Schist Belts of the Benin-Nigeria Shield Reveal a Neoproterozoic History

Belts of metasedimentary rocks (schist belts) in the Benin-Nigeria Shield (BNS) are investigated for the first time using U–Pb dating and Lu-Hf isotope analysis of detrital zircons. We report maximum depositional ages that place their deposition firmly in the Neoproterozoic and link them with strata in the Dahomey Belt, the central African fold belt, and the Borborema Province in South America. The detrital zircon age distribution also includes Archaean dates and is dominated by ~2.1 Ga zircons. The latter are derived from juvenile granitoids, likely forming much of the basement of the BNS. We bracket the detrital zircon data with U–Pb dates and Lu-Hf isotope data of both the oldest (Kaduna Gneiss, 3571 ± 3 Ma) and youngest (Maradun Group rhyolite and related granitoids, 586 ± 2 Ma) Precambrian rocks of the BNS. By doing so, we highlight a 3-billion-year-old record of crustal evolution in central Africa.