Mineralogical and microstructural characterization of El Hadjeb dune sands (Algeria) using XRD and SEM

Abstract

Abstract

This study provides a morphological and mineralogical characterization of sands from the dunes at El Hadjeb, near Biskra, southeastern Algeria. At the transition between Saharan and steppe environments, these dunes are of growing environmental and tourism significance. Representative sand samples from three distinctly different geomorphological positions were characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses. XRD indicated quartz-dominated composition (up to 92.28 wt.%), with subordinate levels of calcite, indicating high mineralogical maturity, characteristic of well-developed aeolian systems. SEM analysis revealed sub-angular to sub-rounded grains with conchoidal fractures, micro-scarps, and pitting, typical of high-intensity mechanical weathering and long-distance transport in winds. The absence of clay coatings, gypsum phases, and biological material further confirms the arid, high-energy deposition setting. These results improve the understanding of the mineralogical maturity and textural characteristics of Saharan dune sands, which is essential for evaluating their suitability in soil rehabilitation, their integration into building materials, and their relevance to regional planning for ecotourism. The combined use of XRD and SEM illustrated how complementary geoscientific methods can provide detailed mineralogical and textural information essential for supporting sustainable management strategies in the studied region.