Evidences Support to The WEGENER Theory
WEGENER stated that all the continents could be United together in a form of supercontinent.He believed that the earth's crust was made of sima and sial .The ocean crust was being made of heavier than Continental crust and situated below the Sial or Continental crust.about 300millons years ago the continents were together in form called as Pangea ,the ocean around it called panthalassa.
In different geological era,the continents were drifted and formed present condition of earth.
Drifting of continents according to geological era as following:
EVIDENCES SUPPORT TO THE THEORY
WEGENER had proved that the unification of the continents in a form of a single masses during Carboniferous age.
Jig Saw Fit
According to WEGENER, the west part of the Africa and the eastern part of South America are fitted together and both parts of the coast are similar Geographically.
Similarity of Physical Features
Caledonian mountain and Hercynian mountain in Europe and Appalachian mountain in USA seems to be one continents in the past.
On the other side,Greenland and Ellesmere and Baffin island fits in well
Distribution of fossils of Plants and Animals:-
There are similarities of plants and animals found in the past history.According to WEGENER ,The Unification of Landmass helped animals to travel from one region to another.
Following are examples of fossils
- CYNOGNATHUS,a Triassic land reptile found in South America and Africa
- LYSTROSAURUS,a Triassic land reptile found in Africa,India and Antarctica.
- MESOSAURUS, a freshwater reptile found in southern part of South America and South Africa
- LEMURS found in India, Madagascar and Africa
- GLOSSOPTERIS,a fossil plant found in South America, Africa, Antarctica, India and Australia.
Contemporary Stratigraphy:-
There is marked that similar Rocks found in South America and Africa,the similar sequence of Appalachian mountain and Caledonian mountain in North America and Europe respectively.
ICE MATCH:-
The evidence of Carboniferous glaciation,Brazil, India, Australia and Antarctica was one landmass. On the other side Glacier stratification shows that radiated outward from the glacier centre over the South Pole in Africa toward the Atlantic Ocean and from the Atlantic ocean onto South America. Therefore,the continents must be joined so that the ice moved across a single land Mass Pangea. The glacier evidences Support the polar wandering.
DRAWBACKS:-
Some drawbacks of WEGENER'S theory of Continental drift
- Concept of Jigsaw Fit:- WEGENER stated that Eastern part of South America and Western part of Africa fits perfectly.but there was difference of 16° angle between them,
- Fail to explain the mechanism of drifting:- WEGENER explained that continents moved due to tidal forces and centrifugal forces.But the forces would not be strong that continents could be moved.
- Distribution of fossils:- According to WEGENER , GLOSSOPTERIS found in South America, Africa,Antarctica, India and Australia. But fossils of glossopteris also found in Siberia, North West Afghanistan,NorthEast Punjab etc.
- WEGENER failed to explain why continents started to move in Mesozoic era,He didn't explain about the movement of continents before.
