The steepest cones form around cinder cone volcanos. Cinder cones form from ash and magma cinders--partly-burned, solid pieces of magma, that fall to the ground following a volcanic eruption. This type of eruption contains little lava, as the magma hardens and breaks into pieces during the explosion. As a result, cinder cone volcanoes tend to be smaller than other types of volcanoes. Italy’s Mt. Vesuvius is a famous cinder cone volcano.
In contrast, shield volcanoes are characterized by a large, broad cone with sides sloping gently away from the center. The lava that erupts from these volcanoes is a thin liquid that slowly emerges from the center of the volcano as well as from cracks in its sides. The lava spreads in a thin layer before cooling. Hawaii’s Mauna Loa is a famous example of a shield cone volcano.
A third type of volcanic cone is a composite cone. Composite cone volcanoes are also called stratovolcanoes. They form when different types of eruptions deposit different materials around the sides of a volcano. Alternating eruptions of volcanic ash and lava cause layers to form. Over time these layers build up. The result is a cone that has a gentler slope than a cinder cone but is steeper than a shield volcano. Washington state’s Mt. St. Helens is an example of a composite cone volcano.
hill created by tiny bits of lava blown out of a volcano and fallen down around the volcanic vent. Also called a scoria cone.
release of material from an opening in the Earth's crust.
active volcano in the U.S. state of Washington. (2,549 meters/8,364 feet)
active volcano in southwest Italy. (1,190 meters/3,900 feet)
large, gently sloping volcano made from fluid lava.
steep volcano made of hardened lava, rock, and ash. Also known as a composite volcano.
fragments of lava less than 2 millimeters across.
hill created by a volcanic eruption.