鄂、湘两省山地土壤粘粒矿物的研究 Ⅰ.大别山南坡土壤中的粘粒矿物

STUDIES ON THE CLAY MINERALS OF MOUNTAIN SOILS IN HUBEI AND HUNAN PROVINCES I. THE CLAY MINERALS OF SOILS ON THE SOUTH SLOP OF THE DABIE MOUNTAINS

对大别山南坡不同海拔高度的7个土壤剖面的粘粒矿物组合、化学组成及表面化学特性进行了研究。结果表明:14埃矿物、高岭石是供试土壤的主要粘粒矿物,其次是水云母。山麓土壤中多蛭石,随海拔升高,蛭石迅速减少,14埃过渡矿物逐渐增多,山体中、上部出现少量绿泥石。随海拔升高,高岭石含量稍减,但结晶度增强、水云母含量增多,并有少量12埃混层矿物。三水铝石在海拔920米处的底土层中开始出现,并随海拔继续升高而增多。供试土壤粘粒化学组成和表面化学性质随海拔升高的变化与其粘粒矿物组成的变化相符。根据研究结果,主要讨论了14埃过渡矿物与蛭石的区分和三水铝石的成因。

The association and chemical composition of clay mineral and cation exchange properties of 20 soil horizons in 7 soil profiles on the south slop of the Dabie Mountains in Hubei Province were studied. The results indicated that: 1). the 14(?) minerals and kaolinite were the main clay minerals in the soils examined, and the secondary was illite. The 14(?) clay mineral of soil on the feet of mountains was vermiculite. The content of vermiculite decreased whereas the content of 14(?) intergrade mineral in soils increased with the rising of the altitude. The chlorite was found in the middle and upper parts of the mountains. And with an rising of the altitude, the content of kaolinite decreased slightly but the degree of crystalinity was enhanced and the content of illite increased as well as a small ammount of 12(?) interstratified mineral was found. 2). the gibbsite was found in the subsoil at an altitude of 920m, then it not only was found in all horizons of soil profiles but also its ammount increased as the elevation was going up. 3). the chemical composition of soil clay fraction, even the surface chemical properties varied with the rising of altitude, which was quite agreeable to the change of clay minerals. 4). between the 14(?) clay minerals, vermiculite and 14(?) intergrade mineral in soils, there were apparent differences in their CEC, pH value and the ammount of exchangeable aluminum. The methods for identification of these minerals and the formation of gibbsite are discussed.