| |
dacite -- Igneous volcanic rock, less mafic than andesite, typically fine-grained and light in color; rough volcanic equivalent of granodiorite.
But the presence of normative quartz (leftover silica, after we assign all other SiO2 to the other minerals), technically makes this rock type a dacite.
Felsic magma contains relatively high quantities of sodium, aluminum, potassium, and silica. Its solidification produces granite, dacite, rhyolite, and granodiorite. Each of these rocks has a unique mineral composition and grain size.
 See also: Region, Volcanic, Surface, Area, Fault
|
