Our results show that crustal element ratios and clay contents distinguish dust aerosols from arid western coastal areas and humid eastern inland regions in Southern Africa. This dust contains key micronutrients that can become bioaccessible during atmospheric transport to nearby and remote marine ecosystems. It is also enriched in carbonates and K-feldspar, serving as a source of cloud condensation and ice nuclei, with potential implications ranging from regional to sub-hemispheric scales.