Fig. 129. 



Fig. 130. 



Fig. 129 — Composition of slopes at Puquiura, Vilcabamba Valley, elevation 9,000 

 feet (2,740 m.). The second prominent spur entering the valley on the left has a 

 flattish top unrelated to the rock structure. Like the spurs on the right its blunt end 

 and fiat top indicate an earlier erosion cycle at a lower elevation. 



Fig. 130 — Inclined Paleozoic strata truncated by an undulating surface of erosion 

 at 15,000 feet, southwest of C'uzeo. 



