1. For India, the Himalayan Belt in the north and the Naga-Lushai hills in the east are the regions of mountain-building movement.
2. Most of this area, which presents some of the most magnificent scenery in the world, was under marine conditions in the Tethys Sea.
3. During the uplift of the mountains, their marine sediments rose to great heights. Weathering and erosive agents worked on these to produce the present relief.
