Repeated eruptions cause layers of cooled lava and ash to build up, eventually forming the characteristic mountain shape known as a volcanic edifice . Stages of Activity
When plates collide, one often slides beneath another. The sinking landmass experiences intense heat and pressure, causing rock to melt and form magma . volcanoi
Most volcanoes are created by the movement of —massive slabs of the Earth's lithosphere that are constantly shifting. Repeated eruptions cause layers of cooled lava and
Magma is the term for molten rock while it is still underground. Once it breaks through the surface, it is called lava . it is called lava .