大理点苍山地区白雀寺地层剖面的化学风化特征及其古环境

THE CHEMICAL WEATHERING CHARACTERS AND ITS ANCIENT ENVIRONMENT OF THE STRATUM SECTION IN BAIQUESI OF DIANCANG MOUNTAIN IN DALI

本文根据系统测定的大理点苍山—洱海地区白雀寺地层剖面的氧化矿物含量数据,对该剖面的风化系数和风化变率及其古环境意义进行了深入的探讨;在此基础之上,选择出其中的硅铁化变率曲线,主要采用函数转换法就古环境中温度升降过程的波动幅度进行了推算。揭示出云南北部晚更新世大理冰期中存在着短时的气温回暖期,而在大理冰期内气候的冷暖波动较低,高纬地区的更加剧烈。经与低、高纬地区古气候变化曲线的比较研究,证明大理白雀寺地层剖面风化变率所示的气候变化曲线与其基本一致,但也存在着明显的地域差异性。

According to the oxidized mineral content's data of the Baiquesi stratum section of the Dianeang Mountain-Erhai Lake in Dali Prefecture, the paper approaches deeply the mean- ings of the section's weathering rates, the weathering changing rate and the ancient environment. On the basis, the curve of the Sire changing rate is chosen to calculate the fluctuated range of the temperature motion in the ancient environment, the period of the short returning to warm is discovered in Dali Ice Age of Pleistocene in the north of Yunnan, and, in the Ice Age, the cold-warm motion in Dali is smaller than its in high-latitude area. According to the comparing research of the ancient climatic changing curves in lowand high-latitude areas, the climatic changing ones, but there is the obvious regional difference.