桂北四堡群火山岩锆石SHRIMP年龄及其地层学意义  

SHRIMP age of the lava from the Sibao Group in Guilin and its chronostratigraphic significance

作　　者：李利阳[1,2] 游国庆[3] 张传恒[1] 贾龙龙[1] 韩瑶[1] 张恒[3] 刘博[2] 冯欣[2] 李新发[2] 张金龙[2] LI Li-yang;YOU Guo-qing;ZHANG Chuan-heng;JIA Long-long;HAN Yao;ZHANG Heng;LIU Bo;FENG Xin;LI Xin-fa;ZHANG Jin-long(School of Earth Sciences and Resources, China University Of Geosciences (Beijing) , Beijing 100083, China;No. 4 Gold Geological Party of CAPF, Liaoyang 111000, Liaoning, China;Institute of Geology Chinese Academy of Geological Sciences,Beijing 100037, China)

机构地区：[1]中国地质大学(北京)地球科学与资源学院,北京100083 [2]武警黄金第四支队,辽宁辽阳111000 [3]中国地质科学院地质研究所,北京100037

出　　处：《中国地质》2016年第6期1992-1998,共7页Geology in China

基　　金：中国地质调查局项目"中国构造区划及其在全国地质志中的应用"(1212011120115)资助~~

摘　　要：四堡群为一套出露于桂北黔东南地区、变形强烈的浅变质、陆源碎屑岩火山岩、系,厚度大于5000 m,其下未见底,上被丹洲群(下江群相当地层)所覆盖。桂北四堡群自下而上划分为九小组、文通组和鱼西组3组。样品A20140731-3采自于文通组,岩性为灰绿色熔结火山岩,首次分选出600余粒岩浆型锆石,完成SHRIMP U-Pb定年测点15个,获得加权平均年龄(860±13)Ma。这表明四堡群主体属于新元古界,进而分析、讨论了江南造山带主要地层对比关系。The Sibao Group, outcropped in the north part of Guangxi and southeast part of Guizhou, is composed of over 5000 mthick succession of strongly-deformed, low-grade metamorphic volcanic rocks and terrigenous clastic rock, overlain unconformity by the Danzhou Group (Xiajiang Group). It is divided into three Formations: Jiuxiao Formation, Wentong Formation and YuxiFormation. Sample A20140731-3 is lava, collected from the upper part of the Wentong Formation, and over 600 grains of zirconwere sorted out from it. Fifteen of the zircons were analyzed with SHRIMP, and a weighed-mean U-Pb age of(860±13)Ma wasobtained, which indicates that the volcanic rocks of the Sibao Group belong to Neoproterozoic. Based on this new zircon SHRIMPU- Pb age combined with the other high- quality ages obtained recently in the Jiangnan Orogen, the authors investigated thestratigraphic correlation between Sibao Group and the other main strata, such as Lengjiaxi Group, Shuangqiaoshan Group, andFanjingshan Group.

关 键 词：四堡群 锆石SHRIMP年龄 新元古界 江南造山带 

分 类 号：P597.3[天文地球—地球化学]