Previous Year Question

The Chambal River is an important example of Superimposed Drainage. In superimposed drainage, the initial course of a river develops over relatively younger overlying rock layers. Later, when erosion exposes the older rocks with a different underlying structure, the river continues to maintain its previously established course.

Consequently, instead of adjusting its course according to the underlying folds, faults or resistant and less-resistant rock structures, the river may cut across them. Thus, its course is not completely controlled by the present geological structure.

In India, Damodar, Banas and Subarnarekha, along with Chambal, are also cited as examples of superimposed drainage.

An important conceptual difference should be remembered—under Antecedent Drainage, a river existed before the uplift of the land and maintains its course despite that uplift; whereas under Superimposed Drainage, the river course develops on overlying cover rocks and is later superimposed upon the older underlying structure.