Resistance of selected clay systems to erosion by water

Rates of erosion of selected clay systems were determined by subjecting molded samples to a uniform erosive force. Increased concentrations of clay minerals generally induced greater stability. Increased bulk densities, however, had little influence on stability. The influence of clay particle orientation and antecedent water content (water content at the start of the test) was not consistent but varied depending upon the clay mineral mixture. Stability increased with increased antecedent water for the Grenada silt loam and for illitic, montmoril‐lonitic, and oriented kaolinitic samples. Stability decreased with increased antecedent water for unoriented kaolinitic samples. Increased orientation of the Grenada silt loam reduced stability but did not change the influence of antecedent water. Greater erosion rates occurred as the temperature of the eroding water was increased. (Key words: Erosion; soil; clay minerals.)