萨拉乌苏河流域末次间冰期古土壤化学风化与古气候  

Chemical Weathering of the Milanggouwan Paleosols in the Salawusu River Valley and Their Paleoclimatic Implication during the Last Interglacial Period

作　　者：欧阳椿陶[1] 李保生[1] 欧先交[1] 温小浩[1] 曾兰华[1] 杨艺[1] 刘宇飞[1] 

机构地区：[1]华南师范大学地理科学学院,广州510631

出　　处：《地理学报》2007年第5期518-528,共11页Acta Geographica Sinica

基　　金：国家重点基础研究发展计划(973计划)(2004CB720206);国家自然科学基金(49971009);中国科学院知识创新工程重要方向(KZCX2-SW-118)~~

摘　　要：内蒙萨拉乌苏河流域米浪沟湾剖面末次间冰期发育5层古土壤。对这5层古土壤的形态特征、粒度、扫描电镜及化学风化等分析结果表明:(1)这些古土壤具有与华北现代褐土相似的形态特征;(2)粘化率中部高和石英颗粒表面硅质溶蚀—沉淀现象表明古土壤层中发生过风化成壤作用;(3)用K2O/Na2O、Al2O3/Na2O、MnO/Al2O3、CIA及A-CN-K图解与华北现代褐土作对比分析,发现它们的化学风化特征极为相似;(4)用气温及降水量与CIA值的回归关系方程,得出5层古土壤发育时期的水热状况确与华北现代的暖温带半湿润季风性气候大致相同或更显暖湿。形态特征、粒度、石英颗粒表面特征和化学风化特征等多个方面具备了与现代华北褐土类似的化学风化成壤特征,证明这些古土壤是在与华北相似的暖温带半湿润季风性气候条件下形成的。There are five layers of paleosols in Milanggouwan section in Salawusu River valley of Inner Mongolia during the last interglacial period. We have observed the morphological features of these paleosols and analyzed their grain-size, surface textural features and chemical weathering. The results showed that： （1） These paleosols have some morphological features just like the recent cinnamon soils in North China. （2） They are similar to the recent cinnamon soils that have higher clay contents in the middle part than in the other parts of the soil and SiO2 solution and precipitation can be observed on the surface of the quartz grain, indicating that chemical weathering and pedogenic process have taken place. （3） On the basis of CaO/MgO, K2O/Na2O, Al2O3/Na2O, MnO/Al2O3, CIA and A-CN-K diagram, the comparison results show that the intensity of chemical weathering in paleosols is very similar to the recent cinnamon soils in North China. （4） Using the regression equation of CIA, the values of annual temperature and precipitation of those paleosols can be calculated respectively, and with those values, it is easy to ascertain that the climate conditions are similar to that of North China.

关 键 词：萨拉乌苏河 古土壤 化学风化 末次间冰期 古气候 

分 类 号：P532[天文地球—古生物学与地层学]