中国内蒙古下白垩统白彦华群胜利组的首个同位素年龄  

THE FIRST RADIOMETRIC AGE OF THE SHENGLI FORMATION(LOWER CRETACEOUS)OF INNER MONGOLIA,CHINA

作　　者：沈豪轩 张春晖[3] 吴云飞 吕苗[1] 王鑫[1] SHEN Hao Xuan;ZHANG Chun Hui;WU Yun Fei;Lü Miao;WANG Xin(State Key Laboratory of Palaeobiology and Stratigraphy,Nanjing Institute of Geology and Palaeontology,Chinese Academy of Sciences、Nanjing 210008;University of Chinese Academy of Sciences,Beijing 100049;State Key Laboratory for Mineral Deposits Research,School of Earth Sciences and Engineering,Nanjing University,Nanjing 210093;Shenhua Beidian Victory Energy Limited,Xilinhot 026015)

机构地区：[1]中国科学院南京地质古生物研究所,现代古生物学和地层学国家重点实验室,江苏南京210008 [2]中国科学院大学,北京100049 [3]南京大学地球科学与工程学院内生金属矿床成矿机制研究国家重点实验室,江苏南京210093 [4]神华北电胜利能源有限公司,内蒙古锡林浩特026015

出　　处：《地层学杂志》2021年第2期204-209,共6页Journal of Stratigraphy

基　　金：中国科学院战略性先导科技专项B类(XDB26000000);国家自然科学基金(91514302、91114201)共同资助。

摘　　要：由于丰富的煤炭资源,内蒙古的下白垩统地层具有重要的经济价值。但长期以来相关地层一直缺乏同位素测年研究,影响了区域地层对比工作的开展。本文对内蒙古锡林浩特下白垩统胜利组煤层夹层中的火山灰锆石应用LA-ICP-MS进行U-Pb法测年,结果显示胜利组5煤(层)和6煤(层)形成于大约109—107Ma(早白垩世阿尔布期)。这是胜利组所属的下白垩统白彦华群的首个同位素年龄,有助于我国东北地区与全球同时代地层对比工作的开展。Abundant coal resources make the Lower Cretaceous economically important in Inner Mongolia and northeastern China.However,there are few isotopic datings of these coaliferous strata,making the stratigraphy and geological history in the region elusive.Here we report the outcome of isotopic U-Pb single zircon grain dating by LA-ICP-MS of tuff layers sandwiched in the coal layers of the Shengli Formation in Xilinhot,Inner Mongolia.The tuff layers in Coal Layer 5 are dated as 107.44±0.9 Ma and 107.3±1.4 Ma,while those in Coal Layer 6 are dated as 108.4±1.4 Ma and 108.9±2 Ma,indicating that these two coal layers were formed 109–107 Ma,an Albian age in the Early Cretaceous.This is the first isotopic age for the Baiyanhua Group(including Shengli Formation),and will be helpful for the stratigraphic correlation in northeastern China as well as worldwide.

关 键 词：阿尔布期 白垩纪 煤 胜利组 内蒙古 同位素年龄 

分 类 号：P534.53[天文地球—古生物学与地层学]