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Earth and Space Sciences · Glossary

What is Granodiorite?

Definition 22.6 High School Earth and Space Sciences · Chapter 22 — Magmatism at Subduction Zones

Granodiorite is a coarse-grained plutonic rock like granite, but with more plagioclase than potassium feldspar: 20 to 60 %60\,\% of its light minerals are quartz, and 65 to 90 %90\,\% of its feldspar is plagioclase; it often holds biotite or hornblende.

Left: andesite, a fine-grained volcanic rock of arcs. Right: granodiorite of the Sierra Nevada, with white plagioclase, grey quartz and black biotite and hornblende. Photographs James St. John (CC BY 2.0). Left: andesite, a fine-grained volcanic rock of arcs. Right: granodiorite of the Sierra Nevada, with white plagioclase, grey quartz and black biotite and hornblende. Photographs James St. John (CC BY 2.0).
Left: andesite, a fine-grained volcanic rock of arcs. Right: granodiorite of the Sierra Nevada, with white plagioclase, grey quartz and black biotite and hornblende. Photographs James St. John (CC BY 2.0).
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