andesite

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.

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

Wikidata facts

Image: Amygdaloidal andesite.jpg

Show 2 more facts

Commons category: Andesite
exact match: purl.obolibrary.org/obo/ENVO_01000441

Sources (6)

via Wikidata · CC0

~11 min read

Article

13 sections

Contents

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 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.