andesite
Sign in to saveAndesite () is a volcanic rock of intermediate composition. In a general sense, it is the intermediate type between silica-poor basalt and silica-rich rhyolite. It is fine-grained (aphanitic) to porphyritic in texture, and is composed predominantly of sodium-rich plagioclase plus pyroxene or hornblende.
AI overview
Andesite is a volcanic rock that falls between basalt and rhyolite in terms of silica content, making it an intermediate type of igneous rock. It is composed mainly of sodium-rich plagioclase minerals along with pyroxene or hornblende, and has a fine-grained texture that may include some larger crystals visible to the naked eye.
AI-generated from the Wikipedia summary — may contain errors.
Key facts
- Rock.name
- Andesite
- Rock.type
- Igneous
- Rock.image
- Amygdaloidal andesite.jpg
- Rock.caption
- A sample of andesite (dark groundmass) with amygdaloidal vesicles filled with zeolite. Diameter of view is 8 cm.
- Rock.composition
- Intermediate: plagioclase (often andesine) and pyroxene or hornblende
- Rock.composition_secondary
- Magnetites, biotite, sphene, and quartz
via Wikipedia infobox
Article
13 sectionsContents
- Description
- Andesitic volcanism
- Generation of melts in island arcs
- Genesis
- Fractional crystallization
- Partial melting of the crust
- Magma mixing
- Partial melting of metasomatized mantle
- Notable andesite structures
- Extraterrestrial samples
- See also
- References
- External links
Andesite () is a volcanic rock of intermediate composition. In a general sense, it is the intermediate type between silica-poor basalt and silica-rich rhyolite. It is fine-grained (aphanitic) to porphyritic in texture, and is composed predominantly of sodium-rich plagioclase plus pyroxene or hornblende.
Andesite is the extrusive equivalent of plutonic diorite. Characteristic of subduction zones, andesite represents the dominant rock type in island arcs. The average composition of the continental crust is andesitic. Along with basalts, andesites are a component of the Martian crust.