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Magma is less dense because it is a fluid, is hot, and it is full of gases.
Ultimately a volcano is an expression of the lightest minerals in a magma, mixed with volatile gases. It is true that molten rock takes up more space than cold rock, because the ions involved are in a greater state of excitement. Heat rises, and as it rises it takes with it the molten magma, but as it rises it also loses heat, thereby dropping higher melting point minerals out of solution.
If magma is less dense than the surrounding rock it will rise, according to the physical laws of gravity. Magma finds its own level, where it is in density equilibrium with its surrounding rocks.
Fractionation can occur within the magma body, where the heavy minerals created will crystallize and sink within the body, and the lighter fluid will rise until it finds another density equilibrium.
Magma created in subduction zones generally contains more volatile gases than other knids of magma because a lot of water has been incorporated within the subducting slab as zeolites. This reduces the melting point of the magma.
Aso, from a slight;y different perspective, there is an interchange between granite and its surrounding greywacke, both are very similar in density, and in the vicinity of a felsic orogeny bits of granite can be found in greywacke, and bits of greywacke (xenoliths) can be found in granite .
Wiki User
∙ 13y ago
Wiki User
∙ 13y agoGenerally speaking, wood has the ability to have more air pockets. This means there is less "wood" and rock is more uniform with less free space. There are some types of rock, however, that are not very dense at all, and some woods that are astoundingly dense.
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Light colored igneous rocks are less what than dark igneous rocks?
basaltic rocks are darker because they are more dence granitic rocks are less dence so they are lighter
In general how does the density of a light colored igneous rock differ from that of a dark colored igneous rock?
Light-coloured igneous rocks, such as granite, have a higher silica content and lower iron and magnesium than darker ones, such as basalt. Since iron and magnesium are very dense minerals, this makes darker igneous rocks more dense than lighter ones.
Why is water located above the earths crust but below the air?
Because it is less dense than the material that makes up the earth's crust, but more dense than the material that makes up the air.
What is always less dense than solids?
Gases are less dense than solids.
Is saliva less dense than oil?
No, oil is less dense than saliva.
Why is granite less dense than other rocks in earths mantle?
Because its less dense
Light-colored igneous rocks are less what than dark-colored igneous rocks are?
less dense
Is earths atmosphere much thinner and less dense than mercury's?
No
What has less density--the crustal rocks or the mantle rocks?
Crustal rock is normally less dense than mantle rock.
Light colored igneous rocks are less what than dark igneous rocks?
basaltic rocks are darker because they are more dence granitic rocks are less dence so they are lighter
Which statement correctly describes the density of Earth's mantle compared to the density of Earths core?
The mantle is less dense than the core but more dense than the crust.
In general how does the density of a light colored igneous rock differ from that of a dark colored igneous rock?
Light-coloured igneous rocks, such as granite, have a higher silica content and lower iron and magnesium than darker ones, such as basalt. Since iron and magnesium are very dense minerals, this makes darker igneous rocks more dense than lighter ones.
Why is water located above the earths crust but below the air?
Because it is less dense than the material that makes up the earth's crust, but more dense than the material that makes up the air.
Would it be easier for a plane to fly higher in an atmosphere less dense than Earths?
i No, ;it would be easier in denser air. Less dense air gives nothing for the wings of the plane to use to propel itself upwards. Less dense air would make the plane crash.
Continents float on the Earth's mantle because continental rocks are than sea floor rocks?
lighter continental rock (mainly granite) is less dense than mantle material.continental rock is also less dense than oceanic crust (basalt) but sea floor rocks are not the same thing as mantle material.granite = 2.7 g/cm3basalt = 3.0 g/cm3
Is ice less dense or more dense than water?
no
What does rocks in earths mantle contain a higher percentage of what than rocks in earths crust?
iron and magnesium
