THE CONTINENTAL DRIFT

INTRODUCTION

Originally given by Sir Alfred Wegner of Germany, primarily a meteorologist profounded the continental drift theory, he carefully studied the accounts of paleo-climatologist, geophysicists, paleontologist, for the evidences to support his theory, his main problem was related to climate change. according to the theory, all the continents were once united in form of one single landmass and it was named Pangea by Wegener, this Pangea was surrounded by mega ocean called Panthalasa during the Carboniferous period, Due to the unstable condition of earth's interior and endogenetic forces this Pangea broke down into many pieces this breakdown of continents into smaller parts continued for about millions of years, the continents drifted apart, collided with each other and the present shape and size of continents were formed
                          

continents joined altogether forming one landmass

Forces responsible for the movements

for the main forces behind the movements of these continents were

1. Tidal force

2. Gravitational force

the tidal force was generated by the moon the gravitational pull of the moon made these vast continents move apart from each other, the tidal force applied made the continents to move towards west.

the gravitational force was generated by the endogenetic forces coming from within the earth, the contraction in size of the earth due to the cooling would have generated this type of force. this force was mainly responsible for the movement of the continents towards the equator.

 EVIDENCES SUPPORTING THE THEORY

1. The jigsaw fit of the continents, if bought together the coastline of continents have remarkable similarities with each other especially the east coast of South America and the west coast of Africa. these two continents have almost identical coastline separated by a long stretch of Atlantic ocean.

2. The geological evidence denotes that the Caledonian and Hercynian mountain systems of the Western and the eastern coastal areas of the Atlantic are similar and identical. The Appalachians of the northeastern regions of North America are compatible with mountain system of Ireland, Wales, and north-western Europe. 

3. There is a marked similarity between the fossils found on the Eastern coast of South America and western coast of Africa.

4. The distribution of glossopteris flora in India, South America Antarctica, Falkland Islands etc proves the fact that the landmass were previously united and in form of Pangea.

5. It has been reported from the geodetic evidence that Greenland is drifting westward at the rate of 20cm per year. the evidence of seafloor spreading after 1960 have been confirmed the movement of landmass with respect to each other.

MOVEMENT OF CONTINENTS

The continents which drifted apart were once united in form of one landmass, due to the two forces applied to these continents it started to break down into pieces the Pangea first broke into two landmass to the northward which was called the Laurasia and the southward continents was called the Gondwana land.

These two landmasses further broke down into many pieces, the two America's drifted toward the west due to the tidal force of the moon, the Gondwana land which consists of today's India, Australia, Antarctica, South Africa, Madagascar also broke down and drifted apart from each other India started its movement towards the equator and collided with southern part of Laurasia which gave birth to the Himalayas.

Respectively Australia broke apart from India and further drifted toward the east the African plate collided with the European plate the African plate further moved towards the north. South pole was located near present Durban (near Natal in southern Africa) during the Carboniferous period. Antarctica drifted more towards the south, and thus the present shape of continents was achieved.