Want this question answered?
Plinian eruptions are usually associated with felsic magmas.
No. Lava flow in a volcanic eruption is a factor of the temperature, chemistry, and amount of trapped gas in the lava. Highly viscous, felsic, gas charged magmas tend to explode upon eruption. Low viscosity, basaltic magmas tend to flow upon eruption.
Felsic rocks have a lower melting point than mafic rocks and felsic magma has a lower temperature. In other words, felsic magma is not hot enough to melt mafic rock while mafic magma is hot enough to melt felsic rock.
Felsic magmas produce the most violent reputations. This is because felsic magmas are the most viscous and thus can hold the most gasses. These trapped gases can expand explosively when they reach lower pressure near the surface.
Granite is the result of slow cooling processes of felsic magmas.
Plinian eruptions are usually associated with felsic magmas.
Silica content increases from mafic to felsic, and Mg and Fe content decreases. These differences affect things such as viscosity, density and colour. Felsic magmas are the most viscous and least dense, and felsic rocks are the lightest in colour.
No. Lava flow in a volcanic eruption is a factor of the temperature, chemistry, and amount of trapped gas in the lava. Highly viscous, felsic, gas charged magmas tend to explode upon eruption. Low viscosity, basaltic magmas tend to flow upon eruption.
Felsic rocks have a lower melting point than mafic rocks and felsic magma has a lower temperature. In other words, felsic magma is not hot enough to melt mafic rock while mafic magma is hot enough to melt felsic rock.
Heat from the mantle melts part of the lower crust
Felsic magmas produce the most violent reputations. This is because felsic magmas are the most viscous and thus can hold the most gasses. These trapped gases can expand explosively when they reach lower pressure near the surface.
Granite is the result of slow cooling processes of felsic magmas.
Felsic magma is very viscous, so if often gets "stuck" in plutons rather than erupting.
== == Felsic lava has a higher silica content than mafic lava. Felsic lava is slower moving (high viscosity) than the less viscous mafic lava. Mafic lava is higher in dark minerals and higher in the elements iron and magnesium.
Volcanic eruptions are always caused by magma. This applies if the eruption is quiet or explosive, or whether the magma is felsic or mafic.
Mafic magma has extremely high ferromagnesian content, produced by decompression melting. As the plates move apart, mantle rises to fill the void. As it melts, it forms mafic magma. Where plates are meeting, the compression of crust forms magma with higher silica content, thus forming felsic and intermediate magmas.
There are many different types of ignoues rock, but as a general description, mafic, felsic and intermediate rocks are formd from basaltic, granitic, and andesitic magmas respectively.