MARSTERS, PHYSIOGRAPHY OF THE PERUVIAN ANDES 2^5 



From the point of view selected, we see a billowy mass of ridges whose 

 summits correspond roughly to the level of those on which we are stand- 

 ing. This view passes across the Intercordilleran Belt, while the former, 

 in part, belongs to the East Cordillera. From a physiographic point of 

 view, we thus have, first, the Intercordilleran Belt, a highly dissected 

 plateau, longitudinally drained hj the Apurimac and its branches head- 

 ing against the east flank of the "West Cordillera; second, the East Cor- 

 dillera, behind which run the Urubamba and Villcanota systems, also in 

 longitudinal position ; but these finally succeed in cutting their way across 

 the final range to join the Ucayali, which passes west of north through 

 the Department of Loreto and drains for many miles the inner edge of 

 the Amazonian plains. It is on this river that the important inland city 

 of Iquitos is situated. 



Cerro de Pasco Section. — Let us now examine the topographic charac- 

 teristics to be observed in a cross section passing through the mining town 

 of Cerro de Pasco and connecting with that which we have already de- 

 scribed under the name of the Huacho-Oyon section. In this way, we 

 can get a long-distance view of the principal features of these geographic 

 provinces extending from the coast to the East Cordillera. As we have 

 already stated, Oyon stands on the western slope of the West Eange. Let 

 us now go from Oyon to an advantageous point of view in the TJchuc- 

 chacua section, where we may obtain a clear view both to the east and to 

 the west. Such a point may be found near the main trail from Oyon to 

 Cerro de Pasco and not far from the "pass," with an elevation between 

 16,000 and 17,000 feet above sea level. To the west and southwest will 

 be seen the western slope of the West Cordillera, as already described. 

 To the east, we will see, some 3,000 or 4,000 feet below us, a stretch of 

 rolling undulating country extending to and beyond Cerro de Pasco. 

 Occasional knobs and ridges may be seen at various points standing on 

 the plain and serving as guides and mileposts to the explorer. From the 

 same point of view, on a clear clay, the East Eange may be seen, away 

 to the east and northeast of Cerro de Pasco. Here may be found the 

 grandest and most magnificent group of ridges and peaks rearing their 

 summits far above the line of permanent snow. There are peaks here 

 that pass far above the 20,000-foot level. Into this Intercordilleran 

 Belt the headwaters of the Huallaga have cut their way southward into 

 the vicinity of Cerro de Pasco, having pushed through a part at least of 

 the East Eange. It is important to note here that the Huallaga did not 

 succeed in cutting its way through the entire East Cordillera to join the 

 Ucayali, but was forced to maintain a longitudinal position as far as 

 Huanco. Then it broke through the East Cordillera to join the Marahon 



