新疆萨吾尔山花岗岩类的形成时代

Formation Time of Granitoids in Sawuer Mountains, Xinjiang

新疆萨吾尔山存在两期不同成因的花岗岩类，其 Ｒｂ － Ｓｒ 同位素年龄值分别为３１４ ．９ ～３２０ ．３ Ｍａ 和２９５ ～２９６ Ｍａ 。结合其侵位的地层及其与火山岩的关系等确定这两种不同类型花岗岩的时代分别为海西中期和晚期。

There exist two periods of genetically different granitoids in Sawuer Mountain of Xinjiang, whose Rb-Sr isotopic ages are 314.9～320.3 Ma and 295～296 Ma respectively. Based on these data in combination with their emplaced strata and their relations with volcanic rocks, it is considered that these two types of granitoids are of Middle and Late Hercynian respectively.