崇山剪切带混合岩化长英质脉体锆石U-Pb年龄及其意义  

Zircon U-Pb Age of Migmatized Felsic Vein in Chongshan Shear Zone and Its Significance

作　　者：郭小飞 荆一洪 刘佳琪 GUO Xiao-fei;JING Yi-hong;LIU Jia-qi(School of Resource and Environmental Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, China;Jiangxi Key Laboratory of Mining Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, China)

机构地区：[1]江西理工大学资源与环境工程学院,赣州341000 [2]江西理工大学江西省矿业工程重点实验室,赣州341000

出　　处：《科学技术与工程》2022年第5期1768-1774,共7页Science Technology and Engineering

基　　金：江西理工大学博士启动基金(jxxjbs17068);江西省教育厅基金(GJJ170539)。

摘　　要：受印度和欧亚板块碰撞影响,西南三江地区新生代以来发育一系列大型走滑剪切带。为了确定其中碧罗雪山-崇山-澜沧江剪切带的剪切属性和时限,对崇山剪切带大理永平县永保桥地区进行了详细的野外地质考察和室内分析,观测资料表明其左行走滑剪切特征明显。同时,获得崇山剪切带内混合岩化长英质脉体激光剥蚀-等离子体质谱仪(laser ablation-inductive coupled plasma-mass spectrometer,LA-ICP-MS)锆石U-Pb年龄为(24.6±2.0)Ma,表明该带在晚渐新世处于走滑剪切深熔阶段。结合前人研究成果,在新生代剪压应变分解条件下,碧罗雪山北段、碧罗雪山至崇山段、澜沧江段分别具有右行走滑、左行走滑和右行走滑特征。Influenced by the collision between India and Eurasia Plates,a series of large strike slip shear zones have developed in the Sanjiang area since Cenozoic.In order to determine the shear property and time of the Biluoxueshan-Chongshan-Lancangjiang shear zone,a detailed field geological survey and indoor analysis were carried out in Yongbao Bridge,Yongping County,Dali City of Chongshan shear zone.The observation data show that the left strike slip shear feature is obvious.Meanwhile,the laser ablation-inductive coupled plasma-mass spectrometer(LA-ICP-MS)zircon U-Pb age of migmatized felsic veins in Chongshan shear zone is(24.6±2.0)Ma,indicating that the belt was in the stage of strike slip shear anatexis in the late Oligocene.Combined with the previous research results,under the condition of Cenozoic shear compression strain decomposition,the north of Biluoxueshan,Biluoxueshan-Chongshan section and Lancangjiang section are characterized by right strike slip,left strike slip and right strike slip respectively.

关 键 词：崇山剪切带 长英质脉体 U-PB年龄 剪切属性 构造指示 

分 类 号：P597[天文地球—地球化学]