CORE Mineral regions and the peninsular core
Indian mineral geography begins with rock age and structure. Old peninsular blocks contain most metallic minerals because crystalline, metamorphic and volcanic rocks have been fractured, intruded and weathered for long periods. The Chotanagpur mineral belt is the densest teaching example: the Chotanagpur Plateau, Odisha Plateau, West Bengal and neighbouring Jharkhand-Chhattisgarh carry coal, iron ore, mica, bauxite and manganese in close map distance. That is why coalfields, iron-steel plants and heavy industries cluster in eastern India rather than in the Ganga alluvial plain. Rajasthan forms the western comparison rather than an exception to the rule. Its Aravalli rocks, especially around Udaipur, Bhilwara, Ajmer, Nagaur and Jaisalmer, host lead-zinc, copper, rock phosphate, gypsum and limestone. The distinction is not east versus west; it is old hard-rock belts versus young alluvial cover. Chotanagpur mineral belt should therefore be read with Zawar-Rampura Agucha lead-zinc belt and Jhamarkotra rock phosphate deposit. The first shows coal-iron-mica concentration; the second shows non-ferrous and fertilizer minerals in Rajasthan's Aravalli terrain. This section also explains why mineral maps use belts rather than isolated dots. A belt links the ore, host rock, transport corridor, power source and nearby consuming industry. Chotanagpur's coal and iron ore serve steel clusters, while Rajasthan's limestone and gypsum feed cement, fertilizer and building-material industries across north-west India. Mineral belts also explain transport corridors. Heavy ores are costly to move, so railway lines, power plants, washeries, smelters and cement factories tend to grow near the ore body or between the ore and the consuming market. This is visible in the Damodar-Chotanagpur steel region and in Rajasthan's quarry-to-cement districts.