Previous Year Question

The Imphal Basin/Imphal Valley lies in the central part of Manipur and is an extensive flat valley surrounded by hills on all sides.

The valley contains thick fluvio-lacustrine deposits of clay, silt and sand. Lacustrine means deposited in or associated with a lake. Thus, its sedimentary characteristics indicate its relationship with an earlier lake environment.

Official descriptions of Manipur state that the present flat valley area was once occupied by a large lake, which was gradually filled by sediments brought by rivers and streams flowing down from the surrounding hills.

The present Loktak Lake is associated with the remnant of this former extensive lake system. As sedimentation progressed and the lake area contracted, an extensive flat plain developed.

For this reason, the Imphal Basin is considered a good example of a Lacustrine Plain, rather than a Loess, Glacial or ordinary Alluvial Plain.