安徽南部盆地紫色岩系上土壤的发生特性

在安徽南部采集不同地质年代、不同层位紫色沉积岩发育的6个土壤剖面,研究其发生特性和成土特点。结果显示,紫色沉积岩发育的土壤,在一定程度上继承了母岩的特点,化学风化作用微弱。大多数土壤的粉粒/粘粒比值都在1.3以上,土壤B层粘粒硅铝率均大于3.7,游离铁含量(16～29)g/kg,土壤发育程度明显低于同地区的花岗岩风化物发育的湿润淋溶土。大多数土壤盐基饱和度>50%,2个土壤剖面盐基饱和度<30%,而且铝饱和度较高为60%～90%。

Genetic Properties of Soils Derived From Purple Sedimentary Rocks in the Basin in South Anhui Province

This paper deals mainly with soil-forming characters and genetic properties in the southern Anhui. The results show that the soils have, in varying degree inherited some properties of purple sedimentary rocks for their very weak chemical weathering. The slit/clay ratios of most soils are above 1.3, silica-alumina ratios (SiO_2/Al_2O_3) of the B or major genetic horizons are above 3.7, and the content of free iron oxide ranges from 16-29 g/kg, much lower than that of the Udic Argosols derived from granite in the same area. Most of the soils studied are eutrophic with base saturation (BS) above 50%, and two soil profiles have high aluminum saturation (AS) from 60% to 90%, with the BS lower than 30% or even 20%.