Keywords

An igneous rock of any composition that contains conspicuous phenocrysts in a fine-grained groundmass; a porphyritic igneous rock.

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.