Andesite - Wikipedia
Andesite is an aphanitic (fine-grained) to porphyritic (coarse-grained) igneous rock that is intermediate in its content of silica and low in alkali metals. It has less than 20% quartz and 10% feldspathoid by volume, with at least 65% of the feldspar in the rock consisting of plagioclase.
Andesite: Igneous Rock - Pictures, Definition & More - Geology.com
Andesite is a fine-grained rock that forms when the magma erupts onto the surface and crystallizes quickly. Andesite and diorite have a composition that is intermediate between basalt and granite. This is because their parent magmas formed from the …
Andesite | Properties, Composition, Formation, Uses - Geology …
2023年9月4日 · Andesite is an intermediate sub-alkalic rock with SiO2 contents ranging between 57 and 63 wt. %, and Na2O + K2O contents around 5 wt. %. Intermediate rocks are also characterized by an increased CaO content compared to that in acidic rocks.
Everything You Ought to Know about Andesite Rock
2023年7月3日 · Andesite is a fine-grained, intermediate volcanic or extrusive igneous rock. Its composition lies between basalt and dacite, and it has mainly sodium-rich plagioclase and one or more mafic minerals, especially pyroxenes or hornblende.
Andesite | Volcanic, Igneous, Magma | Britannica
andesite, any member of a large family of rocks that occur in most of the world’s volcanic areas. Andesites occur mainly as surface deposits and, to a lesser extent, as dikes and small plugs.
Andesite - Geology Hub
Andesite is a fine-grained volcanic rock (aphanitic texture) that forms through the rapid cooling of magma at the Earth’s surface. Its silica content ranges from 57-63%, placing it between the mafic and felsic rocks.
What Is Andesite? - WorldAtlas
2018年8月10日 · Andesite is a type of igneous rock that is formed by volcanic activity. It is usually dark grey or bown in colour. It usually exists as the solid form of volcanic lava or magma.
Andesite Rock Composition and Formation | Earth Know
2024年3月28日 · Andesite is an intermediate volcanic or extrusive igneous rock. Intermediate rocks are moderate in silica (52-63 wt.%), mafic, and felsic minerals. Mafic minerals are dark-colored rock-forming minerals rich in iron and magnesium.
Properties and Uses of Andesite Rock - Science Struck
Andesite is an extrusive igneous rock that has a porphyritic texture. This rock is formed from molten magma, which has medium viscosity. Read this ScienceStruck article to know the facts, origin, formation, and properties of andesite rocks.
USGS: Volcano Hazards Program Glossary - Andesite
Andesite is a gray to black volcanic rock with between about 52 and 63 weight percent silica (SiO2). Andesites contain crystals composed primarily of plagioclase feldspar and one or more of the minerals pyroxene (clinopyroxene and orthopyroxene) and lesser amounts of hornblende.