Field investigations including lake shoreline measurement and 14 C chronology have been carried out on the Alxa Plateau to better understand the formation and evolution of the high lake levels in northwest China during the late Pleistocene.Comprehensive field investigations show that there are at least ten shorelines at different elevations at Juyan Lake,at least four on the northwest side of the Jilantai Salt Lake,and nine shorelines and one terrace on the northeast margin of Zhuye Lake.Stratigraphic correlations and chronological evidence indicate that the paleo-lakes have the highest lake levels in Marine Isotope Stage (MIS) 3.Though the optically stimulated luminescence (OSL) results which have been reported by some scholars do not support this view,the fact that the paleo-lakes have the highest lake levels in MIS 3 can not be denied.Differences between OSL and 14 C results from this work might indicate that high lake levels existed on the Alxa Plateau during two different periods.It also suggests that the high lake levels may exist in both MIS 5 and early MIS 3.This paper also provides the basic hydrological information for further water resources research in this arid region.
WANG NaiAng LI ZhuoLun CHENG HongYi LI Yu HUANG YinZhou
