Water-susceptible primordial noble gas components in less-altered CR chondrites: A possible link to cometary materials

Obase, Tomoya; Nakashima, D.; Choi, Joonsung; Enokido, Yuma; Matsumoto, Megumi; Nakamura, Tomoki

doi:10.1016/j.gca.2021.08.012

Cited by 9 publications

(9 citation statements)

References 97 publications

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“…Hence, admixing of chondritic material to the first 4 km represents a minimum estimate. We discuss in the Supplementary Materials that the CR chondrite provides the most likely endmember for the impacting material, consistent with both cosmochemical observations (30,31) and dynamical models (29). However, if we consider CO chondrites that have the least anomalous 54 Cr composition [ 54 Cr = 50 ppm (25)] as an alternative endmember, then 49% impactor material is expected in the final mixtures, which requires either a restricted mixing zone (2 km for the basin-forming impactors and a thin Mars crust for dichotomy-forming impact) or twice the amount of impactor mass than assumed here (fig.…”

Section: Determination Of the Mass Of Exotic Materials Delivered To M...supporting

confidence: 82%

“…The Renazzo-type carbonaceous (CR) chondrites are inferred to have formed in an outer solar system reservoir that is distinct from most carbonaceous chondrites, possibly initially located beyond the gas giants where cometary objects accreted ( 30 , 31 ). Thus, CR chondrites provide a proxy for the composition of the material accreted beyond Neptune and delivered to the terrestrial planet–forming region in the aftermath of the migration of the gas giants (see Supplementary Text).…”

Section: Resultsmentioning

confidence: 99%

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Late delivery of exotic chromium to the crust of Mars by water-rich carbonaceous asteroids

et al. 2022

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The terrestrial planets endured a phase of bombardment following their accretion, but the nature of this late accreted material is debated, preventing a full understanding of the origin of inner solar system volatiles. We report the discovery of nucleosynthetic chromium isotope variability (μ 54 Cr) in Martian meteorites that represent mantle-derived magmas intruded in the Martian crust. The μ 54 Cr variability, ranging from −33.1 ± 5.4 to +6.8 ± 1.5 parts per million, correlates with magma chemistry such that samples having assimilated crustal material define a positive μ 54 Cr endmember. This compositional endmember represents the primordial crust modified by impacting outer solar system bodies of carbonaceous composition. Late delivery of this volatile-rich material to Mars provided an exotic water inventory corresponding to a global water layer >300 meters deep, in addition to the primordial water reservoir from mantle outgassing. This carbonaceous material may also have delivered a source of biologically relevant molecules to early Mars.

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Section: Determination Of the Mass Of Exotic Materials Delivered To M...supporting

confidence: 82%

Section: Resultsmentioning

confidence: 99%

Late delivery of exotic chromium to the crust of Mars by water-rich carbonaceous asteroids

et al. 2022

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“…The Ar-rich gas is also found in some less-altered CR and CM chondrites ( 41 , 44 ). It has been suggested that the host phase of Ar-rich gas is susceptive to aqueous alteration, with amorphous silicate being one of its host phases ( 41 , 43 , 44 ). Our measurements of the Ryugu samples do not show the presence of Ar-rich gas, but they do indicate the presence of SW gas—likely acquired recently, during surface exposure on Ryugu.…”

Section: Ryugu’s Parent Bodymentioning

confidence: 91%

“…In addition to P1 and presolar noble gas components, Ningqiang (like many other nonhydrated meteorites) contains another noble gas component, referred to as Ar-rich gas (28), which is lost during hydrothermal experiments (42,43). The Ar-rich gas is also found in some less-altered CR and CM chondrites (41,44). It has been suggested that the host phase of Arrich gas is susceptive to aqueous alteration, with amorphous silicate being one of its host phases (41,43,44).…”

Section: Ryugu's Parent Bodymentioning

confidence: 99%

Noble gases and nitrogen in samples of asteroid Ryugu record its volatile sources and recent surface evolution

Okazaki

Marty

Busemann

et al. 2023

Science

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The near-Earth carbonaceous asteroid (162173) Ryugu is expected to contain volatile chemical species that could provide information on the origin of Earth’s volatiles. Samples of Ryugu were retrieved by the Hayabusa2 spacecraft. We measure noble gas and nitrogen isotopes in Ryugu samples, finding they are dominated by pre-solar and primordial components, incorporated during Solar System formation. Noble gas concentrations are higher than those in Ivuna-type carbonaceous (CI) chondrite meteorites. Several host phases of isotopically distinct nitrogen have heterogeneous abundances between the samples. Our measurements support a close relationship between Ryugu and CI chondrites. Noble gases produced by galactic cosmic rays, indicating ~5 Myr exposure, and from implanted solar wind, record the recent irradiation history of Ryugu after it migrated to its current orbit.

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“…Thus, the spatial resolution of >20 μm by conventional SIMS is too large to study the distribution of the solar wind in the particles. Furthermore, the detection limit of conventional SIMS is ∼10 19 cm −3 , 4 while the most abundant bulk 4 He concentration in meteorites is ∼10 −2 cm 3 STP g −1 , 7,8 corresponding to a 4 He concentration of ∼10 18 cm −3 . Therefore, conventional SIMS is insufficient for identifying solar wind He in meteorites.…”

Section: ■ Introductionmentioning

confidence: 99%

In Situ Helium Isotope Microimaging of Meteorites

Bajo,

Kawasaki,

Sakaguchi

et al. 2024

Anal. Chem.

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Isotope imaging is commonly used to investigate the localization of trace elements and their isotopes. In situ noble gas analysis of meteorites revealed the distribution of primordial noble gases that were trapped in the building blocks of asteroids and planets during the early stage of the solar system evolution. Solar wind noble gases are among the primordial gases present in meteorites and were trapped through exposure to solar wind. Micrometer-resolution in situ noble gas analysis has not been achieved due to the lack of sensitivity and spatial resolution. The microscale imaging technique is crucial for identifying the carrier phase of the solar wind noble gases. We have developed 4 He isotope imaging utilizing secondary neutral mass spectrometry with strong field postionization. This technique achieved a lateral resolution of 2 μm and a 4 He detection limit of 2 × 10 17 cm −3 . This development allows for the study of a solar wind gas-rich meteorite, Northwest Africa 801 carbonaceous chondrite, with micrometer resolution. The solar wind 4 He carriers are fine-grained particles and are sparsely scattered in the matrix region.

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Water-susceptible primordial noble gas components in less-altered CR chondrites: A possible link to cometary materials

Cited by 9 publications

References 97 publications

Late delivery of exotic chromium to the crust of Mars by water-rich carbonaceous asteroids

Late delivery of exotic chromium to the crust of Mars by water-rich carbonaceous asteroids

Noble gases and nitrogen in samples of asteroid Ryugu record its volatile sources and recent surface evolution

In Situ Helium Isotope Microimaging of Meteorites

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