First evidence for Cambrian rift-related magmatism in the West African Craton margin: The Derraman Peralkaline Felsic Complex

摘要: Abstract West of the southern, Archean, part Reguibat Rise African Craton Oulad Dlim Massif consists metamorphic nappes stacked during Mauritanides (Variscan) orogeny. In Derraman region, about 12 km west nappes, we have found strongly deformed hypersolvus aegirine-riebeckite A1-type granites with SHRIMP zircon U–Pb ages ca. 525 ± 3 Ma, e(Nd) 525Ma (− 5.2 to − 6.8.) and Nd model T CR  ≈ 1.85 Ga. These define two km-sized bodies a few smaller satellites. One body is emplaced within 3.12 Ga leucocratic gneiss. The other its satellites are an Archean low-grade metasedimentary sequence detrital zircons that peak at 2.84 Ga, 2.91 Ga, 3.15 Ga. gneisses metapelite rocks tectonic unit, hereafter called Derraman-Bulautad-Leglat (DBL) which was formed from basement very margin WAC. ~ 525 Ma oldest post-Archean in this unit were generated intraplate rifting environment melting crustal fenites ubiquitous Cambrian event affected northern Gondwana. At present level knowledge, however, cannot decide whether “old” isotope signature resulted old (Paleoproterozoic) fenite source or reflects mantle-derived metasomatising fluids. just-discovered strikingly similar rift-related Cambrian–Ordovician aegirine–riebeckite widespread North Understanding potential connections between them would help understand breakdown