Sedimentological, mineralogical, and geochemical characterization of sand dunes in Saudi Arabia

This paper investigates the morphology, texture, composition, mineralogy, and geochemistry, and provenance of sand dunes from 10 locations in Saudi Arabia. Morphologically, these sand dunes include linear, parallel to subparallel ridge, parabolic, barchans, and star sand dunes. Sixty-seven samples were collected from these different sand dune types. Generally, sands from dunes in all locations were characterized by fine to coarse mean grain size, were moderately sorted, and had near symmetrical skewness with mesokurtic distribution. Skewness and mesokurtic distribution characterize sand dunes in most locations except the Red Sea, Qassim, central Arabia, and the Eastern Province where sand dunes all show of subangular grains. The sand dunes are composed of quartz, feldspar, calcite, and mica. Quartz dominates the mineralogy of all sand dunes, although significant amounts of feldspars and mica are found in Najran, the Red Sea, and Central Arabia. While calcite is present in sand dunes at Sakaka and NW Rub' Al-Khali. Basement-related sand dunes at Najran (N1), central Arabia (C5), and the Red Sea are mineralogically submature. However, nonbasement sand dunes at other locations are mature. Both petrographic and geochemical analyses of sand dunes indicated that most sand dunes are classified as quartz arenite, except in the basement-related sand dunes at Najran (N1), central Arabia (C5), and the Red Sea, where they range from subarkose to litharenite. Moreover, major, trace, and rare earth elements indicated an active continental margin tectonic setting for sand dunes from the Red Sea, basement-related Najran (N1), and central Arabia (C5) sand dunes, and passive continental margins for the other locations.