Science Olympiad Dynamic Planet Practice Test

What type of rocks form from the cooling of magma?

1. Metamorphic

2. Igneous

3. Sedimentary

4. Volcanic

The correct answer is: Igneous

The formation of igneous rocks occurs through the cooling and solidification of magma, which is molten rock found beneath the Earth's surface. When magma rises to the surface and cools, it can solidify into igneous rock. This process can happen either below ground, where the cooling is slower (resulting in larger crystals), or above ground after a volcanic eruption, where quick cooling occurs. This leads not only to the formation of granitic rocks in intrusive environments but also basaltic rocks in extrusive volcanic settings. While volcanic refers specifically to rocks that form from magma that has erupted onto the surface, the broader category that encompasses both forms, including those which cool below ground, is igneous. Therefore, igneous is the most comprehensive term that captures the entirety of this rock formation process linked to magma.