摘要
随着同位素测试技术的提高,采用碎屑锆石的SHRIMP或LA-ICP-MS等高精度测年方法分析和推测沉积盆地的形成时代、碎屑物来源及形成的大地构造背景等已广泛使用。运用LA-ICP-MS锆石U-Pb测年法对头屯河组砂岩中的碎屑锆石进行相关研究。结果表明,碎屑锆石年龄主要为400~450 Ma、450~485 Ma、301~348 Ma,另分布有几粒古老锆石年龄,主要为701~2174 Ma、(3144±22)Ma。结合锆石矿物学特征、CL图像、Th/U比值、砂岩岩相学特征及区域年代学资料等可知,头屯河组砂岩主体物源可能来源于乌孙山及南部那拉提山地区出露的石炭—奥陶纪中酸性侵入岩,但并未反映出为蒙其古尔铀矿区提供相关的铀源信息。
With the improvement of isotope analytical techniques,SHRIMP or LA-ICP-MS dating methods of detrital zircons have been widely used to analyze and predict the formation age of sedimentary basins,the source and their formation geotectonic background of clastic materials.In this paper,the in situ U-Pb dating on zircons by LA-ICP-MS is used to study detrital zircons in Toutunhe Formation sandstones.The results show that zircon ages are mainly 400~450 Ma,450~485 Ma and 301~348 Ma.In addition,there are several ancient zircon ages,mainly 701~2174 Ma and(3144±22)Ma.Based on the zircon mineralogical characteristics,CL images,Th/U ratio,petrographical characteristics of sandstones and regional geochronology datas,it is considered that the main source of the sandstones in Toutunhe Formation is mainly from the Carboniferous-Ordovician intermediate-acid intrusive rocks which exposed in the Wusun Mountain and Nalati Mountain area,and they do not reflect the relevant uranium source information for the Mengqiguer uranium mining area.
作者
黄广文
黄广楠
薛万文
潘家永
陈正乐
宋泰忠
吴德海
Huang Guangwen;Huang Guangnan;Xue Wanwen;Pan Jiayong;Cheng Zhengle;Song Taizhong;Wu Dehai(Qinghai Province Key Laboratory of Geological Process and Mineral Resources of Northern Qinghai-Tibet Plateau,Qinghai Geological Survey Institute,Xining,Qinghai,810012,China;No.105 Exploration Team,Qinghai Bureau of Coal Geological Exploration,Xining,Qinghai,810007,China;State Key Laboratory of Nuclear Resources and Environment,East China University of Technology,Nanchang,Jiangxi,330013,China;Institute of Geomechanics,Chinese Academy of Geological Sciences,Beijing,100081,China)
出处
《新疆地质》
CAS
CSCD
北大核心
2019年第4期546-554,共9页
Xinjiang Geology
基金
青海省青藏高原北部地质过程与矿产资源重点实验室开放课题（2019-KY-04）
国家自然科学基金重点支持项目（U1403292）
江西省研究生创新专项基金项目（YC2018-B082）联合资助
