Particle orientation in clayey soils according to transmission diffractometry data

An experimental study of the orientation of clay particles was performed un der laboratory conditions. The application of the quantitative X-ray diffra ctometry allowed us to characterize the orientation of clay particles in st ructural elements of Vertisols (for undisturbed samples) and to reveal the changes in their orientation under different moisture conditions. A model e xperiment on the orientation of clay particles during the sedimentation of polymineral and polydispersed soil material was also performed. it was foun d that, in spite of the general tendency toward the worsening of particle o rientation in the course of pedogenesis, clayey soils possess some mechanis ms that lead to a better orientation of particles. The main factors affecti ng the orientation-disorientation processes in Vertisols were revealed.