Age and hafnium isotope evolution of Sudanese Butana and Chad illuminates the Stenian to Ediacaran evolution of the south and east Sahara

The Saharan Metacraton is a poorly known tract of pre-Neoproterozoic continental crust that occupies the area between juvenile Arabian Nubian Shield, in east, and Tuareg Shield to west. Neoproterozoic orogenesis (i.e. Oubanguides East African orogenies) affect west, south east metacraton, respectively, which led deformation, emplacement igneous bodies, localised episodes rift-related magamatism. Details about interior regions are known, with much it covered by Phanerozoic rocks. basement outcrops Sudan, Chad, Algeria Libya have been subject few modern geochronological studies. Here we present results from first zircon geochronology in-situ hafnium isotope investigations both Sudanese Butana central Chad. terranes Butana, formed Metacraton, oldest magmatism (ƐHf(t) +4.89 +7.89) at ca. 839 Ma, followed subsequent 787 Ma. Ma event (seen elsewhere Orogen) interpreted represent volcanic-arc collision accretion kernel Metacraton. contemporaneous Tonian (ca. 850 Ma) arc marks subduction magmatic history Ouaddaï region Chad begins late Mesoproterozoic, rifting, resulting granites 1030 Ma). Cryogenian Ediacaran reveal complicated deformation. Age data show (from melting Mesoproterozoic crust: ƐHf(t) = +2.04 −4.07) 665–654 coeval main Orogeny other ANS 650–580 youngest tectonothermal within recorded 580 550 values −17 −31) southern