Where does felsic magma generally form?
Where does felsic magma generally form?
A. Intermediate and felsic magmas form around convergent margins with a subduction zone. 3. these volcanic mountain chains often form arc shapes, because that is the shape produced when a flat plate (tectonic plate) intersects a sphere (Earth).
What type of volcano does felsic magma form?
Composite volcanoes
Composite volcanoes are constructed of felsic to intermediate rock. The viscosity of the lava means that eruptions at these volcanoes are often explosive.
What is felsic magma made of?
Felsic refers to silicate minerals, magma, and rocks which are enriched in the lighter elements such as silicon, oxygen, aluminium, sodium, and potassium. Felsic magma or lava is higher in viscosity than mafic magma/lava.
What are the 3 ways magma can form?
There are three principal ways rock behavior crosses to the right of the green solidus line to create molten magma: 1) decompression melting caused by lowering the pressure, 2) flux melting caused by adding volatiles (see more below), and 3) heat-induced melting caused by increasing the temperature.
What is felsic magma?
Felsic refers to silicate minerals, magma, and rocks which are enriched in the lighter elements such as silicon, oxygen, aluminium, sodium, and potassium. Felsic magma or lava is higher in viscosity than mafic magma/lava. Felsic rocks are usually light in color and have specific gravities less than 3.
How are felsic volcanoes formed?
Explosive Eruptions Felsic magmas erupt explosively because of hot, gas-rich magma churning within its chamber. Magma, rock, and ash burst upward in an enormous explosion creating volcanic ash called tephra.
What rocks are created from felsic lava and magma?
Felsic magma is viscous and does not flow easily. Most felsic magma will stay deeper in the crust and will cool to form igneous intrusive rocks such as granite and granodiorite.
What process forms magma?
Magma is a mixture of melted crystals, rocks and dissolved gases. It is magma that causes volcanic eruptions. These eruptions can be either explosive or non-explosive. Magma is formed by both wet and dry melting processes.
What are ways magma is formed?
Magma forms from partial melting of mantle rocks. As the rocks move upward (or have water added to them), they start to melt a little bit. These little blebs of melt migrate upward and coalesce into larger volumes that continue to move upward. They may collect in a magma chamber or they may just come straight up.
Is felsic lava hotter than mafic lava?
The tendency for felsic lava to be cooler than mafic lava increases the viscosity difference. Lava viscosity determines the kind of volcanic activity that takes place when the lava is erupted. The greater the viscosity, the greater the tendency for eruptions to be explosive rather than effusive.
What is highly viscous felsic magma?
Felsic refers to silicate minerals, magma, and rocks which are enriched in the lighter elements such as silicon, oxygen, aluminium, sodium, and potassium. Felsic magma or lava is higher in viscosity than mafic magma/lava. Felsic rocks are usually light in color and have specific gravities less than 3.
What are two elements does felsic magma contain?
Mafic magmas are low in silica and contain more dark, magnesium and iron rich mafic minerals, such as olivine and pyroxene. Felsic magmas are higher in silica and contain lighter colored minerals such as quartz and orthoclase feldspar. The higher the amount of silica in the magma, the higher is its viscosity.
Is felsic denser than mafic?
Mafic igneous rocks are generally more dense than felsic igneous rocks. Higher metamorphic grade rocks such as eclogite and amphibolite are more dense than low grade metamorphic rocks such as slate and phyllite.
