shield volcano

There are two main types of volcano, but three distinctive cone shapes. Composite volcanoes emit a stiff, rapidly solidifying lava which forms high, steep-sided cones. Volcanoes that regularly throw out ash build up flatter domes known as cinder cones. The lava from a shield volcano is not ejected violently, flowing over the crater rim forming a broad low profile.

Broad, flat volcano formed at a constructive margin between tectonic plates or over a hot spot. The magma (molten rock) associated with shield volcanoes is usually basalt - thin and free-flowing. An example is Mauna Loa on the Pacific island of Hawaii. A composite volcano, on the other hand, is formed at a destructive margin.

Shield volcanoes are found along the rift valleys and ocean ridges of constructive plate margins. The lava flows for some distance over the surface before it sets, so forming low, broad volcanoes. The lava of a shield volcano is not ejected violently, but simply flows over the crater rim.