Table of Contents
Which rock is the densest?
The heaviest rocks would be those that are made up of dense, metallic minerals. Two of the heaviest or densest rocks are peridotite or gabbro. They each have a density of between 3.0 to 3.4 grams per cubic centimeter. Interestingly, peridotite are the rocks that naturally occurring diamonds are found in.
Are felsic rocks heavy or light?
Felsic refers to silicate minerals, magma, and rocks which are enriched in the lighter elements such as silicon, oxygen, aluminium, sodium, and potassium. Felsic magma or lava is higher in viscosity than mafic magma/lava. Felsic rocks are usually light in color and have specific gravities less than 3.
Is mafic or felsic more viscous?
Composition: he more felsic the lava (the more silica in the lava), the higher the viscosity because silica forms chains in the cooling lava even before it crystallizes. The more mafic the lava (the less silica in it), the lower the viscosity.
Is felsic intrusive or extrusive?
For example, a coarse-grained, felsic igneous rock is not only a granite, it is an intrusive igneous rock that formed from slow cooling and crystallization of a body of magma within the earth’s crust. The intrusion of large bodies of granite—batholiths—is usually part of the origin of a mountain range.
What cools faster mafic or felsic?
Felsic magmas tend to be cooler than mafic magmas when crystallization begins (because they don’t have to be as hot to remain liquid), and so they may start out crystallizing pyroxene (not olivine) and plagioclase.
Are felsic rocks less dense?
The densities for some common rocks, minerals, and other materials are summarized below. Igneous and metamorphic rock are generally more dense than sedimentary rocks. Mafic igneous rocks are generally more dense than felsic igneous rocks.
Which rock is the least dense Why?
Sedimentary rocks (and granite), which are rich in quartz and feldspar, tend to be less dense than volcanic rocks. And if you know your igneous petrology, you will see that the more mafic (rich in magnesium and iron) a rock is, the greater its density.
Why are felsic rocks lighter than mafic?
Mafic rocks are rich in the heavy minerals, iron and magnesium. This gives these rocks their characteristic dark green or greenish-black colour. Whereas, felsic rocks are rich in silica and aluminium along with oxygen, sodium and potassium that gives the light shade for these rocks.
Is felsic light or dark?
Felsic minerals (quartz, K feldspar, etc) are light colored while mafic minerals (hornblende, pyroxenes) are normally dark colored. Felsic minerals have the lowest melting points (600 to 750 °C) and mafic minerals have higher melting points (1000 to 1200 °C).
Is felsic magma more dense?
It forms within the upper mantle, much deeper than felsic magma. Because of the depth, it is hotter and contains more high density materials, such as iron and magnesium….
| MAGMA COMPARISON | ||
|---|---|---|
| Property | Mafic Magma | Felsic Magma |
| Density | higher (3 g/cm3) | lower (2.7 g/cm3) |
| Viscosity | lower | higher |
| Formation Temp. | higher | lower |
Is mafic always either ferromagnesian or felsic?
Mafic materials can also be described as ferromagnesian. 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
Is felsic an intrusive or extrusive rock?
Chemical Composition. Felsic rocks are high in silica (65\% +). They are usually light-colored. Some examples are: Rhyolite (extrusive) and granite (intrusive). Intermediate rocks have lower silica content (55-65\%). They are darker than felsic rocks but lighter than mafic rocks. Some examples are: Andesite/dacite…
What are some examples of felsic rocks?
Granite is a great example of Felsic rocks and muscovite, quartz, and some feldspar are the best examples of Felsic minerals. All Felsic rocks contain a high percentage of silica. For example, granite contains around 70\% of silica.
What is an example of a mafic rock?
In addition to magnesium and iron silicates, mafic igneous rock may include other minerals, such as calcium-plagioclase feldspar, pyroxene, olivine and amphibole. Gabbro is an example of slow-cooling mafic igneous rock. Basalt is an example of fast-cooling mafic igneous rock.