大巴山北坡土壤的粘粒矿物特征

大巴山北坡不同海拨6个土壤类型中,粘粒矿物以2:1型为主,1:1型高岭石很少。硅铝率在3.06～4.34之间,硅铝铁率在2.38～3.23之间。随海拨升高,蛭石及水云母在矿物中所占比重下降,绿泥石逐渐成为主要矿物。亚高山草甸土及山地暗棕壤以绿泥石为主,水云母次之,伴少量蒙脱石;棕色石灰土、山地棕壤、山地黄棕壤以水云母及蛭石为主,伴有蒙脱石及高岭石,其矿物组合各有特点;黄褐土以水云母,蒙脱石为主,伴有蛭石及高岭石。

Soil Clay Mineral Features of the North Slope of the Dabashan Mountains

In six types sampled from different elevations on the north slope of the Dabashan Mountains above sea level, 2: 1 type clay mineral is in the domiant but with very little type of 1: 1 kaolinite. The ration of SiO2/Al2O3 in clay fraction is about 3. 06~ 4. 34 and that of SiO2/R2O2 about 2. 38~3. 23. with the elevation increasing,the proportion of vermiculate and nhydromica in the clay mineral decreases and chlorite gradually becomes the major mineral. The subalpine medow soil,mountain dark brown earth domi-nantly contain chlorite with a certain amount of hydromica and a small quantity of mont-morillenite and Kaolinite. The clay mineral constitutes of which are different from those of each other. The yellow cinnamon soil dominantly contains hydromica and montmor-tillonite with a few vermiculate and Kaolinite.