Tuesday, January 26, 2016

INDIA : GEOGRAPHICAL COMPOSITION



PHYSICAL FEATURES OF INDIA : 

India is having all the features that earth have in its physical structure like mountain, plain, deserts, plateaus, islands, rivers, sea, lakes etc.


How did these features form earlier?-this question  can be answered by the views of Earth Scientists and their study tells us about the formation of various parts of the earth. There are various theories given earlier one of which is the "theory of tectonics"


THEORY OF TECTONICS :


 According to this theory " the crust (upper part )of the earth has been formed out of the seven major and some minor plates.

    The movement of the plates result in the building up of stresses within the plates and continental rocks above loading to 

  1. Folding 
  2. Faulting
  3. Volcanic activity 
TYPES OF MOVEMENT OF PLATES

 There are three types of movement of plates :

  1. Convergent Movement: Plates coming towards each other, coming closure they may either collide or crumble or one may slide under the other. This gives birth to mountains.
  2. Divergent Movement : Movement of plates away from each other.
  3. Transformation Boundary Movement : Movement of plates side by side. This changes the size and position of the continents but takes millions of years.
NOTE :

  1. Most of the earthquakes are located at the plate margins but some do occur at the middle of the plates.
  2. The complete South part and much of north part of India is the part of GONDWANA LAND.

GONDWANA LAND: It is the southern part of super continent PANGEA  with Angara land in the Northern Part.

VARIATIONS IN THE LAND OF INDIA:

Main points can be brought out as:

  1. Geologically, Paninsular plateau constitutes one of the ancientlandmasses on the earth surface. It was supposed to be the most stable land blocks.
  2. The Himalayas and Northern Plains are the most recent landforms. from the view points of geography,Himalayan mountains form an unstable zone. The whole mountain system of himalaya represents a very youthful topography with high peaks, deep valleys and fast flowing rivers.
  3. The Northern plains are formed of alluvial deposits.
  4. The Peninsular Plateau is composed of igneous and metamorphic rocks with gently rising hills and valleys. 


MAJOR PHYSIOGRAPHIC DIVISIONS :



The Physical features of Indian union are composed of the following physio-graphic divisions:
GEOGRAPHICAL DIVISION OF INDIA
  1. The Himalayan Mountains
  2. The Northern Plains
  3. The Peninsular Plateau
  4. The Indian Desert
  5. The Coastal Plains
  6. The Islands