Which of the following are the evidences of the phenomenon of continental drift? 

I. The belt of ancient rocks from Brazil coast matches with those from Western Africa. 

II. The gold deposits of Ghana are derived from the Brazil plateau when the two continents lay side by side. 

III. The Gondwana system of sediments from India is known to have its counterparts in six different landmasses of the Southern Hemisphere.   

Select the correct answer using the code given below.   

  • I and III only   
  • I and II only   
  • I, II and III   
  • II and III only  

Answer: (c) I, II and III 

  • Radiometric dating techniques have confirmed that the rock formations along the eastern coast of South America (Brazil) and the western coast of Africa are similar in age, type, and structure. This is one of the most compelling geological evidences supporting the theory of continental drift.
  • Ghana, located on the west coast of Africa, has rich gold deposits along its coast, yet there is no local source rock to account for this mineral wealth. The likely explanation is that these gold deposits originated from the Brazil Plateau which, before the continents drifted apart, lay adjacent to what is now Ghana. This is one of the pieces of evidence supporting the theory of continental drift.
  • The Gondwana system of sedimentary rocks, particularly tillite deposits (sediments formed from glacial activity), found in India, have strikingly similar counterparts in Africa, Antarctica, Australia, Madagascar, Falkland Islands, and South America. These similarities provide evidence that these landmasses were once part of a supercontinent called Gondwanaland.
Evidence in support of Continental Drift
Evidence in support of Continental Drift
  • Apparent Affinity of Physical Features
    • The bulge of Brazil (South America) seems to fit into the Gulf of Guinea (Africa).
    • Greenland seems to fit in well with Ellesmere and Baffin islands of Canada.
    • The west coast of India, Madagascar and Africa seem to have been joined.
    • North and South America on one side and Africa and Europe on the other fit along the mid-Atlantic ridge.
    • The Caledonian and Hercynian mountains of Europe and the Appalachians of USA seem to be one continuous series.
  • Botanical Evidence
    • Presence of glossopteris vegetation in Carboniferous rocks of India, Australia, South Africa, Falkland Islands (Overseas territory of UK), Antarctica, etc. (all split from the same landmass called Gondwana) can be explained from the fact that parts were linked in the past.
  • Distribution of Fossils
    • The observations that Lemurs occur in India, Madagascar and Africa led some to consider a contiguous landmass “Lemuria” linking these three landmasses.
    • Mesosaurus was a small reptile adapted to shallow brackish water. The skeletons of these are found only in South Africa and Brazil. The two localities presently are 4,800 km apart with an ocean in between them.
  • Rocks of Same Age Across the Oceans
    • The belt of ancient rocks of 2,000 million years from Brazil coast matches with those from western Africa.
  • Tillite deposits
    • Tillite deposits are sedimentary rocks formed out of deposits of glaciers.
    • The Gondwana system of sediments are found in India, Africa, Falkland Island, Madagascar, Antarctica and Australia (all were previously part of Gondwana).
    • Overall resemblance demonstrates that these landmasses had remarkably similar histories.
  • Placer Deposits
    • Rich placer deposits of gold are found on the Ghana coast (West Africa) but the source (gold-bearing veins) are in Brazil, and it is obvious that the gold deposits of Ghana are derived from the Brazil plateau when the two continents lay side by side.