The outermost range of the Himalayas is called the Shiwaliks. They extend over a width of 10-50 km and have an altitude varying between 900-1100 metres. These ranges are composed of unconsolidated sediments brought down by rivers from the main Himalayan ranges located farther north. Shiwalik hills were formed from the Tethys sea like Himlayas. With the collision of Eurasia plate with Gondwana land, the land moved up and took the form of mountains.