152 



C. SKOTTSBERG 



Fig. 68. Entrance to Quebr. de las \'acas. — Photo C. Skottsberg "/j 1917. 



entrance and 210 m above the sea the passage is obstructed by a threshold dam- 

 ming up a deep pool which cannot be passed round, and into this pool the 

 water comes down in a cascade. O. Casas drains C. Atravesado. The eroding 

 power of the current is great, and I suppose that the stream is more or less 

 permanent during the winter half year, but it must ha\ e taken a very long time 

 to dig a gorge 1000 m deep through the hard basalt. 



C. del Barril. Between Casas and Vacas lies a sloping, triangular table- 

 land, about 1.5 km wide along the top of the coastal escarpment, which is 125 m 

 high in this place, and extending west c. 2 km, where the cordon proper begins. 

 The ruin seen on fig. 66 lies 190 m above the sea; the tilt, corresponding to 

 the dip of the lava beds, is 20"^ E. Three small gullies break the monotony of 

 the grass-land, O. Chica, O. Blindado and O. Cabreros. Q. CJiica ( = small) is very 

 shallow and dry, but some luma trees are seen. O. del Blindado (B. means 

 ironclad cruiser, but may have a very different significance here) is much larger 

 and the water comes down over a threshold about 500 m upstream and has dug 

 out a miniature canyon. There is good forest between 400 and 500 m and some 

 groups of trees a little farther down. There is some forest also in O. de los 

 Cabreros (Goat-hunters' valley). Where the narrowing rocky l^arril ridge, which 

 has its name from a barrel-shaped monolith, begins, the elevation is 730 m. By 

 and by the crest gets very narrow, but the rise is gentle, and there is a goat 

 track all the way up to C. Atravesado (fig. 6']). The ridge slopes 50 — 60° on 



