Intrusive rocks main content.

Intrusive rocks

Part of Hall of Planet Earth.

Intrusive rocks

Magma is molten rock. As the mantle or crust melts, magma separates from the solid rock, rises through cracks, and collects to form chambers of varying sizes. Frequently, it reaches the surface to erupt as lava from volcanoes. But many large bodies of magma never get that far. Instead, they solidify in the crust to form intrusive rocks. There is an enormous variety of these rocks,