^1,2Christy Caudill,^1,2Gordon R. Osinski,³Rebecca N. Greenberger,^1,2Livio L. Tornabene,^1,2Fred J. Longstaffe,^1,2Roberta L. Flemming,^3,4Bethany L. Ehlmann
Meteoritics & Planetary Science (in Press) Link to Article [https://doi.org/10.1111/maps.13600]
¹Department of Earth Sciences, The University of Western Ontario, 1151 Richmond St, London, Ontario, N6A 5B7 Canada
²Institute for Earth and Space Exploration, The University of Western Ontario, 1151 Richmond St, London, Ontario, N6A 5B7 Canada
³Division of Geological & Planetary Sciences, California Institute of Technology, Pasadena, California, 91125 USA
⁴Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, 91109 USA
Published by arrangement with John Wiley & Sons

The impact melt‐bearing breccias at the Ries impact structure, Germany, host degassing pipes: vertical structures that are inferred to represent conduits along which gases and fluids escaped to the surface, consistent with hydrothermal activity that occurs soon after an impact event. Although the presence of degassing pipes has been recognized within the well‐preserved and long‐studied ejecta deposits at the Ries, a detailed mineralogical study of their alteration mineralogy, as an avenue to elucidate their origins, has not been conducted to date. Through the application of high‐resolution in situ reflectance imaging spectroscopy and X‐ray diffraction, this study shows for the first time that the degassing pipe interiors and associated alteration are comprised of hydrated and hydroxylated silicates (i.e., Fe/Mg smectitic clay minerals with chloritic or other hydroxy‐interlayered material) as secondary hydrothermal mineral phases. This study spatially extends the known effects of impact hydrothermal activity into the ejecta deposits, beyond the crater rim. It has been suggested that the degassing pipes at the Ries are analogous to crater‐related pit clusters observed in impact melt‐bearing deposits on Mars, Ceres, and Vesta. The results of this work may inform on the presence of crustal volatiles and their interaction during the impact process on rocky bodies throughout the solar system. The Mars 2020 Perseverance rover may have the opportunity to investigate impact‐related features in situ; if so, this work suggests that such investigations may provide key information on the origin and formation of clay minerals on Mars as well as hold exciting implications for future Mars exploration.

¹S.Anderson et al. (>10)
Meteoritics & Planetary Science (in Press) Link to Article [https://doi.org/10.1111/maps.13615]
¹School of Earth & Planetary Sciences, Curtin University, GPO Box U1987, Perth, Western Australia, 6845 Australia
Published by arrangement with John Wiley & Sons

Murrili, the third meteorite recovered by the Desert Fireball Network, is analyzed using mineralogy, oxygen isotopes, bulk chemistry, physical properties, noble gases, and cosmogenic radionuclides. The modal mineralogy, bulk chemistry, magnetic susceptibility, physical properties, and oxygen isotopes of Murrili point to it being an H5 ordinary chondrite. It is heterogeneously shocked (S2–S5), depending on the method used to determine it, although Murrili is not obviously brecciated in texture. Cosmogenic radionuclides yield a cosmic ray exposure age of 6–8 Ma, and a pre‐atmospheric meteoroid size of 15–20 cm in radius. Murrili’s fall and subsequent month‐long embedment into the salt lake Kati Thanda significantly altered the whole rock, evident in its Mössbauer spectra, and visual inspection of cut sections. Murrili may have experienced minor, but subsequent, impacts after its formation 4475.3 ± 2.3 Ma, which left it heterogeneously shocked.