The three physiographic divisions of India are
(ii) Plains of North’ India
(iii) Peninsular India.
Formation of Himalayas. According to the geologists, the area, where the Himalayas stand today, was occupied by a sea, called Tethys. It was an elongated and shallow sea sandwiched between the Angaraland in the North and the ‘Gondwanaland’ in the South. For millions of years denudation of these two land masses resulted in deposition of silt into Tethys. In the course of time these two land masses split up and moved apart from each other. In this process the basin of the Tethys compressed and buckled up. Thus, the Himalayas came into existence.
Characteristics. The Himalayas have three ranges that run almost parallel to one another.
These are :
(i) The Great Himalayas or the ‘Himadri’ is the highest of all. These run from Indus to Brahmaputra. The highest snowy peaks of the Himalayas occur in this range e.g. Mt. Everest (8848 meters), Kanchenjunga, Dhaulagiri, Mt. Godwin Austin, Nanda Devi.
(ii) Middle or Lesser Himalayas. These are also called the Himachal. All the important hill station such as Dalhousie, Dharamsala, Shimla, Mussoorie, Nainital and Daijeeling belong to this range.
(iii) Outer Himalaya or Shiwalik. These are made of unconsolidated river deposits and are formed from earthquakes and land-slides. Soil erosion is at worst in these areas.
Purvanchal. It contains the hills of Garo, Kliasi, Jaintia, etc.
Western off-shoots. It contains Sulaimau Range etc.