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Mafic minerals are often found near the bottom of a pluton and felsic minerals near the top what process is this because of?
Wiki User
∙ 13y ago
The process is painful love. When the mafic minerals fall in love with the felsic minerals they fall to the bottom. The felsic is often there too and sees the minerals falling toward them so they scared to be in love again and go to the top. This makes the mafic mad and it stays there. The felsic is afraid to go back and stays on the top. :(
<333 love hurts
If I remember my geology, plutons are considered intrusions, and reflect the mineral composition of the magma they were formed from. That being said, what minerals are present in a pluton are directly a result of what they were made from, and the minerals condense out following Bowen's Reaction series. This means mafic minerals condense out at a higher temp and higher pressure, so as the pluton continues to intrude, it cools and depressurizes. Thus minerals lower in the reaction series cool and crystallize before the felsic minerals towards the top. You can also find contact metamorphic rocks on the edges of plutons. Some of these may wrongfully appear to be mafic rocks like Olivine.
http://en.wikipedia.org/wiki/Bowen's_reaction_series
Wiki User
∙ 13y ago
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What is lighter gabbro or granite?
Granite is lighter because its composed of felsic minerals while gabbro is made up of dark ferromagnesian minerals.
Why are mafic rocks denser than felsic rocks?
Mafic rocks are denser than felsic rocks because they contain heavier compounds, minerals and other materials, they are ferromagnesian in composition.
Is pegmatite felsic or mafic?
It is felsic because it is lightly colored. Most rocks that are light are also felsic. The exception is obsidian which is dark and felsic.
How does fractional crystallization lead to magmatic differentiation?
As a magma crystallizes it undergoes fractional crystallization in which mafic minerals crystallize first and felsic minerals crystallize last. Therefore, as fractional crystallization occurs the magma becomes increasingly less mafic and increasingly more felsic. The viscosity also increases as a magma becomes more felsic.
How does mafic lava turn into felsic lava?
Mafic lava, before cooling, has a low viscosity, in comparison to felsic lava, due to the lower silica content in mafic magma. Water and other volatiles can more easily and gradually escape from mafic lava, so eruptions of volcanoes made of mafic lavas are less explosively violent than felsic lava eruptions. Most mafic lava volcanoes are oceanic volcanoes, like Hawaii.Felsic is a term used in geology to refer to silicate minerals, magmas, and rocks which are enriched in the lighter elements such as silicon, oxygen, aluminium, sodium, and potassium. The term combines the words "feldspar" and "silica." Felsic minerals are usually light in color and have specific gravities less than 3. Common felsic minerals include quartz, muscovite, orthoclase, and the sodium-rich plagioclase feldspars. The most common felsic rock is granite. On the opposite side of the rock spectrum are the iron and magnesium-rich mafic and ultramafic minerals and rocks.There are a few means by which felsic magma can be generated from mafic magma. Felsic materials have lower melting points than mafic materials and so will tend to melt first during partial melting. This can shift composition to something more felsic. Another process is called fractional crystalization. Here, more mafic material crystallizes and settles out of a magma chamber, making the remaining molten material more felsic. Finally, as mafic magma moves though continental crust, which is generally felsic in composition, it incorporates some of the rock and becomes more felsic.
What is lighter gabbro or granite?
Granite is lighter because its composed of felsic minerals while gabbro is made up of dark ferromagnesian minerals.
Why are mafic rocks denser than felsic rocks?
Mafic rocks are denser than felsic rocks because they contain heavier compounds, minerals and other materials, they are ferromagnesian in composition.
What rocks are felsic?
Felsic rock are igneous rocks that are rich of quartz, orthoclase and plagioclase minerals. Here is the list of felsic rocks: granites, rhyolites, aplites, and pegmatites.
What is the comaprison of felsic and mafic?
Felsic minerals are Silicon-rich; whereas Mafic ones are low in Silicon, but contain Iron and Magnesium.
Is sandstone felsic or mafic?
Neither. The terms mafic and felsic refer to the composition of igneous rocks, which are dominated by silicate minerals. Marble is a metamorphic rock composed of carbonate minerals. The terms mafic and felsic do no apply to it.
What minerals are in pumice?
Because pumice is primarily vesicular volcanic glass, it contains no minerals. The ejected molten volcanic rock cooled too quickly for minerals to form. Chemically, it is similar to felsic rock, high in silicon and aluminum.
What minerals are present in felsic rocks and mafic rocks?
Felsic refers to igneous rocks that are relatively high in silica and aluminum. Mafic refers to igneous rocks that are higher in magnesium and iron than felsic rocks.
Is pegmatite felsic or mafic?
It is felsic because it is lightly colored. Most rocks that are light are also felsic. The exception is obsidian which is dark and felsic.
What happens if the percentage of felsic minerals in a rock increase?
it becomes darker and density will decrease (a)
How does fractional crystallization lead to magmatic differentiation?
As a magma crystallizes it undergoes fractional crystallization in which mafic minerals crystallize first and felsic minerals crystallize last. Therefore, as fractional crystallization occurs the magma becomes increasingly less mafic and increasingly more felsic. The viscosity also increases as a magma becomes more felsic.
Why is the main reason that oceanic crust is heavier than continental crust?
Oceanic crust is mafic in composition and continental crust is felsic in composition. Mafic minerals generally have a higher density than felsic minerals and therefore, the oceanic crust is heavier.
Which minerals is rarely found in felsic igneous rocks?
they are found in approximetily 90 %in the earth crust
