of the Cuzco Valley, Peru. 



67 



conglomerate beds is interrupted by insignificant amounts of 

 finer-grained material; at certain other localities the conglom- 

 erate strata are widely spaced. In places beds a few feet thick 

 consisting chiefly of pebbles exceeding 1 inch in diameter may 

 be traced continuously for more than a mile ; elsewhere the 

 conglomerate is displayed as lenses 3 to 10 feet thick and a few 



Fig. 34. 



Fig. 34. Molle-Orcco conglomerate in vertical position at Molle-Orcco. 



hundreds of feet long. At some localities the conglomerate 

 forms merely a patch 3 to 6 inches thick overlying gray or 

 brown sandstone. Individual pebbles 2 to 3 inches in diameter 

 occupying isolated positions in several cubic feet of sandstone, 

 as well as strings of pebbles entirely detached from their 

 neighbors, are not uncommon. 



The Huayllabamba formation, including the Molle-Orcco 

 conglomerate, is well displayed for study on the Cuzco-Ayus- 

 bamba trail leading up the Huancaro Valley (fig. 35). 



