阿勒吞昆多蛇绿混杂岩斜长花岗岩锆石SHRIMP测年及时限  

Time Constraints and SHRIMP of Zircon from Plagioclase Granite of Ophiolitic in Aletunkunduo

作　　者：秦彪[1] 

机构地区：[1]中国建筑材料工业地质勘查中心新疆总队,新疆乌鲁木齐830000

出　　处：《西北地质》2012年第3期20-25,共6页Northwestern Geology

基　　金：新疆伊吾县阿尔通盖一带1:5万区域地质矿产调查项目(XJQDZ2009-7)

摘　　要：在大量查阅分析和研究前人资料基础上,提出阿勒吞昆多蛇绿混杂岩是卡拉麦里蛇绿岩带的向东延伸部分。卡拉麦里蛇绿岩带西起卡拉麦里—塔克扎勒—大黑山至伊吾县阿勒吞昆多一带,向东可能延伸至蒙古境内。该蛇绿混杂岩中斜长花岗岩产于辉长岩顶部,二者呈突变或渐变接触关系。应用SHRIMP方法对斜长花岗岩进行了锆石U-Pb定年,获得了(351±6Ma)的年龄,这一年龄反映阿勒吞昆多蛇绿岩形成于早石炭世。同时,该蛇绿混杂岩上覆岩系的时代为晚石炭世,表明阿勒吞昆多蛇绿混杂岩侵位时代不晚于晚石炭世。On the basis of analysis and research of previous datum, it is put forward that ophiolitic melange of Aletunkunduo is the extended eastward part of ophiolitie belt from Kalameili, which starts from the belt of Kalameili-Tazale-Daheishan-Aletunkunduo in the west. Plagioelase granite in the ophiolitic melange occurs in the top of gabbro, they have gradually or abruptly changing contact relationship. With SHRIMP method Zircon U-Pb Dating is carried out with Plagioclase granite, the result is （351--4-6 Ma） that reflects that ophiolitic melange of Aletunkunduo have formed in 351Ma. Meanwhile the study on ophiolitic melange overlying rocks in the Late Carboniferous can also state that ophiolitic melange from Aletunkunduo emplacement ages is not later than Late Carboniferous.

关 键 词：斜长花岗岩 蛇绿混杂岩 侵位时限 上覆岩系 

分 类 号：P597[天文地球—地球化学]