What is the difference between felsic and mafic composition

Felsic rocks are igneous rocks that are rich in feldspar and silicon. The word 'felsic' was made up from parts of those words. Because they are made of lighter elements, they tend to be more buoyant than mafic rocks, which are rocks high in magnesium and iron, like basalt. Granite is the most common felsic rock. Is Obsidian mafic? Though obsidian is usually dark in color, similar to mafic rocks such as basalt, obsidian's composition is extremely felsic.

Crystalline rocks with a similar composition include granite and rhyolite. Where are mafic rocks formed? Mafic minerals crystallize at higher temperatures, which Bowen's Reaction Series describes. Therefore, rocks composed of mafic minerals are formed at higher temperatures. They are found in locations deep within the earth and also in tectonic spreading environments, like the seafloor.

Is Basalt felsic? Granite and rhyolite are considered felsic, while basalt and gabbro are mafic click here for more information on mafic and felsic. Felsic rocks, in general, form the bulk of the continental plates, while mafic basalt forms the seafloor. Does felsic have high silica? The term comes from FEL for feldspar in this case the potassium-rich variety and SIC, which indicates the higher percentage of silica. The more silica you have in a rock, the paler it tends to be. Felsic rocks have high silica content, because they contain lots of quartz and another mineral called feldspar.

These are rocks like basalt, which is very darkly coloured. Granite and rhyolite are considered felsic, while basalt and gabbro are mafic click here for more information on mafic and felsic. In the same respect, granite is the cooled and exposed magma chamber for extrusive rhyolite.

Begin typing your search term above and press enter to search. Press ESC to cancel. Skip to content Home Physics What is the difference between the composition of felsic and mafic igneous rocks? Ben Davis July 21, What is the difference between the composition of felsic and mafic igneous rocks? What is the texture and composition of igneous rocks?

Sometimes, felsic volcanic rocks contain small amounts i. Felsic rocks are given chemical names as determined by the TAS Total Alkali Silica classification, a system of assigning types of volcanic rocks relative to their alkali and silica content.

In addition, if a felsic rock is found to be metamorphic with no traces of volcanic protolith i. Phaneritic felsic rocks are named using the QAPF diagram. A phaneritic felsic rock is composed of crystals large enough to be seen with the naked eye.

In geology, these terms are descriptive of the chemicals that make up igneous rocks, magmas, and silicate minerals. In terms of chemistry, this means that mafic and felsic minerals and rocks are at opposite ends of the elemental spectrum.

In contrast, felsic rocks are made up of a combination of feldspar and silica and are typically light colored rocks. One key to what makes the eruption unique is the chemical composition of the magma that feeds a volcano, which determines 1 the eruption style, 2 the type of volcanic cone that forms, and 3 the composition of rocks that are found at the volcano.

Different minerals within a rocks melt at different temperatures and the amount of partial melting and the composition of the original rock determine the composition of the magma.

Magma collects in magma chambers in the crust at kilometers miles beneath the surface of a volcano. The words that describe composition of igneous rocks also describe magma composition. 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. Viscosity determines what the magma will do.

Mafic magma is not viscous and will flow easily to the surface. 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.

If felsic magma rises into a magma chamber, it may be too viscous to move and so it gets stuck. Dissolved gases become trapped by thick magma and the magma chamber begins to build pressure. The type of magma in the chamber determines the type of volcanic eruption. A large explosive eruption creates even more devastation than the force of the atom bomb dropped on Nagasaki at the end of World War II in which more than 40, people died.