Search results
Results from the WOW.Com Content Network
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 .
[1] [3] On shield volcanoes forming from level seafloor without neighboring vents, flank rifting occurs more evenly distributed around the vent. [1] However, where the flanks of a volcano may be supported on one side by the presence of a pre-existing feature, or burdened with various planes of weakness, rift zone formation promulgates according ...
There were three main shield volcanoes built on the seamount base (from north to south): the Northern Edifice, the Central Edifice and the Jandia Edifice. [75] [27] The central shield volcano is the oldest, built mostly from 22 to 18 Ma but with a later phase from 17.5 to 13 Ma. The southern shield volcano formed from 21 to 14 Ma.
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)
A shield is that part of the continental crust in which these usually Precambrian basement rocks crop out extensively at the surface. Shields can be very complex: they consist of vast areas of granitic or granodioritic gneisses , usually of tonalitic composition, and they also contain belts of sedimentary rocks, often surrounded by low-grade ...
Orogenic belts are associated with subduction zones, which consume crust, thicken lithosphere, produce earthquake and volcanoes, and often build island arcs.These island arcs may be added to a continental margin during an accretionary orogeny.
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]
They are one of the largest volcanic features on Earth, taking the form of a large shield volcano. [2] They consist of many layers of solidified flood basalt that together are more than about 2,000 metres (6,600 ft) thick, cover an area of about 500,000 square kilometres (200,000 sq mi), [ 3 ] and have a volume of about 1,000,000 cubic ...