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Liquid water on Mars less than 227 million years ago

By 14th June 2019 June 21st, 2019 No Comments

Researchers from the Laboratoire Magmas et Volcans (LMV / UCA / CNRS / IRD / UJM, Clermont-Ferrand) and the Centre de Recherches Pétrographiques et Géochimiques (CRPG / UL / CNRS) have identified traces of late aqueous weathering in the Black Beauty Mars meteorite (NWA 7533/7034).  This weathering, recorded in the mineral zircon (ZrSiO4), is believed to have occurred on Mars between 227 and 56 million years ago during the Amazonian era. “This finding largely expands the time duration over which liquid water was available near the Martian surface, thereby suggesting that Mars might still be habitable,” say the researchers.

zircon-1

Electron backscattered SEM image of a terrestrial zircon that has undergone weathering similar to that of Martian zircons in Black Beauty (from M. Guitreau’s personal collection). Weathered areas appear as dark grey veins or spots while unaltered areas are light grey in colour. A primary concentric (magmatic) zonation can be seen in some clear areas, and is marked by growth bands with radially arranged fractures. This fracturing occurs by swelling of the crystal lattice in adjacent areas due to the disintegration of radioactive uranium and thorium. These fractures thus provide efficient pathways for fluids to penetrate the zircon. Photo credit: Martin Guitreau

The discovery, published in Nature Communications is important for our understanding of the evolution of the Martian surface because it shows that liquid water was available near the surface in the relatively recent past and that this could still be the case today. The results suggest that Mars could have been habitable for most of its history since water is the first ingredient necessary for life to emerge.

Read the research paper: Record of low-temperature aqueous alteration of Martian zircon during the late Amazonian. M. Guitreau, J. Flahaut. Nature Communications 10.1038/s41467-019-10382-y