Downslope movement of in situ clasts on forested hillslopes,Virginia

Downslope movements of 109 clasts ranging in intermediate diameter from 30 to 870 mm were monitored over a five-year period on hillslopes in the Valley and Ridge province of southwest Virginia. Gradients ranged from 8° to 42°. Regression on slope tangent, depth of clast base below ground surface, clast size, and clast shape explained 70 per cent of clastmovement variance. A substantial part of the unexplained variance appears due to variation in substrate and slope aspect. Additional measurements made on two steep boulder streams showed extremely low rates.