Insights into Martian water reservoirs from analyses of Martian meteorite QUE94201
- Creators
- Leshin, Laurie A.
Abstract
The martian atmospheric D/H value of 5.2 times terrestrial is significantly higher than any found on Earth, and has been ascribed to preferential loss of H relative to D from the atmosphere through Jeans escape over time. Here, based on ion microprobe analyses of apatite grains from martian meteorite QUE94201, it is shown that the pre-Jeans escape martian water reservoir has a D/H value ∼twice that of terrestrial water, rather than the "terrestrial" value that has been assumed in prior work. The data support a two-stage history for martian volatiles in which early hydrodynamic escape enriched martian water to ∼2x terrestrial D/H values. Subsequent Jeans escape to produce the current atmospheric values has thus been responsible for less D-enrichment than previously thought. A martian crust containing 2–3 times more water than previously proposed is implied by the results.
Additional Information
I thank R. Harvey, T. McCoy, K. McKeegan, H. McSween, D. Paige, A. Pathare, J. Tyburczy, and M. Wahdwa for helpful discussions and assistance. S. Nadeau provided the apatite standard. I thank the Antarctic Meteorite Curation Facility at JSC for loan of sections and G. Crozaz and H. McSween for use of section QUE,5. Helpful reviews from Bruce Jakosky and an anonymous reviewer are appreciated. The ion microprobe facility at UCLA is supported by NSF. This work was supported by NASA.Attached Files
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Additional details
- Eprint ID
- 119792
- Resolver ID
- CaltechAUTHORS:20230307-650641000.77
- NSF
- NASA
- Created
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2023-03-08Created from EPrint's datestamp field
- Updated
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2023-03-08Created from EPrint's last_modified field