1,2,1,3,4,- 1Università di Bologna, Dipartimento di Scienze Biologiche, Geologiche e Ambientali, Bologna, Italy (barbara.cavalazzi@unibo.it)
- 2Università degli studi di Bari – Aldo Moro, Dipartimento di Scienze della Terra e Geoambientali, Bari, Italy
- 3International Research School of Planetary Sciences, Università d’Annunzio, Dipartimento di Ingegneria e Geologia, Pescara, Italy
- 4Italian Space Agency, Science and Innovation Directorate, Rome, Italy
- 5Botswana International University of Science and Technology, Department of Mineral Resources, School of Earth Sciences and Engineering, Palapye, Botswana
- 6University of Bern, Physics Institute, Space Reseach and Planetary Sciences, Bern, Switzerland
- 7Université Kasdi MERBAH, Département des Sciences Biologiques, Ouargla, Algérie
Sabkha environments—marked by temporary water, high salinity, and extreme daily temperature shifts—create conditions that can favor the preservation of biosignatures, or chemical and structural traces of past life. This study examines two contrasting continental sabkha systems: the Makgadikgadi salt pan in Botswana and the Tanezrouft salt flat in Algeria (Franchi et al., 2025; Tarozzi, 2025; Abdelali et al., in prep.).
Despite their different locations and climates, both sites display mineral precipitation processes—such as halite, gypsum, and carbonates—that can rapidly trap microbial mats and organic matter. By combining sedimentological, mineralogical, and microbiological data, we explore how these minerals contribute to the early fossilisation of biological material and how post-depositional changes affect its long-term preservation.
The results underline the importance of microbial activity, wet-dry cycles, and the in-situ formation of minerals in protecting biosignatures. These findings not only deepen our understanding of how life may be recorded in Earth’s ancient evaporitic environments, but also have strong astrobiological relevance. The processes observed in these sabkhas offer valuable analogues for potential habitable environments on Mars and other planetary bodies, where similar saline and evaporitic conditions may have once existed and where traces of past life might still be preserved.
We acknowledge financial support under the NaRonal Recovery and Resilience Plan (NRRP), Mission 4, Component 2, Investment 1.1, Call for tender No. 104 published on 2.2.2022 by the Italian Ministry of University and Research (MUR), funded by the European Union – NextGeneraRonEU – CUP J53D23001630006 - Grant Assignment Decree No. 2022LFXTKY adopted by the Italian Ministry of Ministry of University and Research (MUR).
References
- Abdelali A., Pondrelli M., Caddeo Y., Mancini F., Youcef Sellam, Sakina Khallef, Cavalazzi B., IN PREPARATION. Geology of the Ahnet Basin (Southern Algeria) and possible field analogues to Mars.
- Franchi F., Cassaro A., Cavalazzi B., Lebogang L., Tarozzi A., Kahsay T.H., Pacelli C., 2025. Microbial abundance across a salinity and mineralogical transect in the Ntwetwe Pan of Botswana: A terrestrial analogue for playa deposits on Mars. Planetary and Space Science, 255: 106028.
- Tarozzi A., 2025. Morphological and compositional characterization of microbiota living in arid environments, the salt crust of the Makgadikgadi Pans, Botswana. Unpublished UNIBO MSc thesis, 70 pages.
How to cite: Cavalazzi, B., Tarozzi, A., Franchi, F., Abdelali, A., Caddeo, Y., Mancini, F., Cassaro, A., Pacelli, C., Lebogand, L., Kashay, T. H., Sellam, Y., and Khallef, S.: Evaporitic Ecosystems as Analogues for Life Detection:A Study of Makgadikgadi and Tanezrouft Sabkhas, EPSC-DPS Joint Meeting 2025, Helsinki, Finland, 7–12 Sep 2025, EPSC-DPS2025-68, https://doi.org/10.5194/epsc-dps2025-68, 2025.
