An Encyclopaedia of Indian Archaeology v1.c14.s9.3

v1.c14.s9.3

Terraces can further be distinguished as (1) paired or unpaired; and (2) erosionai or aggradational. Most of the terraces are usually unpaired, i.e., the surfaces of the two banks of the river are not at the same level; this is generally due to lithology and layout of the initial drainage. In some river valleys the processes of erosion and deposition take place in a sequential order. Thus the river cuts its valley deeper due to steep gradient or increase in the flow of water due to climatic changes. The surfaces occurring on both banks will be the (oldest) rock-cut terraces with a thin veneer of river-flood sediments. The deeper valley may get filled with sediments, again due to amelioration of climate causing aggradation. During the subsequent rejuvenation the river will degrade its bed and will thus be formed an aggradational terrace below the older erosional terrace. These are of the cut-and-fill type which are common in peninsular rivers.