The name is derived from the type locality of tonalites, adjacent to the Tonale Line, a major structural lineament and mountain pass, Tonale Pass, in the Italian and Austrian Alps.
It is widely accepted that most Archaean granite–greenstones are dominated by TTG, although Late Archaean terranes, such as in the Yilgarn Craton, are dominated by potassium-rich granitoid rocks that are derived through remelting of older felsic TTG-dominated crust.
tonalite |
One of the unusual and notable rock formations is the Casibari Boulders, which are tonalite rocks seen to the north of Hooiberg.