An analysis of the basic characteristics of the Upper Pleistocene Salawusuan Stage in the Salawusu River Valley, Inner Mongolia

Abstract：This paper gives a summarized description of the preliminary research results of Salawusuan Stage, an Upper Pleistocene chronostratigraphic unit along the Jiufangtai section of the Salawusu River Valley in Inner Mongolia. The bottom of Salawusuan stage is yellowish brown sand layer. The age of the bottom boundary of the Salawusuan Stage is tentatively identified as 150 ka B．P., and that of the top boundary is around 10 ka B．P．. The boundary age between the upper part and the lower part of the Salawusuan Stage is about 75 ka B．P. . The lower part of the Salawusuan Stage consists of limnetic sediments interbedded with fluvio-aeolian accumulation, and the upper part is composed of aeolian sands supplemented by limnetic sediments. This region has experienced 3 times of water body expansion and 3 times of blown sand invasion since 150 ka B．P．. The representative fossils of ancient vertebrate are Ordos Homo sapiens, Bubohus wansjocki, Palaeoloxodon naumanni, Megaloceros ordosianus, Spirocerus kiakhtensis, etc. in the lower part of the Salawusuan Stage, and Coelodonta antiquitatis, Equus hemionus, etc. in the upper part. The paleoclimate in this region was mainly warm and wet during 150～75 ka B．P．，but was repeatedly interrupted by dry and cool climate intervals. During 75～60 ka B．P．, the climate became arid, cold and windy. It was warm and wet during 60～20 ka B．P．. During 20～10 ka B．P．, however, the temperature somewhat got lower again.