鄂尔多斯盆地桃112井和陕473井中奥陶统达瑞威尔阶的牙形石及其生物地层意义  

DARRIWILIAN(MIDDLE ORDOVICIAN)CONODONTS FROM TWO DRILL CORE SECTIONS WITHIN THE ORDOS BASIN,NORTH CHINA AND THEIR BIOSTRATIGRAPHIC SIGNIFICANCE

作　　者：尹升菊 景秀春[1,2] 付玲 李亚 李国帅 YIN Sheng Ju;JING Xiu Chun;FU Ling;LI Ya;LI Guo Shuai(School of Earth Science and Resources,China University of Geosciences(Beijing),Beijing 100083;State Key Laboratory of Palaeobiology and Stratigraphy,Nanjing Institute of Geology and Palaeontology,Chinese Academy of Sciences,Nanjing 210008;PetroChina New Energy Branch,Beijing 100007)

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]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 [3]中国石油油气和新能源分公司,北京100007

出　　处：《地层学杂志》2024年第3期293-306,共14页Journal of Stratigraphy

基　　金：国家自然科学基金(41502026);现代古生物学和地层学国家重点实验室开放基金(213107)共同资助。

摘　　要：本文对鄂尔多斯盆地桃112井和陕473井的北庵庄组和马家沟组开展详细的牙形石分类学和生物地层学研究,共采集90件碳酸盐岩岩心样品,经处理后在35件样品中获得353枚牙形石。所获牙形石可归入10属12种,以暖水类型为主,表现出强烈的地方特征,同时也见到少量广布类型牙形石。在所采井段层位可识别出3个牙形石生物带,自下而上分别是Histiodellaholodentata-Tangshanodustangshanensis带、Aurilobodusaurilobus带、Plectodina onychodonta带,时代为中奥陶世达瑞威尔期中期。该牙形石带序列可与河北唐山、山东莱芜、河南巩县及安阳的同期序列进行直接对比,也可与新疆塔里木盆地和北美中大陆区相当层位进行良好对比,此外还可与华南的同期化石带建立对比关系。本文的材料丰富了华北地区奥陶纪牙形石动物群的组成,深化了其与国内外同期典型牙形石动物群及化石带序列的对比,但精细的洲际对比尚需开展进一步工作,今后尤其需要关注的是来自台地和台缘交界处的钻井剖面的化石材料。Documented in this report are the conodont identification and biostratigraphy of the Beianzhuang and Majiagou formations at the Tao-112 and Shan-473 wells in the Ordos Basin,North China.A total of 353 conodonts were obtained from 35 productive samples out of 90 carbonate samples processed.Conodonts recovered are represented by 12 species belonging to 10 genera.They are dominated by warm-water forms showing strong endemism,along with the appearance of several widely distributed species.Three conodont biozones were recognized in the studied strata,i.e.,in ascending order,the Histiodella holodentata-Tangshanodus tangshanensis Biozone,the Aurilobodus aurilobus Biozone and the Plectodina onychodonta Biozone,which are assigned to the middle Darriwilian(Middle Ordovician).These conodont biozones can be directly correlated with the coeval successions in the Tangshan area of Hebei Province,in the Laiwu area of Shandong Province,and in the Gongxian and Anyang areas of Henan Province.It could be also compared to the contemporaneous sequences in the Tarim Basin,North America and South China.The present study has added new occurrence data for a more precise regional and intercontinental correlation of the conodont biozonal successions of the platform facies in North China.

关 键 词：鄂尔多斯盆地 达瑞威尔阶 暖水型牙形石 生物地层 洲际对比 

分 类 号：P534.42[天文地球—古生物学与地层学]