Source-area controls on the composition of beach and fluvial sands on the southern side of the Gibraltar Strait and Western Alboran Sea (Flysch Basin, Internal and External, Domains, Northern Rif Chain)

Modern beach and fluvial sands of the southern side of Gibraltar and the Western Alboran Sea display three distinct petrologic littoral provinces, from the east to the west and from the north to the south, respectively, designated as: (i) the Tangier-Bel Younech Littoral Province with 90% of sand derived from erosion of Flysch Nappes (Flysch Basin Domain); (ii) the Bel Younech-Sebta Littoral Province with 64% of sand fed mainly by the metamorphic Units of Upper Sebtides and (iii) the Sebta-Ras Mazari Littoral Province with 74% of sand supplied from the epimetamorphic Palaeozoic Ghomaride Nappes and Alpine cover rather than Mesozoic and Cenozoic sedimentary successions of the “Dorsale Calcaire” Units. Comparison of detrital modes of fluvial and coastal marine environments highlights their dispersal pathways and drainage patterns of actualistic sand petrofacies.