The Relationship Between Gradient and the Size of Rock Fragments on Debris Slopes on Dolerite-Capped Inselbergs in the Southern Orange Free State

Abstract

The aim of this study was to determine whether a statistically significant relationship exists between the angle of inclination and the size of rock fragments on debris slopes on dolerite-capped inselbergs in the southern Orange Free State. Rock debris in excess of 30 mm diameter and slope angle of nine profiles were measured on four inselbergs. Pearsonian correlation coefficients (r) were calculated for all the profiles. Only about 30 percent of the size distribution is accounted for by slope angle. The rather low correlation can be attributed to the fact that slow creep has limited sorting power, and to the rapid mass movement of large boulders on to low slope angles.