广东花岗岩发育几种红壤的矿物组成

本文通过化学分析、X射线衍射、差热分析和电镜观察,研究了广东省花岗岩发育的红壤、赤红壤和砖红壤各粒级的矿物组成。分析结果表明,长石类矿物可直接形成埃洛石和高岭石,进一步转变为三水铝石。云母类矿物则形成针铁矿、赤铁矿、14A矿物和绢云母。斜长石亦能转变成绢云母,再脱钾便生成水云母。 土壤次生粘粒矿物和原生矿物组合的不同,不完全是生物气候为主导的成土因素和地带性的影响,而是各成土因素的综合反映,其中还要注意构造运动的作用。从海南岛花岗岩发育的砖红壤矿物组成特点看来,其风化强度与赤红壤、红壤相比,并非最强,故其能否属砖红壤,值得商讨。

MINERALOGICAL STUDIES OF SEVERAL MAJOR SOIL TYPES DEVELOPED FROM GRANITE IN GUANGDONG

This study deals with the mineral composition of every class of red earth, latcritic fed earth and latosol developed from granite in Guangdong Province by analyses of chemistry, X-ray diffraction, differential therm and electron microscope. According to the results of analyses,minerals of feldspar group are directly formed into halloysite and kao-linite and then kaolimte is transformed into gibbsite .Minerals of mica group are formed intogoethjte, hematite, 14A mineral and sericite. Plagioclase may change into sericite, and further into hydromica by depotassiumation. In the light of different compositions of primary and secondary minerals in the soil,it is suggested that the composition characteristics of soil minerals be affected not only by factors of soil formation that are dominated by zonality and bioclimatfc conditions, but also by complex reflection of all other factors of soil formation. Moreover, the neotectonic movement may also be one of the affecting factors .The intensity of weathering to minerals of latosol developed from granite in Hainan Island is not the strongest one in comparison with lateritic red earth and red earth. Whether it belongs to latosol needs further discussion.