Question

Explain briefly the theory of the ‘Indobrahm’ river as believed by some geologists. Also mention the two principal grounds on which the theory has been discarded.

Answer 1

Some geologists believe that in the past, a single large river called the ‘Indobrahm’ or ‘Shivalik River’ flowed along the base of the Himalayas, collecting waters from major rivers like the Indus, Ganga, and Brahmaputra. This river is thought to have flowed westward, draining into the Arabian Sea.

1. Difference in Drainage Patterns: The river systems of the Indus, Ganga, and Brahmaputra show different drainage patterns, making it unlikely that they were once a single river.
2. Gaps in Sediments: There is no continuous layer of sediments across the plains to prove a single ancient river flowed through the region.