古脊椎动物学报2009，Vol.47Issue(2)：111-134,24.
内蒙古中部敖尔班地区的岩石及生物地层
A NEW EARLY TO LATE MIOCENE FOSSILIFEROUS REGIONIN CENTRAL NEI MONGOL: LITHOSTRATIGRAPHY AND BIOSTRATIGRAPHY IN AOERBAN STRATAWANG Xiao-Ming, QIU Zhu-Ding,LI Qiang,Yukimitsu TOMIDA, Yuri KIMURA,Zhijie Jack TSENG, WANG Hong-Jiang
摘要
Abstract
Vertebrate fossil localities of Early Miocene age are rare in north China in general and in Nei Mongol in particular. Here we report a recently discovered, richly fossiliferous Early Miocene through Late Miocene sequence in central Nei Mongol. The new Aoerban strata from Sonid Zuoqi represent one of the longest exposures in the region, spanning up to 50 m in total thickness, and produce fossils along much of the section with distinct lithologies, resulting in an easily correlated in situ fossil collection with excellent stratigraphic documentation.Three lithologic units are recognized. We formally name the Aoerban Formation at the lower part of the section, which contains three discrete members of fine-grained sediments altered by paleosols: 1 )Lower Red Mudstone Member, 2) Middle Green Mudstone Member, and 3 ) Upper Red Mudstone Member. Resting disconformably above the Aocrban Formation is the Balunhalagen bed, which is char-acterized by basal conglomerates followed by orange-colored mudstones and sihstones. Cutting into the Balunhalagen bed is the Bilutu bed, which is another unit of channel gravel sediments and overbank de-posits.Paleontologically four discrete faunal units are clearly recognizable, mostly based on small mam-mals obtained from five wash sites. We distinguish two Early Miocene faunas. The Lower Aocrban Fauna and Upper Aoerban Fauna, produced from the Lower Red Mudstone and Upper Red Mudstone Mem-bers, respectively, contain characteristic Early Miocene elements of north China and/or Europe. The Balunhalagen Fauna, derived from the Balunhalagen bed, is characteristic of the Middle to Late Mio-cene transition. The Bilutu Fauna from the capping Bilutu bed features a mixed composition of Middle and Late Miocene taxa. Both faunal and sedimentological evidence suggest that some of the earlier fau-nal elements have been reworked into the later Bilutu deposits; thus the Bilutu Fauna is mostly likely of Late Miocene age.关键词
内蒙古/中新世/敖尔班组/岩石地层/生物地层Key words
Nei Mongol, Miocene, Aoerban Formation, lithostratigraphy, biostratigraphy分类
天文与地球科学引用本文复制引用
王晓鸣,邱铸鼎,李强,富田幸光,木村由莉,曾志杰,王洪江..内蒙古中部敖尔班地区的岩石及生物地层[J].古脊椎动物学报,2009,47(2):111-134,24.基金项目
中国科学院知识创新工程重要方向项目(编号:KZCX2-YW-120)、国家自然科学基金重点项目(编号:40730210)、现代古生物学和地层学国家重点实验室(中科院南京地质古生物研究所,编号:083106)和National Science Foundation(US)(EAR-0446699).National Geographic Society(N06.6004-97 and 6771-00)资助. （编号:KZCX2-YW-120）
