Ayusbamba (Peru) Fossil Beds. 



129 



swell the Amazon, has entrenched itself 4000 feet below the 

 general level. In passing from Cnzco to Ayusbamba the divid- 

 ing flats and low ridges form a roughly level surface extending 

 over sedimentary beds in various attitudes, and of unequal 



Fig. 3. 



Fig. 3. View froni Senor Calvo's garden looking north across the Chi- 

 pura gorge. The trail to Cuzco traverses the rock terrace, passes through 

 the village of Ccoypa and ascends the valley of the Mollemolle. 



resistance to erosion. Although deeply dissected, the highland 

 area suggests a widespread though imperfectly developed pene- 

 plain resulting from erosion in late Mesozoic time. "Where 

 unaffected by glaciation, the valleys cut into this ancient, base- 

 leveled floor have reached a stage of development approaching 



