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.
- (a) I and III only
- (b) I and II only
- (c) I, II and III ✓ UPSC's answer
- (d) II and III only
Why the answer is (c)
• Alfred Wegener's continental drift theory (1912) was supported by geological, palaeontological and climatic evidence showing that now-separated continents were once joined.
• Statement I is correct: the belt of ancient (Precambrian) rocks along the Brazilian coast matches those of West Africa, showing the two coasts were once contiguous.
• Statement II is correct: the gold-bearing veins of Ghana have no local source rock; their source lies in the Brazilian plateau, explicable only if the two lay side by side.
• Statement III is correct: the Gondwana sediments (Permo-Carboniferous glacial tillites, coal seams and Glossopteris flora) of India have counterparts in Africa, South America, Australia, Antarctica, Madagascar and the Falklands.
• Hence I, II and III, option (c).
Why the other options are wrong
- (a) I and III only
- Statement II on Ghana's gold is also a standard piece of drift evidence.
- (b) I and II only
- Statement III on Gondwana sediments is also correct.
- (d) II and III only
- Statement I on matching rock belts is also correct.
Asked in the GS Paper I of the UPSC Civil Services Preliminary Examination 2025, held on 25 May 2025. Question and answer key: Union Public Service Commission. Explanation: UPSC Answer Check.