3. Lofty residual mountains composed of resistant, highly deformed rock, now sculptured into a maze of serrate ridges and sharp commanding peaks.
4. Among the forms of high importance, yet causally unrelated to the other closely associated types, are the volcanic cones and plateaus of the western Cordillera.
5. At the valley heads are a full complement of glacial features, such as cirques, hanging valleys, reversed slopes, terminal moraines, and valley trains.
6. Finally there is in all the valley bottoms a deep alluvial fill formed during the glacial period and now in process of dissection.
Though there are in many places special features either remotely related or quite unrelated to the principal enumerated types, they belong to the class of minor forms to which relatively small attention will be paid, since they are in general of small extent and of purely local interest.
Fig. 126—Block diagram of the typical physiographic features of the Peruvian Andes.