Mineralogical and geochemical composition of the subsurface sediments at the mouth of Wadi Al- Hamd, Red Sea coast, Saudi Arabia: implication for provenance and climate

Abstract

The present work is related to mineralogy and geochemistry of sedimentary successions of the modern Red Sea coastal plain at the mouth of Wadi Al-Hamd, Northern Saudi Arabia. It identifies the provenance, weathering effect, and paleoenvironment of the area. The mineralogical composition is dominated by quartz, plagioclase, and trace of feldspars, clay minerals, mica, and hornblende. Additionally, traces of non-detrital minerals including high and low Mg calcite, dolomite, halite, and anhydrite were locally detected. Four chemo-facies, dominated by three associations of element groups linked with detrital minerals, grain size properties, and biogenic products were recognized. The mineralogical and geochemical indices showed that sediments were derived from the intermediate igneous rocks at active continental margin and continental island arc settings. Weathering indices showed that the sediments were poorly weathered, consistent with the arid-to-semi-arid climate of the area. The spatial and vertical variations of mineralogical and chemical composition reflect variation depositional environments, hydraulic sorting, and the influence of coastal processes.