摘要
本文根据岩石地层、哺乳动物化石及古地磁资料的综合分析研究,将泥河湾地区晚新生代生物地层划分为5个生物地层时限带(biostratigraphicinterval-zone)并推算出每个带的年限,它们是:(1)Hipparionhoufenense时限带,?~3.30Ma;(2)Mimomysorientalis时限带,3.30~2.48Ma;,(3)Mimomysyouhenicus时限带,2.48~1.87Ma;(4)Allophaionyscfpliocaenicus时限带,1.87~0.97Ma;(5)Microtus时限带,0.97~0.30Ma(以后).同时探讨了第四纪下限,指出Equus到达泥河湾地区的时间可能接近3.00Ma。
Based on designation of two biostiatigraphic composite reference sections for Late Cenozoic biostratigraphic strata in the Nihewan basin, establishment of stratigraphic ranges of 37 mammalian taxa in the reference sections and correlation of the two sections with each other and with the resulted stratigraphic and magnetostratigraphic framework, five continuous biostiatigraphic interval-zones are defined.The proposed interval-zones are bounded by six important faunal events which are identified in the reference sections. Compared the magnetic-polarity stratigraphy of the reference sections with the standard magnetic polarity time scale, the five proposed interval-zones and the approximate ages of their lower and upper boundaries in the reference sections are determined as follows. (1)Hipparion Houfenense interval-zone, ?  ̄ 3.30 Ma;(2)Mimomys orientalis interval-zone, 3.30  ̄ 2.48Ma, (3) Mimomys youhenicus interval-zone, 2.48  ̄ 1.87Ma; (4)Allophaiomys cf. pliocaenicus interval-zone, 1.87  ̄ 0.97 Ma, (5)Microtus interval-zone, 0.97  ̄ 0.73Ma(later). The lower boundary of the Quaternary is also briefly diseussed here.The faunal events suggest that Equus arrived at Nihewan around 3.00 Ma, which is the earliest Equus record in China.
出处
《地球科学(中国地质大学学报)》
EI
CAS
CSCD
北大核心
1995年第1期35-42,共8页
Earth Science-Journal of China University of Geosciences
关键词
泥河湾地区
晚新生代
生物地层
时限带
Nihewan basin, Late Cenozoic, biostratigraphic interval-zone.