0
Felsic magma tends to have large amounts of gas, chiefly water vapor, carbon dioxide, and sulfur dioxide, trapped in it under pressure. When it gets near the surface the pressure drops. The gas is released and expands rapidly, creating an explosion. The effect is similar to opening a freshly shaken can of soda, only much more violent.
There are two ways this can happen. One mechanism is fractional crystallization. As a mass of mafic magma cools the more mafic minerals tend to solidify first. The remaining liquid becomes more felsic as a result. Anothr mechanism is the incorporation of country rock. The heat of the magma melts the surrounding rock. More felsic minerals tend to melt first. Additionally, if the magma is intruding into continental crust, the native rock will likely be felsic to begin with. In most cases this transition occurs due to a combination of these preocesses.
Felsic magma tends to have a high gas content. The gases in magma are what create explosive eruptions.
Add your answer:
Earn +20 pts
What term is used to describe magma that is rich in feldspars and silica?
Felsic magma. This type of magma is viscous with high silica content, resulting in explosive eruptions and the formation of light-colored rocks.
A volcano with a magma supply which is felsic and has a high viscosity will tend to have what type of eruption?
A volcano with felsic magma and high viscosity will likely have explosive eruptions due to the build-up of pressure from gas bubbles being trapped within the thick magma. This can lead to violent eruptions with ash, gas, and volcanic rocks being ejected forcefully from the volcano.
What type of magma will produce explosive eruptions?
Magma with high silica content (felsic magma) tends to produce explosive eruptions because it is more viscous and traps gases, leading to pressure build-up before they are released explosively. This type of magma commonly forms in subduction zones where oceanic plates are being subducted beneath continental plates.
Does Krakatoa have felsic magma or mafic?
Krakatoa volcano typically has mafic magma, which is low in silica content and high in magnesium and iron. This type of magma tends to be more fluid and can lead to explosive eruptions due to the rapid release of gases.
Is felsic magma viscous?
Yes. Felsic magma is very viscous.
What term is used to describe magma that is rich in feldspars and silica?
Felsic magma. This type of magma is viscous with high silica content, resulting in explosive eruptions and the formation of light-colored rocks.
A volcano with a magma supply which is felsic and has a high viscosity will tend to have what type of eruption?
A volcano with felsic magma and high viscosity will likely have explosive eruptions due to the build-up of pressure from gas bubbles being trapped within the thick magma. This can lead to violent eruptions with ash, gas, and volcanic rocks being ejected forcefully from the volcano.
What type of magma will produce explosive eruptions?
Magma with high silica content (felsic magma) tends to produce explosive eruptions because it is more viscous and traps gases, leading to pressure build-up before they are released explosively. This type of magma commonly forms in subduction zones where oceanic plates are being subducted beneath continental plates.
Does Krakatoa have felsic magma or mafic?
Krakatoa volcano typically has mafic magma, which is low in silica content and high in magnesium and iron. This type of magma tends to be more fluid and can lead to explosive eruptions due to the rapid release of gases.
What do quiet lava eruptions generally result from?
Volcanic eruptions are always caused by magma. This applies if the eruption is quiet or explosive, or whether the magma is felsic or mafic.
Is felsic magma viscous?
Yes. Felsic magma is very viscous.
What does magma with high silica content form?
When it cools and crystallizes into rock, the rock will be described as felsic igneous rock. Examples of felsic igneous rocks are granite, rhyolite, and pumice.
Is felsic magma eruptive?
Not usually. Because it is so viscous, felsic magma does not erupt as easily as mafic magma. While eruptions of felsic magma do occur, most felsic rocks are intrusive, meaning they solidify underground.
What magma composition does Mt Hekla have?
Mt. Hekla in Iceland has a composition of intermediate to felsic magma, which is rich in silica, giving it a higher viscosity compared to basaltic magma. This type of magma can lead to explosive eruptions.
Is mafic magma explosive?
Not usually. Mafic magma usually has a low gas content than felsic or intermediate magma, so eruptions are often effusive. Cinder cones primarily erupt mafic lava with a low level of explosivity. Explosive eruptions can also occur if the magma comes in contact with groundwater.
What makes Felsic lava more explosive?
Felsic lava has a high viscosity due to its high silica content, which prevents gases from escaping easily. This trapped gas can accumulate and build pressure, leading to explosive eruptions when the pressure is released. Additionally, felsic lava tends to form thicker lava domes that can collapse and trigger explosive pyroclastic flows.
What type pf magma does mt Cleveland have?
Mount Cleveland in Alaska is known to have andesitic magma, which is a type of magma with intermediate silica content. This type of magma typically leads to explosive eruptions.
