1) Shield Volcanoes-basaltic lava, which flows easily. forms a broad volcano with gently slopping sides. Largest type of volcanoes. Form where Earth's plates are separating and magma is forced upward between plates.
2) Cinder Cone Volcanoes-high gas content in magma. Explosive, but short lived eruptions. Forms a small come of tephra.
3) Composite Volcanoes-made of alternating layers of lava and tephra. Steep sided mountains. Forms where Earth's plates collide and one is forced underneath each other called subduction zones.
4) Fissure Eruption- Magma is fluid. Ozzes from the cracks in the earth. Magma flows freely across land called flood basalts. Most of the Earth's crust beneath the ocean is flood basalts.
