The Ntem Complex represents the northwestern margin of Congo Craton in southern Cameroon. It consists mainly of charnockites, TTG suites, potassic grantitoids, minor supracrustal and mafic rocks. The latter include gabbronorite enclave or sill, gabbro and dolerite dykes. The metagabbro are basaltic to andesitic in composition and show geochemical features of low-La Archean tholeiitic basalts, and LREE-depleted (La N /Sm N < 1) akin to modern N-MORB. The doleritic dykes show high TiO 2 /P 2 O 5 (7.50-11.47) and (La/Yb) N ratios, and low Nb\ \Ta values similar to modern intraplate continental basalts and intermediate-La Archean tholeiitic basalt, least affected by contamination from granitic continental crust. The partial melting of low-to high-K mafic rocks of oceanic and continental arc affinity generated the charnockites and low−/medium-pressure TTGs. The potassic granites were formed by partial melting of charnockite or TTG, and inherited many geochemical features of their sources. New LA-ICP-MS U\ \Pb zircon dates suggest that the charnockites and TTG suites formed at 3155-2850 Ma. The gabbro intrusion was dated at 2866 ± 6 Ma. Migmatisation of TTG-gneiss was coeval whit the regional high-grade metamorphism event at 2843 ± 7 Ma. The potassic granites were probably crystallized at~2758 Ma. The garnet-whole rock Sm\ \Nd age of 2744 ± 31 Ma may represent the age of the second anatexis event coeval with D2 deformation. Literature data indicate the disruption or open isotopic systems in the Ntem Complex around 2500-2600 Ma.

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Sangmelima granite-greenstone terrains (SGB) provide a new overview of the evolution of the Ntem Complex (South Cameroon), the northwestern part of the Congo Craton. The regional deformation is marked by a strong steep dips foliation and steeply plunging mineral-stretching. D 1 -related structures are folding and shearing by a D 2 deformation that is synchronous with extraction granitic dykes. D 1 -D 2 structures were developed during regional E-W sub-horizontal shortening under ductile conditions associated with steeply dipping principal stretching in a transpressive regime, progressive strain localization along strike-slip shear zones. Syn-D 1 mineral assemblages and high strain microstructures suggest that ductile deformation D 1 occurred under high-grade metamorphic conditions, whereas D 2 microstructures suggest a brittle deformation. The strain patterns in the SGB recorded a long-lasting Archean tectonic history within the Archean Ntem Complex (ca. 2.83-2.72Ga). Finally, some Archean structures were reactivated during a brittle deformation (D 3 ), likely during the Eburnean event.The Archean block in the north-western margin of the Congo Craton (Fig. 1a), corresponds to the Ntem-Chaillu Block (here after called

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