Which type of rock is formed from cooling and solidification of lava?

Question

Which type of rock is formed from cooling and solidification of lava?

1. A. Igneous (Correct answer)
2. B. Sedimentary
3. C. Crystal
4. D. Metamorphic

Correct Answer

Option A — Igneous

Detailed Solution & Explanation

The correct answer is Igneous.

Key Points

• Igneous rocks are formed by the cooling and solidification of molten material — magma (below the surface) or lava (on the surface).
• When lava erupted by a volcano cools and hardens, it forms extrusive/volcanic igneous rocks such as basalt; when magma solidifies deep underground, it forms intrusive/plutonic igneous rocks such as granite.
• Igneous rocks are also called 'primary rocks' because they are the first to form.
• Sedimentary rocks (like sandstone, limestone) form from the compaction of sediments, and Metamorphic rocks (like marble, slate) form when existing rocks are transformed by intense heat and pressure. 'Crystal' is not a rock type, so option (A) Igneous is correct.

Additional Information

• Igneous rocks are called primary rocks because all other types ultimately derive from them.
• The intrusive/extrusive split matters: magma cooling slowly underground gives coarse crystals (granite), lava cooling fast at the surface gives fine ones (basalt).
• The Deccan Traps are basalt flows, and their weathering produces India's fertile black cotton (regur) soil.