An international study has revealed a new piece of Mars’ geological puzzle. The research, led by Brock University (St. Catharines, ON, Canada), in collaboration with the Royal Ontario Museum (Toronto, ON, Canada) and with the contribution of the University of Trieste, has identified for the first time the presence of garnet in a Martian meteorite, opening up new perspectives on the complexity of the processes that shaped the Red Planet.

The study, published in the international peer-reviewed journal Geochemical Perspectives Letters of the European Association of Geochemistry, involved Ana Černok, a researcher at the University of Trieste.

Garnet is a very common mineral on Earth, often associated with metamorphic rocks and with processes occurring under conditions of high temperature, high pressure or in the presence of hot fluids. Until now, however, it had never been recognised in samples from Mars or directly on the Martian surface. Its identification therefore expands the known mineralogical diversity of the planet and suggests the possibility that Mars may have undergone more complex geological processes than previously documented.

The sample analysed is a fragment of the Martian meteorite NWA 8171, preserved in the collections of the Royal Ontario Museum. During the mineralogical and chemical analyses, the research team identified an unexpected composition, initially attributed to a more common mineral such as pyroxene. Further investigations, carried out using specialised instruments, made it possible to recognise the presence of garnet.

The discovery could point to the existence of a previously unknown type of Martian rock, formed through metamorphic or metasomatic processes, or through new forms of magmatic differentiation. The authors of the study, however, remain cautious: further investigations will be required, particularly into the isotopic signatures of the sample, to establish whether the garnet actually formed on Mars or whether it has an “extra-Martian” origin, linked to a celestial body that was later incorporated into the planet’s surface.

Ana Černok’s contribution focused on the mineralogical and geochemical interpretation of the sample, drawing on her expertise in the study of meteorites and planetary materials. The scientific collaboration originated within the doctoral research of the first author, Tanya Kizovski, then based at the Royal Ontario Museum in Toronto and now a faculty member at Brock University. Černok contributed to this work as a member of the supervisory team and as a scientific mentor.

“If chemical elements are the letters of the alphabet, then minerals are the words through which planets tell their story,” explains Ana Černok. “Discovering a new mineral on another world is like finding a lost word from an ancient language. Garnet tells us that Mars experienced more complex geological processes than we previously thought, adding a new piece to the story of its evolution.”

The work is the result of an international collaboration involving institutions from Canada, the United Kingdom and Italy, including Brock University, the Royal Ontario Museum, the University of Toronto, the University of Portsmouth, The Open University and the University of Trieste.

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The study Expanding Mars’ lithologic diversity: discovery of a garnet-bearing clast in NWA 8171 was published in Geochemical Perspectives Letters.

Publication link: https://doi.org/10.7185/geochemlet.2619