1. Unveiling microbial preservation under hyperacidic and oxidizing conditions in the Oligocene Rio Tinto deposit
- Author
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Laura Sánchez-García, Ricardo Amils, Per Malmberg, Daniel Carrizo, Philippe Schmitt-Kopplin, Ting Huang, D. C. Fernández-Remolar, Mourad Harir, David Gómez-Ortiz, European Commission, and UAM. Departamento de Biología Molecular
- Subjects
0303 health sciences ,Multidisciplinary ,010504 meteorology & atmospheric sciences ,Science ,Geochemistry ,Noachian ,Mars Science Laboratory ,Mars Exploration Program ,Astrobiology ,Biología y Biomedicina / Biología ,01 natural sciences ,Article ,03 medical and health sciences ,13. Climate action ,Mars Craters ,Oxidizing agent ,Planetary science ,Crater ,Medicine ,Gossan ,Geology ,030304 developmental biology ,0105 earth and related environmental sciences - Abstract
The preservation of biosignatures on Mars is largely associated with extensive deposits of clays formed under mild early Noachian conditions (> 3.9 Ga). They were followed by widespread precipitation of acidic sulfates considered adverse for biomolecule preservation. In this paper, an exhaustive mass spectrometry investigation of ferric subsurface materials in the Rio Tinto gossan deposit (~ 25 Ma) provides evidence of well-preserved molecular biosignatures under oxidative and acidic conditions. Time of flight secondary ion mass spectrometry (ToF-SIMS) analysis shows a direct association between physical-templating biological structures and molecular biosignatures. This relation implies that the quality of molecular preservation is exceptional and provides information on microbial life formerly operating in the shallow regions of the Rio Tinto subsurface. Consequently, low-pH oxidative environments on Mars could also record molecular information about ancient life in the same way as the Noachian clay-rich deposits, (Grant No. ANR-15-IDEX-02), European Regional Development Fund (Grant No. RYC2018-023943-I), Horizon 2020 Framework Programme (Grant No. RYC-2014-19446)
- Published
- 2021