Weathering

The in-situ breakdown of rocks and minerals at or near Earth's surface through physical disintegration (mechanical weathering: freeze-thaw, thermal expansion, salt crystallisation) and/or chemical decomposition (hydrolysis, oxidation, carbonation, hydration) without significant transport of the weathered products. Weathering produces regolith and is the first stage in the denudation process; chemical weathering rates are highest in hot, humid tropical regions, which explains the deep lateritic profiles of peninsular India. Differential weathering is responsible for distinctive landforms such as tors, exfoliation domes, and honeycombed rocks, all UPSC-relevant geomorphological features.