RELATION BETWEEN TRACE‐ELEMENT CONCENTRATIONS IN SOIL AND PARENT MATERIAL

Abstract

Summary An examination of nineteen soil profiles from Queensland and eighteen from Central Australia, both lots formed from a variety of parent materials, and of seventeen profiles formed from dolerite in Tasmania, has shown that the relation between the concentration of a trace element in a soil and its concentration in the parent material is often not close enough for satisfactory estimation of the former from the latter. This is because pedogenic factors other than parent material also play important parts in determining the concentration in the solum. During the weathering processes the range of concentration of a trace element may be greatly increased, and at a later stage the range may be reduced almost to its original value. Although the increase may be quite general, the reduction in range appears t o occur mainly within taxonomic groups. Thus no more than a rough indication of the average concentration of a trace element in a solum can usually be obtained from its concentration in the original parent rock. There may, however, be a fairly close relation between the concentrations in the solum and the C horizon (weathered parent material) of a profile, particularly when effects produced by disturbing factors within taxonomic groups are excluded.