Petrography and geochemistry of the Moloundou pelite–chert complex and high-grade iron ore, southeast Cameroon: implications for provenance and tectonic setting

The Moloundou area hosts high-grade iron ore (> 65 wt%) associated with pelite–chert complex within the Lower Dja Series, next to the Congo craton in southeast Cameroon. Here we report petrographic and geochemical data for the Moloundou pelite–chert complex and iron ore to constrain their source, tectonic setting, and the ore genetic model. The cherts are characterized by low ratios of Al/Al + Fe + Mn (mean = 0.04) and moderate contents of Fe 2 O 3 (mean = 1.44 wt%), indicating their hydrothermal origin. The pelites have geochemical features of immature sediments (mean ICV = 2.65), which have undergone low to moderate weathering (mean CIA = 65.39, Th/U = 4.02), sorting, and recycling (mean Th/Sc = 1.39, Zr/Sc = 30.32) in their source area. The Th/Co (1.03–1.34), Th/Sc (1.32–1.48), and La/Sc (5.84–7.40) ratios of the studied pelites suggest that they were derived from felsic rocks consisting of Proterozoic granitoids of the Dja Series in southeast Cameroon and southwest Central African Republic. Geochemical data for the cherts and pelites indicate that these rocks were deposited along a continental margin at the northern edge of the Congo craton. The Moloundou iron ore is classified as high-grade iron ore since it contains Fe grade > 65 wt% and minor amount of deleterious elements (e.g., SiO 2 , Al 2 O 3 , and P 2 O 5 ). The iron ore is martite–goethite and originated from an early hypogene magnetite oxidation followed by supergene enrichment leading to goethite mineralization in voids.