How diverse is the source? Age, provenance, reworking, and overprint of Precambrian meta-sedimentary rocks of West Gondwana, Cameroon, from zircon U-Pb geochronology

Abstract The Nyong Complex and the Yaounde Group represent two crustal sequences of West Gondwana in Cameroon. We use U-Pb zircon geochronology on meta-sedimentary rocks to analyze their depositional age, provenance, and age of the high-grade metamorphic overprint. Due to the undoubtedly Precambrian age of these rocks, we also pursue questions regarding the veiling of the provenance signal by subsequent overprints, the diversity of the sources, and the role of crustal reworking in such an old setting. Although both the Nyong and the Yaounde meta-sedimentary rocks were strongly affected by the Pan-African orogeny, Discordia analysis and the evaluation of remnant concordant zircons allow addressing these classic provenance questions with the LA-ICP-MS U-Pb zircon technique. We show that the Nyong Complex meta-sedimentary rocks likely have a 2.2 Ga depositional age (∼Rhyacian, early-middle Paleoproterozoic) and were locally sourced from the Meso-Neoarchean Congo Shield (∼2.8 Ga); they were overprinted during the Paleoproterozoic Eburnean orogeny (∼2.2–2.0 Ga). The Yaounde Group meta-sedimentary rocks likely have a