Which of the following processes do not come under diastrophism?

Question

UnlockIAS · Accepted Answer

Correct — B, Heterogenic. The standard classification of diastrophism (crustal deformation by internal/endogenic forces) covers orogenic movements (mountain-building, mainly compressive folding and faulting at plate margins) and epeirogenic movements (broad, largely vertical upliftment/subsidence of continental blocks). Plate tectonics is the modern theory explaining what drives these movements, and earthquakes are the sudden release of the stress that diastrophic forces build up along faults. 'Heterogenic' is not a recognised term in this classification — it does not name a real geological process — so it is the one that does not come under diastrophism.

Why the other options are wrong — (a) Orogenic movements ARE a core category of diastrophism — the mountain-building process driven by intense, mainly compressive crustal forces.  (c) Earthquakes are the sudden release of stress built up by ongoing diastrophic (tectonic) deformation along faults — closely tied to diastrophism, not separate from it.  (d) Plate tectonics is the driving mechanism behind diastrophic crustal movements (both orogenic and epeirogenic), not a process excluded from it.

Concept: Diastrophism is the deformation of the Earth's crust by internal (endogenic) forces, traditionally split into two categories: epeirogenic movements (slow, large-scale, chiefly vertical upliftment or subsidence of continental crust) and orogenic movements (more intense, mainly horizontal compressive forces that fold and fault rock to build mountain ranges). Plate tectonic theory explains what drives both, and earthquakes are a direct, sudden expression of the stress these movements build up.

State PCS 2023 Q54 — Geography PYQ with Answer

State PCS 2023 Q54 — Geography PYQ with Answer