Basalt, which forms the Deccan Plateau, is an example of which type of rock?

Basalt forms when lava erupts onto the surface and cools quickly, so it is an extrusive (volcanic) igneous rock with fine grains. Granite is the standard intrusive igneous rock, cooling slowly below the surface with large crystals. Sedimentary rocks such as sandstone arise from deposited material, and metamorphic rocks such as marble arise from heat and pressure on existing rocks. The Deccan Traps are lava flows.