Definitions Found:
dark-colored volcanic rock composed essentially of plagioclase feldspar and one or more mafic minerals, as hornblende or biotite
- andesiticdark-colored volcanic rock composed essentially of plagioclase feldspar and one or more mafic minerals, as hornblende or biotite
- andesitesdark-colored volcanic rock composed essentially of plagioclase feldspar and one or more mafic minerals, as hornblende or biotite
- andesitedark-colored volcanic rock composed essentially of plagioclase feldspar and one or more mafic minerals, as hornblende or biotite
- trachytefine-grained volcanic rock consisting essentially of alkali feldspar and one or more subordinate minerals, as hornblende or mica: the extrusive equivalent of syenite
- plagioclasea fine-grained volcanic rock of intermediate composition, consisting largely of plagioclase and one or more mafic minerals
- plagioclasesPLAGIOCLASE, a fine-grained volcanic rock of intermediate composition, consisting largely of plagioclase and one or more mafic minerals