.:-*:; • 





Fig. 180. 





Fig. 181. 



Fig. 180 — Urubamba Valley between Ollantaytambo and Torontoy, showing (1) 

 more moderate upper slopes and steeper lower slopes of the two-cycle mountain spurs; 

 (2) the extensive alluvial deposits of the valley, consisting chiefly of confluent alluvial 

 fans heading in the glaciated mountains on the left. See Fig. 179. 



Fig. 181 — Glacial features of the Central Ranges (see Fig. 204). Huge lateral 

 moraines built by ice streams tributary to the main valley north of Chuquibambilla. 

 That the tributaries persisted long after the main valley became free of ice is shown 

 by the descent of the lateral moraines over the steep border of the main valley and 

 down to the floor of it. 



