What is intermediate magma?

Intermediate magma is liquefied rock with a silica content higher than mafic magma, but also lower than felsic magma. In general, the silica content of intermediate magma is around 60 percent silicate minerals.

What are the types of magma composition?

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 type of volcano has intermediate magma?

Composite volcanoes Composite volcanoes are constructed of felsic to intermediate rock. The viscosity of the lava means that eruptions at these volcanoes are often explosive.

What causes intermediate magma?

Intermediate magma most commonly transforms into andesite due to the transfer of heat at convergent plate boundaries. Andesitic rocks are often found at continental volcanic arcs, such as the Andes Mountains in South America, after which they are named.

What is the magma composition of a composite volcano?

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.

What is felsic magma?

Felsic refers to silicate minerals, magma, and rocks which are enriched in the lighter elements such as silicon, oxygen, aluminium, sodium, and potassium. Felsic magma or lava is higher in viscosity than mafic magma/lava. Felsic rocks are usually light in color and have specific gravities less than 3.

How is intermediate magma formed?

Initial Composition of Magma In general more siliceous magmas form by low degrees of partial melting. As the degree of partial melting increases, less siliceous compositions can be generated. So, melting a mafic source thus yields a felsic or intermediate magma.

Which of the following is a composite type of volcano?

A stratovolcano, also known as a composite volcano, is a conical volcano built up by many layers (strata) of hardened lava and tephra.

What type of eruption is composite volcano?

Composite volcanoes: steep slopes; thick, sticky lava; lava does not flow quickly or far; erupt violently. Shield volcanoes: gentle slopes; runny lava; lava flows quickly; lava may flow far; erupt less violently.

Which rock has an intermediate composition?

Intermediate is a composition between felsic and mafic. It usually contains roughly-equal amounts of light and dark minerals, including light grains of plagioclase feldspar and dark minerals like amphibole.

What is an intermediate igneous rock?

Igneous Rocks by Composition Intermediate rocks are roughly even mixtures of felsic minerals (mainly plagioclase) and mafic minerals (mainly hornblende, pyroxene, and/or biotite). There is little or no quartz.

What is a composite volcano made of?

steep volcano made of hardened lava, rock, and ash. Also known as a composite volcano.

What type of magma does composite volcanoes have?

Magma Composition Composite volcanoes usually erupt a range of compositions from basalt to rhyolite, but intermediate (andesitic) and dacitic magmas are most common. Mount Rainier has less compositional diversity than many composite cones as it consists of mostly andesitic lava flows and lahar deposits.

Which igneous rocks are intermediate?

Typical intermediate rocks include andesite, dacite and trachyandesite among volcanic rocks and diorite and granodiorite among plutonic rocks.

Is basalt intermediate?

Compilations of many rock analyses show that rhyolite and granite are felsic, with an average silica content of about 72 percent; syenite, diorite, and monzonite are intermediate, with an average silica content of 59 percent; gabbro and basalt are mafic, with an average silica content of 48 percent; and peridotite is …

What is intermediate composition of rock?

Intermediate rocks are roughly even mixtures of felsic minerals (mainly plagioclase) and mafic minerals (mainly hornblende, pyroxene, and/or biotite). There is little or no quartz. Felsic rocks are mostly feldspar (especially K-feldspar), at least 10% quartz, and less than 15% mafic minerals (biotite, hornblende).

What type of magma makes a composite volcano?

Composite volcanoes usually erupt a range of compositions from basalt to rhyolite, but intermediate (andesitic) and dacitic magmas are most common. Mount Rainier has less compositional diversity than many composite cones as it consists of mostly andesitic lava flows and lahar deposits.

What type of eruptions do composite volcanoes have?

Composite volcanoes: steep slopes; thick, sticky lava; lava does not flow quickly or far; erupt violently. Shield volcanoes: gentle slopes; runny lava; lava flows quickly; lava may flow far; erupt less violently.

What type of eruption is composite?

Which of the following is the best describes a composite volcano?

Which of the following BEST describes a composite volcano? hardened, thick layers of rock.

What igneous rocks are intermediate?

Typical intermediate rocks include andesite, dacite and trachyandesite among volcanic rocks and diorite and granodiorite among plutonic rocks.

What rocks are intermediate?

Intermediate rocks are grey in color and contain somewhat equal amounts of minerals that are light and dark in color. Primary intermediate rocks are andesite (extrusive) and diorite (intrusive).

What makes a 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.

What volcanoes are mafic?

So mafic/basaltic volcanoes are fairly quiescent, intermediate/andesitic volcanic eruptions are moderately explosive, and felsic/rhyolitic volcanoes may be extremely explosive. So, mafic lavas are hot , low in silica and volatiles, and have relatively low viscosity.

What is basaltic magma?

Basaltic (or mafic) magma predominates in nonexplosive volcanic eruptions. It is a high-temperature magma (1,200 °C (about 2,200 °F)) characterized by flowing lava, and it is made up of about 45–55 percent silica (SiO2) by weight.

What is rhyolitic magma?

Rhyolitic lavas are viscous and tend to form thick blocky lava flows or steep-sided piles of lava called lava domes. Rhyolite magmas tend to erupt explosively, commonly also producing abundant ash and pumice.

Is rhyolite an intermediate?

Rhyolite. Medium silica content (intermediate). A fine-grained volcanic rock of granitic composition.

Is basalt mafic felsic or intermediate?

Igneous Rocks by Composition

Coarse-Grained Textures	Fine-Grained Textures
Peridotite = Ultramafic	Komatiite (Ultramafic, but too rare to worry about at this point in your life)
Gabbro = Mafic	Basalt = Mafic
Diorite = Intermediate	Andesite = Intermediate
Granite = Felsic	Rhyolite = Felsic

What is intermediate igneous rock?

In igneous petrology an intermediate composition refers to the chemical composition of a rock that has 52-63 wt% SiO2 being an intermediate between felsic and mafic compositions.

What are the intermediate mafic?

Mafic rocks are dominated by plagioclase and pyroxene (even if you can't see them with the naked eye) and smaller amounts of olivine. Intermediate rocks are roughly even mixtures of felsic minerals (mainly plagioclase) and mafic minerals (mainly hornblende, pyroxene, and/or biotite). There is little or no quartz.