What is the most mafic mineral?
A mafic mineral or rock is a silicate mineral or igneous rock rich in magnesium and iron. Most mafic minerals are dark in color, and common rock-forming mafic minerals include olivine, pyroxene, amphibole, and biotite. Common mafic rocks include basalt, diabase and gabbro.
What minerals compose mafic igneous rocks?
Igneous Rocks: textures and compositions
| Felsic | Mafic | |
|---|---|---|
| Coarse- grained | granite | gabbro |
| Fine- grained | rhyolite | basalt |
| Minerals | quartz, K-feldspar, amphibole, muscovite, biotite | olivine, pyroxene, Ca-feldspar (plagioclase) |
Feb 23, 2005
What mineral composition is most characteristic of intermediate rocks?
Intermediate rocks are roughly even mixtures of felsic minerals (mainly plagioclase) and mafic minerals (mainly hornblende, pyroxene, and/or biotite).
What is the most common type of mafic rock?
The most common mafic igneous rocks are the dark-colored gabbro and basalt. Other mafic igneous rocks include the following: Breccia. Diabase.
What is the composition of mafic rocks?
mafic rock, in geology, igneous rock that is dominated by the silicates pyroxene, amphibole, olivine, and mica. These minerals are high in magnesium and ferric oxides, and their presence gives mafic rock its characteristic dark colour.
What is mafic composition?
Definition. The adjective mafic refers to a silicate mineral or rock (magmatic, either intrusive or extrusive) having a chemical composition rich in iron and magnesium and relatively poor in silicium.
What makes a rock or mineral mafic felsic or intermediate?
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.
Which minerals are most characteristic of a mafic rock like basalt or gabbro?
Silicic magmas, which crystallize at lower temperatures, produce rocks that contain minerals at the bottom of the series. So mafic rocks such as basalt or gabbro commonly contain olivine, pyroxene and Ca-rich plagioclase. Felsic rocks such as rhyolite or granite are generally rich in K-feldspar and quartz.
What are the features of mafic minerals?
Mafic minerals – These are minerals which are rich in Fe (iron) and Mg (magnesium). Mafic minerals are generally dark in colour – usually green, brown or black. The derivation of the term is ma for magnesium and fic for iron (from ferric).
How do you identify a mafic rock?
2:323:55Igneous Rocks-(Extrusive-Intrusive-Mafic …YouTube
What rocks are mafic?
Common rock-forming mafic minerals include olivine, pyroxene, amphibole, biotite mica, and the plagioclase feldspars. Mafic magmas are usually produced at spreading centers, and represent material which is newly differentiated from the upper mantle. Common mafic rocks include basalt and gabbro.
How is mafic rock formed?
Mafic rocks that constitute the igneous oceanic crust are created at mid-ocean ridge seafloor spreading centers as a byproduct of partial melt from upwelling mantle. Through various parts of the spreading process, permeability can be generated in both the intrusive gabbros and extrusive basalts.