(Fig.2.6) Shield Volcano.

     Shield volcanoes are huge in size.  They are built by many layers of runny lava flows. Lava spills out of a central vent or group of vents.  A broad shaped, gently sloping cone is formed.  This is caused by the very fluid, basaltic lava which can't be piled up into steep mounds.

     Shield volcanoes may be produced by hot spots which lay far away from the edges of tectonic plates.   Shields also occur along the mid-oceanic ridge, where sea-floor spreading is in progress and along subduction related volcanic arcs.

     The eruptions of shield volcanoes are characterized by low-explosivity lava-fountaining that forms cinder cones and spatter cones at the vent.  Famous shield volcanoes can be found for example in Hawaii (e.g. Mauna Loa and Kilauea).