Match List-I with List-II and select the answer using the code given below the Lists : List-I (Island / Nation) A. Comoros B. Baffin Island C. Sri Lanka D. Andaman Islands List-II (Tectonic Plate) 1. North American Plate 2. African Plate 3. Eurasian Plate 4. Indo-Australian Plate Code :

Correct — D, A-2 B-1 C-4 D-3. Three of the four pairings fall out of ordinary map knowledge and the fourth is the question. Comoros is an archipelago of volcanic islands at the northern mouth of the Mozambique Channel, between the African mainland and Madagascar, so it belongs to the African Plate — pairing A with 2. Baffin Island is the largest island of the Canadian Arctic Archipelago, in Nunavut, and sits solidly on the North American Plate — pairing B with 1. Sri Lanka lies on the same continental block as peninsular India and rides the Indian Plate, which older and most textbook usage still calls the Indo-Australian Plate — pairing C with 4. That leaves the Andaman Islands, and here the obvious answer is the wrong one. The Andamans do not travel on the Indian Plate. They stand on the Burma plate, a sliver of lithosphere between the Sunda Plate to its east and the Indian Plate to its west, and the Burma plate is normally treated as part of the larger Eurasian Plate — which is why the paper's list, offering no Burma or Sunda option, pairs the Andamans with 3. The mechanism explains the geography: the Indian Plate is being consumed beneath the Burma sliver along the Sunda subduction zone, and the Andaman and Nicobar chain is the ridge thrown up on the overriding side of that trench, with the volcanic arc behind it carrying Barren Island. A plate that is descending cannot also carry the islands raised above it, and that is the point of the item.

• (a)A-3 B-4 C-1 D-2 — Wrong on all four. It sends Comoros to Eurasia, Baffin Island to the Indo-Australian Plate, Sri Lanka to North America and the Andamans to Africa.
• (b)A-3 B-1 C-4 D-2 — Gets Baffin Island and Sri Lanka right but swaps the other two, putting Comoros on the Eurasian Plate and the Andaman Islands on the African Plate — neither of which is anywhere near either.
• (c)A-2 B-4 C-1 D-3 — Gets Comoros and the Andamans right and then exchanges the two remaining islands, sending Baffin Island to the Indo-Australian Plate and Sri Lanka to the North American Plate.

The lithosphere is broken into seven major plates — African, Antarctic, Eurasian, Indo-Australian, North American, Pacific and South American — together with a set of minor plates such as the Arabian, Nazca, Cocos, Caribbean, Philippine and Scotia, and a further set of small slivers or microplates. The Burma plate is one of those slivers: about 1.1 million square kilometres, lying between the Indian Plate on the west and the Sunda Plate on the east, and often treated as part of Eurasia. Its western edge is the Sunda subduction zone, where the Indian Plate goes down; its eastern edge is a transform boundary running through the Andaman Sea, which has been opening as a marginal spreading centre for roughly the last four million years and pushing the Andaman-Nicobar-Sumatra arc away from the Asian mainland. The great Sumatra-Andaman earthquake of December 2004, and the tsunami it caused, ruptured that subduction boundary.

Match-the-list items on plates are usually easy on three pairings and hard on one, and the hard one is chosen precisely where political or physical geography pulls against tectonics. Here the pull is strong: the Andaman and Nicobar Islands are Indian territory, they lie in the Bay of Bengal, and every instinct says Indian Plate. Tectonics does not follow sovereignty. The islands stand on the overriding plate of a subduction zone whose descending slab is the Indian Plate, which is why the chain exists at all — an accretionary ridge raised at the front of the overriding block, with a volcanic arc behind it. The same logic explains why Barren Island, the only confirmed active volcano in the Indian subcontinent, sits east of the main island chain rather than on it. A second useful habit for these questions is to fix each island by the continent it hangs off: Comoros off Africa, Baffin off Canada, Sri Lanka off India, and the Andamans off Myanmar and Sumatra rather than off the Indian mainland, which is the geographical hint that the tectonic answer follows.

• The Andaman and Nicobar Islands stand on the Burma plate, a microplate usually treated as part of the Eurasian Plate, not on the Indian Plate.
• The Indian Plate is subducting beneath the Burma plate along the Sunda subduction zone, and the islands are the ridge raised on the overriding side.
• The Andaman Sea, east of the islands, is opening at a marginal spreading centre that began working about four million years ago.
• Comoros lies at the northern end of the Mozambique Channel between Africa and Madagascar, on the African Plate; Baffin Island is in Nunavut, Canada, on the North American Plate.
• Barren Island in the Andaman Sea is the only confirmed active volcano in the Indian subcontinent, standing on the volcanic arc of this subduction system.

• Assigning islands to plates by which country owns them. The Andamans are Indian territory on a plate that is not the Indian Plate.
• Forgetting that a subducting plate does not carry the islands raised above it — those belong to the overriding plate.
• Treating the Indo-Australian Plate as a single undivided unit. Many modern accounts separate an Indian Plate from an Australian Plate, though exam lists usually keep the combined name.

As a match-the-list item pairing islands, mountain ranges or seas with plates, with one pairing chosen to defy political geography.

• practice — not a real PYQ

  The Andaman and Nicobar Islands lie on which one of the following tectonic units?

  • (a)The Indian Plate, which is subducting beneath Southeast Asia
  • (b)The Burma plate, generally treated as part of the Eurasian Plate
  • (c)The Pacific Plate
  • (d)The African Plate

  Answer(b) The Burma plate, generally treated as part of the Eurasian Plate — the Indian Plate descends beneath it at the Sunda subduction zone, and the islands are the ridge raised above.

• practice — not a real PYQ

  Comoros, an island nation at the northern end of the Mozambique Channel, lies on which one of the following plates?

  • (a)Eurasian Plate
  • (b)African Plate
  • (c)Antarctic Plate
  • (d)South American Plate

  Answer(b) African Plate — the archipelago sits between the African mainland and Madagascar, both of which ride the same plate.