U.S. scientists have successfully used laboratory techniques and sediment cores from the ocean to trace how rivers change course over millions of years. Over the past 30 million years the Indus River has been discharging erosion materials. Scientists Peter Clift of the University of Aberdeen in Scotland and Jerzy Blusztajn of the Woods Hole Oceanographic Institution reconstructed it and found — the source of those sediments changed 5 million years ago.
It was until then, the erosion of mountains to the north of the collision zone between India and Asia was producing the Indus River sediments. But, it was 5 million years ago, when much more sediment starting coming from the southern Himalayas, part of the deformed Indian plate.
Can you imagine it? The major rivers of the Punjab region have been rerouted into the Indus River, where they flow into the Arabian Sea west of India. Previously these rivers flowed east and joined the Ganges River before reaching the Bay of Bengal, east of India.