Illustrated Volcano Glossary

Updated: Jun 5, 2023 23:01 GMT - refresh

dacite: Volcanology

A dacitic lava-dome at Nisyros Island in Greece

Dacite is an igneous, volcanic rock with a high iron content found at many lava-domes.

Dacite (pronounced /deɪsaɪt/) is an igneous, volcanic rock with a high iron content. It is intermediate in compositions between andesite and rhyolite, and, like andesite, it consists mostly of plagioclase feldspar with biotite, hornblende, and pyroxene (augite and/or enstatite). It has an aphanitic to porphyritic texture with quartz as rounded, corroded phenocrysts, or as an element of t... Read all
debris avalanche: Volcanology

A sudden collapse of volcanic material from an unstable side of a volcano. Debris avalanches are a particularly violent type of pyroclastic flows (in its broader meaning).

Related keywords (1):
pyroclastic flow
diorite: Volcanology

Diorite sample (image: Michael C. Rygel via Wikimedia Commons)

Diorite is an intrusive igneous rock of intermediate silica content (53-63%). It is the equivalent of its extrusive (volcanic) counterpart andesite.

Diorite is composed principally of the silicate minerals plagioclase feldspar (typically andesine), biotite, hornblende, and/or pyroxene. The chemical composition of diorite is intermediate between gabbro and granite. Read all

Related keywords (2):
andesite - granite

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