南天山库勒湖蛇绿岩锆石年龄及其地质意义  

Dating for zircons of gabbro from Kulehu ophiolite,southern Tianshan,and its geological implication

作　　者：马中平[1] 夏林圻[2] 徐学义[2] 李向民[1] 夏祖春[2] 王立社[2] 

机构地区：[1]西北大学地质学系,陕西西安710069 [2]西安地质矿产研究所基础处,陕西西安710054

出　　处：《西北大学学报（自然科学版）》2007年第1期107-110,共4页Journal of Northwest University（Natural Science Edition）

基　　金：中国地质调查局综合研究资助项目(2003130000631212010611804);国家自然科学基金资助项目(40472044)

摘　　要：目的准确测定南天山库勒湖蛇绿岩的形成时代,探讨其地质意义。方法采用激光剥蚀等离子质谱(LA-ICP-MS)法,对库勒湖蛇绿岩中辉长岩锆石进行U-Pb同位素定年。结果辉长岩形成年龄(或结晶年龄)为418.2 Ma±2.6 Ma(MSWD=0.80)。结论南天山库勒湖蛇绿岩的形成时代为末志留世—早泥盆世早期,与古南天山洋盆的俯冲-消减时代相当,它的形成很有可能与古南天山洋盆的俯冲-消减作用有关。Aim Todate precisely for Kulehu opiolite, and discuss its geological implication. Methods Dating for zircons of gabbro from Kulehu ophiolite by LA-ICP-MS. Results The crystallizing age of magma of gabbro is 418. 2 ± 2. 6 Ma （ MSWD = 0. 80）. Conclusion Kulehu ophiolite formed in Late Silurian to Early Devonian corre- sponding to the subducting time of Palaeo-southern Tianshan Ocean, and it stands a good chance that the formation of kulehu ophiolite is related to the subduction of Palaeo-Southern Tianshan Ocean.

关 键 词：锆石U-PB定年 蛇绿岩 库勒湖 南天山 

分 类 号：P597.3[天文地球—地球化学]