Volcanes

Volcanoes provide insight into Earth's interior. They originate below the surface, where intense heat melts rock into magma. This magma can rise and erupt as lava, which flows like a river and solidifies into rock. Observing a volcano reveals rock that once erupted from deep within the planet.

How does lava behave when it flows down the slope of a volcano?

What does cooled lava harden into?