Physical Geography of India / Peninsular Block — UPSC Mains Model Answer

The Peninsular Block is largely a stable, rigid landmass that has experienced minimal folding since the Precambrian era. However, differential vertical movements along fault lines have caused submergence of parts of the western coast, creating a drowned coastline characterised by estuaries, lagoons, and backwaters — notably along Kerala's coast. This is a recognised tectonic feature associated with the block.

The Eastern Ghats, being discontinuous and dissected, represent ancient fold mountains that have been worn down over geological time into residual ranges. Hills such as the Veliconda range and Mahendragiri in Odisha and Andhra Pradesh are classic examples of such residual formations, reflecting prolonged denudation of once-higher terrain.

Rivers draining the Peninsular Block flow over hard, resistant crystalline rocks on a relatively flat plateau surface, typically forming broad, shallow valleys with gentle gradients. Deep V-shaped valleys are characteristic of young, fast-flowing rivers in geologically active mountain regions — not of the mature, aged rivers of the Peninsula. This feature is therefore not associated with the Peninsular Block.

Understanding peninsular geology informs disaster risk management, particularly for coastal erosion, groundwater policy in hard-rock aquifer zones, and infrastructure planning in ecologically sensitive hill ranges under environmental protection frameworks.