| Abstract from DBPedia | A cinder cone (or scoria cone) is a steep conical hill of loose pyroclastic fragments, such as volcanic clinkers, volcanic ash, or scoria that has been built around a volcanic vent. The pyroclastic fragments are formed by explosive eruptions or lava fountains from a single, typically cylindrical, vent. As the gas-charged lava is blown violently into the air, it breaks into small fragments that solidify and fall as either cinders, clinkers, or scoria around the vent to form a cone that often is symmetrical; with slopes between 30 and 40°; and a nearly circular ground plan. Most cinder cones have a bowl-shaped crater at the summit.スコリア丘（スコリアきゅう、英語: scoria cone）は、玄武岩質から安山岩質のマグマによる噴火活動により地表面にスコリア（岩滓。マグマが吹き上げられて飛散冷却してできる岩塊で、多孔質で黒っぽいもの）が放出され、火口の周りに積もって崖錐斜面をつくり、円錐台形の山を成したものを指す。小規模な火山の一種である。「噴石丘」とも言う。 (Source: http://dbpedia.org/resource/Cinder_cone) |
