滇中路南石林地区钙华特征与更新世气候变迁

TRAVERTINE CHARACTER OF LUNAN STONE FOREST AND PALEOCLIMATE CHANGE IN MIDDLE PLEISTOCENE IN CENTRAL YUNNAN PROVINCE

钙华层是岩溶记录中古气候环境及地下水演变信息的载体 ,在重建古气候环境和恢复古水文地质条件等方面具有重要意义。通过对滇中路南石林地区的钙华沉积层进行大量地质研究 ,用 ESR法测定其生成年代 ,结合钙华层的主要矿物 (方解石 )的生长发育特征 ,获得了该区距今 33× 10 4 a～ 4 .4× 10 4 a的地质活动、古气候环境的变迁信息。其年龄可与全球深海岩芯同位素记录和西南岩溶洞穴石笋所揭示的古气候记录对比 ,认为自从中更新世以来 ,路南石林地区经历了 6次较大的气候变化 ,与全球古气候变化波动基本一致。

Travertine layer is the comprehensive and systematical paleoclimatic environment information carrier of the karstification record and plays an important role in the reconstruction of paleoclimatic environment and hydrogeology condition.Based on the geological research,ESR dating and mineralogical analysis on the travertines formation from Lunan Stone Forest in central Yunnan Province,the paleoclimatic environment evolution from 329 ka B P to 48 ka B P in this area is recognized.The ages of Lunan Stone Forest and central Yunnan Province area corresponded to that of global deep cores (or sediments) and stalagmites from the karstic cave in Southern China. The results show that since Middle Pleistocene Epoch six large climate changes have taken place in Lunan Stone Forest Area,which coincides with the fluctuation of global paleoclimatic change.