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Where does the word felsic come from?
The term “felsic” combines the words “feldspar” and “silica”. The similarity of the term felsic to the German words Fels, meaning “rock”, and felsig, meaning “rocky”, is purely accidental, as feldspar is a borrowing from German Feldspat, which derives from German Feld, meaning “field”.
What is the difference between mafic and felsic?
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.
What is another word for felsic?
Rocks with greater than 90% felsic minerals can also be called “leucocratic”, meaning ‘light-coloured’.
What are some examples of felsic?
Common felsic minerals include quartz, muscovite, hornblende, orthoclase, and the sodium rich plagioclase feldspars. The most common felsic rock is granite.
What is felsic used to describe?
In geology, felsic refers to igneous rocks that are relatively rich in elements that form feldspar and quartz. It is contrasted with mafic rocks, which are relatively richer in magnesium and iron.
What are different mafic and felsic?
Difference Between Mafic and Felsic. • Mafic rocks are rich in iron and magnesium, whereas Felsic rocks are rich in silica and aluminum. • Mafic rocks are denser and heavier than Felsic rocks. • Mafic rocks are darker in color than Felsic rocks. • Lava made up of Felsic rocks is slow moving and has a higher viscosity than Mafic lava.
Is felsic denser than mafic?
Chemically, mafic rocks are enriched in iron, magnesium and calcium and typically dark in color. In contrast, the felsic rocks are typically light in color and enriched in aluminium and silicon along with potassium and sodium. The mafic rocks also typically have a higher density than felsic rocks.
Is biotite felsic or mafic?
Biotite is a “brown” mica group incorporating Mg and Fe. Given their chemical differences you find them in different rocks. As you would expect, white mica would be found in light-coloured felsic rocks, dark mica in Fe/Mg-rich dark, mafic rocks (or in their weathering products).