FABRIC ANALYSIS OF A DESERT DEBRIS SLOPE - BELL MOUNTAIN, CALIFORNIA

The fabric of coarse particles mantling a debris slope on Bell Mountain, California, is investigated to identify the dominant process moving such particles. This slope is typical of debris slopes in the Mojave Desert underlain by closely jointed and/or mechanically weak rocks. Samples of rods and disks analyzed from five sites ranging in gradient from 11.17° to 33.17° are found to display essentially the same fabric: particles tend to be aligned downslope and to lie flat on the ground surface. There is no evidence of imbrication signifying sliding or creep nor of transverse modes indicating rolling. It is concluded that the fabric is probably produced by hydraulic action, and that this process is mainly responsible for moving coarse particles on gradients up to 33° on debris slopes underlain by closely jointed and/or mechanically weak rocks. -Authors