What is a tonalite in geology ?
Tonalite : definition
Tonalite is a grainy plutonic rock with quartz, plagioclase surrounded by a border of alkaline feldspar, hornblende and biotite.
It is the most common variety of quartz diorite, which forms small massifs associated with granitoids and diorite. another variety of quartz diorite, close to tonalite, is trondhjemite.
It is the most common variety of quartz diorite, which forms small massifs associated with granitoids and diorite. another variety of quartz diorite, close to tonalite, is trondhjemite.
