A morpho-synthetic system for the higher level description of microfabrics of bauxitic, kaolinitic soils. A first approximation

Micromorphology is the best technique to characterise the formation and evolution of parent materials and soils in terms of chronology and macro horizon sequence. The morpho-analytical description of soils gives an enumeration of the morphological characteristics that appear unrelated in many cases. It deals with the lowest level of classification and is most useful for genetic interpretation. However, higher levels of classification of microfabrics are needed to avoid the incorporation of lengthy descriptions. The classification should be synthetic and reflect the pathway of soil formation. This paper attempts to elaborate a higher level classification system for microfabrics of soils containing a bauxite or bauxitic laterite horizon. It takes into account the grain size distribution of the material (including mineral pseudomorphs), its nature and the presence of characteristic features. The proposed concepts are applied to soils developed on granite in Southern Johore (West Malaysia).