Provenance, weathering, and tectonic setting of the Yoyo, Kribi, and Campo beach sediments in the southern Gulf of Guinea, SW Cameroon

The coastal and landward sectors of the southern Gulf of Guinea are dominated by igneous, sedimentary, and metamorphic rocks of Precambrian and Paleozoic ages. However, the lithology and extent of the basement rocks hidden under thick lateritic covers are not well documented. To establish more precisely the provenance, paleoweathering, and tectonic setting, the mineralogy and chemical composition of beach sediments were examined. Beach sediments are fine to medium-grained and compositionally matured, revealed by the high SiO 2 /Al 2 O 3 ratio and Zircon–Tourmaline–Rutile (ZTR) index values. Th/Sc vs. Zr/Sc bivariate and Al 2 O 3 –TiO 2 –Zr triangular diagrams suggested that the sediments were recycled. Ternary diagrams (A–CN–K and (A–K)–C–N) and chemical indices such as the chemical index of alteration (CIA), the plagioclase index of alteration (PIA), and the chemical index of weathering (CIW) indicated that the beach sediments were undergone moderate weathering. Numerous provenance discrimination plots based on TiO 2 , Al 2 O 3 , Zr, Th, Co, La, Sc, V, and Ni, and chondrite normalized rare earth element (REE) patterns suggested a felsic provenance for the beach sediments. Quartzose sedimentary provenance is also inferred through major element concentrations, reflecting the influence of abundant metasediments from the Nyong Paleoproterozoic, Pan-African Neoproterozoic, and Douala–Kribi–Campo basins. Paleotectonic analyses indicated rift and passive margin settings, which may be linked to the pre-Eburnean rifting (older than ca. 2500 Ma), the opening of Nyong intracontinental basins, and the development of a passive margin setting on the Congo craton’s northern border. Research highlights Yoyo, Kribi, and Campo beach sediments are quartz rich. The beach sediments investigated underwent a moderate degree of weathering. The sediments were derived from the Precambrian metamorphic and Paleozoic sedimentary rocks. Geochemical data indicated the combination of rift and passive margin settings.