Q. 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.
Exp) Option c is the correct answer.
Statement 1 is correct. 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.
Statement 2 is correct. 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.
Statement 3 is correct. 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.
Source: NCERT-class 11-Fundamentals of Physical geography-chapter-4 DISTRIBUTION OF OCEANS AND CONTINENTS-page-30,31
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