An acid‐etch study of the Kapoeta achondrite: Implications for the argon‐36/argon‐38 ratio in the solar wind

Becker, R. H.; Schlutter, D. J.; Rider, Paul E.; Pepin, R. O.

doi:10.1111/j.1945-5100.1998.tb01612.x

Cited by 29 publications

(7 citation statements)

References 12 publications

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“…It is consistent with the average SWC foil ratio of 5.4 ± 0.3 (Geiss et al, 2004) and also within the stated uncertainties (1r) of the values for coronal hole-and inter-stream-related SW (5.5 ± 0.6 and 5.6 ± 0.7) observed with SOHO/CELIAS/MTOF by Weygand et al (2001). However, it is lower than the bulk value reported by Mabry et al (2007b) of 5.501 ± 0.005 (1r) in the Genesis AloS target or values of 5.58 ± 0.03 (Becker et al, 1998) and 5.48 ± 0.05 (1r) (Benkert et al, 1993) derived from solar gas-rich meteorites and relatively recently irradiated lunar soils, respectively. Approximate implantation depth of 20 Ne according to SRIM (nm) SRIM Fig.…”

Section: Argoncontrasting

confidence: 69%

Solar wind helium, neon, and argon isotopic and elemental composition: Data from the metallic glass flown on NASA’s Genesis mission

Grimberg

Baur

Bühler

et al. 2008

Geochimica et Cosmochimica Acta

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Section: Argoncontrasting

confidence: 69%

Solar wind helium, neon, and argon isotopic and elemental composition: Data from the metallic glass flown on NASA’s Genesis mission

Grimberg

Baur

Bühler

et al. 2008

Geochimica et Cosmochimica Acta

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“…Benkert et al, 1993), at least in samples like 71501 which collected their solar wind relatively recently. A 36 Ar/ 38 Ar value of 5.58 ± 0.02 previously obtained from the gas-rich meteorite Kapoeta by a similar in-vacuo etch technique (Becker et al, 1998) as used for lunar samples is higher than the Genesis DOS and lunar values. We consider it unlikely that this small difference indicates a longterm variability of the Ar isotopic composition in the solar wind.…”

Section: Comparison With Previous Solar Wind Data -Isotope Compositionmentioning

confidence: 97%

Noble gas composition of the solar wind as collected by the Genesis mission

Heber

Wieler

Baur

et al. 2009

Geochimica et Cosmochimica Acta

177

304

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“…7), Ott et al (1985a,b) suggested that these ureilitic noble gases must be closely related to the primordial Q noble gases, although they reside in achondritic, heavily differentiated and partly shocked meteorites (Goodrich, 1992). Component Xe-Q has been also found in other achondrite classes such as lodranites, acapulcoites, brachinites, and even the solar gas-rich howardite Kapoeta (e.g., Eugster and Weigel, 1993;McCoy et al, 1996;Swindle et al, 1998;Becker et al, 1998). Few data are available for Kr-Q and related components.…”

Section: Q-gases In Chondrites and Ureilitesmentioning

confidence: 99%

Primordial noble gases in “phase Q” in carbonaceous and ordinary chondrites studied by closed‐system stepped etching

Busemann

Baur

Wieler

2000

Meteorit & Planetary Scien

285

507

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Abstract-The HF/HCl-resistant residues of the chondrites CM2 Cold Bokkeveld, CV3 (ox.) Grosnaja, C03.4 Lance, C03.7 Isna, LL3.4 Chainpur, and H3.7 Dimmitt have been measured by closed-system stepped etching (CSSE) in order to better characterise the noble gases in "phase Q", a major carrier of primordial noble gases. All isotopic ratios in phase Q of the different meteorites are quite uniform, except for (20NeP2Ne)Q. As already suggested by precise earlier measurements (Schelhaas et ul., 1990;Wieler et al., 1991Wieler et al., , 1992, (20NePzNe)Q is the least uniform isotopic ratio of the Q noble gases. The data cluster -10.1 for Cold Bokkeveld and Lance and 10.7 for Chainpur, Grosnaja, and Dimmitt, respectively. No correlation of (20NeP2Ne)q with the classification or the alteration history of the meteorites has been found. The Ar, Kr, and Xe isotopic ratios for all six samples are identical within their uncertainties and similar to earlier Q determinations as well as to Ar-Xe in ureilites. Thus, an unknown process probably accounts for the alteration of the originally incorporated Ne-Q. The noble gas elemental compositions provide evidence that Q consists of at least two carbonaceous carrier phases "Ql" and "42" with slightly distinct chemical properties. Ratios (Ar/Xe)Q and (Kr/Xe)Q reflect both thermal metamorphism and aqueous alteration. These parent-body processes have led to larger depletions of Ar and Kr relative to Xe. In contrast, meteorites that suffered severe aqueous alteration, such as the CM chondrites, do not show depletions of He and Ne relative to Ar but rather the highest (He/Ar)Q and (Ne/Ar)Q ratios. This suggests that Q1 is less susceptible to aqueous alteration than 4 2 . Both subphases may well have incorporated noble gases from the same reservoir, as indicated by the nearly constant, though very large, depletion of the lighter noble gases relative to solar abundances. However, the elemental ratios show that Q1 and 4 2 must have acquired (or lost) noble gases in slightly different element proportions. Cold Bokkeveld suggests that Q1 may be related to presolar graphite. Phases Q1 and 4 2 might be related to the subphases that have been suggested by Gros and Anders (1977). The distribution of the 20NeP2Ne ratios cannot be attributed to the carriers Q1 and Q2. The residues of Chainpur and Cold Bokkeveld contain significant amounts of Ne-E(L), and the data confirm the suggestion of Huss (1997) that the 22Ne-E(L) content, and thus the presolar graphite abundances, are correlated with the metamorphic history of the meteorites.

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An acid‐etch study of the Kapoeta achondrite: Implications for the argon‐36/argon‐38 ratio in the solar wind

Cited by 29 publications

References 12 publications

Solar wind helium, neon, and argon isotopic and elemental composition: Data from the metallic glass flown on NASA’s Genesis mission

Solar wind helium, neon, and argon isotopic and elemental composition: Data from the metallic glass flown on NASA’s Genesis mission

Noble gas composition of the solar wind as collected by the Genesis mission

Primordial noble gases in “phase Q” in carbonaceous and ordinary chondrites studied by closed‐system stepped etching

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