赣皖交界婺源地区中生代花岗岩体的锆石LA-ICP-MS U-Pb年龄及其地质意义  

Zircon LA-ICP-MS U-Pb Dating of Mesozoic Granitic Plutons and Its Geological Significance in Wuyuan Region,the Southern Border Between the Jiangxi and Anhui Provinces

作　　者：胡鹏[1] 陈能松[1,2] 徐先兵[3] 张璐[1] 巴金[4] 李源[3] 

机构地区：[1]中国地质大学地球科学学院,武汉430074 [2]中国地质大学地质过程与矿产资源国家重点实验室,武汉430074 [3]中国地质大学地质调查研究院,武汉430074 [4]四川省地质调查院,成都610081

出　　处：《地质科技情报》2014年第4期24-30,共7页Geological Science and Technology Information

基　　金：中国地质调查局中国地质大调查项目(1212011120837)

摘　　要：邦彦坑岩体、段莘岩体和青山岭岩体位于江南造山带东段,是赣东北中生代花岗岩群的重要组成部分,然而它们的确切形成年龄仍不清楚。采用LA-ICP-MS技术测定了上述3个岩体的锆石U-Pb年龄。这些锆石的CL图像及Th/U比值均具岩浆成因特征;测试结果指示邦彦坑岩体并不是形成于晚青白口世,而是形成于晚侏罗世（约151Ma）,而段莘岩体和青山岭岩体形成于早白垩世（128-125Ma）。邦彦坑岩体和段莘、青山岭岩体可能分别为华南中生代晚期180-155Ma和129-122Ma 2个岩石圈伸展事件的岩浆作用产物。The Bangyankeng,Duanxin and Qingshanling granitic plutons which intruded in the eastern Jiangnan orogenic belt are the important components of the Mesozoic granites in northeasternmost Jiangxi Province.However,their formation ages are still unknown,and the Banyankeng granite has become a controversial topic.In this study,the zircon U-Pb ages of the three granites were determined by LA-ICPMS technique.The CL images and Th/U rations of zircons revealed the characteristics of magmatic origin.The results show that the Bangyankeng granite was formed at-151Ma,but not the late Qingbaikou Epoch from previous study,and the Duanxin and Qingshanling granites were formed at-128-126Ma.This result indicates that the formation ages of Banyankeng granite,Duanxin granite,and Qingshanling granites were probably the magmatic links to the lithospheric stretching events in the South China Block at 180-155Ma and 129-122Ma,respectively.

关 键 词：中生代花岗岩 LA-ICP-MS锆石 U-PB定年 赣东北江南造山带 岩石圈伸展 

分 类 号：P597[天文地球—地球化学]