¹P.Beck et al. (>10)
Earth and Planetary Science Letters 656, 119256 Open Access Link to Article [https://doi.org/10.1016/j.epsl.2025.119256]
¹Univ. Grenoble Alpes, CNRS, IPAG, 38000 Grenoble, France
Copyright Elsevier

On Earth, silica-rich phases from opal to quartz are important indicators and tracers of geological processes. Hydrated silica, such as opal, is a particularly good matrix for the preservation of molecular and macroscopic biosignatures. Cherts, a type of silica-dominated rocks, provide a unique archive of ancient terrestrial life while quartz is the emblematic mineral of the Earth’s continental crust. On Mars, hydrated silica has been detected in several locations based on remote sensing and rover-based studies. In the present article we report on the detection of cobbles made of hydrated silica (opal or chalcedony), as well as well-crystallized quartz. These detections were made with the SuperCam instrument onboard Perseverance (Mars 2020 mission), using a combination of LIBS, infrared and Raman spectroscopy. Quartz-dominated stones are detected unambiguously for the first time on the Martian surface, and based on grain size and crystallinity are proposed to be of hydrothermal origin. Although these rocks were all found as float, we propose that these detections are part of a common hydrothermal system, and represent different depths / temperatures of precipitation. This attests that hydrothermal processes were active in and around Jezero crater, possibly triggered by the Jezero crater-forming impact. These silica-rich rocks, in particular opaline silica, are very promising targets for sampling and return to Earth given their high biosignature preservation potential.

¹Fang, Linru,¹Moynier, Frédéric,¹Chaussidon, Marc,¹Limare, Angela,¹Makhatadze, Georgy V.,²Villeneuve, Johan
Science Advances 11, eadp9381 Open Access Link to Article [DOI 10.1126/sciadv.adp9381]
¹Université Paris Cité, Institut de Physique du Globe de Paris, CNRS, Paris, 75005, France
²Université de Lorraine, CNRS, CRPG, UMR7358, Nancy, F-54000, France

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^1,5Stude, Joan,¹Aufmhoff, Heinfried,¹Schlager, Hans,^1,2Rapp, Markus,¹Baumann, Carsten,⁴Arnold, Frank,³Strelnikov, Boris
Atmospheric Chemistry and Physics 25, 383-396 Open Access Link to Article [DOI 10.5194/acp-25-383-2025]
¹German Aerospace Center (DLR), Institute of Atmospheric Physics, Oberpfaffenhofen, Germany
²Atmospheric Physics, Ludwig-Maximilians-Universität München (LMU), Munich, Germany
³Leibniz Institute of Atmospheric Physics (IAP), Kühlungsborn, Germany
⁴Max Planck Institute for Nuclear Physics (MPIK), Heidelberg, Germany
⁵Division of Space and Plasma Physics, Royal Institute of Technology (KTH), Stockholm, Sweden

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