Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Tracing martian surface interactions with the triple O isotope compositions of meteoritic phosphates
Swedish Museum of Natural History, Department of Geology. (Nordsim)ORCID iD: 0000-0003-2227-577X
Show others and affiliations
2020 (English)In: Earth and Planetary Science Letters, ISSN 0012-821X, E-ISSN 1385-013X, Vol. 531, article id 115977Article in journal (Refereed) Published
Abstract [en]

The triple oxygen isotope compositions of phosphate grains in six martian meteorites have been measured by Secondary Ion Mass Spectrometry (SIMS) and combined together with their chlorine isotope and halogen concentrations have been used to constrain hydrosphere-lithosphere interactions on Mars. These samples include three enriched shergottites (Zagami, Roberts Massif 04262 and Larkman Nunatak 12011), one depleted shergottite (Tissint), an orthopyroxenite (Allan Hills 84001), and a regolith breccia (Northwest Africa 7533). The phosphates measured here have a range in δ18O [(18O/16O)sample/(18O/16O)Standard-1] × 103] from +1.0 to +6.8‰ and could be a result of indigenous mantle values, mixing with martian water, or replacement reactions taking place on the surface of Mars. Three samples have a Δ17O [δ17O-1000(1 + δ18O /1000)0.528-1] in equilibrium with the martian mantle (ALH 84001, Tissint, and Zagami), while three samples (LAR 12011, RBT 04262, and NWA 7533) have an elevated positive Δ17O outside of analytical uncertainty of the martian fractionation line (MFL). The phosphates in the latter group also have positive and negative δ37Cl [(37Cl/35Cl)sample/(37Cl/35Cl)standard – 1] × 103] and enrichments in halogens not seen in the rest of the sample suite. Perchlorate formation on Earth fractionates Cl in both positive and negative directions and generates a correlated positive Δ17O. Further, perchlorate has been detected in wt% amounts on the martian surface. Thus, these results strongly suggest the presence of multiple Cl isotope reservoirs on the martian surface that have interacted with the samples studied here over the last ca. 2 Ga of geologic time. The weighted average of Δ17O measurements from phosphate grains (n = 13) in NWA 7533, which are the explicit result of exchange reactions on the martian surface, yields a statistically robust mean value of 1.39 ± 0.19‰ (2σ, MSWD = 1.5, p = 0.13). This value likely represents an accurate estimate for an oxidized surface reservoir on Mars.

Place, publisher, year, edition, pages
2020. Vol. 531, article id 115977
Keywords [en]
Mars, martian atmosphere, phosphates, triple oxygen, martian surface, Cl isotopes
National Category
Geochemistry
Research subject
The changing Earth
Identifiers
URN: urn:nbn:se:nrm:diva-3929DOI: 10.1016/j.epsl.2019.115977OAI: oai:DiVA.org:nrm-3929DiVA, id: diva2:1507064
Available from: 2020-12-06 Created: 2020-12-06 Last updated: 2021-12-13Bibliographically approved

Open Access in DiVA

No full text in DiVA

Other links

Publisher's full texthttp://www.sciencedirect.com/science/article/pii/S0012821X19306697

Search in DiVA

By author/editor
Whitehouse, Martin J.Kenny, G. G.Merle, Renaud E.
By organisation
Department of Geology
In the same journal
Earth and Planetary Science Letters
Geochemistry

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 271 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf