Oxygen isotopic evidence that Gale crater, Mars, was home to an Early Hesperian water reservoir that underwent significant evaporation.

ABSTRACT: Simultaneous measurements of HDO, H₂¹⁸O, and H₂¹⁶O in water evolved during pyrolysis of powdered rock samples acquired by the Curiosity rover within Gale crater's clay-bearing units indicate extreme and variable heavy-isotope enrichments averaging ~4.5 times the D/H ratio and ~1.03 times the ¹⁸O/¹⁶O ratio of terrestrial seawater. These enrichments are recorded in water desorbed from mineral surfaces and evolved from poorly crystalline phases, hydrated salts, jarosite, and clays. All evolved waters are deuterium-enriched relative to common terrestrial waters, reflecting hydrogen loss to space. Because oxygen in structurally bound hydroxyl groups is least likely to exchange with other sources over geologic timescales, we focus

SUBMITTER: Hofmann AE 

PROVIDER: S-EPMC12582284 | biostudies-literature | 2025 Oct

REPOSITORIES: biostudies-literature