Clay mineralogy of selected alluvial soils from Peninsular Malaysia

Abstract

Some soils sampled from the alluvial plains of Kelantan, Trengganu, Johore, Perak and Kedah-Perlis were studied for their mineralogy. The deposits, believed to be of Holocene age, are termed as T 2 terrace deposits. X-ray diffraction and thermal analyses showed that the clay fractions ofthese soils contain kaolinite, gibbsite, geothite, mica, chlorite, mixed layers and anatase. The dominance of kaolinite and sesquioxides is reflected by the low cation exchange capacity. The amount of gibbsite and anatase is related to the texture and drainage conditions. Above pH 5.5, kaolinite appears to control the buffering action of the soils. The studied soils are either in the recent or intermediate stage of weathering.