Andesite (pronounced /ˈændəsaɪt/) is an extrusive igneous, volcanic rock, of intermediate composition, with aphanitic to porphyritic texture. In a general sense, it is the intermediate type between basalt and dacite. The mineral assemblage is typically dominated by plagioclase plus pyroxene and/or hornblende. Magnetite, zircon, apatite, ilmenite, biotite, and garnet are common accessory minerals. Alkali feldspar may be present in minor amounts. The quartz-feldspar abundances in andesite and other volcanic rocks are illustrated in QAPF diagrams. Relative alkali and silica contents are illustrated in TAS diagrams. (Source wikipedia)
Nevado del Ruiz is a stratovolcano, so the composition of the magma likely varies over time. The tragic eruption of 1985 involved magma of andesite or dacite composition.
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Minerals have a definite chemical composition, are solid, are inorganic, are naturally occurring, and have a crystalline structure.
State the chemical composition of the sterol that is present in high levels in most people who belong to the high-risk group.
A mineral has a fixed chemical composition, and crystal format. Sometimes we may have two minerals with the same chemical formula - e.g. calcite and aragonite, but differ in crystallization.
basalt and dacite, and ranges from 57 to 63% silicon dioxide (SiO2)
The composition of the rock will determine whether it is a rhyolite or an andesite.
Dacite is an extrusive rock that has a composition similar to andesite. Both rocks are rich in silica and belong to the intermediate composition category. They form from the volcanic eruption of magma that is intermediate in composition between felsic and mafic.
Andesite is a rock with an intermediate composition. It contains minerals such as plagioclase feldspar, amphibole, and pyroxene, giving it a balance between light and dark minerals. Andesite forms from the cooling of magma with a composition between basalt and granite.
Andesite has an intermediate composition between "basic" and "acid."
Andesite is a type of extrusive igneous rock with moderate levels of silica. Andesitic is an adjective used to describe volcanic material with the composition of andesite. For example, andesitic lava will cool to form andesite.
The main difference between dacite and andesite lies in their silica content. Dacite has a higher silica content than andesite, making it more viscous. Dacite also typically contains more quartz and less mafic minerals than andesite.
The mineral composition (silica content) is the chemical property most commonly used to classify igneous rocks. This can help differentiate between different types of igneous rocks, such as basalt, andesite, and granite.
Andesite is considered an intermediate rock between granite (felsic igneous rock) and basalt (mafic igneous rock), based on chemical composition.
Intrusive: Extrusive Equivalent Granite: Rhyolite Diorite: Andesite Gabbro: Basalt
The Cotopaxi volcano in Ecuador is primarily composed of andesite and dacite rock types. Andesite is a volcanic rock with an intermediate composition between basalt and rhyolite, while dacite has a similar composition to andesite but with more silica content.
It varies in composition, but is usually andesite, dacite, or rhyolite.