摘要
Langbapu Palaeolake is located in the west of Yuanmou Basin.A complete lacustrine sediments stratum(27m-thick) was preserved and the ESR dating was accomplished in this paper.The research results showed that Langbapu Lake existed from 216±20 to 121±10 kaBP,which covered the end of the penultimate interglacial,the penultimate glaciation as well as the beginning of the last interglacial.Based on the analysis of grain size,magnetic susceptibility and pollen,the palaeoclimatic changes during 216±20 and 121±10 kaBP of Yuanmou Basin has been reconstructed.During 216~185 kaBP,the mean pollen concentration was the highest and Cycadaceae and Cyperaceae,as well as Sedge vegetation appeared,which indicated that the climate was relatively hygrothermal.During 185~150 kaBP,the pollen concentration decreased rapidly.In the 160 kaBP,the pollen concentration was only 8.67 grain/100 g,which was corresponding to the glacial maximum of penultimate glaciation.During 150~122 kaBP,several sandy gravel layers appeared.The proportion of herb increased.The palaeoclimate became warmer but drier,which was very similar to today’ s climate.The Langbapu Lake shrank and disappeared at last.The mean pollen concentration of lake sediments was only 34.35 grain/100 g,so we thought that dry-hot climate was already significantly before the penultimate interglacial.The characteristics of dry-hot climate were very similar to modern status after the last interglacial.