- 1 What is mafic and felsic?
- 2 What is a mafic magma?
- 3 What does mafic mean geology?
- 4 What is a mafic composition?
- 5 Is diorite a mafic?
- 6 Is granite a mafic?
- 7 What are the three main components of magma?
- 8 What are the 3 ways magma can form?
- 9 What are the three main types of magma?
- 10 Is Granite felsic or mafic?
- 11 Why are mafic minerals dark?
- 12 Is Obsidian mafic?
- 13 Is Quartz a mafic mineral?
- 14 Is pumice felsic or mafic or intermediate?
- 15 How is mafic magma produced?
What is mafic and felsic?
In geology, felsic is an adjective describing 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. Felsic rocks are usually light in color and have specific gravities less than 3.
What is a mafic magma?
Describes magma that contains lower amounts of silica and is generally less viscous and less gas-rich than silicic magma. Tends to erupt effusively, as lava flows.
What does mafic mean geology?
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. It corresponds to the older term basic as in basic rock.
What is a mafic composition?
Mafic is a term used to describe both minerals that are rich in iron and magnesium and rocks that are rich in those minerals. Common examples of mafic minerals include olivine, biotite, hornblende, and pyroxene. The opposite of mafic minerals are felsic minerals, which are poor in iron and magnesium.
Is diorite a mafic?
Diorite is a plutonic igneous rock with intermediate composition between mafic and felsic rocks. It is visibly crystalline and usually has a granular texture (composed of roughly equally sized crystals) although the appearance may vary widely. Its volcanic (fine-grained) analogue is andesite.
Is granite a mafic?
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.
What are the three main components of magma?
Magma and lava contain three components: melt, solids, and volatiles. The melt is made of ions from minerals that have liquefied.
What are the 3 ways magma can form?
The three ways that magma can be formed are through heat transfer, decompression melting and flux melting. The process of magma creation is referred to by geologists as magmagenesis and occurs at the upper mantle of the Earth’s crust due to plate tectonic effects.
What are the three main types of magma?
There are three basic types of magma: basaltic, andesitic, and rhyolitic, each of which has a different mineral composition. All types of magma have a significant percentage of silicon dioxide. Basaltic magma is high in iron, magnesium, and calcium but low in potassium and sodium.
Is Granite felsic or mafic?
Igneous Rocks by Composition
|Coarse-Grained Textures||Fine-Grained Textures|
|Peridotite = Ultramafic||Komatiite (Ultramafic, but too rare to worry about at this point in your life)|
|Gabbro = Mafic||Basalt = Mafic|
|Diorite = Intermediate||Andesite = Intermediate|
|Granite = Felsic||Rhyolite = Felsic|
Why are mafic minerals dark?
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.
Is Obsidian mafic?
It is sometimes classified as a mineraloid. Though obsidian is usually dark in colour similar to mafic rocks such as basalt, obsidian’s composition is extremely felsic. Obsidian consists mainly of SiO2 (silicon dioxide), usually 70% or more. Crystalline rocks with obsidian’s composition include granite and rhyolite.
Is Quartz a mafic mineral?
Mafic minerals are usually dark in color and have relatively high specific gravities (greater than 3.0). Common rock-forming mafic minerals include olivine, pyroxene, amphibole, biotite mica, and the plagioclase feldspars. Common felsic minerals include quartz, muscovite mica, and the orthoclase feldspars.
Is pumice felsic or mafic or intermediate?
Classification of Igneous Rocks
How is mafic magma produced?
In general, melting of a mantle source (garnet peridotite) results in mafic /basaltic magmas. Melting of crustal sources yields more siliceous magmas. In general more siliceous magmas form by low degrees of partial melting. So, melting a mafic source thus yields a felsic or intermediate magma.