A 48.5-ka climate record from Wulagai Lake in Inner Mongolia, Northeast China

摘要

A 3.6-m long sediment core was collected from Wulagai Lake in the Northern Inner Mongolia Plateau, Northeast China. Data of grain size and loss on ignition at 550 ℃ (LOI550) were used to reconstruct the climatic changes since the late Marine Isotope Stage (MIS) 3. The climate was generally warm and humid between 48.5 and 30 cal ka BP, but was interrupted by a cold and dry period between 37.7 and 33.5 cal ka BP. Cold and dry climate occurred between 30 and 11.5 cal ka BP, especially during the Last Glacial Maximum (LGM). Beginning at 11.5 cal ka BP until present day, the climate was generally warm and humid. Our results are similar to the climate records from the Chinese Loess Plateau since the late MIS 3, which indicates that intensification and weakness of the Asian summer monsoon responding to high and low June insolation are the main mechanism of climate evolution in Wulagai Lake area since the late MIS 3. However, LOI550 content increased in Wulagai Lake since 2.5 cal ka BP, which probably resulted from human activities.