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Likely Ferromagnetic Minerals Identified by the Perseverance Rover and Implications for Future Paleomagnetic Analyses of Returned Martian Samples
  • +13
  • Elias N. Mansbach,
  • Elias N Mansbach,
  • Tanya V Kizovski,
  • Eva L Scheller,
  • Tanja Bosak,
  • Lucia Mandon,
  • Briony Horgan,
  • Roger C Wiens,
  • Christopher D K Herd,
  • Sunanda Sharma,
  • Jeffrey R Johnson,
  • Travis S J Gabriel,
  • Olivier Forni,
  • Yang Liu,
  • Mariek E Schmidt,
  • Benjamin P Weiss
Elias N. Mansbach

Corresponding Author:[email protected]

Author Profile
Elias N Mansbach
Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology
Tanya V Kizovski
Department of Earth Science, Brock University
Eva L Scheller
Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology
Tanja Bosak
Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology
Lucia Mandon
Division of Geological and Planetary Science, California Institute of Technology
Briony Horgan
Department of Earth, Atmospheric, and Planetary Sciences, Purdue University
Roger C Wiens
Department of Earth, Atmospheric, and Planetary Sciences, Purdue University
Christopher D K Herd
Department of Earth and Atmospheric Sciences, University of Alberta
Sunanda Sharma
Jet Propulsion Laboratory, California Institute of Technology
Jeffrey R Johnson
Johns Hopkins University Applied Physics Laboratory
Travis S J Gabriel
U.S. Geological Survey, Astrogeology Science Center
Olivier Forni
Institut de Recherche en Astrophysique et Planétologie
Yang Liu
Jet Propulsion Laboratory, California Institute of Technology
Mariek E Schmidt
Department of Earth Science, Brock University
Benjamin P Weiss
Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology

Abstract

Although Mars today does not have a core dynamo, magnetizations in the Martian crust and meteorites suggest a magnetic field was present prior to 3.7 billion years (Ga) ago. However, the lack of ancient, oriented Martian bedrock samples available on Earth has prevented accurate estimates of the dynamo’s intensity, lifetime, and direction. Constraining the nature and lifetime of the dynamo are vital to understanding the evolution of the Martian interior and the potential habitability of the planet. The Perseverance rover, which is exploring Jezero crater, is providing an unprecedented opportunity to address this gap by acquiring absolutely oriented bedrock samples with estimated ages from ~2.3 to > 4.1 Ga. As a first step in establishing whether these samples could contain records of Martian paleomagnetism, it is important to determine their ferromagnetic mineralogy, the grain sizes of the phases, and the form of any natural remanent magnetization. Here, we synthesize data from various Perseverance instruments to achieve those goals and discuss the implications for future laboratory paleomagnetic analyses. Using the rover’s instrument payload, we find that cored samples likely contain iron oxides enriched in Cr and Ti. The relative proportions of Fe, Ti, and Cr indicate that the phases may be titanomagnetite or Fe-Ti-Cr spinels that are ferromagnetic at room temperature, but we cannot rule out the presence of non-ferromagnetic ulvöspinel, ilmenite, and chromite due to signal mixing. Importantly, the inferred abundance of iron oxides in the samples suggests that even <1 mm-sized samples will be easily measurable by present-day magnetometers. 
16 May 2024Submitted to ESS Open Archive
21 May 2024Published in ESS Open Archive