Q. Which rock type produces black soil?
Answer: Basalt
Notes: Black soil, also called regur soil, forms from weathering of basalt rocks. In Jharkhand, black soil is found in areas with Rajmahal basalt traps. Basalt-derived soil is rich in clay, potash, iron oxide, lime, and magnesia, resulting in high fertility. Granite and gneiss decomposition typically produce red soils. The geology of Jharkhand includes the Chhotanagpur granite-gneiss complex and Rajmahal basalt, with black soil specifically linked to basalt formations.