Archean crustal generation and Neoproterozoic partial melting in the Ivindo basement, NW Congo craton, Republic of Congo: Petrology, geochemistry and zircon U–Pb geochronology constraints

We present systematic petrographic descriptions, geochemical and geochronological data from Souanké, Bomalinga, Elogo and Zoula areas in the Ivindo basement to understand the evolution of NW Congo Craton, Republic of Congo. Hornblende tonalite, biotite granodiorite, usually with hornblende-bearing enclaves, and granitic leucosome veins are ubiquitous in all areas. Specifically, coarse-grained muscovite-garnet-bearing pegmatite cross-cutting ancient mafic tonalite and felsic granodiorite in the Souanké area. Overall, three well-defined chemical patterns are described: (1) low SiO2 (57–63 wt%), high MgO + FeO (9–19 wt%) and metaluminous composition with intermediate LREE/HREE ratios and slightly positive Eu anomaly for tonalite, (2) middle SiO2 (67–73 wt%), MgO + FeO (7–1.5 wt%) and peraluminous composition with intermediate LREE/HREE ratios for granodiorite and (3) high SiO2 (72–75 wt%), low MgO + FeO (∼