Continental Drift Theory

 Continental Drift:

              The concept of the continental Drift was developed in the early part of the 20th century. According to this concept " all the continents were once joined together as a single huge continental landmass which has rifted and drifted apart over the Earth's surface. This movement was considered as the primary factor of climatic changes and formation of land forms such as mountains, Islands, volcanoes etc.

             Continental Drift Theory was mainly developed by Alfred Wegner. But he considered the views of F.B.  Taylor into account and claimed that the changes in the appearance of Earth were largely due to shifting of continents.

FB Taylor's Views:

              FB Taylor's postulated his concept of " horizontal displacement of continents" in the year 1908. But it was published in the year 1910. The main objective of his hypothesis was to explain  the origin of fold mountains on the surface of the Earth and their relative distribution. He wanted to explain the North-south arrangement of the Rockies and Andes range and the East-west extent of the Alpine mountains ( Alps, Caucasus, Himalayas). According to Taylor's, there were two landmasses during Cretaceous period. These were Angaraland ( Laurasia) and Gondwanaland. They were located near North and South pole respectly.

Assumptions:

(i). Continent were made of SiAl and they moved towards the equator.

(ii). The main driving force behind continental drift the tidal force.

(iii). Continent were displaced in two ways- Equator ward and West ward under the influence of tidal force.

       

                Taylor stated that Laurasia moved away from from North pole, because of enormous tidal force of the Moon towards the equator. It caused splitting and rapture in the landmass which formed Baffin bay, Labrador sea and Davis strait. Similarly, the Great Australian Bight and Ross sea were formed due to Gondwanaland splitting and rupturing. He also propounded that landmasses began to move in lobe form while drifting through the zones of lesser resistance.

                 Thus, mountains were formed in frontal part of moving lobes e.g. Caucasu, Himalayas and Alps. Rockies and Andes were formed due to westward movement of landmasses.

                  The concept of " horizontal displacement of continents" is considered as the first attempt in describing the Theory of continental Drift.