^1,2Rebecca N. Greenberger, ¹John F. Mustard, ^3,4,5Gordon R. Osinski, ^3,4,6Livio L. Tornabene, ^3,4,7Alexandra J. Pontefract, ^3,4Cassandra L. Marion, ^3,4Roberta L. Flemming, ⁸Janette H. Wilson, ⁹Edward A. Cloutis
Meteoritics & Planetary Science (in Press) Link to Article [DOI: 10.1111/maps.12716]
¹Department of Earth, Environmental, and Planetary Sciences, Brown University, Providence, Rhode Island, USA
²Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
³Centre for Planetary Science and Exploration, University of Western Ontario, London, Ontario, Canada
⁴Department of Earth Sciences, University of Western Ontario, London, Ontario, Canada
⁵Department of Physics and Astronomy, University of Western Ontario, London, Ontario, Canada
⁶SETI Institute, Mountain View, California, USA
⁷Planetary Science Institute, Tucson, Arizona, USA
⁸Headwall Photonics, Inc., Fitchburg, Massachusetts, USA
⁹Department of Geography, University of Winnipeg, Winnipeg, Manitoba, Canada
Published by arrangement with John Wiley & Sons

Meteorite impacts on Earth and Mars can generate hydrothermal systems that alter the primary mineralogies of rocks and provide suitable environments for microbial colonization. We investigate a calcite–marcasite-bearing vug at the ~23 km diameter Haughton impact structure, Devon Island, Nunavut, Canada, using imaging spectroscopy of the outcrop in the field (0.65–1.1 μm) and samples in the laboratory (0.4–2.5 μm), point spectroscopy (0.35–2.5 μm), major element chemistry, and X-ray diffraction analyses. The mineral assemblages mapped at the outcrop include marcasite; marcasite with minor gypsum and jarosite; fibroferrite and copiapite with minor gypsum and melanterite; gypsum, Fe3+ oxides, and jarosite; and calcite, gypsum, clay, microcline, and quartz. Hyperspectral mapping of alteration phases shows spatial patterns that illuminate changes in alteration conditions and formation of specific mineral phases. Marcasite formed from the postimpact hydrothermal system under reducing conditions, while subsequent weathering oxidized the marcasite at low temperatures and water/rock ratios. The acidic fluids resulting from the oxidation collected on flat-lying portions of the outcrop, precipitating fibroferrite + copiapite. That assemblage then likely dissolved, and the changing chemistry and pH resulting from interaction with the calcite-rich host rock formed gypsum-bearing red coatings. These results have implications for understanding water–rock interactions and habitabilities at this site and on Mars.