黔东北石阡地区志留纪地层新知:来自坉坪剖面的证据  

NEW OBSERVATIONS OF THE SILURIAN STRATA IN THE SHIQIAN AREA,NORTHEASTERN GUIZHOU:EVIDENCE FROM THE TUNPING SECTION

作　　者：王建华 蔡家琛 朱敏[2,3,4] 乔妥[2,3] 贾连涛 赵文金[2,3,4] WANG Jian Hua;CAI Jia Chen;ZHU Min;QIAO Tuo;JIA Lian Tao;ZHAO Wen Jin(Research Center of Natural History and Culture,Qujing Normal University,Key Laboratory of Yunnan Province Universities of Qujing Natural History and Early Vertebrate Evolution,Qujing 655011;Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences,Institute of Vertebrate Paleontology and Paleoanthropology,Chinese Academy of Sciences,Beijing 100044;Center for Excellence in Life and Paleoenvironment,Chinese Academy of Sciences,Beijing 100044;University of Chinese Academy of Sciences,Beijing 100049)

机构地区：[1]曲靖师范学院自然历史文化研究中心云南省高校曲靖自然历史与古鱼演化重点实验室,云南曲靖655011 [2]中国科学院古脊椎动物与古人类研究所,中国科学院脊椎动物演化与人类起源重点实验室,北京100044 [3]中国科学院生物演化与环境卓越创新中心,北京100044 [4]中国科学院大学,北京100049

出　　处：《地层学杂志》2023年第1期59-79,共21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(42072026、42130209、92255301);云南省基础研究计划青年项目(202001AU070145);云南省张弥曼院士工作站(202205AF150002)共同资助。

摘　　要：贵州东北石阡地区的志留系出露良好、化石丰富,是华南志留系研究程度较高的经典区域之一。本文报道在该地区志留系经典剖面——雷家屯剖面以北新揭露的坉坪剖面。坉坪剖面上的志留系兰多维列统自下而上依次为“龙马溪组”、香树园组、雷家屯组、马脚冲组、溶溪组、秀山组和迴星哨组,可分别与其层型剖面进行良好对比,且沉积连续、化石丰富,特别是在溶溪组中部首次发现中国志留系中最低的含鱼化石层位。经过详细的地层、古生物、碳稳定同位素地层学等研究,在理清坉坪剖面志留纪地层的沉积、化石特征及序列的基础上,本文首次揭示该剖面志留系兰多维列统δ^(13)Ccarb的连续变化曲线,并在香树园组、雷家屯组和秀山组中识别出3次全球性δ^(13)Ccarb事件——早埃隆事件(Early Aeronian Event)、晚埃隆事件(Late Aeronian Event)和瓦勒古事件(Valgu Event),同时结合前人的研究成果,探讨了石阡地区志留纪的沉积环境演变。The Shiqian area in northeastern Guizhou Province,South China,is one of the typical areas for Silurian stratigraphy,in which the Silurian strata are well developed and continuously exposed with abundant fossils.Herein we report our recent studies of a new Silurian geological section in the area,the Tunping Section,which contains,in ascending order,the“Lungmachi”,Xiangshuyuan,Leijiatun,Majiaochong,Rongxi,Xiushan and Huixingshao formations.The section is located not far to the north of the classic Leijiatun Section in the Shiqian area,and from both sections the Silurian strata and yielded invertebrate fossils are almost identical,which facilitates a close correlation.Three fish-bearing beds are found in the Tunping Section,the middle part of the Rongxi Formation,the lower part of the Xiushan Formation,and the Huixingshao Formation,respectively.The fossil fishes found from the middle part of the Rongxi Formation(the lowermost Silurian fish-bearing beds in China so far),including galeaspids,placoderms and chondrichthyans,are abundant and evidence the initial diversification of vertebrates in early Silurian.Specifically,the finding of the oldest jawed vertebrates in the Shiqian Fish Assemblage(assigned to the Zhangjiajie Vertebrate Fauna)from this horizon will make the Tunping Section a focus of global paleoichthyologists.Based mainly on the detailed researches of stratigraphy,paleontology,and stable carbon isotope stratigraphy of the Tunping Section,together with a review of previous researches of the Silurian in the Shiqian area,we tentatively draw the following conclusions.Firstly,we investigated the characteristics and sequence of the strata and fossils in the Tunping Section,and affirmed that the Silurian strata range from A.ascensus Zone(early Rhuddanian)to M.griestoniensis Zone(middle Telychian).Secondly,a continuous carbonate carbon isotope curve(δ^(13)Ccarb)is obtained for the first time,ranging from the early Rhuddanian to middle Telychian,in which three distinct positive excursions ofδ^(13)Ccarb value

关 键 词：地层序列 碳稳定同位素地层学 沉积环境 志留系 坉坪剖面 贵州 

分 类 号：P534.43[天文地球—古生物学与地层学]