Fig. 235.—Section across the great lenticular threads of alluvial deposits which compose the veneer of the High Plains (after W. D. Johnson).
Fig. 236.—Distributaries of the foothills superimposed upon an earlier series (after W. D. Johnson).
Character profiles.—In contrast with the profiles in the landscapes of humid regions (see [Fig. 187], [p. 177]), those of arid lands are marked by straighter elements ([Fig. 237]). Almost the only exception of importance is furnished by the domes of massive granite monoliths, which are sometimes broken in half by great displacements. Below the horizon the secondary lines in the landscape betray the same straightness of the component elements by the gabled slopes of talus which are many times repeated so as almost to reproduce the lines in a house of cards, since the sloping lines are maintained at the angle of repose of the materials ([Fig. 482], [p. 443]). Wherever the waves of desert lakes have made an attack upon the rocks and have retired the projecting spurs, other gables characterized by slightly different slopes are introduced into the landscape.
Fig. 237.—Character profiles in the landscapes of arid lands.
Plate 9.
Reading References for Chapters XV and XVI