The magmatic, metamorphic and tectonic evolution of the Northern Marginal Zone of the Limpopo Belt in Zimbabwe

The Northern Marginal Zone of the Limpopo Belt in southern Africa comprises a Plutonic Assemblage of granitoids and a much less abundant Supracrustal Assemblage of metabasites and iron formations. These rocks are at granulite facies above a normal thickness of continental crust. The Plutonic Assemblage may have been derived from partial melting of a mafic source. The reverse-sense shear zone forms the boundary of the Northern Marginal Zone with the Zimbabwe craton. The southern boundary is the Triangle shear zone. Crustal thickening occurred both magmatically and tectonically in the late Archaean, and was accompanied by synchronous uplift. Protracted magmatism provides a mechanism to incorporate supracrustal rocks into the lower crust, and can explain the occurrence of more than a single thermal event. -from Authors