Tonalite-trondhjemite-granodiorite (or TTG suite, a term coined by Jahn et al. 1981) is an association of rocks that compose a large part of Archean continental crust. It is widely accepted that this rock suite formed by melting of hydrous metabasalts at high pressure, yet the geodynamic setting in which this melting took place is discussed. Two main sources of melt are proposed: (1) basaltic material that was previously underplated beneath thickened crust (e.g., Smithies 2000) and (2) basaltic rocks in subducting oceanic slabs that melted in a hotter Archean mantle (e.g., Martin et al. 2005).
References and Further Reading
- Bédard J (2006) A catalytic delamination-driven model for coupled genesis of Archaean crust and subcontinental lithospheric mantle. Geochim Cosmochim Acta 70:747–771Google Scholar
- Brown GC (1986) Processes and problems in the continental lithosphere: geological history and physical implications. In: Snelling N (ed) Geochronology and geological record. Geological Society of London Special Publication, LondonGoogle Scholar