Pb isotopes - A multi-function tool for assessing tectonothermal events and crust-mantle recycling at late Archaean convergent margins

Lead isotopes are a powerful tool in studying Archaean granitoids and continental growth, because 207Pb is a sensitive indicator of involvement of lead from old Archaean crustal sources. This paper aims to demonstrate the significance and promote the use of lead isotopes by reviewing the theory, concepts, and traditions for interpretations of Pb isotope data as well as by introducing a global model based on crust-mantle recycling for discriminating late Archaean convergent margin settings of granitoids. Case plots of K-feldspar and whole-rock data of ca. 2.7 Ga granitoids from several Archaean cratons show that lead isotope systematics, when interpreted in the correct geological context, can be used for resolving many questions on crustal evolution from magmatic and tectonothermal history of individual intrusions to large-scale tectonics and supercontinent correlations.