Question

Bring about the basic difference between the drift theory and Plate tectonics.

Answer 1

Drift theory: Alfred Wegener a German meteorologist put forth “the continental drift theory”. According to him, all continents formed a single continental mass called PANGAEA All oceans formed a single universal ocean called PANTHALASSA. He argued that, around 200 million years ago, the super continent, Pangaea, began to split. Pangaea first broke into two large continental masses as Laurasia and Gondwanaland forming the northern and southern components respectively. Subsequently, Laurasia and Gondwan al and continued to break into various smaller continents that exist today.

Plate Tectonics: This theory emerged in 1967, by McKenzie and Parker and also Morgan. A tectonic plate is also called lithospheric plate. It is a massive, irregularly-shaped slab of solid rock, generally composed of both continental and oceanic lithosphere. Plates move horizontally over the asthenosphere as rigid units. The lithosphere includes the crust and top mantle with its thickness range varying between 5-100 km in oceanic parts and about 200 km in the continental areas. Pacific plate is largely an oceanic plate whereas the Eurasian plate may be called a continental plate. The theory of plate tectonics proposes that the earth’s lithosphere is divided into seven major and some minor plates.