鄂尔多斯西南缘陕西崛山剖面马家沟组牙形刺兼论马家沟组顶界的穿时性  

UPPER ORDOVICIAN CONODONTS OF THE MAJIAGOU FORMATION IN THE JUESHAN SECTION, SHAANXI, SOUTHWESTERN ORDOS BASIN, AND THE DIACHRONEITY OF THE TOP BOUNDARY OF THE MAJIAGOU FORMATION

作　　者：戴霜 薛春玲[2] 陈中阳 汪卫国[4] 席海雨 田超 DAI Shuang;XUE Chunling;CHEN Zhongyang;WANG Weiguo;XI Haiyu;TIAN Chao(Key Laboratory of Mineral Resources in Western China(Gansu Province)and School of Earth Sciences,Lanzhou University,Lanzhou 730000,China;Key Laboratory of Western China’s Environmental Systems,Ministry of Education and College of Resources and Environment,Lanzhou University,Lanzhou 730000,China;State Key Laboratory of Palaeobiology and Stratigraphy,Nanjing Institute of Geology and Palaeontology and Center for Excellence in Life and Paleoenvironment,Chinese Academy of Sciences,Nanjing 210008,China;Third Institute of Oceanography,Ministry of Natural Resources of China,Xiamen 361005,China)

机构地区：[1]兰州大学地质科学与矿产资源学院,甘肃省矿山环境和城市地质工程研究中心,兰州730000 [2]兰州大学资源环境学院,西部环境教育部重点实验室,兰州730000 [3]中国科学院南京地质古生物研究所和生物演化与环境卓越创新中心,现代古生物学和地层学国家重点实验室,南京210008 [4]自然资源部第三海洋研究所,厦门361005

出　　处：《微体古生物学报》2020年第4期317-327,共11页Acta Micropalaeontologica Sinica

基　　金：第二次青藏高原综合科学考察研究(2019QZKK0704);中央高校基本科研业务费专项资金重点项目(lzujbky-2017-k27);国家自然科学基金(41972213)联合资助;IGCP652项目“利用多重地层学方法研究古生代沉积岩石记录的地质年代信息”;IGCP653项目“奥陶纪生物大辐射的启动过程”的阶段成果。

摘　　要：鄂尔多斯盆地西南缘奥陶系出露广泛且分布连续,而有关马家沟组的时代在不同地区存在较大的差异,制约了盆地周缘地层划分和对比。陕西岐山地区崛山剖面的马家沟组上部识别出牙形刺6属10种,属于上奥陶统Belodina compressa带至Belodina confluens带。因此,崛山剖面马家沟组上部的时代为晚奥陶世早—中期。通过对各地区马家沟组的时代对比,发现马家沟组的顶界穿时,范围下至中奥陶统达瑞威尔阶中上部,上达上奥陶统凯迪阶下部。Six conodont genera and 10 species from the Belodina compressa biozone to the Belodina confluens biozone recognized in the upper part of the Majiagou Formation of the Jueshan section(Shaanxi,southwestern Ordos Basin)indicate that the age of the upper part of the Majiagou Formation in the Qishan area is the Late Ordovician.Correlation of the Majiagou Formation reveals its top boundary is diachronous.In Wuhai,the top boundary of the Majiagou Formation corresponds to the lower Darriwilian(Middle Ordovician),while to the lower Katian(Upper Ordovician)in Yaoxian and Qishan areas.

关 键 词：牙形刺 穿时性 马家沟组 上奥陶统 崛山 鄂尔多斯西南缘 

分 类 号：Q913.85[天文地球—古生物学与地层学] P534.4[生物学—古生物学]