Preliminary digital terrain map of mélange and intact rock determined by interpretation of terrain details in the junction area of Coastal and Central belts of the Franciscan Complex between Gualala and Ukiah, northern California Coast Ranges

A terrain-based map of a large area of Franciscan Complex delineates varied areas of erosionally resistant topography and contrasting subdued topography distinguished using differences in the detailed shapes of individual topographic elements that in these rocks indicate relatively intact rock or mélange. Most of the line work in the map is based on interpretation of small-scale aerial photographs (less than about 1:50,000) or of slope and curvature maps prepared from a 10-meter elevation grid.