CHARACTERISTICS OF SOILS ON DEBRIS APRONS IN THE SOUTHERN BLUE RIDGE,NORTH CAROLINA

Aprons of bouldery diamicton frequently have been observed in concave landscape positions in the Southern Blue Ridge. Because of their relatively flat topography, large aprons often are the focus of local economic activity. An environmentally sound development of these landforms can benefit from systematic pedological studies. The present research provides characterization data, and examines spatio-geomorphic variability, for some pedons that have developed on these debris aprons under a warm to temperate humid climate. This study also compares the pedons to those derived from nearby saprolite. Thirteen pedons, located variously on the foot slopes and the apices of the aprons, were studied in three sequences of multiple deposits. The pedons typically contain high amounts of rock fragments and have clay contents that are related to age. Most pedons have lithologic discontinuities. Some of these discontinuities result from the stacking of different deposits, whereas others represent internal variations within one deposit. Because of the heterogeneity in parent material, many soil characteristics do not possess systematic trends with depth. Depth to maximum clay mass and free-iron mass accumulation, however, systematically increase from foot to apex positions, and from topographically low to high deposits. deposits. Key words: debris flows, soils, lithologic discontinuities, Blue Ridge.]