206 THE ANDES OF SOUTHERN PERU 



clad mountains near the equator are really quite rare. Mount 

 Kenia rising from a great jungle on the equator, Kilimandjaro 

 with its two peaks, Kibo and Mawenzi, two hundred miles farther 

 south, and Ingomwimbi in the Euwenzori group thirty miles north 

 of the equator, are the chief African examples. A few mountains 

 from the East Indies, such as Kinibalu in Borneo, latitude 6° north, 

 have been found glaciated, though now without a snow cover. In 

 higher latitudes evidences of an earlier extensive glaciation have 

 been gathered chiefly from South America, whose extension 13° 

 north and 56° south of the equator, combined with the great height 

 of its dominating Cordillera, give it unrivaled distinction in the 

 study of mountain glaciation in the tropics. 



Furthermore, mountain summits in tropical lands are delicate 

 climatic registers. In this respect they compare favorably with 

 the inclosed basins of arid regions, where changes in climate are 

 clearly recorded in shoreline phenomena of a familiar kind. Lofty 

 mountains in the tropics are in a sense inverted basins, the lower 

 snowline of the past is like the higher shoreline of an interior 

 basin ; the terminal moraines and the alluvial fans in front of them 

 are like the alluvial fans above the highest strandline ; the present 

 snow cover is restricted to mountain summits of small areal ex- 

 tent, just as the present water bodies are restricted to the lowest 

 portions of the interior basin; and successive retreatal stages are 

 marked by terminal moraines in the one case as they are marked 

 in the other by nights of terraces and beach ridges. 



I made only a rapid reconnaissance across the Cordillera Vilca- 

 pampa in the winter season, and cannot pretend from my limited 

 observations to solve many of the problems of the field. The data 

 are incorporated chiefly in the chapter on Glacial Features. 

 In this place it is proposed to describe only the more prominent 

 glacial features, leaving to later expeditions the detailed descrip- 

 tions upon which the solution of some of the larger problems must 

 depend. 



At Choquetira three prominent stages in the retreat of the ice 

 are recorded. The lowermost stage is represented by the great fill 

 of morainic and outwash material at the junction of the Choque- 



