Which of the following is also called ‘Molassis Basin’?

Question

UnlockIAS · Accepted Answer

Correct — C, Mizoram. Mizoram's hill ranges are part of the young, actively rising Indo-Burman (Purvanchal) fold mountains, built up of thick Tertiary sedimentary rocks — sandstones and shales eroded off the rising ranges and deposited in the adjoining trough. Because these deposits are geologically classed as 'molasse' (soft, poorly consolidated sediment shed from a young orogenic belt), the region is also referred to as the Molasse Basin.

Why the other options are wrong — (a) Also part of the hilly north-eastern Indo-Burman ranges, but it is Mizoram, not Manipur, that carries the 'Molasse Basin' label.  (b) Also built of young Tertiary hill ranges in the north-east, but the 'Molasse Basin' designation is specifically applied to Mizoram, not Tripura.  (d) Home to the Naga Hills, another part of the same Indo-Burman fold-mountain system, but again it is Mizoram, not Nagaland, that carries the 'Molasse Basin' name.

Concept: 'Molasse' is a geological term for the soft, poorly consolidated sedimentary rocks (sandstone, shale, conglomerate) shed by erosion from a young, actively rising fold-mountain belt and deposited in an adjoining basin. Mizoram — part of the Indo-Burman/Purvanchal ranges formed by the same tectonic collision that built the Himalayas — is composed of such young Tertiary sedimentary sequences, which is why the region is also known as the Molasse Basin.

State PCS 2023 Q60 — Geography PYQ with Answer

State PCS 2023 Q60 — Geography PYQ with Answer