甘肃兰州盆地的第三纪地层及哺乳动物群

THE TERTIARY AND LOCAL MAMMALIAN FAUNAS IN LANZHOU BASIN,GANSU

介绍近二十多年来兰州盆地第三系研究的新成果 ,将兰州盆地的第三系和地方哺乳动物群重新进行了划分 ,将咸水河组提升为咸水河群 ,时代自早渐新世晚期至晚中新世。咸水河群中新建八个组 ,从下往上为 :韩家井组(E1 - 23) ,产南坡坪动物群 ;甘家滩组 (E23) ,产峡沟动物群 ;皋兰山组 (N1 1 ) ,产兰州动物群 ;瞿家川组 (N21 ) ,产庙嘴子动物群 ;黄羊头组 (N31 ) ,产张家坪动物群 ;饲马沟组 (N4 1 ) ,产对亭沟动物群 ;下街组 (N51 ) ,产泉头沟动物群 ;龙骨山组(N6 1 ) 。

This paper introduces some achievements in study of the Tertiary of the Lanzhou Basin obtained during the last twenty years. The Tertiary and local mammalian faunas of the Lanzhou Basin, Gansu, has been subdivided (from upper to lower): The Pliocene Linxia Formation(N 2);the Xianshuihe Formation is raised to a group rank, with the age ranging from late Early Oligocene to Late Miocene, and the Xianshuihe Group is divided ascendingly into eight formations:the Longgushan Formation (N 6 1) containing the Xingjiawan local mammalian fauna comparable to MN11～MN13 in European time scale,the Xiajie Formation (N 5 1) containing the Quantougou local mammalian fauna comparable to MN7 in European time scale,the Simagou Formation (N 4 1) containing the Duitinggou local mammalian fauna comparable with the MN4～MN5 in European chronology,the Huangyangtou formation (N 3 1) containing the Zhangjiaping local mammalian fauna comparable to MN3 in European time scale,the Qujiachuan Formation (N 2 1) containing the Miaozuizi local mammalian fauna, comparable to MN2 in European time scale,the Gaolanshan Formation (N 1 1) containing the Lanzhou local mammalian fauna, comparable to Ageninan MN1 in European Neogene mammal chronology,the Ganjiatan Formation (E 2 3) containing the Xiagou local mammalian fauna which is better to be assigned to late Oligocene,the Hanjiajing Formation (E 1 2 3) containing the Nanpoping local mammalian fauna, all the fossils in this fauna tend to pinpoint the age to late Early Oligocene;the Lower Oligocene-Lower Eocne Yehucheng Formation (E 1 2 2-E 1 1 3) and the Lower Eocne Paleocene Xiliougou Formation (E 1-E 1 1 2) .