Volcano types, illustration. Four types of volcano are shown here, from left: lava escaping from between separating tectonic plates (fissure vent); fast-moving lava flows forming the layers of a shield volcano; slower-moving lava forming a steep-sided lumpy 'dome' with vents (lava dome); and a cone shape with explosive eruptions and lava interleaved with volcanic ash (stratovolcano). The resulting layers are shown, with the magma chamber of each volcano partially seen across bottom.