Weathering and Soil Clays

Abstract

Continental areas are subject to weathering and pedogenesis. Three distinct phenomena are to be considered (Duchaufour, 1960):

• 1° The disintegration and progressive alteration of the rocks leading to what pedologists call the “weathering complex” which, in the case of crystalline rocks, is represented most frequently by an arène. A part of the material is removed in solution;

• 2° The biological colonization by plants, microbes and animals, which brings organic matter into play;

• 3° The displacement or migration of the soluble or very fine-grained elements of the weathering complex under the influence of percolating solutions. These migrations lead to the development of impoverished horizons (A horizons) or to accumulative horizons (B horizons).