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配合《伊朗古生代地层与古生物》课题 ,于 1991年 6～ 12月开展伊朗同位素地质研究。重点是提供早古生代界线地质年龄 ,同时 ,亦对伊朗地质中具有重要意义的其它岩石进行同位素测试 ,由此建立伊朗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。在伊朗全境 11地区的 33地质点 ,采集约 2 0 0 0kg各类岩矿标本 ,全部运回中国以供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朗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 ,地幔时标 ,基底年代以及地球化学信息。据此 ,提出初步地质解释 ,在伊朗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。主要结论 :1 伊朗蛇绿岩的年代( 1)伊朗三大主要类型 (Mashhad ,Neyriz ,Rasht)蛇绿岩样品测试获得非常珍贵的年龄值 ,都老于围岩的时代 ,应是冷侵位 (构造 )成因 ,代表蛇绿岩源区的地幔时标。而且 ,三大类型具有不同的形成年龄 :Mashhad源区最老 ( 140 6± 13Ma) ,Neyriz其次 ( 10 34± 6Ma和10 32± 3 6Ma) ,Rasht源区最新 ( 912± 6Ma) ,极有可能处于不同板块的会聚边界。( 2 )岩石组合、系列亦不?
In line with the “Paleozoic stratigraphy and paleontology in Iran” project, from June to December 1991 to carry out Iran isotope geology research. The focus of the study is to provide pre-Paleozoic boundary geologic age. At the same time, isotope tests on other rocks of great significance in Iranian geology are also carried out to establish the Paleozoic magmatism in Iran, the geologic movement stages, the mineralization age and material source of important deposits With special emphasis on the isotopic geology of sedimentary rocks, ophiolites, granites and volcanic rocks near the boundary. A total of about 20 000 kg rock samples were collected from 33 geological sites in 11 regions of Iran and all were returned to China for selection for isotopic test purposes. All the tests have been completed in China. A great deal of achievements obtained are of great value and significance for solving many basic geological problems in Iran: mineralization mechanism, material source, mantle time scale, basement age and geochemical information. Therefore, it is the first time to put forward the preliminary geological interpretation and systematically study the isotope geology in Iran’s complex geological environment and achieve important results. MAIN CONCLUSIONS: 1. Age of the Iranian ophiolite (1) The samples of the three major types of Iranian ophiolite (Mashhad, Neyriz, Rasht) obtained very precious age values that were older than the age of the surrounding rock and should be characterized by cold emplacement (Tectonic) genesis, representing the mantle time scale of the ophiolitic source area. Moreover, the three major types have different age of formation: the oldest source of Mashhad (140 6 ± 13 Ma), Neyriz (10 34 ± 6 Ma and 10 32 ± 36 Ma), the latest Rasht source (912 ± 6 Ma) May be in the convergence of different sections of the border. (2) rock combination, the series is not?