Å 
GEOMORPHOLOGY 131 
these slopes nearer to the lofty summits of the mountains the 
„euchilla“-sculpture changes into quite a broadlined one (fig. 24). 
_ The very summits are often almost plain. This feature is naturally 
due to the youthful stage of the erosion, according to which the 
high parts still remain unaffected by it. | 
The „cuchilla“-sculpture of the crystalline rock ground stands in a 
marked contrast to the detail-forms, developed in the continental sand- 
stone terranes on the lower hills at the foot of the great blocks and also 
on the cores of the sheet flood cones, when these have been dissected 
Fig. 24. Highland topography near the crest of the Sierra de ano ridge. 
View to the east with the Nevado de Famatina in the distance. (Height of 
observation point about 3000 m.) 
to a higher degree. The sandstone-forms are generally more rounded 
and broader than is the case with those in the crystalline ground. 
The shape of the ridges of the sandstones depends naturally on the 
dip of the strata. When they lie horizontally or dip gently, the 
table- or „meseta“ -forms dominate. When they stand vertically the 
result is a wild Jabyrinth of steep gorges. Such a country is mostly 
impossible to traverse. Characteristical of the sandstone terranes 
are the numerous bluffs or vertical walls, sometimes several hundred 
meters in height. They -nay partly be the result of faults, but often they 
are but erosion forms. The bluffs occur especially in places, where 
the strata dip under angles of about 30°. 
