What is the difference between mafic and felsic eruptions?

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.

How can you tell if a volcano is mafic intermediate or felsic?

So, mafic lavas are hot , low in silica and volatiles, and have relatively low viscosity. They flow easily outward from the vent (where it comes out of the ground), and may travel great distances before completely solidifying. Felsic lavas are not as hot, high in silica and volatiles, and have a high viscosity.

What is the difference between felsic mafic and intermediate magma?

In a widely accepted silica-content classification scheme, rocks with more than 65 percent silica are called felsic; those with between 55 and 65 percent silica are intermediate; those with between 45 and 55 percent silica are mafic; and those with less than 45 percent are ultramafic.

Where does intermediate and felsic lava erupt?

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’s the difference between mafic and felsic lava?

Before cooling, mafic lava has a very low viscosity. The below picture is of the mafic rock basalt. Felsic Magmas: The rocks that form from this type of magma are representative of continental rocks. They tend to have high Silicon content, also known as Silica content.

What kind of eruption is associated with felsic magma?

In turn, felsic magma is associated with the volatile stratovolcano characterized by Plinian eruptions (mushroom cloud) followed by a deadly pyroclastic flow of hot ash, gas, and lava.

How are mafic, intermediate, and felsic magmas formed?

Mafic melts don’t have enough silica to crystallize potassium feldspar, quartz, etc. Felsic magmas, on the other hand, have much more SiO2 (65% to 75%) and Na2O + K2O (around 10%) and much less FeO and MgO plus CaO (about 5%). Felsic melts don’t have enough iron, magnesium, and calcium to form olivine, pyroxene, or calcium plagioclase.

Why are continental rocks mafic and oceanic rocks felsic?

This is why continental rocks are felsic and oceanic rocks are mafic. The below picture is of the felsic rock granite. Mafic Volcanoes: volcanoes that produce mafic lava have a very low explosivity due to the how easily the lava flows and how few volatiles (such as oxygen and silicon) are present within the lava.