黄土中古土壤研究的新进展

New Dvelopment in Paleosol Study in Loess

本文介绍了作者近年来在古土壤研究方面取得的新进展，主要内容包括以下几方面：黄土是冷干气候条件下发育的黄色古土壤，微弱的成壤作用和连续的风尘堆积更使其土壤剖面不清楚，黄土所属土壤主要是灰钙土型、棕钙土型等新成土（ｅｎｔｉｓｏｌ）；其中红色古土壤的粘粒土胶膜是生物作用形成的，主要是植物根系在腐解过程中产生的，其主要粘土矿物为蒙脱石；黄土地层中粘土胶膜不能显示Ｆｅ２Ｏ３、Ａｌ２Ｏ３发生什么移动，不指示森林植被下淋溶性土壤的发育；黄土地层是在沉积、成壤、成岩三种作用同时同地发生的条件下形成的。

New development gained by the authors in paleosol study in recent years is introduced.Main content is as follow. Loess was yellow paleosols developed under cold arid climate,reason why soil horizons are not obvious is mainly weak soil formation and continuous dust deposition,the soil types to which loess belong are Brown soil,Sierozems and Loessial Sols.Clay film in which montmorillonite is main mineral in red paleosols was formed by living things and formed by degenerating plant roots.The clay film in loess strata can not represent movenment of Fe 2O 3,Al 2O 3 and not indicate the development of forest vegetation and leached soils.Loess strata was formed in the process where deposition,soil formation and lithification occured at same time and same site,and it developed in large geolgical cycles and small living things cycles mingled with each other.