19(a). What do you understand by the theory of continental drift? Discuss the prominent evidences in its support.

    Continental drift theory explains how continents keep shifting their position. It states that, the continents have been formed the  break up of Pangaea(asuper continent). The idea was first put forward by Alfred Wagner. It was rejected as Wagner couldn't give reasons for the drift. Plate tectonics explains the movement of the continental plates upon the asthenosphere as caused primarily by endogentic forces.

    Prominent evidences of continental drift are,

1. Similar fossils of animals and vegetation found  accross continents. They suggested that these continents were once located insame climatology and harboured same flaura and fauna.
2. The jig-saw puzzle shape of the continental boundary. Similarities along the coasts made Wagner comment that, they just fit together.
3. Paleomagnetism observed in rocks of similar age indicated latitudinal variance suggesting that drift of continents.
4. Presence of gold deposits along  the South American coast despite no known resources in the continent. It suggested that they were deposited prior to the breaking of Pangaea from the African continent.
5. Current satellite observation have beyond doubt confirmed that the continents are indeed drifting.
6. The relatively young age of the sea bed suggesting they have been continually been moving and renewed by fresh deposition.