What is the definition of composite, cinder cone, and shield volcanoes?????

Question

What is the definition of composite, cinder cone, and shield volcanoes?????

Answer 1

Composite volcanoes are constructed from multiple eruptions, sometimes recurring over hundreds of thousands of years, sometimes over a few hundred. Andesite magma, the most common but not the only magma type forming composite cones, produces lava more brittle than basaltic lava because of its higher viscosity. Although andesitic composite cones are constructed dominantly of fragmental debris, some of the magma intrudes the cones as d**e or sills. In this way, multiple intrusive events build a structural framework that knits together the voluminous accumulation of volcanic rubble, which can stand higher than cones composed solely of fragmental material. Composite cones can grow to such heights that their slopes become unstable and susceptible to collapse from the pull of gravity. Famous examples of composite cones are Mayon Volcano Philippines, Mount Fuji in Japan, and Mount Rainier, Washington, U.S.A. Some composite volcanoes attain two to three thousandmeters in height above their bases. Most composite volcanoes occur in chains and are separated by several tens of kilometers. There are numerous composite volcano chains on earth, notably around the Pacific rim, known as the "Ring of Fire".

Cinder cones are mounds of basaltic scoria that forms by streaming gases that carry lava blobs and ribbons into the atmosphere to form lava fountains. The lava blobs commonly solidify during flight through the air before landing on the ground. If gas pressure drops, the final stage of building a cinder cone may be a lava flow that breaks through the base of the cone. If there is abundant water in the environment, magma interacts with water to build a maar volcano rather than a cinder cone. The longer the eruption the higher the cone. Some are no larger than a few meters and others rise to as high as 610 meters or more, such as Paricutin volcano, Mexico that was in nearly continuous eruption from 1943 to 1952. Accompanying the pyroclastic activity were lava flows that emerged from its base to destroy the village of Paricutin. Cinder cones can occur alone but commonly occur in groups or fields.

Shield volcanoes are large volcanic forms with broad summit areas and low-sloping sides (shield shape) because the extruded products are mainly low viscosity basaltic lava flows. A good example of a shield volcano is the Island of Hawaii (the "Big Island"). The Big Island is formed of five coalesced volcanoes of successively younger ages, the older ones apparently extinct.