Complex sentence: As the Indian plate migrated northwards away from the Reunion mantle hotspot, rapid subsidence was accompanied by major clastic input from the Indus river and deposition of up to 9 km of Oligocene to Recent sediments.
Split into simpler sentences: As the Indian plate drifted northwards away from the Reunion mantle hotspot, the basin subsided rapidly. This was accompanied by major clastic influx from the Indus river and leading to deposition of up to 9 km of Oligocene to Recent sediments.