中国陆相上中新统灞河阶底界层型的选择  

Selection of the Lower Boundary Stratotype of the Terrestrial Upper Miocene Bahean Stage in China

作　　者：邓涛[1,2] 侯素宽[1] 史勤勤[1] 

机构地区：[1]中国科学院古脊椎动物与古人类研究所,脊椎动物演化与人类起源重点实验室,北京100044 [2]西北大学地质学系,陕西西安710069

出　　处：《地球学报》2015年第5期523-532,共10页Acta Geoscientica Sinica

基　　金：全国地层委员会项目(编号:1212011120142);国家自然科学基金重点项目(编号:41430102);国家重点基础研究发展计划项目(编号:2012CB821906)联合资助

摘　　要：2014年全国地层委员会最新出版的《中国地层表》中正式采用了将上中新统两分为灞河阶和保德阶的方案。"灞河"一名源自同名岩石地层单位灞河组,典型剖面位于陕西省蓝田县灞河左岸的水家嘴。灞河阶对应于国际地层表中海相的托尔托纳阶,其共同的底界定义为古地磁Chron C5r.2n的底部,年龄为11.6 Ma,这条界线在蓝田地区的灞河组并不存在。在中国晚中新世早期的哺乳动物群中,甘肃临夏盆地的郭泥沟动物群、大深沟动物群,青海柴达木盆地的托素动物群、深沟动物群,内蒙古苏尼特右旗的阿木乌苏动物群,西藏比如盆地的布隆动物群,陕西府谷的喇嘛沟动物群和云南元谋的小河动物群均属于灞河期。甘肃省东乡县的郭泥沟剖面是灞河阶底界层型最有利的候选剖面。In 2014, the National Commission on Stratigraphy of China formally suggested dividing the Chinese Upper Miocene Series into the Bahean Stage and Baodean Stage in the newly published ＂Chinese Stratigraphical Chart＂. The name ＂Babe＂ is derived from the lithostratigraphic unit Babe Formation, and its typical section is located at Shuijiazui on the left bank of the Bahe River in Lantian County, Shaanxi Province. The Bahean Stage is correlated to the marine Tortonian Stage in the International Stratigraphical Chart, and they share the same definition of the lower boundary at the bottom of the paleomagnetic Chron C5r.2n, with an age of 11.6 Ma. At the Shuijiazui section in the Lantian area, this boundary is missing. Among the early Late Miocene mammalian faunas in China, the Guonigou and Dashengou faunas from the Linxia Basin in Gansu, the Tuosu and Shengou faunas from the Qaidam Basin in Qinghai, the Amuwusu fauna from Sonid Right Banner, Inner Mongolia, the Bulong fauna from the Biru Basin in Tibet, the Lamagou fauna from Fugu, Shaanxi, and the Xiaohe fauna from the Yuanmou Basin in Yunnan are correlated to the Bahean Age. The Guonigou section in Dongxiang, Gansu is the most advantageous candidate stratotype of the lower boundary of the Bahean Stage.

关 键 词：灞河阶 底界层型 晚中新世 生物标志 古地磁年龄 中国 

分 类 号：P534.621[天文地球—古生物学与地层学] Q915.87[天文地球—地质学]