Clay Mineralogy of Red- and Yellow-colored Soils from Korea

Open Access
Publisher Website
Google Scholar
Abstract
Clay mineralogy, together with silt and sand mineralogy and some chemical and physical characteristics, was investigated for samples from 10 profiles of Red-Yellow Podzolic soils (Inceptisols, Alfisols, and Ultisols) from Korea. The soils were generally strongly acid in reaction, except for those developed on limestone and from cultivated lands. Soil texture varied with profiles and horizons, ranging generally from silty clay to light clay to heavy clay. The silt fraction consisted, in all the profiles, principally of quartz with a small amount of feldspars and layer silicates, and the sand fraction was dominated by quartz and feldspars, with fair amounts of dolomite, micas, rock fragments, iron concretions, or clay aggregates depending on the profiles. Such mineralogical composition of the silt and sand fractions reflected well the Iithological nature of the parent materials or the stage of soil development. Clay mineralogical composition varied from profile to profile, though not very much in the sequence of mineral species but in their proportion. Respective profiles showed, however, no essential differences in the composition among different horizons, except for three profiles, K-S (Songjeong series), K-8 (Jeonnam), and K-9 (Mureong), where gradual or abrupt change of the composition in terms of the proportion of mineral species was observed between the upper and lower horizons. Kaolinite, illite, and more or less chloritized vermiculite were the most common and abundant minerals, with chlorite, iIIite/vermiculite or iIIite/chlorite regular mixed layer, gibbsite, and halloysite as accessory or minor constituents, through all the profiles. Profile K-2 (Pyeongchang series), which was slightly alkaline in reaction, contained a smectite mineral in a fair amount, and profile K-10 (Yeongrag series) carried a considerable amount of noncrystalline materials in which iron oxides accounted for the greatest part. Presence of vermiculite- and/or smectite-kaolinite random mixed layer was suspected, in most profiles, though in small amount in general.

This publication has 4 references indexed in Scilit: