THE APPLICATIONS AND MINERAL COMPOSITIONS OF RESIDUAL SOILS DISTRIBUTED IN SOUTH KOREA(Asian Clay Special Paper)
The yellowish-reddish brown residual soils are widely distributed in S. Korea. The residual soils have been widely used for the various applications. In the present study, the mineral and chemical eompositions and other properties ofsome representative residual soils were investigated and cornpared according to parent rock type. Vlarious applications ofresidual soils in Korea and the basic ideas of each application were introdnced. The mineral and major element compositions of residnal soils
... f residnal soils were different according to parent rock type, but the difTerence in the residual soils isnit significant compared with the difference in the parent rocks. Residual soils contain varying amounts of clay rninorals such as kaolinite, illite and micas/vermiculite, Tlie color and density as well as mineral and chemical compositions vary with panicle size. The color and density become more reddish and highcr, respectively, with decreasing panicle size because of increasing amount of iron oxide. The amoullts of clay minerals are inereasing with decreasing particle size. These results are coincjdent wjth the yariations in chemical cornpositions. The unique applications ofresidual soils are a characteristic feature in Korea unlike in other countries. The reddish residua1 soils have been widely used for various applications such as red tide reduction, censtmction materials, animal feeding, cosmetics, food, natural pigment and various healthy products. The main reasons of application are to use the properties of clay minerals contained in residual soil.