Unveiling microbial preservation under hyperacidic and oxidizing conditions in the Oligocene Rio Tinto deposit
Journal article, 2021
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.
Author
David C. Fernández-Remolar
Macau University of Science and Technology
Grenoble Alpes University
CNSA Macau Center for Space Exploration and Science
Daniel Carrizo
Centro de Astrobiologia (CAB)
Mourad Harir
Helmholtz
Ting Huang
Macau University of Science and Technology
R. I. Amils
Universidad Autonoma de Madrid (UAM)
Centro de Astrobiologia (CAB)
Philippe Schmitt-Kopplin
Helmholtz
Technical University of Munich
Laura Sánchez-García
Centro de Astrobiologia (CAB)
David Gómez-Ortiz
Rey Juan Carlos University (URJC)
Per Malmberg
Chalmers, Chemistry and Chemical Engineering, Chemistry and Biochemistry
Scientific Reports
2045-2322 (ISSN) 20452322 (eISSN)
Vol. 11 1 21543Subject Categories
Analytical Chemistry
Other Earth and Related Environmental Sciences
Textile, Rubber and Polymeric Materials
Infrastructure
Chemical Imaging Infrastructure
DOI
10.1038/s41598-021-00730-8