北天山巴音沟蛇绿岩斜长花岗岩锆石SHRIMP测年及其意义  

SHRIMP Dating of Plagiogranite from Bayingou Ophiolite in the Northern Tianshan Mountains

作　　者：徐学义[1] 马中平[1,2] 夏林圻[1] 王彦斌[3] 李向民[1,2] 夏祖春[1] 王立社[1,2] 

机构地区：[1]中国地质调查局西安地质矿产研究所 [2]西北大学地质学系,西安710069 [3]中国地质科学院北京离子探针中心

出　　处：《地质论评》2005年第5期523-527,共5页Geological Review

基　　金：中国地质调查局综合研究项目(编号200313000063)国家自然科学基金资助项目(编号40472044)的成果。

摘　　要：北天山巴音沟蛇绿岩中斜长花岗岩仅产于辉长岩顶部,二者呈突变或渐变接触关系。本文应用SHRIMP方法对斜长花岗岩进行了锆石U-Pb定年,获得了324.8±7.1Ma(2σ)的年龄,这一年龄精确反映了巴音沟蛇绿岩形成于早石炭世。巴音沟蛇绿岩代表了天山晚古生代“红海型”洋盆的地质记录。The sensitive high-resolution ion microprobe （SHRIMP） U-Pb zircon dating of plagiogranite from the Bayingou ophiolite in the northern Tianshan Mountains indicates that the magmatic age of the plagiogranite is 324. 8±7. 1Ma （2a）, which shows the Bayingou ophiolite was formed in the early Carboniferous. This suggests the existence of the late Paleozoic “Red Sea type” ocean basin in the northern Tianshan Mountains and the Baiyingou ophiolite is the remnant of the oceanic crust.

关 键 词：斜长花岗岩 巴音沟蛇绿岩 SHRIMP 早石炭世 SHRIMP测年 蛇绿岩 北天山 锆石 接触关系 地质记录 

分 类 号：P597.3[天文地球—地球化学] P588.121[天文地球—地质学]