桂东南地区大容山—十万大山花岗岩带SHRIMP锆石U-Pb定年  

SHRIMP U-Pb Zircon Dating of the Darongshan—Shiwandashan Granitoid Belt in Southeastern Guangxi, China

作　　者：邓希光[1,2] 陈志刚[1] 李献华[1] 刘敦一[3] 

机构地区：[1]中国科学院广州地球化学研究所 [2]广州海洋地质调查局战略所,510760 [3]中国地质科学院地质研究所

出　　处：《地质论评》2004年第4期426-432,共7页Geological Review

基　　金：中国科学院知识创新工程重要方向项目 (编号 KZCX2 -10 2 )资助成果

摘　　要：桂东南地区大容山—十万大山花岗岩以含过铝质矿物为特征 ,是华南地区显生宙典型的 S型花岗岩岩带。虽然前人对该岩带的侵入年代进行了许多研究工作 ,认为其为海西—印支期产物 ,但由于以往测年方法和技术的一些局限性 ,对于华南是否存在海西期花岗岩一直存在不同意见。本文对大容山、旧州岩体和台马岩体进行了高精度锆石 SHRIMP定年 ,3个岩体的形成年龄分别为 2 33± 5 Ma、2 30± 4 Ma和 2 36± 4 Ma,说明该花岗岩岩带形成于印支期 ,是由推覆构造引起地壳增厚、地壳重熔形成的。There is a typical S-type granitic belt—the Darongshan-Shiwandashan granitic belt in South China. Many previous dating ages show that these granites were formed at the Hercynian-Indosinian period. Because of the disadvantage of previous chronological methods, the age of these granites should be dated again in order to find out whether there are Hercynian granites in South China. The p aper reports the zircon SHRIMP ages of granites from the Darongshan-Shiwandasha n granitic belt, which are 233±5, 230±4 and 236±4Ma respectively. The data in dicate that these granites are Indosinian instead of Hercynian. Geological and o ther evidence show that these granites were formed due to thickening and remelti ng of the lower crust caused by nappe structure in South China.

关 键 词：SHRIMP 锆石U-PB年龄 花岗岩 桂东南地区 

分 类 号：P597.3[天文地球—地球化学]