Several lines of geological evidence confirm the existence of a high-energy fluvial regime in western Rajasthan during the Late Quaternary period. Geomorphic description of the extinct river system matches well with the Saraswati River described so vividly in the Rig Veda. The Vedic river which presumably flowed parallel to the Aravalli Mountains during its initial stages, migrated westward during neotectonic uplift of the Aravalli Mountains. The neotectonic movements, which brought about the down-sagging of the northern part of Aravalli Mountains also forced the Yamuna River to swap its original course to flow across the flattened 'mountain'. The river presumably pirated the Saraswati waters while it drifted eastward to join the Ganges
