Indigenous Organic‐Oxidized Fluid Interactions in the Tissint Mars Meteorite.

The observed fall and rapid recovery of the Tissint Mars meteorite has provided minimally contaminated samples of the Martian surface. We report analyses of Tissint for organic compounds by pyrolysis‐gas chromatography‐mass spectrometry and for soluble salts by ion chromatography. Pyrolysis‐gas chromatography‐mass spectrometry analysis shows the presence of organic compounds similar to those in the Mars EETA79001 and Nakhla meteorites. The organic profile is dominated by aromatic hydrocarbons, including oxygen and nitrogen‐containing aromatics, and sulfur‐containing species including thiophenes. The soluble salts in Tissint are dominated by sulfate and various oxidation states of chlorine, including perchlorate. The organic compounds and salts in the soils from the Tissint recovery strewn field differ significantly from those found in Tissint suggesting minimal terrestrial contamination. Our results support the hypothesis that the soluble inorganic components of Tissint are most likely a result of indigenous fluid inclusion, thus providing a glimpse into the composition of early Martian fluids. Plain Language Summary: Meteorites that come from Mars usually become contaminated after landing on Earth. One Mars meteorite, named Tissint, was seen falling in the dry Moroccan desert, and many of its pieces were collected within months. We analyzed the meteorite and the local soil for organic compounds and soluble salts. We found differences between the Tissint meteorite and the local soil that suggest that Tissint is uncontaminated. The analyses also showed that the soluble salts in Tissint most likely came from Martian fluids that were similar to terrestrial seawater. Key Points: Results support hypothesis that indigenous fluids incorporated into Tissint fissures on Mars and resulting chemical signatures preservedDifferences between soluble chemistry of Tissint and strewn field soil suggest that terrestrial contamination from recovery site is unlikelyAnalyses provide a glimpse into the chemical composition of a potentially habitable brine on early Mars [ABSTRACT FROM AUTHOR]