Search results
Results from the WOW.Com Content Network
The magma then rises through the crust, incorporating silica-rich crustal rock, leading to a final intermediate composition. When the magma nears the top surface, it pools in a magma chamber within the crust below the stratovolcano. [7] The processes that trigger the final eruption remain a question for further research.
Types of volcanic eruptions. Some of the eruptive structures formed during volcanic activity (counterclockwise): a Plinian eruption column, Hawaiian pahoehoe flows, and a lava arc from a Strombolian eruption. Several types of volcanic eruptions —during which material is expelled from a volcanic vent or fissure —have been distinguished by ...
Volcanic arc formation along a subducting plate. A volcanic arc (also known as a magmatic arc[ 1]: 6.2 ) is a belt of volcanoes formed above a subducting oceanic tectonic plate, [ 2] with the belt arranged in an arc shape as seen from above. Volcanic arcs typically parallel an oceanic trench, with the arc located further from the subducting ...
If the erupted magma contains 52–63% silica, the lava is of intermediate composition or andesitic. Intermediate magmas are characteristic of stratovolcanoes. [48] They are most commonly formed at convergent boundaries between tectonic plates, by several processes. One process is the hydration melting of mantle peridotite followed by ...
Mount McLoughlin. Grizzly Peak. Drake Peak. It is a stratovolcano or an andesitic volcanic complex. Strawberry Mountain. This feature is one of the three only stratovolcanoes within Eastern Oregon. It is also the most notable. Dooley Mountain. Powder River Volcanics.
Intermediate composition magma, such as andesite, tends to form cinder cones of intermingled ash, tuff and lava, and may have a viscosity similar to thick, cold molasses or even rubber when erupted. Felsic magma, such as rhyolite , is usually erupted at low temperature and is up to 10,000 times as viscous as basalt.
In geology, igneous differentiation, or magmatic differentiation, is an umbrella term for the various processes by which magmas undergo bulk chemical change during the partial melting process, cooling, emplacement, or eruption. The sequence of (usually increasingly silicic) magmas produced by igneous differentiation is known as a magma series .
Hawaiian eruption. A Hawaiian eruption is a type of volcanic eruption where lava flows from the vent in a relatively gentle, low level eruption; it is so named because it is characteristic of Hawaiian volcanoes. Typically they are effusive eruptions, with basaltic magmas of low viscosity, low content of gases, and high temperature at the vent.