Introduction Hypersaline lakes and coastal brines are today’s best terrestrial analogues for Martian bodies of water. In particular, columns of magnesium sulfate (Mg-SO4) brines and sulfate-rich salt deposits present chemical settings that resemble deposits inferred on Mars. This study evaluates how lipid biosignatures—such as fatty acids, alkanes, and ether-bound lipids—are produced and preserved in modern…