Origin of radiogenic 129Xe variations in carbonaceous chondrites
Affiliations | Corresponding Author | Cite as | Funding information- Share this article
-
Article views:525Cumulative count of HTML views and PDF downloads.
- Download Citation
- Rights & Permissions
top
Abstract
Figures
Figure 1 Neon three isotope plot for bulk samples of Tarda, Tagish Lake and Orgueil. The compositions of Ne-Q, Air, Ne-HL, Ne-E and cosmogenic (purple range) are also shown for comparison (see Ott, 2014 and Krietsch et al., 2021 and refs. therein). The two dashed lines represent mixing arrays between Ne-Q and cosmogenic neon and Ne-HL and cosmogenic neon. Error bars (1σ) are smaller than the symbols. | Figure 2 Isotopic composition of total xenon extracted from bulk Tarda, Tagish Lake and Orgueil samples. Isotopic ratios are normalised to Q-Xe (Busemann et al., 2000) and expressed with the delta notation (δiXeQ = ((iXe/130Xe)sample/(iXe/130Xe)Q − 1) × 1000). Errors are at 1σ. | Figure 3 Average 129Xe* excesses relative to SW-Xe (expressed in δ notation with δ129XeSW = (129Xe/132Xe)bulk/(129Xe/132Xe)SW − 1 × 1000) for the different types of chondrites and the comet 67P/C-G (data from Mazor et al., 1970; Marty et al., 2017 and this study). The average δ129XeSW is plotted as a function of (a) the 127I content (data from Clay et al., 2017), (b) the carbon content (data from Vacher et al., 2020 and Marrocchi et al., 2021), and (c) the matrix abundance (data from Alexander et al., 2018). TTL = Tarda and Tagish Lake. |
Figure 1 | Figure 2 | Figure 3 |
top
Introduction
Noble gases trapped in primitive meteorites (chondrites) allow quantification of the physical processes that operated during the evolution of the protoplanetary disk (e.g., Kuga et al., 2015
Kuga, M., Marty, B., Marrocchi, Y., Tissandier, L. (2015) Synthesis of refractory organic matter in the ionized gas phase of the solar nebula. Proceedings of the National Academy of Sciences 112, 7129–7134. https://doi.org/10.1073/pnas.1502796112
). Although these elements are present in different carriers contained in meteorites (including presolar SiC, diamonds, graphite; Ott, 2014Ott, U. (2014) Planetary and pre-solar noble gases in meteorites. Chemie der Erde - Geochemistry 74, 519–544. https://doi.org/10.1016/j.chemer.2014.01.003
), they are mainly hosted in a phase − referred to as phase Q − whose nature is still poorly characterised (Busemann et al., 2000Busemann, H., Baur, H., Wieler, R. (2000) Primordial noble gases in “phase Q” in carbonaceous and ordinary chondrites studied by closed-system stepped etching. Meteoritics & Planetary Science 35, 949–973. https://doi.org/10.1111/j.1945-5100.2000.tb01485.x
). Notwithstanding this uncertainty, it has been shown that phase Q dominates the heavy noble gas budget of chondrites and is closely associated with carbonaceous material that survives HF/HCl attack of bulk meteorites (Lewis et al., 1975Lewis, R.S., Srinivasan, B., Anders, E. (1975) Host Phase of a Strange Xenon Component in Allende. Science 190, 1251–1262.
). Thanks to its extreme sensitivity to oxidation, the xenon isotopic composition of phase Q has been precisely determined, revealing a mass dependent isotopic fractionation relative to solar wind (SW-Xe) in favour of the heavy isotopes relative to the light ones (Wieler et al., 1991Wieler, R., Anders, E., Baur, H., Lewis, R.S., Signer, P. (1991) Noble gases in “phase Q”: Closed-system etching of an Allende residue. Geochimica et Cosmochimica Acta 55, 1709–1722. https://doi.org/10.1016/0016-7037(91)90141-Q
; Busemann et al., 2000Busemann, H., Baur, H., Wieler, R. (2000) Primordial noble gases in “phase Q” in carbonaceous and ordinary chondrites studied by closed-system stepped etching. Meteoritics & Planetary Science 35, 949–973. https://doi.org/10.1111/j.1945-5100.2000.tb01485.x
; Gilmour, 2010Gilmour, J.D. (2010) “Planetary” noble gas components and the nucleosynthetic history of solar system material. Geochimica et Cosmochimica Acta 74, 380–393. https://doi.org/10.1016/j.gca.2009.09.015
). However, the commonly used Xe-Q isotopic composition hinges on the average of measurements of several carbonaceous chondrites (CCs) showing distinct Xe isotopic compositions between and within each group, especially for 129Xe (Busemann et al., 2000Busemann, H., Baur, H., Wieler, R. (2000) Primordial noble gases in “phase Q” in carbonaceous and ordinary chondrites studied by closed-system stepped etching. Meteoritics & Planetary Science 35, 949–973. https://doi.org/10.1111/j.1945-5100.2000.tb01485.x
). Such 129Xe excesses result from the decay of extinct 129I (t1/2 = 16 Myr), which was producing radiogenic 129Xe* during the first ∼100 million years of the solar system (Jeffery and Reynolds, 1961Jeffery, P.M., Reynolds, J.H. (1961) Origin of excess Xe129 in stone meteorites. Journal of Geophysical Research 66, 3582–3583. https://doi.org/10.1029/JZ066i010p03582
). The measurement of xenon isotopes in the coma of comet 67P/Churyumov-Gerasimenko revealed extreme 129Xe enrichment relative to 132Xe and the solar composition (Marty et al., 2017Marty, B. Altwegg, K., Balsiger, H., Bar-Nun, A., Bekaert, D.V., Berthelier, J.J., Bieler, A., Briois, C., Calmonte, U., Combi, M., De Keyser, J., Fiethe, B., Fuselier, S.A., Gasc, S., Gombosi, T.I., Hansen, K.C., Hässig, M., Jackel, A., Kopp, E., Korth, A., Le Roy, L., Mall, U., Mousis, O., Owen, T., Reme, H., Rubin, M., Semon, T., Tzou, C.Y., Waite, J.H., Wurz, P. (2017) Xenon isotopes in 67P/Churyumov-Gerasimenko show that comets contributed to Earth’s atmosphere. Science 356, 1069–1072. https://doi.org/10.1126/science.aal3496
). As this large monoisotopic excess would require unlikely 129I enrichment, it has been interpreted as originating from a specific nucleosynthetic process producing 129Xe that was sampled by icy bodies formed in the outer solar system (Marty et al., 2017Marty, B. Altwegg, K., Balsiger, H., Bar-Nun, A., Bekaert, D.V., Berthelier, J.J., Bieler, A., Briois, C., Calmonte, U., Combi, M., De Keyser, J., Fiethe, B., Fuselier, S.A., Gasc, S., Gombosi, T.I., Hansen, K.C., Hässig, M., Jackel, A., Kopp, E., Korth, A., Le Roy, L., Mall, U., Mousis, O., Owen, T., Reme, H., Rubin, M., Semon, T., Tzou, C.Y., Waite, J.H., Wurz, P. (2017) Xenon isotopes in 67P/Churyumov-Gerasimenko show that comets contributed to Earth’s atmosphere. Science 356, 1069–1072. https://doi.org/10.1126/science.aal3496
). Interestingly, the carbon-rich primitive chondrites Tagish Lake and Tarda are thought to originate from D-type asteroids (Hiroi et al., 2001Hiroi, T., Zolensky, M.E., Pieters, C.M. (2001) The Tagish Lake Meteorite: A Possible Sample from a D-Type Asteroid. Science 293, 2234–2236. https://doi.org/10.1126/science.1063734
; Marrocchi et al., 2021Marrocchi, Y., Avice, G., Barrat, J.-A. (2021) The Tarda Meteorite: A Window into the Formation of D-type Asteroids. The Astrophysical Journal Letters 913, 8. https://doi.org/10.3847/2041-8213/abfaa3
) considered to have formed at large heliocentric distances beyond the current orbit of Saturn, and potentially as far as the Kuiper Belt (i.e. 30–50 astronomical units = au; Levison et al., 2009Levison, H.F., Bottke, W.F., Gounelle, M., Morbidelli, A., Nesvorný, D., Tsiganis, K. (2009) Contamination of the asteroid belt by primordial trans-Neptunian objects. Nature 460, 364–366. https://doi.org/10.1038/nature08094
). Here we report the results of a comprehensive study of the isotopic compositions of noble gases contained in Tagish Lake and Tarda to evaluate if material accreted in the outer solar system presents specific signatures. We compare our data to other CCs and discuss the origin of the variable radiogenic 129Xe excesses between and within each CC groups.top
Material and Methods
Noble gases were extracted from bulk fragments of Tarda, Tagish Lake and Orgueil meteorites by a laser step-heating method and measured with a noble gas mass spectrometer. Uncertainties on isotope ratios include internal uncertainties, external uncertainties assessed by measurements of standard aliquots, and uncertainties on the blank contribution. Details on the analytical procedure are in the Supplementary Information.
top
Results of Noble Gas Measurements and Cosmic-ray Exposure Ages
Abundances and isotopic compositions of Ne, Ar, Kr and Xe extracted from bulk Tarda, Tagish Lake and Orgueil samples are reported in Table S-1. Elemental abundances of Ne, Ar, Kr and Xe in Tarda, Tagish Lake and Orgueil are similar to those reported for other volatile-rich carbonaceous chondrites (Table S-1; Mazor et al., 1970
Mazor, E., Heymann, D., Anders, E. (1970) Noble gases in carbonaceous chondrites. Geochimica et Cosmochimica Acta 34, 781–824. https://doi.org/10.1016/0016-7037(70)90031-1
). Most heating steps show a similar 20Ne/132Xe ratio (average value of 22 ± 4), slightly lower than the range reported for the HL component (50 ± 20; Huss and Lewis, 1994Huss, G.R., Lewis, R.S. (1994) Noble gases in presolar diamonds I: Three distinct components and their implications for diamond origins. Meteoritics 29, 791–810. https://doi.org/10.1111/j.1945-5100.1994.tb01094.x
). For all samples, 36Ar/132Xe and 84Kr/132Xe ratios plot close to the Q component although the first, low temperature, heating steps are systematically plotting toward higher 84Kr/132Xe ratios, which are compatible with a contribution from weakly bound atmospheric gases (Fig. S-1). For all heating steps, the isotopic composition of neon indicates the presence of abundant trapped neon in the different meteorite samples (Fig. 1). Data points of heating steps of Tarda and Tagish Lake samples plot slightly below a mixing line defined by Ne-HL (Huss and Lewis, 1994Huss, G.R., Lewis, R.S. (1994) Noble gases in presolar diamonds I: Three distinct components and their implications for diamond origins. Meteoritics 29, 791–810. https://doi.org/10.1111/j.1945-5100.1994.tb01094.x
) and cosmogenic neon (Supplementary Information). The two first heating steps of Orgueil samples plot on the Ne-Q/cosmogenic mixing line while the high temperature extraction steps show lower 21Ne/22Ne ratios and plot close to the Ne-Q/Ne-HL mixing line. For argon, 38Ar/36Ar ratios are compatible with either the atmospheric 38Ar/36Ar ratio (≈0.188; Ozima and Podosek, 2002Ozima, M., Podosek, F.A. (2002) Noble Gas Geochemistry. Cambridge University Press, Cambridge.
) or the 38Ar/36Ar ratio of argon in phase Q (≈0.187; Ott, 2002Ott, U. (2002) Noble gases in meteorites - Trapped Components. Reviews in Mineralogy and Geochemistry 47, 71–100. https://doi.org/10.2138/rmg.2002.47.3
). However, the 40Ar/36Ar ratios range from 3 to 43, well below the atmospheric value (≈300, Ozima and Podosek, 2002Ozima, M., Podosek, F.A. (2002) Noble Gas Geochemistry. Cambridge University Press, Cambridge.
), but typical for trapped argon contained in carbonaceous chondrites (Krietsch et al., 2021Krietsch, D., Busemann, H., Riebe, M.E.I., King, A.J., Alexander, C.M.O’D., Maden, C. (2021) Noble gases in CM carbonaceous chondrites: Effect of parent body aqueous and thermal alteration and cosmic ray exposure ages. Geochimica et Cosmochimica Acta 310, 240–280. https://doi.org/10.1016/j.gca.2021.05.050
). The isotopic ratios of Kr and Xe are distinct from those of air, as well, and are similar again, to those measured for bulk carbonaceous chondrites (e.g., Krietsch et al., 2021Krietsch, D., Busemann, H., Riebe, M.E.I., King, A.J., Alexander, C.M.O’D., Maden, C. (2021) Noble gases in CM carbonaceous chondrites: Effect of parent body aqueous and thermal alteration and cosmic ray exposure ages. Geochimica et Cosmochimica Acta 310, 240–280. https://doi.org/10.1016/j.gca.2021.05.050
). The first heating steps of Tarda and Tagish Lake samples reveal the presence of weakly bound atmospheric gases (Fig. S-2). For the 129Xe/130Xe ratio, high temperature heating steps of Tarda and Tagish Lake samples gave reproducible results with an average value of 6.37 ± 0.01 (1σ s.d.). This value is 8.3 ± 3.4 ‰ lower than the 129Xe/130Xe measured for Q-Xe (Busemann et al., 2000Busemann, H., Baur, H., Wieler, R. (2000) Primordial noble gases in “phase Q” in carbonaceous and ordinary chondrites studied by closed-system stepped etching. Meteoritics & Planetary Science 35, 949–973. https://doi.org/10.1111/j.1945-5100.2000.tb01485.x
). High temperature heating steps of Orgueil samples reveal the presence of excess radiogenic 129Xe compared to Q-Xe.The presence of abundant trapped Ne in both Tarda and Tagish Lake prevents us from determining precisely the cosmogenic 22Ne/21Ne ratio and thus cosmogenic 21Ne production rates (Supplementary Information). Tarda has a cosmic ray exposure (CRE) age within 5–12 Ma, very similar to Tagish Lake (5–8 Ma), while for Orgueil, the possible CRE age ranges from 6 to 11 Ma. The nominal (K-Ar) radiogenic gas retention ages are 2.4–2.7 Ga for Tarda, 2.0–2.8 Ga for Tagish Lake, and 2.2–2.7 Ga for Orgueil.
top
Discussion
Based on multiple isotopic systems (i.e. H, C, N and O), it has recently been proposed that Tarda and Tagish Lake could be genetically related (Marrocchi et al., 2021
Marrocchi, Y., Avice, G., Barrat, J.-A. (2021) The Tarda Meteorite: A Window into the Formation of D-type Asteroids. The Astrophysical Journal Letters 913, 8. https://doi.org/10.3847/2041-8213/abfaa3
). This hypothesis can be tested in the light of noble gas measurements reported here. In the three isotope diagram, the neon isotopic compositions of bulk chondrites plot within a space defined by cosmogenic Ne, Ne-Q and a pole with (20Ne/22Ne) slightly below that of Ne-HL carried by presolar nanodiamonds (Fig. 1; Huss and Lewis, 1994Huss, G.R., Lewis, R.S. (1994) Noble gases in presolar diamonds I: Three distinct components and their implications for diamond origins. Meteoritics 29, 791–810. https://doi.org/10.1111/j.1945-5100.1994.tb01094.x
; Krietsch et al., 2021Krietsch, D., Busemann, H., Riebe, M.E.I., King, A.J., Alexander, C.M.O’D., Maden, C. (2021) Noble gases in CM carbonaceous chondrites: Effect of parent body aqueous and thermal alteration and cosmic ray exposure ages. Geochimica et Cosmochimica Acta 310, 240–280. https://doi.org/10.1016/j.gca.2021.05.050
). The latter is likely due to the presence of Ne-E from presolar SiC or graphite (Riebe et al., 2020Riebe, M.E.I., Busemann, H., Alexander, C.M.O’D., Nittler, L.R., Herd, C.D.K., Maden, C., Wang, J., Wieler, R. (2020) Effects of aqueous alteration on primordial noble gases and presolar SiC in the carbonaceous chondrite Tagish Lake. Meteoritics & Planetary Science 55, 1257–1280. https://doi.org/10.1111/maps.13383
). The data points from Tarda and Tagish Lake plot on the lower part of this isotopic space with similar Ne isotopic compositions, which are clearly resolved from that of the CI chondrite Orgueil (Fig. 1). Our results show that both Tarda and Tagish Lake have similar bulk Xe spectra and 129Xe* excesses (Fig. 2), with δ129XeSW =10 ± 3 ‰ (Fig. 3a). In addition, both chondrites show similar cosmic-ray exposure and radiogenic retention ages: 5–10 Ma and 2.4–2.7 Ga for Tarda, and 5–8 Ma and 2.0–2.8 Ga for Tagish Lake. Altogether, our results thus reinforce the genetic link between Tarda and Tagish Lake, which share similar isotopic signatures for elements having drastically different geochemical behaviour (Marrocchi et al., 2021Marrocchi, Y., Avice, G., Barrat, J.-A. (2021) The Tarda Meteorite: A Window into the Formation of D-type Asteroids. The Astrophysical Journal Letters 913, 8. https://doi.org/10.3847/2041-8213/abfaa3
).Xenon in the Jupiter-family comet 67P/Churyumov-Gerasimenko (67P/C-G) presents a 129Xe excess and important, tens of percent 134−136Xe deficits relative to SW-Xe (Marty et al., 2017
Marty, B. Altwegg, K., Balsiger, H., Bar-Nun, A., Bekaert, D.V., Berthelier, J.J., Bieler, A., Briois, C., Calmonte, U., Combi, M., De Keyser, J., Fiethe, B., Fuselier, S.A., Gasc, S., Gombosi, T.I., Hansen, K.C., Hässig, M., Jackel, A., Kopp, E., Korth, A., Le Roy, L., Mall, U., Mousis, O., Owen, T., Reme, H., Rubin, M., Semon, T., Tzou, C.Y., Waite, J.H., Wurz, P. (2017) Xenon isotopes in 67P/Churyumov-Gerasimenko show that comets contributed to Earth’s atmosphere. Science 356, 1069–1072. https://doi.org/10.1126/science.aal3496
). The former has been attributed as resulting from the contribution of parentless 129Xe and the latter of a mixture of two nucleosynthetic processes (i.e. s- and r-process; Marty et al., 2017Marty, B. Altwegg, K., Balsiger, H., Bar-Nun, A., Bekaert, D.V., Berthelier, J.J., Bieler, A., Briois, C., Calmonte, U., Combi, M., De Keyser, J., Fiethe, B., Fuselier, S.A., Gasc, S., Gombosi, T.I., Hansen, K.C., Hässig, M., Jackel, A., Kopp, E., Korth, A., Le Roy, L., Mall, U., Mousis, O., Owen, T., Reme, H., Rubin, M., Semon, T., Tzou, C.Y., Waite, J.H., Wurz, P. (2017) Xenon isotopes in 67P/Churyumov-Gerasimenko show that comets contributed to Earth’s atmosphere. Science 356, 1069–1072. https://doi.org/10.1126/science.aal3496
) different from the one measured for most inner solar system material (Avice et al., 2020Avice, G., Moreira, M., Gilmour, J.D. (2020) Xenon Isotopes Identify Large-scale Nucleosynthetic Heterogeneities across the Solar System. The Astrophysical Journal 889, 68. https://doi.org/10.3847/1538-4357/ab5f0c
). This is however not observed in Orgueil, Tarda and Tagish Lake (Fig. 2) whereas they are generally thought to have formed in the outer solar system, at large heliocentric distances >10 au (Desch et al., 2018Desch, S.J., Kalyaan, A., Alexander, C.M.O’D. (2018) The Effect of Jupiter’s Formation on the Distribution of Refractory Elements and Inclusions in Meteorites. The Astrophysical Journal Supplement Series 238, 11. https://doi.org/10.3847/1538-4365/aad95f
; Fujiya et al., 2019Fujiya, W., Hoppe, P., Ushikubo, T., Fukuda, K., Lindgren, P., Lee, M.R., Koike, M., Shirai, K., Sano, Y. (2019) Migration of D-type asteroids from the outer Solar System inferred from carbonate in meteorites. Nature Astronomy 460, 364. https://doi.org/10.1038/s41550-019-0801-4
; Marrocchi et al., 2021Marrocchi, Y., Avice, G., Barrat, J.-A. (2021) The Tarda Meteorite: A Window into the Formation of D-type Asteroids. The Astrophysical Journal Letters 913, 8. https://doi.org/10.3847/2041-8213/abfaa3
). These meteorites are even showing among the weakest 129Xe* excesses measured in CCs (Fig. 3a; Mazor et al., 1970Mazor, E., Heymann, D., Anders, E. (1970) Noble gases in carbonaceous chondrites. Geochimica et Cosmochimica Acta 34, 781–824. https://doi.org/10.1016/0016-7037(70)90031-1
). Some rare CMs show similar 129Xe/132Xe but suffered from significant heating (Alexander et al., 2012Alexander, C.M.O’D., Bowden, R., Fogel, M.L., Howard, K.T., Herd, C.D.K., Nittler, L.R. (2012) The Provenances of Asteroids, and Their Contributions to the Volatile Inventories of the Terrestrial Planets. Science 337, 721–723. https://doi.org/10.1126/science.1223474
; Krietsch et al., 2021Krietsch, D., Busemann, H., Riebe, M.E.I., King, A.J., Alexander, C.M.O’D., Maden, C. (2021) Noble gases in CM carbonaceous chondrites: Effect of parent body aqueous and thermal alteration and cosmic ray exposure ages. Geochimica et Cosmochimica Acta 310, 240–280. https://doi.org/10.1016/j.gca.2021.05.050
). In addition, when combining data from all CCs and the comet 67P (Mazor et al., 1970Mazor, E., Heymann, D., Anders, E. (1970) Noble gases in carbonaceous chondrites. Geochimica et Cosmochimica Acta 34, 781–824. https://doi.org/10.1016/0016-7037(70)90031-1
; Clay et al., 2017Clay, P.L., Burgess, R., Busemann, H., Ruzié-Hamilton, L., Joachim, B., Day, J.M.D., Ballentine, C.J. (2017) Halogens in chondritic meteorites and terrestrial accretion. Nature 551, 614–618. https://doi.org/10.1038/nature24625
; Marty et al., 2017Marty, B. Altwegg, K., Balsiger, H., Bar-Nun, A., Bekaert, D.V., Berthelier, J.J., Bieler, A., Briois, C., Calmonte, U., Combi, M., De Keyser, J., Fiethe, B., Fuselier, S.A., Gasc, S., Gombosi, T.I., Hansen, K.C., Hässig, M., Jackel, A., Kopp, E., Korth, A., Le Roy, L., Mall, U., Mousis, O., Owen, T., Reme, H., Rubin, M., Semon, T., Tzou, C.Y., Waite, J.H., Wurz, P. (2017) Xenon isotopes in 67P/Churyumov-Gerasimenko show that comets contributed to Earth’s atmosphere. Science 356, 1069–1072. https://doi.org/10.1126/science.aal3496
), we observe an anti-correlation of their 127I content and the 129Xe excess (Fig. 3a), regardless of the available iodine dataset used (Fig. S-4). As previously noticed (Mazor et al., 1970Mazor, E., Heymann, D., Anders, E. (1970) Noble gases in carbonaceous chondrites. Geochimica et Cosmochimica Acta 34, 781–824. https://doi.org/10.1016/0016-7037(70)90031-1
; Gilmour et al., 2001Gilmour, J.D., Whitby, J.A., Turner, G. (2001) Negative correlation of iodine-129/iodine-127 and xenon-129/xenon-132: Product of closed-system evolution or evidence of a mixed component. Meteoritics & Planetary Science 36, 1283–1286. https://doi.org/10.1111/j.1945-5100.2001.tb01961.x
), such an inverse correlation could not result from the heterogeneous 129I distribution in the early solar system as the absolute concentrations of radiogenic 129Xe* vary by only a factor of ∼4 among CCs, while relative 129Xe* enrichments differ by a factor of 400.CCs contains variable amounts of carbon with Tarda, Tagish Lake, CI and CM chondrites showing the highest concentrations (Fig. 3b; Kerridge, 1985
Kerridge, J.F. (1985) Carbon, hydrogen and nitrogen in carbonaceous chondrites: Abundances and isotopic compositions in bulk samples. Geochimica et Cosmochimica Acta 49, 1707–1714. https://doi.org/10.1016/0016-7037(85)90141-3
; Vacher et al., 2020Vacher, L.G., Piani, L., Rigaudier, T., Thomassin, D., Florin, G., Piralla, M., Marrocchi, Y. (2020) Hydrogen in chondrites: Influence of parent body alteration and atmospheric contamination on primordial components. Geochimica et Cosmochimica Acta 281, 53–66. https://doi.org/10.1016/j.gca.2020.05.007
; Marrocchi et al., 2021Marrocchi, Y., Avice, G., Barrat, J.-A. (2021) The Tarda Meteorite: A Window into the Formation of D-type Asteroids. The Astrophysical Journal Letters 913, 8. https://doi.org/10.3847/2041-8213/abfaa3
). With the exception of Tarda and Tagish Lake, the carbon content of CCs is directly related to the abundance of fine grained matrix (see Fig. 3 in Alexander et al., 2018Alexander, C.M.O’D., McKeegan, K.D., Altwegg, K. (2018) Water Reservoirs in Small Planetary Bodies: Meteorites, Asteroids, and Comets. Space Science Reviews 214, 47. https://doi.org/10.1007/s11214-018-0474-9
). Interestingly, the 129Xe* excess is also anti-correlated with the bulk C content of CCs (Fig. 3b), thus implying that the (i) 129I carrier was located in the CC matrices, and (ii) variations of 129Xe* excesses observed in CCs result from a dilution effect by trapped Xe located in phase Q. Such an effect can be summarised as follows: the less carbon, the less phase Q, the less trapped 129Xe, the more the effect of 129I decay is visible (and vice versa). This also indicates that the initial Xe budget (and likely that of other noble gases) in CCs is directly controlled by the abundance of matrix (Fig. 3c). Of note, similar 129Xe*-C anti-correlations are also observed within several CC groups (see Fig. S-5).Although both Tarda and Tagish Lake are depleted in fine grained matrix relative to CI chondrites (65–80 vs. 100 vol. %, Fig. 3c; Alexander et al., 2018
Alexander, C.M.O’D., McKeegan, K.D., Altwegg, K. (2018) Water Reservoirs in Small Planetary Bodies: Meteorites, Asteroids, and Comets. Space Science Reviews 214, 47. https://doi.org/10.1007/s11214-018-0474-9
), they appear enriched in C (i.e. ∼4 vs. 3.3 wt. %, Fig. 3b; Vacher et al., 2020Vacher, L.G., Piani, L., Rigaudier, T., Thomassin, D., Florin, G., Piralla, M., Marrocchi, Y. (2020) Hydrogen in chondrites: Influence of parent body alteration and atmospheric contamination on primordial components. Geochimica et Cosmochimica Acta 281, 53–66. https://doi.org/10.1016/j.gca.2020.05.007
; Marrocchi et al., 2021Marrocchi, Y., Avice, G., Barrat, J.-A. (2021) The Tarda Meteorite: A Window into the Formation of D-type Asteroids. The Astrophysical Journal Letters 913, 8. https://doi.org/10.3847/2041-8213/abfaa3
). This excess has been attributed to the unusual abundance of carbonates in some highly altered lithologies of Tagish Lake (Alexander et al., 2018Alexander, C.M.O’D., McKeegan, K.D., Altwegg, K. (2018) Water Reservoirs in Small Planetary Bodies: Meteorites, Asteroids, and Comets. Space Science Reviews 214, 47. https://doi.org/10.1007/s11214-018-0474-9
). However, the bulk C content of Tagish Lake is relatively homogenous (Marrocchi et al., 2021Marrocchi, Y., Avice, G., Barrat, J.-A. (2021) The Tarda Meteorite: A Window into the Formation of D-type Asteroids. The Astrophysical Journal Letters 913, 8. https://doi.org/10.3847/2041-8213/abfaa3
) regardless of the abundance of carbonates (i.e. 4.1 ± 0.1 wt. %). In addition, Tarda shows a carbon content similar to Tagish Lake whereas no specific carbonate-rich lithology has been described so far (Marrocchi et al., 2021Marrocchi, Y., Avice, G., Barrat, J.-A. (2021) The Tarda Meteorite: A Window into the Formation of D-type Asteroids. The Astrophysical Journal Letters 913, 8. https://doi.org/10.3847/2041-8213/abfaa3
and references therein). This thus requires an additional source of carbon for accounting for the diluted 129Xe* excesses observed in both Tarda and Tagish Lake (Figs. 2, 3a). It has been recently proposed that peculiar carbon isotopic compositions of carbonates in Tagish Lake (i.e. δ13C ≈ 70 ‰; Fujiya et al., 2019Fujiya, W., Hoppe, P., Ushikubo, T., Fukuda, K., Lindgren, P., Lee, M.R., Koike, M., Shirai, K., Sano, Y. (2019) Migration of D-type asteroids from the outer Solar System inferred from carbonate in meteorites. Nature Astronomy 460, 364. https://doi.org/10.1038/s41550-019-0801-4
) cannot be explained without invoking the accretion of large amounts of 13C-rich CO2 cometary ices. This implies that the parent body of Tagish Lake (and Tarda) formed beyond 10 au, in regions of the protoplanetary disk that were cold enough for CO2 to condense.top
Conclusions
Results obtained in this study demonstrate that Tarda and Tagish Lake, in addition to C, H, N isotope systematics (Marrocchi et al., 2021
Marrocchi, Y., Avice, G., Barrat, J.-A. (2021) The Tarda Meteorite: A Window into the Formation of D-type Asteroids. The Astrophysical Journal Letters 913, 8. https://doi.org/10.3847/2041-8213/abfaa3
), present very similar compositions for noble gases. This implies that those meteorites are genetically related and may have sampled similar environments of the accretion disk. A key feature of xenon present in these two meteorites is a very low excess of radiogenic 129Xe*. When compared to literature data of carbonaceous chondrites, these carbon-rich meteorite samples present inverse correlations between 129Xe* and carbon or iodine content. We interpret these anti-correlations as evidence for a dilution effect of radiogenic 129Xe* by primordial xenon trapped in organic matter.top
Author Contributions
GA and YM designed the study. GA performed the measurements. MM reconstructed the cosmic histories. All authors worked on the data and on the manuscript.
top
Acknowledgements
Matthieu Gounelle is warmly thanked for fruitful discussions on iodine nucleosynthesis. We acknowledge the financial support of the “Programme National de Planétologie” (PNP). We thank Wataru Fujiya and Henner Busemann for helpful reviews, and Maud Boyet for editorial handling.
Editor: Maud Boyet
top
References
Alexander, C.M.O’D., Bowden, R., Fogel, M.L., Howard, K.T., Herd, C.D.K., Nittler, L.R. (2012) The Provenances of Asteroids, and Their Contributions to the Volatile Inventories of the Terrestrial Planets. Science 337, 721–723. https://doi.org/10.1126/science.1223474
Show in context
Some rare CMs show similar 129Xe/132Xe but suffered from significant heating (Alexander et al., 2012; Krietsch et al., 2021).
View in article
Alexander, C.M.O’D., McKeegan, K.D., Altwegg, K. (2018) Water Reservoirs in Small Planetary Bodies: Meteorites, Asteroids, and Comets. Space Science Reviews 214, 47. https://doi.org/10.1007/s11214-018-0474-9
Show in context
The average δ129XeSW is plotted as a function of (a) the 127I content (data from Clay et al., 2017), (b) the carbon content (data from Vacher et al., 2020 and Marrocchi et al., 2021), and (c) the matrix abundance (data from Alexander et al., 2018).
View in article
With the exception of Tarda and Tagish Lake, the carbon content of CCs is directly related to the abundance of fine grained matrix (see Fig. 3 in Alexander et al., 2018).
View in article
Although both Tarda and Tagish Lake are depleted in fine grained matrix relative to CI chondrites (65–80 vs. 100 vol. %, Fig. 3c; Alexander et al., 2018), they appear enriched in C (i.e. ∼4 vs. 3.3 wt. %, Fig. 3b; Vacher et al., 2020; Marrocchi et al., 2021).
View in article
This excess has been attributed to the unusual abundance of carbonates in some highly altered lithologies of Tagish Lake (Alexander et al., 2018).
View in article
Avice, G., Moreira, M., Gilmour, J.D. (2020) Xenon Isotopes Identify Large-scale Nucleosynthetic Heterogeneities across the Solar System. The Astrophysical Journal 889, 68. https://doi.org/10.3847/1538-4357/ab5f0c
Show in context
The former has been attributed as resulting from the contribution of parentless 129Xe and the latter of a mixture of two nucleosynthetic processes (i.e. s- and r-process; Marty et al., 2017) different from the one measured for most inner solar system material (Avice et al., 2020).
View in article
Busemann, H., Baur, H., Wieler, R. (2000) Primordial noble gases in “phase Q” in carbonaceous and ordinary chondrites studied by closed-system stepped etching. Meteoritics & Planetary Science 35, 949–973. https://doi.org/10.1111/j.1945-5100.2000.tb01485.x
Show in context
Although these elements are present in different carriers contained in meteorites (including presolar SiC, diamonds, graphite; Ott, 2014), they are mainly hosted in a phase − referred to as phase Q − whose nature is still poorly characterised (Busemann et al., 2000).
View in article
Thanks to its extreme sensitivity to oxidation, the xenon isotopic composition of phase Q has been precisely determined, revealing a mass dependent isotopic fractionation relative to solar wind (SW-Xe) in favour of the heavy isotopes relative to the light ones (Wieler et al., 1991; Busemann et al., 2000; Gilmour, 2010).
View in article
However, the commonly used Xe-Q isotopic composition hinges on the average of measurements of several carbonaceous chondrites (CCs) showing distinct Xe isotopic compositions between and within each group, especially for 129Xe (Busemann et al., 2000).
View in article
This value is 8.3 ± 3.4 ‰ lower than the 129Xe/130Xe measured for Q-Xe (Busemann et al., 2000).
View in article
Isotopic ratios are normalised to Q-Xe (Busemann et al., 2000) and expressed with the delta notation (δiXeQ = ((iXe/130Xe)sample/(iXe/130Xe)Q − 1) × 1000).
View in article
Clay, P.L., Burgess, R., Busemann, H., Ruzié-Hamilton, L., Joachim, B., Day, J.M.D., Ballentine, C.J. (2017) Halogens in chondritic meteorites and terrestrial accretion. Nature 551, 614–618. https://doi.org/10.1038/nature24625
Show in context
The average δ129XeSW is plotted as a function of (a) the 127I content (data from Clay et al., 2017), (b) the carbon content (data from Vacher et al., 2020 and Marrocchi et al., 2021), and (c) the matrix abundance (data from Alexander et al., 2018).
View in article
In addition, when combining data from all CCs and the comet 67P (Mazor et al., 1970; Clay et al., 2017; Marty et al., 2017), we observe an anti-correlation of their 127I content and the 129Xe excess (Fig. 3a), regardless of the available iodine dataset used (Fig. S-4).
View in article
Desch, S.J., Kalyaan, A., Alexander, C.M.O’D. (2018) The Effect of Jupiter’s Formation on the Distribution of Refractory Elements and Inclusions in Meteorites. The Astrophysical Journal Supplement Series 238, 11. https://doi.org/10.3847/1538-4365/aad95f
Show in context
This is however not observed in Orgueil, Tarda and Tagish Lake (Fig. 2) whereas they are generally thought to have formed in the outer solar system, at large heliocentric distances >10 au (Desch et al., 2018; Fujiya et al., 2019; Marrocchi et al., 2021).
View in article
Fujiya, W., Hoppe, P., Ushikubo, T., Fukuda, K., Lindgren, P., Lee, M.R., Koike, M., Shirai, K., Sano, Y. (2019) Migration of D-type asteroids from the outer Solar System inferred from carbonate in meteorites. Nature Astronomy 460, 364. https://doi.org/10.1038/s41550-019-0801-4
Show in context
This is however not observed in Orgueil, Tarda and Tagish Lake (Fig. 2) whereas they are generally thought to have formed in the outer solar system, at large heliocentric distances >10 au (Desch et al., 2018; Fujiya et al., 2019; Marrocchi et al., 2021).
View in article
It has been recently proposed that peculiar carbon isotopic compositions of carbonates in Tagish Lake (i.e. δ13C ≈ 70 ‰; Fujiya et al., 2019) cannot be explained without invoking the accretion of large amounts of 13C-rich CO2 cometary ices.
View in article
Gilmour, J.D. (2010) “Planetary” noble gas components and the nucleosynthetic history of solar system material. Geochimica et Cosmochimica Acta 74, 380–393. https://doi.org/10.1016/j.gca.2009.09.015
Show in context
Thanks to its extreme sensitivity to oxidation, the xenon isotopic composition of phase Q has been precisely determined, revealing a mass dependent isotopic fractionation relative to solar wind (SW-Xe) in favour of the heavy isotopes relative to the light ones (Wieler et al., 1991; Busemann et al., 2000; Gilmour, 2010).
View in article
Gilmour, J.D., Whitby, J.A., Turner, G. (2001) Negative correlation of iodine-129/iodine-127 and xenon-129/xenon-132: Product of closed-system evolution or evidence of a mixed component. Meteoritics & Planetary Science 36, 1283–1286. https://doi.org/10.1111/j.1945-5100.2001.tb01961.x
Show in context
As previously noticed (Mazor et al., 1970; Gilmour et al., 2001), such an inverse correlation could not result from the heterogeneous 129I distribution in the early solar system as the absolute concentrations of radiogenic 129Xe* vary by only a factor of ∼4 among CCs, while relative 129Xe* enrichments differ by a factor of 400.
View in article
Hiroi, T., Zolensky, M.E., Pieters, C.M. (2001) The Tagish Lake Meteorite: A Possible Sample from a D-Type Asteroid. Science 293, 2234–2236. https://doi.org/10.1126/science.1063734
Show in context
Carbonaceous chondrites are pristine witnesses of the formation of the solar system. Among them, the carbon-rich Tarda and Tagish Lake meteorites are thought to have sampled very distant regions of the outer circumsolar disk (Hiroi et al., 2001).
View in article
Interestingly, the carbon-rich primitive chondrites Tagish Lake and Tarda are thought to originate from D-type asteroids (Hiroi et al., 2001; Marrocchi et al., 2021) considered to have formed at large heliocentric distances beyond the current orbit of Saturn, and potentially as far as the Kuiper Belt (i.e. 30–50 astronomical units = au; Levison et al., 2009).
View in article
Huss, G.R., Lewis, R.S. (1994) Noble gases in presolar diamonds I: Three distinct components and their implications for diamond origins. Meteoritics 29, 791–810. https://doi.org/10.1111/j.1945-5100.1994.tb01094.x
Show in context
Most heating steps show a similar 20Ne/132Xe ratio (average value of 22 ± 4), slightly lower than the range reported for the HL component (50 ± 20; Huss and Lewis, 1994).
View in article
Data points of heating steps of Tarda and Tagish Lake samples plot slightly below a mixing line defined by Ne-HL (Huss and Lewis, 1994) and cosmogenic neon (Supplementary Information).
View in article
In the three isotope diagram, the neon isotopic compositions of bulk chondrites plot within a space defined by cosmogenic Ne, Ne-Q and a pole with (20Ne/22Ne) slightly below that of Ne-HL carried by presolar nanodiamonds (Fig. 1; Huss and Lewis, 1994; Krietsch et al., 2021).
View in article
Jeffery, P.M., Reynolds, J.H. (1961) Origin of excess Xe129 in stone meteorites. Journal of Geophysical Research 66, 3582–3583. https://doi.org/10.1029/JZ066i010p03582
Show in context
Such 129Xe excesses result from the decay of extinct 129I (t1/2 = 16 Myr), which was producing radiogenic 129Xe* during the first ∼100 million years of the solar system (Jeffery and Reynolds, 1961).
View in article
Kerridge, J.F. (1985) Carbon, hydrogen and nitrogen in carbonaceous chondrites: Abundances and isotopic compositions in bulk samples. Geochimica et Cosmochimica Acta 49, 1707–1714. https://doi.org/10.1016/0016-7037(85)90141-3
Show in context
CCs contains variable amounts of carbon with Tarda, Tagish Lake, CI and CM chondrites showing the highest concentrations (Fig. 3b; Kerridge, 1985; Vacher et al., 2020; Marrocchi et al., 2021).
View in article
Krietsch, D., Busemann, H., Riebe, M.E.I., King, A.J., Alexander, C.M.O’D., Maden, C. (2021) Noble gases in CM carbonaceous chondrites: Effect of parent body aqueous and thermal alteration and cosmic ray exposure ages. Geochimica et Cosmochimica Acta 310, 240–280. https://doi.org/10.1016/j.gca.2021.05.050
Show in context
However, the 40Ar/36Ar ratios range from 3 to 43, well below the atmospheric value (≈300, Ozima and Podosek, 2002), but typical for trapped argon contained in carbonaceous chondrites (Krietsch et al., 2021).
View in article
The isotopic ratios of Kr and Xe are distinct from those of air, as well, and are similar again, to those measured for bulk carbonaceous chondrites (e.g., Krietsch et al., 2021).
View in article
Neon three isotope plot for bulk samples of Tarda, Tagish Lake and Orgueil. The compositions of Ne-Q, Air, Ne-HL, Ne-E and cosmogenic (purple range) are also shown for comparison (see Ott, 2014 and Krietsch et al., 2021 and refs. therein).
View in article
In the three isotope diagram, the neon isotopic compositions of bulk chondrites plot within a space defined by cosmogenic Ne, Ne-Q and a pole with (20Ne/22Ne) slightly below that of Ne-HL carried by presolar nanodiamonds (Fig. 1; Huss and Lewis, 1994; Krietsch et al., 2021).
View in article
Some rare CMs show similar 129Xe/132Xe but suffered from significant heating (Alexander et al., 2012; Krietsch et al., 2021).
View in article
Kuga, M., Marty, B., Marrocchi, Y., Tissandier, L. (2015) Synthesis of refractory organic matter in the ionized gas phase of the solar nebula. Proceedings of the National Academy of Sciences 112, 7129–7134. https://doi.org/10.1073/pnas.1502796112
Show in context
Noble gases trapped in primitive meteorites (chondrites) allow quantification of the physical processes that operated during the evolution of the protoplanetary disk (e.g., Kuga et al., 2015).
View in article
Levison, H.F., Bottke, W.F., Gounelle, M., Morbidelli, A., Nesvorný, D., Tsiganis, K. (2009) Contamination of the asteroid belt by primordial trans-Neptunian objects. Nature 460, 364–366. https://doi.org/10.1038/nature08094
Show in context
Interestingly, the carbon-rich primitive chondrites Tagish Lake and Tarda are thought to originate from D-type asteroids (Hiroi et al., 2001; Marrocchi et al., 2021) considered to have formed at large heliocentric distances beyond the current orbit of Saturn, and potentially as far as the Kuiper Belt (i.e. 30–50 astronomical units = au; Levison et al., 2009).
View in article
Lewis, R.S., Srinivasan, B., Anders, E. (1975) Host Phase of a Strange Xenon Component in Allende. Science 190, 1251–1262.
Show in context
Notwithstanding this uncertainty, it has been shown that phase Q dominates the heavy noble gas budget of chondrites and is closely associated with carbonaceous material that survives HF/HCl attack of bulk meteorites (Lewis et al., 1975).
View in article
Marrocchi, Y., Avice, G., Barrat, J.-A. (2021) The Tarda Meteorite: A Window into the Formation of D-type Asteroids. The Astrophysical Journal Letters 913, 8. https://doi.org/10.3847/2041-8213/abfaa3
Show in context
Interestingly, the carbon-rich primitive chondrites Tagish Lake and Tarda are thought to originate from D-type asteroids (Hiroi et al., 2001; Marrocchi et al., 2021) considered to have formed at large heliocentric distances beyond the current orbit of Saturn, and potentially as far as the Kuiper Belt (i.e. 30–50 astronomical units = au; Levison et al., 2009).
View in article
Based on multiple isotopic systems (i.e. H, C, N and O), it has recently been proposed that Tarda and Tagish Lake could be genetically related (Marrocchi et al., 2021).
View in article
Altogether, our results thus reinforce the genetic link between Tarda and Tagish Lake, which share similar isotopic signatures for elements having drastically different geochemical behaviour (Marrocchi et al., 2021).
View in article
The average δ129XeSW is plotted as a function of (a) the 127I content (data from Clay et al., 2017), (b) the carbon content (data from Vacher et al., 2020 and Marrocchi et al., 2021), and (c) the matrix abundance (data from Alexander et al., 2018).
View in article
This is however not observed in Orgueil, Tarda and Tagish Lake (Fig. 2) whereas they are generally thought to have formed in the outer solar system, at large heliocentric distances >10 au (Desch et al., 2018; Fujiya et al., 2019; Marrocchi et al., 2021).
View in article
CCs contains variable amounts of carbon with Tarda, Tagish Lake, CI and CM chondrites showing the highest concentrations (Fig. 3b; Kerridge, 1985; Vacher et al., 2020; Marrocchi et al., 2021).
View in article
Although both Tarda and Tagish Lake are depleted in fine grained matrix relative to CI chondrites (65–80 vs. 100 vol. %, Fig. 3c; Alexander et al., 2018), they appear enriched in C (i.e. ∼4 vs. 3.3 wt. %, Fig. 3b; Vacher et al., 2020; Marrocchi et al., 2021).
View in article
However, the bulk C content of Tagish Lake is relatively homogenous (Marrocchi et al., 2021) regardless of the abundance of carbonates (i.e. 4.1 ± 0.1 wt. %).
View in article
In addition, Tarda shows a carbon content similar to Tagish Lake whereas no specific carbonate-rich lithology has been described so far (Marrocchi et al., 2021 and references therein).
View in article
Results obtained in this study demonstrate that Tarda and Tagish Lake, in addition to C, H, N isotope systematics (Marrocchi et al., 2021), present very similar compositions for noble gases.
View in article
Marty, B. Altwegg, K., Balsiger, H., Bar-Nun, A., Bekaert, D.V., Berthelier, J.J., Bieler, A., Briois, C., Calmonte, U., Combi, M., De Keyser, J., Fiethe, B., Fuselier, S.A., Gasc, S., Gombosi, T.I., Hansen, K.C., Hässig, M., Jackel, A., Kopp, E., Korth, A., Le Roy, L., Mall, U., Mousis, O., Owen, T., Reme, H., Rubin, M., Semon, T., Tzou, C.Y., Waite, J.H., Wurz, P. (2017) Xenon isotopes in 67P/Churyumov-Gerasimenko show that comets contributed to Earth’s atmosphere. Science 356, 1069–1072. https://doi.org/10.1126/science.aal3496
Show in context
The measurement of xenon isotopes in the coma of comet 67P/Churyumov-Gerasimenko revealed extreme 129Xe enrichment relative to 132Xe and the solar composition (Marty et al., 2017).
View in article
As this large monoisotopic excess would require unlikely 129I enrichment, it has been interpreted as originating from a specific nucleosynthetic process producing 129Xe that was sampled by icy bodies formed in the outer solar system (Marty et al., 2017).
View in article
Average 129Xe* excesses relative to SW-Xe (expressed in δ notation with δ129XeSW = (129Xe/132Xe)bulk/(129Xe/132Xe)SW − 1 × 1000) for the different types of chondrites and the comet 67P/C-G (data from Mazor et al., 1970; Marty et al., 2017 and this study).
View in article
Xenon in the Jupiter-family comet 67P/Churyumov-Gerasimenko (67P/C-G) presents a 129Xe excess and important, tens of percent 134−136Xe deficits relative to SW-Xe (Marty et al., 2017).
View in article
The former has been attributed as resulting from the contribution of parentless 129Xe and the latter of a mixture of two nucleosynthetic processes (i.e. s- and r-process; Marty et al., 2017) different from the one measured for most inner solar system material (Avice et al., 2020).
View in article
In addition, when combining data from all CCs and the comet 67P (Mazor et al., 1970; Clay et al., 2017; Marty et al., 2017), we observe an anti-correlation of their 127I content and the 129Xe excess (Fig. 3a), regardless of the available iodine dataset used (Fig. S-4).
View in article
Mazor, E., Heymann, D., Anders, E. (1970) Noble gases in carbonaceous chondrites. Geochimica et Cosmochimica Acta 34, 781–824. https://doi.org/10.1016/0016-7037(70)90031-1
Show in context
Elemental abundances of Ne, Ar, Kr and Xe in Tarda, Tagish Lake and Orgueil are similar to those reported for other volatile-rich carbonaceous chondrites (Table S-1; Mazor et al., 1970).
View in article
Average 129Xe* excesses relative to SW-Xe (expressed in δ notation with δ129XeSW = (129Xe/132Xe)bulk/(129Xe/132Xe)SW − 1 × 1000) for the different types of chondrites and the comet 67P/C-G (data from Mazor et al., 1970; Marty et al., 2017 and this study).
View in article
These meteorites are even showing among the weakest 129Xe* excesses measured in CCs (Fig. 3a; Mazor et al., 1970).
View in article
In addition, when combining data from all CCs and the comet 67P (Mazor et al., 1970; Clay et al., 2017; Marty et al., 2017), we observe an anti-correlation of their 127I content and the 129Xe excess (Fig. 3a), regardless of the available iodine dataset used (Fig. S-4).
View in article
As previously noticed (Mazor et al., 1970; Gilmour et al., 2001), such an inverse correlation could not result from the heterogeneous 129I distribution in the early solar system as the absolute concentrations of radiogenic 129Xe* vary by only a factor of ∼4 among CCs, while relative 129Xe* enrichments differ by a factor of 400.
View in article
Ott, U. (2002) Noble gases in meteorites - Trapped Components. Reviews in Mineralogy and Geochemistry 47, 71–100. https://doi.org/10.2138/rmg.2002.47.3
Show in context
For argon, 38Ar/36Ar ratios are compatible with either the atmospheric 38Ar/36Ar ratio (≈0.188; Ozima and Podosek, 2002) or the 38Ar/36Ar ratio of argon in phase Q (≈0.187; Ott, 2002).
View in article
Ott, U. (2014) Planetary and pre-solar noble gases in meteorites. Chemie der Erde - Geochemistry 74, 519–544. https://doi.org/10.1016/j.chemer.2014.01.003
Show in context
Although these elements are present in different carriers contained in meteorites (including presolar SiC, diamonds, graphite; Ott, 2014), they are mainly hosted in a phase − referred to as phase Q − whose nature is still poorly characterised (Busemann et al., 2000).
View in article
Neon three isotope plot for bulk samples of Tarda, Tagish Lake and Orgueil. The compositions of Ne-Q, Air, Ne-HL, Ne-E and cosmogenic (purple range) are also shown for comparison (see Ott, 2014 and Krietsch et al., 2021 and refs. therein).
View in article
Ozima, M., Podosek, F.A. (2002) Noble Gas Geochemistry. Cambridge University Press, Cambridge.
Show in context
For argon, 38Ar/36Ar ratios are compatible with either the atmospheric 38Ar/36Ar ratio (≈0.188; Ozima and Podosek, 2002) or the 38Ar/36Ar ratio of argon in phase Q (≈0.187; Ott, 2002).
View in article
However, the 40Ar/36Ar ratios range from 3 to 43, well below the atmospheric value (≈300, Ozima and Podosek, 2002), but typical for trapped argon contained in carbonaceous chondrites (Krietsch et al., 2021).
View in article
Riebe, M.E.I., Busemann, H., Alexander, C.M.O’D., Nittler, L.R., Herd, C.D.K., Maden, C., Wang, J., Wieler, R. (2020) Effects of aqueous alteration on primordial noble gases and presolar SiC in the carbonaceous chondrite Tagish Lake. Meteoritics & Planetary Science 55, 1257–1280. https://doi.org/10.1111/maps.13383
Show in context
The latter is likely due to the presence of Ne-E from presolar SiC or graphite (Riebe et al., 2020).
View in article
Vacher, L.G., Piani, L., Rigaudier, T., Thomassin, D., Florin, G., Piralla, M., Marrocchi, Y. (2020) Hydrogen in chondrites: Influence of parent body alteration and atmospheric contamination on primordial components. Geochimica et Cosmochimica Acta 281, 53–66. https://doi.org/10.1016/j.gca.2020.05.007
Show in context
The average δ129XeSW is plotted as a function of (a) the 127I content (data from Clay et al., 2017), (b) the carbon content (data from Vacher et al., 2020 and Marrocchi et al., 2021), and (c) the matrix abundance (data from Alexander et al., 2018).
View in article
CCs contains variable amounts of carbon with Tarda, Tagish Lake, CI and CM chondrites showing the highest concentrations (Fig. 3b; Kerridge, 1985; Vacher et al., 2020; Marrocchi et al., 2021).
View in article
Although both Tarda and Tagish Lake are depleted in fine grained matrix relative to CI chondrites (65–80 vs. 100 vol. %, Fig. 3c; Alexander et al., 2018), they appear enriched in C (i.e. ∼4 vs. 3.3 wt. %, Fig. 3b; Vacher et al., 2020; Marrocchi et al., 2021).
View in article
Wieler, R., Anders, E., Baur, H., Lewis, R.S., Signer, P. (1991) Noble gases in “phase Q”: Closed-system etching of an Allende residue. Geochimica et Cosmochimica Acta 55, 1709–1722. https://doi.org/10.1016/0016-7037(91)90141-Q
Show in context
Thanks to its extreme sensitivity to oxidation, the xenon isotopic composition of phase Q has been precisely determined, revealing a mass dependent isotopic fractionation relative to solar wind (SW-Xe) in favour of the heavy isotopes relative to the light ones (Wieler et al., 1991; Busemann et al., 2000; Gilmour, 2010).
View in article
top
Supplementary Information
The Supplementary Information includes:
Download Table S-1 (Excel).
Download the Supplementary Information (PDF).