Geochemistry and tectonic setting of mafic igneous units in the Neoproterozoic Katangan basin, Central Africa: Implications for Rodinia break-up

Geochemical compositions of mafic igneous rocks in the Katangan basin in Ce ntral Africa (Democratic Republic of Congo, hereafter Congo, and Zambia) pr ovide the basis for the geodynamic interpretation of the evolution of this Neoproterozoic basin located between the Congo and Kalahari cratons. The Ka tangan basin is subdivided into five major tectonic units: the Katangan Aul acogen, the External Fold and Thrust Belt, the Domes Region, the Synclinori al Belt and the Katangan High. The metamorphosed mafic igneous rocks invest igated occur in the Katangan Aulacogen, the External Fold and Thrust Belt a nd the Domes Region. The earliest magmatic activity produced continental th oleiites emplaced on Paleoproterozoic crust during the early stages of intr aplate break-up. This continental tholeiite magmatism was followed by an as sociation of alkaline and tholeiitic basalts emplaced in the Katangan conti nental rift and then by tholeiitic basalts with E-MORB affinity marking a y oung oceanic crust. These volcanic associations mark different stages of ev olution from pre-rift continental break-up up to a continental rift similar to the East African rift system and then to a Red Sea type incipient ocean ic rift. A similar evolution occurs in the Damaran basin in southwestern Af rica, although no pre-rift continental tholeiites have been recorded in thi s segment of the Pan-African belt system.