Relationships between particle size, fabric and other factors in some Australian soils

Abstract

Soil fabrics at the level of related distribution of f-matrix (usually finer material) to f-members (usually coarser units) are considered in relation to particle size distribution for a number of randomly selected Australian profiles. Three major fabric continua are recognized: the chlamydic iunctic and matrigranic sequences. The majority of samples in the first two sequences have ratios of clay to silt greater and less than one, respectively, and successive stages correlate with increasing proportions of silt plus clay; fabrics of samples that fall out of sequence in relation to percentage of silt plus clay are explained on the basis of composition and/or specific processes, especially fine-grained carbonates, organic matter, faunal activity, and illuviation. The matrigranic sequence does not correlate with particle size distribution, but seems to be related to composition and/or specific processes such as faunal activity. The usefulness of the results lies in the possibility of using the conclusions to reduce the number of thin sections required to characterize areas of soil, particularly within restricted areas.