An igneous rock of any composition that contains conspicuous phenocrysts in a fine-grained groundmass; a porphyritic igneous rock.
Source: AGI Glossary of Geology, 4th edition, 1997
Geological keywords, such as “granite”, “lake”. The definitions are generally taken from the AGI Glossary of Geology. Keywords with a geographic context (e.g. Cape Smith Fold Belt, Selwyn Basin, Grenville Province) are assigned to a separate category.
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