Segregation of olivine grains in volcanic sands in Iceland and implications for Mars

► Basaltic sands are affected by aeolian segregation producing olivine-enrichment. ► Olivine enrichment is revealed by paired enrichment in Mg and Ni. ► Olivine enrichment is anti-correlated with the mean grain size. ► Olivine enrichment in basaltic sands should be considered for Mars data.