A review of the Mesoproterozoic to early Palaeozoic magmatic and tectonothermal history of south-central Africa: implications for Rodinia and Gondwana

This paper provides a review of the tectonic evolution of central-southern Africa from Mesoproterozoic to earliest Palaeozoic times, using available geological information and a robust U-Pb zircon database. During the late Mesoproterozoic, the southern margin of the Congo-Tanzania-Bangweulu Craton was characterized by suprasubduction-zone magmatism and the accretion of are and microcontinental fragments. Magmatism within the adjacent Irumide Belt formed by recycling of older continental crust. Ophiolite blocks, possibly part of an olistostromal melange, are present in a Neoproterozoic sequence overlying the Irumide Belt, and the occurrence of high-pressure/low-temperature subduction-zone metamorphism and protracted Neoproterozoic suprasubduction-zone magmatism demonstrates that there was an ocean to the south (present-day coordinates) of the Congo-Tanzania-Bangweulu Craton until the amalgamation of Gondwana at 550-520 Ma, indicating that the Congo-Tanzania-Bangweulu Craton was not part of Rodinia. On the basis of their different ages and styles of magmatism, the Mesoproterozoic Kibaran Belt, Choma-Kalomo Block and Irumide Belt are not components of the same orogen, therefore precluding a sub-Saharan-wide, linked 'Kibaran' (sensu lato) orogenic event. Evidence is presented to illustrate that the Congo-Tanzania-Bangweulu and Kalahari Cratons developed independently until their final collision during the Pan-African Orogeny along the Damara-Lufilian-Zambezi Orogen at c. 550-520 Ma.