气候变化领域集成服务门户(CCPortal): Tracing martian surface interactions with the triple O isotope compositions of meteoritic phosphates

CCPortal

DOI	10.1016/j.epsl.2019.115977
	Tracing martian surface interactions with the triple O isotope compositions of meteoritic phosphates
	Bellucci J.J.; Whitehouse M.J.; Nemchin A.A.; Snape J.F.; Kenny G.G.; Merle R.E.; Bland P.A.; Benedix G.K.
发表日期	2020
ISSN	0012821X
卷号	531
英文摘要	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. © 2019 Elsevier B.V.
关键词	Cl isotopes Mars martian atmosphere martian surface phosphates triple oxygen
英文关键词	Inorganic compounds; Isotopes; Meteorites; Phosphates; Reservoirs (water); Secondary ion mass spectrometry; Structural geology; Substitution reactions; Surface reactions; Analytical uncertainty; Isotope compositions; Mars; Martian atmospheres; Martian meteorites; Martian surface; Replacement reactions; Triple oxygen isotope composition; Chlorine
语种	英语
来源期刊	Earth and Planetary Science Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/202484
作者单位	Department of Geosciences, Swedish Museum of Natural History, Stockholm, SE-104 05, Sweden; School of Earth and Planetary Science, Curtin University, Perth, WA 6845, Australia; Faculty of Earth and Life Sciences, VU Amsterdam, De Boelelaan 1085, Amsterdam, 1081 HV, Netherlands
推荐引用方式 GB/T 7714	Bellucci J.J.,Whitehouse M.J.,Nemchin A.A.,et al. Tracing martian surface interactions with the triple O isotope compositions of meteoritic phosphates[J],2020,531.
APA	Bellucci J.J..,Whitehouse M.J..,Nemchin A.A..,Snape J.F..,Kenny G.G..,...&Benedix G.K..(2020).Tracing martian surface interactions with the triple O isotope compositions of meteoritic phosphates.Earth and Planetary Science Letters,531.
MLA	Bellucci J.J.,et al."Tracing martian surface interactions with the triple O isotope compositions of meteoritic phosphates".Earth and Planetary Science Letters 531(2020).