Skip to main content

ORIGINAL RESEARCH article

Front. Astron. Space Sci.
Sec. Astrobiology
Volume 12 - 2025 | doi: 10.3389/fspas.2025.1503042

The search for ancient life on Mars using morphological and mass spectrometric analysis: an analog study in detecting microfossils in Messinian gypsum

Provisionally accepted
Youcef SELLAM Youcef SELLAM 1*Salome Gruchola Salome Gruchola 1Marek Tulej Marek Tulej 1Peter Keresztes Schmidt Peter Keresztes Schmidt 1Andreas Riedo Andreas Riedo 1Sofiane Meddane Sofiane Meddane 2Peter Wurz Peter Wurz 1
  • 1 University of Bern, Bern, Switzerland
  • 2 University of Science and Technology Houari Boumediene, Bab Ezzouar, Algiers, Algeria

The final, formatted version of the article will be published soon.

    Hydrated sulfate deposits have been detected on Mars. A spaceflight instrument capable of14 detecting microfossils in these salt deposits is highly important for the search for ancient life on15 Mars. This study employed a range of analytical methods, including nondestructive optical16 microscopy and SEM-EDX, as well as spatially resolved laser ablation mass spectrometry (LIMS),17 the latter being designed for in-situ analyses on planetary surfaces, to comprehensively examine18 the morphology, texture, mineralogy, and geochemistry of fossil-bearing gypsum deposits from19 Algeria. These extensive gypsum formations formed during the Messinian Salinity Crisis (MSC)20 and serve as excellent astrobiological analogs for the large-scale hydrated sulfate deposits detected21 on Mars. Significant research on Messinian gypsum reveals notable microbial fossil filaments. This22 study aims to determine whether optical microscopy and LIMS measurements together can detect23 fossil filaments in the gypsum samples, identify their composition, and decipher their biogenicity24 and syngeneity. Spatially resolved depth profiling and chemical mapping analysis of one25 representative fossil filament using LIMS provided detailed mineralogical and compositional26 variations that correlate with distinctive morphological features. These findings collectively27 indicate that the fossil filament exhibits distinct composition and diagenetic processes in28 comparison to the surrounding gypsum host. The microfossil’s syngeneity and biogenicity were29 established based on the presence of morphological biosignatures, biologically relevant elements,30 and biologically induced or influenced minerals such as dolomite and clay minerals. The formation31 of these minerals within the physico-chemical context of ancient Martian lakes was also discussed.32 The same suite of measurements and techniques could be applied to study microfossil-bearing33 gypsum formations on Mars and beyond.

    Keywords: Microfossil biosignatures, Messinian gypsum, Martian surface, Laser ablation ionization mass spectrometry, Astrobiology, In-situ detection, Space Exploration

    Received: 27 Sep 2024; Accepted: 08 Jan 2025.

    Copyright: © 2025 SELLAM, Gruchola, Tulej, Keresztes Schmidt, Riedo, Meddane and Wurz. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence: Youcef SELLAM, University of Bern, Bern, Switzerland

    Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.