- 1 What type of magma is rich in silica?
- 2 Which type of igneous rock has high silica content?
- 3 Which is the correct order of the different types of magma with lowest to highest silica content?
- 4 Does granitic magma have high silica content?
- 5 What type of magma has the lowest silica content highest silica content?
- 6 What are the three major types of magma?
- 7 Which has the most silica content?
- 8 What is the silica content of andesite?
- 9 Do rocks contain silica?
- 10 Is silica rich and or cool?
- 11 Which component of magma is the highest and lowest in value?
- 12 Which type of magma is most explosive?
- 13 Is andesite an intermediate?
- 14 Does basalt have high silica content?
- 15 Why is silica content of a magma important?
What type of magma is rich in silica?
Felsic or silicic magmas have a silica content greater than 63%. They include rhyolite and dacite magmas. With such a high silica content, these magmas are extremely viscous, ranging from 108 cP for hot rhyolite magma at 1,200 °C (2,190 °F) to 1011 cP for cool rhyolite magma at 800 °C (1,470 °F).
Which type of igneous rock has high silica content?
Granite. Granite, the equivalent of its extrusive (volcanic) rock type rhyolite, is a very common type of intrusive igneous rock. It contains more than 68% weight % of silica in composition and is granular and coarse-grained in texture.
Which is the correct order of the different types of magma with lowest to highest silica content?
Three general types are recognized:
- Basaltic magma — SiO2 45-55 wt%, high in Fe, Mg, Ca, low in K, Na.
- Andesitic magma — SiO2 55-65 wt%, intermediate. in Fe, Mg, Ca, Na, K.
- Rhyolitic magma — SiO2 65-75%, low in Fe, Mg, Ca, high in K, Na.
Does granitic magma have high silica content?
These granitic magmas rise slowly because of their high sio2 content and high viscosities until they reach the level in the crust where the temperature and pressure conditions are consistent with freezing or solidification of magma with this composition.
What type of magma has the lowest silica content highest silica content?
The magma types vary from mafic magmas, which have relatively low silica and high Fe and Mg contents, to felsic magmas, which have relatively high silica and low Fe and Mg contents.
What are the three major types of magma?
The high temperatures and pressure under Earth’s crust keep magma in its fluid state. There are three basic types of magma: basaltic, andesitic, and rhyolitic, each of which has a different mineral composition.
Which has the most silica content?
In a widely accepted silica-content classification scheme, rocks with more than 65 percent silica are called felsic; those with between 55 and 65 percent silica are intermediate; those with between 45 and 55 percent silica are mafic; and those with less than 45 percent are ultramafic.
What is the silica content of andesite?
Andesite is a gray to black volcanic rock with between about 52 and 63 weight percent silica (SiO2). Andesites contain crystals composed primarily of plagioclase feldspar and one or more of the minerals pyroxene (clinopyroxene and orthopyroxene) and lesser amounts of hornblende.
Do rocks contain silica?
Most igneous rocks contain between 45 and 65 wt% silica. They range from lower-silica basalt and gabbro to higher-silica rhyolite and granite. For example, basalt and gabbro contain more iron and magnesium than andesite and diorite, and andesite and diorite contain more iron and magnesium than rhyolite and granite.
Is silica rich and or cool?
Less silica-rich lavas generally come out at 1000° C – 1230° C while silica-rich lavas are cooler at 750° C – 900° C. Komatiitic lavas (very rich in magnesium and low in silica) probably erupted at 1300° C – 1400° C and mostly date from the Archean Era when the earth was hotter.
Which component of magma is the highest and lowest in value?
Answer: Felsic magma has the highest silica content of all magma types, between 65-70%. As a result, felsic magma also has the highest gas content and viscosity, and lowest mean temperatures, between 650o and 800o Celsius (1202o and 1472o Fahrenheit).
Which type of magma is most explosive?
Explosive eruptions are favored by high gas content & high viscosity magmas (andesitic to rhyolitic magmas). The explosive bursting of bubbles fragments the magma into clots of liquid that cool as they fall through the air.
Is andesite an intermediate?
Andesite is an extrusive rock intermediate in composition between rhyolite and basalt. The word andesite is derived from the Andes Mountains in South America, where andesite is common. Andesite is the volcanic equivalent of diorite.
Does basalt have high silica content?
Basalt is a hard, black volcanic rock with less than about 52 weight percent silica (SiO2). Because of basalt’s low silica content, it has a low viscosity (resistance to flow). Basalt is the most common rock type in the Earth’s crust (the outer 10 to 50 km). In fact, most of the ocean floor is made of basalt.
Why is silica content of a magma important?
The silica content of the magma determines how thick the magma is, how easily it flows and how easily dissolved gases within the magma can escape; therefore the silica content determines the characteristic of the volcanic eruption and the shape and size of the resulting volcanic cone.