what makes magma flow?
79926
Careful: The questioner is correctly stating that magma is inside the earth's crust (or lithosphere).  Lava is magma that has erupted.  Magma rises up from within the lithosphere because it is more bouyant (wants to float) that the dense rock around it.  Lava is different, once it's on the surface, it does tend to flow with gravity, like water.
71801
It depends on the volcano.\n\nIf magma - molten rock - is erupted it forms new formations when it cools. On the big island of Hawaii, the volcanic eruptions have added a lot of new land to the island.\n\nIf it is a pyroclastic flow - fast, hot gasses and volcanic debris -  like the one that destroyed Pompeii or Mt. St. Helens, there may not be any new land created and the existing land will be radically altered.\n\nIn general, when a land based volcano erupts, the lava and stone and ash build up around the eruption site into a cone shape.\n\nUndersea volcanos spweing lava also build up, but not in a cone shape. Once the hot rock hits water it starts to cool into large pillow-shaped forms.
798171
1) Rhyolites that cool too quickly to grow crystals form a natural glass or vitrophyre, also called obsidian\n\n2) amount of silica di-oxide, texture and color\n\n3) gold is found in quartz veins around igneous intrusion via hydrothermal fluid precipitation\n\n4) If we assume a slower but constant rate of cooling, then both minerals could feasibly form well shaped crystals at the same time (phaneritic texture) .  If we assume a slow than fast cooling, then possibly only plagioclase would form (porphyritic texture) due to its position in Bowen's reaction series.
778520
I'm not going to write this in 6 sentences for you but...\n\nIgneous rocks are formed when molten rock (magma) cools and solidifies, with or without crystallization, either below the surface as intrusive (plutonic) rocks or on the surface as extrusive (volcanic) rocks. This magma can be derived from partial melts of pre-existing rocks in either the Earth's mantle or crust. Typically, the melting is caused by one or more of the following processes -- an increase in temperature, a decrease in pressure, or a change in composition.
737671
Mt. St. Helens was formed from the subduction of the Juan de Fuca Plate underneath the North American Plate.  Subsequent eruptions, producing basalt and andesitic lava flows, have either reshaped or built up the volcano over time.
320094
If I remember from 8th grade science the silica-rich magma has a higher concentration and moves much slower down a hill. the Silica-poor magma is much more water like and moves much quicker. It also makes the volcanoe. It would be a cone volcanoe if it was rich because the lava wouldnt shoot out voilently and just run down the sides to continue to form more layers. Silica-poor magma usually comes out violently and would be more destructive.
678919
hhhmmmm....must be igneous...um...olivine. thats what it says. Pyroxene and plagioclase are also common
796388
A magma chamber, or a magma reservoir if you want to sound like a professional... lol.
652094
It's the rapid flow of material from a volcano that is accelerated by hot gases.\n\nHere's a good link for reference from the US Geological Survey site.  It has some better definitions, pictures, and case studies of pyroclastic flows.\n\n\n"Pyroclastic flows are high-density mixtures of hot, dry rock fragments and hot gases that move away from the vent that erupted them at high speeds. They may result from the explosive eruption of molten or solid rock fragments, or both. " http://volcanoes.usgs.gov/Hazards/What/PF/pcflows.html
229185
It depends on the amount of dissolved gases in the magma.  Magma can contain gases, like carbon dioxide and water vapor, which can vary from .5% to as much as 6% depending on the chemistry of the magma.  These gases are only in solution due to the very high pressure magma is under when it's deep in the Earth.  When it comes up through a volcano, the pressure on the magma is reduced, and the gases can bubble out.  If the gas content is high, this can result in an explosive eruption, if it's low, you get a smooth lava flow.
765041
The two properties of the magma that determine the kind of volcano are:\n\n1)Viscosity\n2)Composition\n\nThe viscosity of the magma is a function of the temperature, the degree of crystallization, degree of polymerization and the composition of the melt.\n\nThe composition of the melt is related to the amount of silica it contains and the amount of volatiles dissolved.\n\n\nThis two property are usually coupled (they act together).\nSilica rich magmas are usually colder that mafic ones, contain more volatiles, and hence they have a higher viscosity compared to mafic magmas, so they form strato volcanoes as opposed to shield volcanoes.
740828
There are two\nINTRUSIVE\nthe magma cooled of slowly, leaving gross crystals (granit)\nEXTRUSIVE\nthe magma cooled off fast, leaving crystal so small you can't see them (basalt)
230570
Mafic lava is very hot and flows easily it contains less silica and are enriched in iron (Fe), magnesium (Mg), and calcium (Ca) and just encase your trying to get a homework answer I will leave it at that if not you will know what I mean ;)
330211
They have a chemical structure which causes it to stay thick (viscous). The first crystals to form as a silicic magma cools slowly are pyroxene, amphibole, and feldspar. In pyroxene, silica tetrahedra (SiO4) form long chains. In amphiboles, silica tetrahedra form double chains. The pyroxene and amphibole crystals that are beginning to form become entangled so the magma becomes viscous.
51754
mafic magma - about 1100 Celcius\nintermediate magma - about 1000 Celcius\nfelsic magma - about 800 Celcius
435645
A, because it's the division between two tectonic plates. the plates move apart and magma from inside the earth comes up and piles up in the form of mountains.
253407
True. Magma can be generated at subducted plate boudaries. \n\nI am still uncertain about the question. Does your question read as "Can magma be formed at subducted plate boundaries" then the answer would be yes