Press "Enter" to skip to content

What are the characteristics of felsic igneous rocks?

Felsic igneous rocks, as a whole rock, tend to have light colors or shades: white, pink, light brown, light gray. Mafic igneous rocks, on the whole, tend to be dark colored, commonly black or dark gray. Most mafic magma originates by melting of rocks in the mantle that are extremely rich in iron and magnesium.

What type of rock has felsic composition?

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)

What minerals are in 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 the difference between mafic and felsic minerals in rocks?

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.

What are some common minerals in felsic rock?

Common felsic minerals include quartz, muscovite, orthoclase, and the sodium-rich plagioclase feldspars (albite-rich).

What two things determine a magma’s composition?

The amount of partial melting and the composition of the original rock determine the composition of the magma.

What are the two top composition 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.

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. The solids are made of crystallized minerals floating in the liquid melt.

Which magma composition is most explosive?


Does lava have high viscosity?

Explosive eruptions produce a mixture of volcanic ash and other fragments called tephra, rather than lava flows. Although lava can be up to 100,000 times more viscous than water, lava can flow great distances before cooling and solidifying because lava exposed to air quickly develops a solid crust.

Does a cinder cone volcano have high or low viscosity?

Spheroidal and spindle-shaped bombs are common at cinder cones. Unlike the violently explosive eruptions that create large stratovolcanoes, cinder cones form when low-viscosity lava with lots of gas erupts, often as liquid fountains. Lava may be spewed hundreds of feet through the air.

Is viscosity dependent on pressure?

Viscosity is normally independent of pressure, but liquids under extreme pressure often experience an increase in viscosity. The viscosity of gases increases as temperature increases and is approximately proportional to the square root of temperature.

What is the effect of temperature on velocity of sound in air?

Temperature is also a condition that affects the speed of sound. Heat, like sound, is a form of kinetic energy. Molecules at higher temperatures have more energy, thus they can vibrate faster. Since the molecules vibrate faster, sound waves can travel more quickly.

What is the effect of temperature pressure and humidity on the velocity of sound?

So when humidity increases in air, its density decreases. This is because water drops have less molecular mass compared to N2 and O2. => So velocity of sound increases with humidity. When temperature increases the speed of sound increases.

What is the effect of humidity on the velocity of sound?

Contrary to the often‐made assumption that the addition of moisture increases the velocity of sound in air, these results show that as moisture is added to dry air the velocity of sound at first decreases. The velocity is minimum at a relative humidity (RH) of about 14%; then it rises.

How does temperature affect frequency?

It can be hypothesized that when temperature increases the string increases in length thus the tension decreases so the frequency is lower and when temperature is decreased the string length is decreased thus the tension increases so the frequency is higher.

Does frequency depend on temperature?

Temperature doesn’t affect the frequency of sound waves, but affects the speed of sound in the air. That speed is higher the higher the temperature, being directly proportional to the average speed of the molecules in air, which increases with temperature.

How does temperature affect resonant frequency?

It is observed that as the temperature increases, the resonant frequency decreases. The resonant frequency of the piezoelectric element is directly proportional to stiffness constant. If the temperature of the piezoelectric element increases, its stiffness decreases, and so the resonant frequency decreases.