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What eruption is worse mafic or silicic?
Eruptions involcing silicic or felsic magma are generally the worst. Eruptions of mafic material are usually effusive or only mildly explosive, producing cinders or lava flows. Eruptions of felsic material often produce large ash clouds and deadly pyroclastic flows.
Is scoria mafic?
Mafic, infact it is often refered to as: "the mafic version of pumice"
What is a low-silica magma?
A magma containing not much silica (= SiO2). For example: a basaltic magma. These magma's have a low viscosity since the lower the SiO2-content, the lower the viscosity; and hence flow easily (↔ a felsic magma).
Why are xenoliths mafic minerals?
Xenoliths are often mafic minerals because they originate from the Earth's mantle, which is composed of mafic rocks such as basalt and gabbro. These minerals are more likely to survive the extreme conditions of volcanic eruptions, which is how xenoliths are transported to the Earth's surface. Additionally, mafic minerals have higher melting points compared to felsic minerals, making them more resistant to being melted and destroyed during volcanic processes.
What kind of magmas produce violent volcanic eruptions?
Magmas with high viscosity and gas content tend to produce violent volcanic eruptions. High viscosity magmas are thicker and have more difficulty releasing gas, leading to pressure build-up and explosive eruptions. This often occurs with felsic or rhyolitic magmas.
What eruption is worse mafic or silicic?
Eruptions involcing silicic or felsic magma are generally the worst. Eruptions of mafic material are usually effusive or only mildly explosive, producing cinders or lava flows. Eruptions of felsic material often produce large ash clouds and deadly pyroclastic flows.
Is scoria mafic?
Mafic, infact it is often refered to as: "the mafic version of pumice"
Where can you find gabbro?
Gabbro is a group of dark, coarse-grained, intrusive mafic igneous rocks. They are often found beneath the Earth's surface where they form into crystals.
What is a low-silica magma?
A magma containing not much silica (= SiO2). For example: a basaltic magma. These magma's have a low viscosity since the lower the SiO2-content, the lower the viscosity; and hence flow easily (↔ a felsic magma).
Why are xenoliths mafic minerals?
Xenoliths are often mafic minerals because they originate from the Earth's mantle, which is composed of mafic rocks such as basalt and gabbro. These minerals are more likely to survive the extreme conditions of volcanic eruptions, which is how xenoliths are transported to the Earth's surface. Additionally, mafic minerals have higher melting points compared to felsic minerals, making them more resistant to being melted and destroyed during volcanic processes.
Why do granitic felsic magmas usually crystallize before reaching earth's surface?
Felsic magma is very viscous, so if often gets "stuck" in plutons rather than erupting.
What kind of magmas produce violent volcanic eruptions?
Magmas with high viscosity and gas content tend to produce violent volcanic eruptions. High viscosity magmas are thicker and have more difficulty releasing gas, leading to pressure build-up and explosive eruptions. This often occurs with felsic or rhyolitic magmas.
How are felsic magmas formed?
Heat from the mantle melts part of the lower crust
What is a type of mafic phaneritic rock?
Gabbro is a type of mafic phaneritic rock. It is composed mainly of pyroxene, plagioclase feldspar, and often contains minor amounts of amphibole, olivine, or biotite. Gabbro forms from the slow crystallization of mafic magma deep within the Earth's crust.
Why are mafic minerals such as olivine and pyroxene so rare in sedimentary rocks?
Mafic minerals like olivine and pyroxene are rare in sedimentary rocks primarily because they are less stable at the Earth's surface and weather quickly into more stable minerals like clay and quartz. These minerals typically form from the cooling of mafic igneous rocks, and when these rocks are weathered and eroded, the more durable minerals are preferentially preserved in sedimentary environments. Additionally, sedimentary rocks are often formed from the accumulation of materials that are derived from continental crust, which is predominantly felsic and contains fewer mafic minerals.
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 is lava with a wrinkled surface that forms when mafic lava hardens?
The lava with a wrinkled surface that forms when mafic lava hardens is called pahoehoe. It is characterized by smooth, undulating, or rope-like textures that result from the flow of lava as it cools and solidifies. Pahoehoe lava flows typically have a low viscosity, allowing the lava to move easily and form these distinctive features.
