INFLUENCE OF DISCONTINUITIES IN PARTICLE SIZE ON THE GENESIS OF TWO SOILS OF THE HONEYWOOD CATENA

Abstract

Particle-size discontinuities were located in two soil profiles of the Honeywood catena. Discontinuities in the distribution of clay, Na-dithionite and NH4-oxalate extractable Fe, Al, and Mn indicated varying degrees of translocation of these elements across the established particle-size discontinuities. The particle-size discontinuities appeared to have influenced the movement and accumulation of clay and extractable Fe, Al, and Mn through their effects on the vertical movement of water within the profiles. The degree of pedogenesis within the profiles was assessed by matching soil horizon boundaries and pedogenesis breaks with the established discontinuities. It was concluded that soil development had progressed more in the Embro profile than in the Honeywood profile. Dithionite-Fe breaks appeared to be useful in identifying the lower boundaries of Ae and Bt horizons, whereas oxalate-Fe breaks appeared to be associated with the illuvial B horizons.