I. Bowman — Physiography of the Central Andes. 381 



Such an interpretation of the central Andes as the quotations 

 afford not only leaves wholly out of consideration the latest 

 events in the geologic history of the region, but also disregards 

 some of the most obvious and important elements of form. 

 The persistence of these elements over a wide area lends to 

 their interpretation an importance equivalent to interpretations 

 of stratigraphic and paleontologic facts as leading to^a more 

 complete record of geologic events. 



Fig. 15. 



Fig. 15. A portion of Caupolican Bolivia (from Whitney, Evans, etc. 

 Geog. Journal, 1903). Disregard scale ratio ; divisions express kilometers. 



Features of the First Cycle of Erosion. 



The more detailed examination of the physiography of the 

 eastern Andes of Bolivia may well begin with the great crown- 

 ing range of the whole region, the Cordillera Real (fig. 14). 

 Its structural features exhibit the solid geometry of the 

 eastern Andes in almost diagrammatic form. It consists of a 

 meridional axis of crystalline rocks — granites, gneisses, etc. — 



