末次间冰期以来黄土古土壤容重特征

通过洛川剖面和白草塬剖面末次间冰期以来黄土古土壤容重序列的建立,对比磁化率、粒度及深海氧同位素分析发现,六盘山东西两侧不同气候区黄土古土壤具有不同的容重值,其成因亦不同。六盘山以东半湿润半干旱气候区黄土古土壤容重值受成壤作用影响,主要由夏季风控制;而六盘山以西半干旱气候区容重值受沉积物粒度影响,主要受冬季风控制。并且在空间上自黄土高原西北向东南容重值呈变大趋势。

Characteristics of Volumetric Weight in Loess-Paleosols Since the Last Interglacial

Through establishing of volumetric weight sequences of loess-paleosols since the last interglacial in both the Luochuan section and Baicaoyuan section,and after comparing between volumetric weight,magnetic susceptibility,particle size and deep sea oxygen isotope,the authors demonstrated that the values of volumetric weight of the loess-paleosols of different climate regions at the east to west sides of the Liupanshan were different and were caused by different causes.To the east of the Liupanshan,loess-paleosols volumetric weight is controlled by East-Asian summer monsoon in semi-humid and semi-arid region and is influenced by pedogenesis,while to the west of the Liupanshan,loess-paleosols volumetric weight is controlled by East-Asian winter monsoon in semi-arid region and is influenced by particle size.Further more,volumetric weight values increase from northwest to southeast in the Chinese Loess Plateau.