The easternmost boundary of himalayas is the Brahmaputra valley. In Arumachal Pradesh beyond the Dhiang valley, the Himalayas take hair pin bent to the south and act as eastern boundary of India and run through the north eastern states. These divisions are known as 'Purvanchal' and mostly composed of sedimentary sand stones. Regionally the Purvanchal are known as Patkai hills, the Naga hills, Manipuri hills, Khasi and Mizo hills
1 5 1