The metamorphic evolution of mafic rocks in the Tugela Terrane, Natal Belt, South Africa

New petrological and mineral chemical data indicate a clockwise P-T path for medium- to high-grade metamorphic mafic rocks in different thrust sheets of the Tugela Terrane within the Mesoproterozoic Natal Belt in KwaZulu-Natal (eastern South Africa). Three metamorphic stages are distinguished: (i) an early upper amphibolite- to lower granulite-facies metamorphic event (M1) is indicated by rare relics of clinopyroxene; (ii) mineral chemical and textural equilibration during M2 at calculated pressure-temperature conditions of 4.5 to 6 kbar and 693 to 750°C; and (iii) partial diffusional resetting of mineral compositions during subsequent uplift and exhumation (M3) under lower amphibolite- to greenschist-facies conditions. No major differences were noted in the tectonothermal regimes at which each of the respective thrust sheets were deformed suggesting that the Tugela Terrane was a homogenous package and experienced uniform P-T conditions. The new data acquired in this study contribute to an improvement in the ongoing development of a tectono-thermal and geodynamic model for the Natal Belt.