Which rock type forms from cooling magma or lava?

Which rock type forms from cooling magma or lava?

• A. Sedimentary Rock
• B. Metamorphic Rock
• C. Igneous Rock
• D. Clastic Rock

Answer: (C)

Rocks that come from cooling molten rock are igneous rocks. When magma underground cools slowly, crystals have time to grow, producing coarse-textured rocks like granite. If lava erupts onto the surface and cools rapidly, it forms fine-grained rocks like basalt or rhyolite, or even volcanic glass like obsidian. This cooling-from-molten-rock process is what sets igneous rocks apart from other types. Sedimentary rocks form from weathered pieces that are deposited and cemented together, or from minerals that precipitate from water. Metamorphic rocks come from existing rocks altered by heat and pressure. Clastic rocks are a subset of sedimentary rocks made of broken fragments.

Rocks that come from cooling molten rock are igneous rocks. When magma underground cools slowly, crystals have time to grow, producing coarse-textured rocks like granite. If lava erupts onto the surface and cools rapidly, it forms fine-grained rocks like basalt or rhyolite, or even volcanic glass like obsidian. This cooling-from-molten-rock process is what sets igneous rocks apart from other types.

Sedimentary rocks form from weathered pieces that are deposited and cemented together, or from minerals that precipitate from water. Metamorphic rocks come from existing rocks altered by heat and pressure. Clastic rocks are a subset of sedimentary rocks made of broken fragments.