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A Field Guide to Finding Fossils on Mars

McMahon, S. and Bosak, T. and Grotzinger, J. P. and Milliken, R. E. and Summons, R. E. and Daye, M. and Newman, S. A. and Fraeman, A. and Williford, K. H. and Briggs, D. E. G. (2018) A Field Guide to Finding Fossils on Mars. Journal of Geophysical Research. Planets, 123 (5). pp. 1012-1040. ISSN 2169-9097. doi:10.1029/2017JE005478.

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The Martian surface is cold, dry, exposed to biologically harmful radiation and apparently barren today. Nevertheless, there is clear geological evidence for warmer, wetter intervals in the past that could have supported life at or near the surface. This evidence has motivated National Aeronautics and Space Administration and European Space Agency to prioritize the search for any remains or traces of organisms from early Mars in forthcoming missions. Informed by (1) stratigraphic, mineralogical and geochemical data collected by previous and current missions, (2) Earth's fossil record, and (3) experimental studies of organic decay and preservation, we here consider whether, how, and where fossils and isotopic biosignatures could have been preserved in the depositional environments and mineralizing media thought to have been present in habitable settings on early Mars. We conclude that Noachian‐Hesperian Fe‐bearing clay‐rich fluvio‐lacustrine siliciclastic deposits, especially where enriched in silica, currently represent the most promising and best understood astropaleontological targets. Siliceous sinters would also be an excellent target, but their presence on Mars awaits confirmation. More work is needed to improve our understanding of fossil preservation in the context of other environments specific to Mars, particularly within evaporative salts and pore/fracture‐filling subsurface minerals.

Item Type:Article
Related URLs:
URLURL TypeDescription
McMahon, S.0000-0001-8589-2041
Grotzinger, J. P.0000-0001-9324-1257
Milliken, R. E.0000-0003-3240-4918
Summons, R. E.0000-0002-7144-8537
Fraeman, A.0000-0003-4017-5158
Williford, K. H.0000-0003-0633-408X
Additional Information:© 2018 The Authors. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made. Received 7 NOV 2017; Accepted 23 APR 2018; Accepted article online 2 MAY 2018; Published online 24 MAY 2018. The data drawn upon for this study are available in the figures and cited references. We are grateful for helpful comments from C. P. McKay, A. H. Knoll, and two anonymous reviewers. Financial support was provided by the NASA Astrobiology Institute NNA13AA90A, Foundations of Complex Life, Evolution, Preservation, and Detection on Earth and Beyond. The Simons Collaboration on Origins of Life provided funding to T. B., J. P. G., and R. E. S. S. M. acknowledges support from the European Union's Horizon 2020 Research and Innovation Programme under Marie Skłodowska‐Curie grant agreement 747877. K. H. W. and A. F. acknowledge support of a grant from the National Aeronautics and Space Administration for work performed at the Jet Propulsion Laboratory, California Institute of Technology.
Funding AgencyGrant Number
Simons Collaboration on Origins of LifeUNSPECIFIED
Marie Curie Fellowship747877
Subject Keywords:Mars; astrobiology; fossils
Issue or Number:5
Record Number:CaltechAUTHORS:20180504-070038553
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Official Citation:McMahon, S., Bosak, T., Grotzinger, J. P., Milliken, R. E., Summons, R. E., Daye, M., et al. (2018). A field guide to finding fossils on Mars. Journal of Geophysical Research: Planets, 123, 1012–1040.
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:86220
Deposited By: Tony Diaz
Deposited On:04 May 2018 15:02
Last Modified:15 Nov 2021 20:36

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