Abstract:

On the basis of TL dating and grain size analysis of the Core HDBZK-1 samples in the Changchun Area, the authors employ K₂O, Na₂O, MgO, CaO, Al₂O₃ and their ratios, K₂O/Na₂O and Al₂O₃/(Al₂O₃+CaO+Na₂O), which are sensitive to environmental changes, combined with pollen analysis, to analyze the climate environment change of the Changchun area during the late Mid-Pleistocene (probably from 280 to 120 kaB.P.). The results show that the Changchun area has experienced four distinctive cold-dry and warm-wet paleo-climate changes during the late Mid-Pleistocene: cold and dry (281.6-244.0 kaB.P.)-moderate warm and slightly wet (244.0-215.0 kaB.P.)-cold and dry (215.0-131.8 kaB.P.)-the climate turned warm and wet again, with an obvious sign of a sudden increase of freshwater algae (131.8-126.4 kaB.P.), which probably comply with the climate cycles reflected by deep-sea oxygen isotope curves.

Key words: geochemistry, pollen, paleo-climate changes, Late Mid-Pleistocene；Changchun area