摘要
北山岩群主要分布于哈萨克斯坦板块南缘的标山一带,主体为一套变质程度较深的陆源碎屑岩夹碳酸盐岩建造。该套变质地层的时代归属缺少古生物化石等定年依据,本次野外调查也未发现该岩群中有生物化石。为限定北山岩群形成时代,对北山岩群长石石英岩中碎屑锆石进行了LA-ICP-MS锆石U-Pb测年,共获得112个碎屑锆石年龄,结果显示,^(207)Pb/^(206)Pb年龄值为1.8~3.3 Ga,最小碎屑锆石年龄为(1 782±18) Ma,代表北山岩群形成时代的下限。通过同位素年龄图谱比较,此次在北山岩群中获得的碎屑锆石年龄频谱图与敦煌岩群类似,推测北山岩群的沉积物源区为敦煌地块。
Beishan Complex-Group is mainly distributed on Biaoshan area of south margin of Kazakhstan plate .The main part of it is built up with Deep deterioration Terrigenousclastic rocks and carbonate and it is also the oldest geologi- cal body of the Kazakhtan plate. The age of this part of stratigraphic is of evidence like paleontology fossil. We did not found the paleontology fossil evidence in Beishan Complex-Group. In order to determine the age of Beishan Complex- Group.The LA-ICP-MS zircon U-Pb method for the determination of the age the detrital zircon in feldsparquartzite of the BeishanComplex-Group has been carried out ,the test results show that the age of zircon 207Pb/206Pb between 1.8-3.3 Ga, the agebetween 2.4-3.2 Ga is about 77% and the age between 1.91-2.07 Ga is about 12.5%, the youngest of the 207Pb/206Pb age of detrital zircon is 1782±18Ma.The result of clastic zircon age of Beishan Complex-Group is similar as Dunhuang Complex-Group. In summary, we presume the original sediments area of Beishan Complex-Group is Dun- huang massif.
作者
徐旭明
程海峰
段炳鑫
薛鹏远
Xu Xuming;Cheng Haifeng;Duan Bingxin;Xue Pengyuan(Hebei Institute of Regional Geological and Mineral Resources Survey,Langfang,Hebei,065000,China)
出处
《新疆地质》
CAS
CSCD
北大核心
2018年第3期393-398,共6页
Xinjiang Geology
基金
内蒙古1:5万标山(K47E013011)
咸味井(K47E013012)
骨头井(K47E014011)
化石山(K47E014012)幅区域地质矿产调查
关键词
内蒙古北山
标山
碎屑锆石
LA-ICP-MS锆石U-PB年龄
Beishan Complex-Group
detrital zircon U-Pb
LA-ICP-MS
U-Pb ages
Inner Mongolia Beishan area
Biaoshan area
