摘要
根据新藏公路沿线实际观察资料和前人的最新成果，总结了新疆西昆仑库地蛇绿岩的构造特征、层序及岩石学特征；对库地蛇绿岩形成时代、原始构造环境等有争议的关键性问题进行了分析和探讨，得出了有关库地蛇绿岩的如下新结论：①形成时代为中元古代—晚元古代，同位素年龄值为大于１６６１．９～６９８．３６Ｍａ；②形成于缓慢扩张的条件下，且没有经历过俯冲消减作用；③岩浆来源为弱亏损的、非单一的上地幔源，并受到了陆壳物质的混染；④原始构造环境为弧后盆地—岛弧—弧间盆地。
On the basis of field investigation along XinJiang-Tibet highway and the previous work, the authors of this paper summarizes the structural characteristics, sequence and petrological characteristics , discusses the age and original geotectonic setting of Kudi ophiolite in western Kunlun Mts , Xinjiang Province. The major new conclusions are as follows : (1)Kudi ophiolite formed during Meso-Neo Proterozoic (>1661.9～698.36 Ma). (2)Kudi ophiolite formed in the slow spreading setting and did not experience subduction. (3)Kudi ophiolite derived from light loss, non single upper mantle magma sources which were hybridized by continental crust composition. (4)Kudi opiolite formed in back arc basin-island arc-interarc basic setting, which belong to transitional geotectonic setting .
基金
"九五"国家科技攻关305项目
关键词
蛇绿岩
地质特征
形成环境
Kudi ophiolite , Meso-Neoproterozoic, back arc basin-island arc-interarc basin setting, western Kunlun Mts.
