伊郎同位素研究新资料及其地质解释

配合《伊朗古生代地层与古生物》课题，于1991年6－12月开展伊郎同位素地质研究。重点是提供早古生代界线地质年龄。同时，亦对伊郎地质中具有意义的其它岩石进行同位素测试，由此建立伊郎古生代岩浆活动期次、地质运动分阶、重要矿床的成矿时代及物质来源，特别着力于研究界线附近沉积岩、蛇绿岩、花岗岩以及火山岩的同位素地质。在伊郎全境11地区的33地质点，采集约2000kg各类岩矿标志，全部运回中国以代选集用于同位素测试目的矿物。全部测试都在中国国内完成，获得的一大批成果对解决伊郎诸多基础地质问题具有重要的价值和意义：成矿机制，物质来源，地幔时代，基底年代以及地球化学信息。据此，提出初步地质解释，在伊郎如此复杂地质环境中系统研究同位素地质并取得重要成果尚属首次。

NEW ISOTOPIC DATING INFORMATION IN IRAN AND ITS GEOLOGICAL INTERPRETATION

The ages of 3 main ophiolites in Iran are separately 1406± 13Ma, 1034± 6Ma and 1032± 3.6Ma, 912 ± 6Ma, which are all older than their wall rock and represent the ages of original areas. It means they are cold intrusions. The age of Qareh Darreh ophiolite in Takab is 33.9Ma, which may be the intrusion time of the last plate convergence. The Zircon age of Doran alkali-feldspar granite near Zanjan is 960 ± 15Ma,which is the age of the oldest basement in Iran until now. The age of Gasht Rudkhan granite in Rasht is 417Ma,which represents the age of the crust movement of Alborz Mountains in a long time lifting and denudation. In Iran, the main Fe deposits are formed in 476-461Ma and the main Pb-Zn deposits are formed in 198.53-233.42Ma.