Do composite volcanoes have mafic magma?

Do composite volcanoes have mafic magma?

Composite volcanoes are normally associated with subduction, and while their magma tends to be intermediate on average, it can range all the way from felsic to mafic. The corresponding differences in magma viscosity lead to significant differences in eruptions style.

What type of lava does a composite volcano have?

Composite volcano magma is felsic, which means it contains silicate-rich minerals rhyolite, andesite, and dacite. Low-viscosity lava from a shield volcano, such as might be found in Hawaii, flows from fissures and spreads.

Which volcanoes have mafic lava?

Mafic lava flows can travel quite far before solidifying completely, and the type of volcano that forms from mafic lava is called a shield volcano (Figure 9.9). Shield volcanoes are very broad at the base and have relatively gentle slopes.

What kind of volcanoes have mafic magma?

Because the viscosity is low, mafic magma tends to produce volcanic cones with gentle slopes, called shield volcanoes. These enormous structures form the largest (in volume and mass) mountains on Earth.

When contrasting lava from a composite volcano to lava from a shield volcano?

When contrasting lava from composite volcanoes to lava from shield volcanoes, composite volcanoes most often produce silica-rich lavas with high viscosities, whereas shield volcanoes produce basaltic lavas with low viscosities.

What type of volcano has felsic lava?

Composite volcanoes
Composite volcanoes are made of felsic to intermediate rock. The viscosity of the lava means that eruptions at these volcanoes are often explosive (figure 2).

What is the description of composite volcano?

Composite cone volcanoes are also called stratovolcanoes. They form when different types of eruptions deposit different materials around the sides of a volcano. Alternating eruptions of volcanic ash and lava cause layers to form. Over time these layers build up. Helens is an example of a composite cone volcano.

What are the characteristics of felsic lava?

Felsic lavas are not as hot, high in silica and volatiles, and have a high viscosity. They are thick and gooey and resist flowing. Their high volatile content makes them potentially highly explosive.

What volcano makes felsic lava?

Do composite volcanoes erupt violently?

Composite volcanoes are some of the most dangerous volcanoes on the planet. They tend to occur along oceanic-to-oceanic or oceanic-to-continental boundaries because of subduction zones. They tend to be made of felsic to intermediate rock and the viscosity of the lava means that eruptions tend to be explosive.

What is the difference between felsic and mafic magma?

Mafic magmas are low in silica and contain more dark, magnesium and iron rich mafic minerals, such as olivine and pyroxene. Felsic magmas are higher in silica and contain lighter colored minerals such as quartz and orthoclase feldspar. The higher the amount of silica in the magma, the higher is its viscosity.

What kind of magma is in a composite volcano?

The volcanoes form steep cones, rather than rounded shapes, because the magma is viscous. Composite volcano magma is felsic, which means it contains silicate-rich minerals rhyolite, andesite, and dacite. Low-viscosity lava from a shield volcano, such as might be found in Hawaii, flows from fissures and spreads.

Are there any composite volcanoes in the Solar System?

To date, composite volcanoes have only been found on one other body in the solar system: Mars. Zephyria Tholus on Mars is believed to be an extinct stratovolcano. Composite volcano magma isn’t fluid enough to flow around obstacles and exit as a river of lava.

How are composite volcanoes different from stratovolcanic volcanoes?

Composite volcano magma isn’t fluid enough to flow around obstacles and exit as a river of lava. Instead, a stratovolcanic eruption is sudden and destructive. Superheated toxic gases, ash, and hot debris are forcefully ejected, often with little warning. Lava bombs present another hazard.

How does a composite volcano affect the environment?

Because they eject matter and gases into the stratosphere, they affect weather and climate. Particulates released by composite volcanoes yield colorful sunrises and sunsets. Although no vehicle accidents have been attributed to volcanic eruptions, the explosive debris from composite volcanoes poses a risk to air traffic.