Likely Ferromagnetic Minerals Identified by the Perseverance Rover and Implications for Future Paleomagnetic Analyses of Returned Martian Samples
Name
JGR Planets - 2024 - Mansbach - Likely Ferromagnetic Minerals Identified by the Perseverance Rover and Implications for.pdf
Description
Published version
Size
4.47 MB
Format
Adobe PDF
Checksum (MD5)
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Author(s)
Mansbach, Elias N
Kizovski, Tanya V
Scheller, Eva L
Bosak, Tanja
Mandon, Lucia
Horgan, Briony
Wiens, Roger C
Herd, Christopher DK
Sharma, Sunanda
Johnson, Jeffrey R
Date Issued
September 22, 2024
Journal
Journal of Geophysical Research: Planets
Publisher
American Geophysical Union
Citation
Mansbach, E. N., Kizovski, T. V., Scheller, E. L., Bosak, T., Mandon, L., Horgan, B., et al. (2024). Likely ferromagnetic minerals identified by the Perseverance rover and implications for future paleomagnetic analyses of returned Martian samples. Journal of Geophysical Research: Planets, 129, e2024JE008505.
Version
Final published version
Abstract
Although Mars today does not have a core dynamo, magnetizations in the Martian crust and in 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 forms 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.
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Creative Commons Attribution-NonCommercial
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DOI of Published Version
https://doi.org/10.1029/2024JE008505
