等时线法时，必须首先对其合理性进行科学判别。

The determination of the timedimension of a mineralization process has been an important and complicated problem. A lot of isotopic age data of many significant ore deposits in China have been obtained, but a certain geologic event in the mineralization process can not be marked by them. Through example analyses, the authors indicate that the geochronological study of ore deposits must be carried out on the substantial basis of field study work of the geological setting. As to age-dating methods,the authors recommend that poly-isotopic-system methods be adopted,but more attentiom be paid to single mineral, Ar-Ar and Re-Os methods and even further to mineral microarea and Ar-Ar methods. In addition,if isochron age methods are employed, their reasonableness must be examined cautiously.