What are the Different Types of Volcanic Cones?

There are several main types of volcanic cones: shield, cinder, composite, and spatter. All volcanoes are caused by ruptures in the Earth's crust which allow magma, hot gas, and chunks of debris to emerge, sometimes explosively. The cone of a volcano is a buildup of debris around the vent in the Earth's crust; cones are classified by the substances they contain and the way in which they form. Different volcanic cones also act differently, so ascertaining the cone type of a volcano is extremely important, especially in populated areas.

When most people think of volcanoes, they think of cinder cones, also sometimes called ash cones, which have a classic volcano shape. These cones are made from loose volcanic fragments which pile up steeply around the vent as they are ejected. Cinder cones are very simple, and they can form extremely quickly; Paricutin in Mexico, for example, grew from nothing to a 1,100 foot (336 meter) volcano over the course of a year. Cinders can vary widely in size, and commonly a cinder cone has several different types of volcanic material.

A shield volcano forms when magma moves slowly, creating a large, gently sloping volcanic cone. A well known example of a shield volcano is Mauna Loa in Hawaii. The lava emitted by a shield volcano has a low viscosity, so it pours out readily, and these volcanoes may form slowly over a long period of time, with fresh lava deposits layering on top of older ones. Volcanic cones of this type have a very low profile, looking rather like a giant warrior's shield lying on the ground.

Volcanic cones of the spatter type are formed by thick lava and magma which erupts violently around a vent, creating gobs of material which fuse together as the lava cools. Spatter cones are characterized by very irregular surfaces, caused by large chunks of lava and other material. Fans of the Lord of the Rings series may be familiar with spatter cones, as Mount Doom is a classic example.

Composite volcanic cones are caused by alternating layers of magma, rock fragments, and ash. They often erupt violently and unpredictably; Vesuvius, Mount St. Helens, and Mt. Shasta are all examples of composite cones. Composite cones can also cause lahars, mudflows of volcanic ash which can be quite devastating.

Finally, a bulge of magma under the Earth's surface which has not fledged into a volcano is known as a lava dome. Lava domes often form in or near volcanoes, but they can appear in other areas with high geologic activity as well. Lava domes could be viewed like pimples on the Earth, and like pimples, they can pop, sometimes quite explosively with a shower of incredibly hot gases, magma, ash, and chunks of rock.

There are three primary types of volcanic cones: cinder cones, composite cones, and shield cones. Cinder cones are the simplest type, formed by the accumulation of volcanic debris around a vent. Composite cones, also known as stratovolcanoes, are large, symmetrical cones built from layers of lava flows, ash, and rock. Shield cones are broad, gently sloping volcanoes built by low-viscosity lava flows.

A cinder cone volcano forms from explosive eruptions that hurl pyroclastic material, such as ash, lapilli, and volcanic bombs, into the air. These materials then fall back to Earth around the vent, creating a circular or oval cone with steep sides. Cinder cones are usually the smallest type of volcano and have a short lifespan.

Composite cones, or stratovolcanoes, are characterized by their layered structure, which is a result of alternating eruptions of viscous lava and more explosive eruptions that produce ash and pyroclastics. This combination creates steep-sided, symmetrical cones that can rise to great heights. They are often associated with powerful and destructive eruptions, as seen in Mount St. Helens in 1980.

Shield volcanoes are called 'shield' cones because their shape resembles a warrior's shield lying on the ground. They have a broad base with gentle slopes, formed by the outpouring of low-viscosity lava that can travel great distances before cooling and solidifying. The Hawaiian Islands are a prime example of shield volcanoes, with Mauna Loa being one of the most famous.

Yes, a single volcano can exhibit more than one type of volcanic cone. For instance, a complex volcano may have a dominant composite cone structure with smaller cinder cones on its flanks, resulting from secondary vents. The combination of different eruption styles and materials can lead to a diverse range of features within a single volcanic system.

The type of volcanic cone that forms is primarily determined by the magma's composition, viscosity, and gas content, as well as the eruption style. Low-viscosity basaltic lava tends to create shield volcanoes, while more viscous lava with higher silica content forms composite cones. Frequent explosive eruptions of pyroclastic material typically lead to the formation of cinder cones.