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A shield volcano is a type of volcano named for its low profile, resembling a shield lying on the ground. It is formed by the eruption of highly fluid (low viscosity) lava, which travels farther and forms thinner flows than the more viscous lava erupted from a stratovolcano. Repeated eruptions result in the steady accumulation of broad sheets ...
A tuff cone, sometimes called an ash cone, is a small monogenetic volcanic cone produced by phreatic (hydrovolcanic) explosions directly associated with magma brought to the surface through a conduit from a deep-seated magma reservoir. They are characterized by high rims that have a maximum relief of 100–800 meters (330–2,620 ft) above the ...
This list of shield volcanoes includes active, dormant and extinct shield volcanoes.Shield volcanoes are one of the three types [specify] of volcanoes. They have a short cone shape, and have basaltic lava which means the lava has low viscosity (viscosity is a measure of the ability for a liquid to flow)
All stratovolcanoes and shield volcanoes have a tendency to form a cone at the surface. However, stratovolcanoes are able to form steeper sides whilst shield volcanoes only form very flat cones. The reason for this is that stratovolcanoes are composed largely of solid, eruptive material, whereas shield volcanoes are built up mainly by fluid ...
Since low-viscosity magma is typically low in silica, shield volcanoes are more common in oceanic than continental settings. The Hawaiian volcanic chain is a series of shield cones, and they are common in Iceland, as well. [25] Olympus Mons, an extinct martian shield volcano is the largest known volcano in the Solar System. [26]
The uppermost shield-forming unit consists of megacrystic trachyte flows that are distributed throughout the western part of the Itcha Range. Formation of the shield was followed by the eruption of basanites, alkali basalts and hawaiites from small cinder cones, tuff rings and fissures in the eastern half of the shield. [6]
Two small Big Raven cinder cones formed in Walkout Creek valley about 18 kilometres (11 miles) southwest of Mount Edziza, both of which produced basaltic lava flows. [3] [182] The larger cone is about 120 metres (390 feet) high and was constructed on top of a slow-moving landslide originating from the northern side of the valley. [170]
The shield originated in oceanic island arcs that formed on the cratons during 900 Ma to 680 Ma, of which relics remain as thrust sheets on top of more rigid bodies. [ 1 ] In Mali, the Tilemsi belt is a complex of intraoceanic arcs that formed above a subduction zone sloping down to the east and were accreted to the shield during the Pan ...