Intermediate composition

In igneous petrology an intermediate composition refers to the chemical composition of a rock that has 52-63 wt% SiO₂ being an intermediate between felsic and mafic compositions. Typical intermediate rocks include andesite, dacite and trachyandesite among volcanic rocks and diorite and granodiorite among plutonic rocks.^[1]

References

Common igneous rocks classified by silicon dioxide content

Type	Ultramafic <45% SiO₂	Mafic 45–52% SiO₂	Intermediate 52–63% SiO₂	Intermediate–felsic 63–69% SiO₂	Felsic >69% SiO₂

Volcanic rocks: Subvolcanic rocks: Plutonic rocks:	Komatiite, Picrite basalt Kimberlite, Lamproite Peridotite	Basalt Diabase (Dolerite) Gabbro	Andesite Microdiorite Diorite	Dacite Microgranodiorite Granodiorite	Rhyolite Microgranite Granite

This article is issued from Wikipedia - version of the 4/16/2014. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.