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Mn−Cr ages of Fe-rich olivine in two Rumuruti (R) chondrites

Abstract

Mn−Cr systematics in olivine of two Rumuruti (R) chondrites was investigated. Mn/52Cr ratios up to 1800 and 1300, and δ53Cr of up to 25‰ and 7‰ were observed for NWA 753 and Sahara 99531, respectively. All data points of NWA 753 show a linear correlation between δ53Cr values and Mn/52Cr ratios on the isochron diagram. The inferred initial 53Mn/55Mn ratio for NWA 753 is (1.84 ± 0.42(2σ)) × 10−6. In the case of Sahara 99531, a positive correlation interpreted as an isochron for 53Mn/55Mn = 2.75 ± 1.55(2σ) × 10−6 was obtained for only one chondrule. Data from other chondrules in Sahara 99531 give an upper limit of 53Mn/55Mn = 0.49 × 10−6. The Mn−Cr ages of NWA 753 and a chondrule in Sahara 99531 are slightly older than that of the angrite LEW 86010 (Lugmair and Shukolyukov, 1998). Other chondrules in Sahara 99531 are at least 5 Ma younger than the LEW 86010. The Mn-Cr ages of olivine in R chondrites correspond to the time when olivine became a closed system either during slow cooling from the peak metamorphic temperature or during rapid cooling by impact excavation. In either case the olivine closure occurred earlier than the final assembly of the brecciated chondrites.

References

  1. Amelin, Y., A. N. Krot, I. D. Hutcheon, and A. A. Ulyanov, Lead isotopic ages of chondrules and calcium-aluminum-rich inclusions, Science, 297, 1678–1683, 2002.

    Article  Google Scholar 

  2. Baker, J., M. Bizzaro, N. Wittig, J. Connelly, and H. Haack, Early planetesimal melting from an age of 4.5562 Gyr for differentiated meteorites, Nature, 436, 1127–1131, 2005.

    Article  Google Scholar 

  3. Bischoff, A., Mineral characterization of primitive, type −3 lithologies in Rumuruti chondrites, Meteoritics & Planet. Sci., 35, 699–706, 2000.

    Article  Google Scholar 

  4. Bischoff, A., T. Geiger, H. Palme, B. Spettel, L. Schultz, P. Scherer, T. Loeken, P. Bland, R. N. Clayton, T. K. Mayeda, U. Herpers, B. Meltzow, R. Michel, and B. Dittrich-Hannen, Acfer 217—A new member of the Rumuruti chondrite group (R), Meteoritics, 29, 264–274, 1994.

    Article  Google Scholar 

  5. Bischoff, A. and G. Srinivasan, Mg-26 excess in hibonites of the Rumuruti chondrite Hughes 030, Meteorotics & Planetary Sci., 38, 5–12, 2003.

    Article  Google Scholar 

  6. Dixon, E. T., D. D. Bogard, and D. H. Garrison, 39Ar-40Ar chronology of R chondrites, Meteoritics & Planetary Sci., 38, 341–355, 2003.

    Article  Google Scholar 

  7. Ebisawa, N., J. Park, and K. Nagao, Noble gases in Northwest Africa 753 (NWA 753), Rumuruti chondrites, Geochim. Cosmochim. Acta, 67(A84), 2003.

    Google Scholar 

  8. Greenwood, J. P., A. E. Rubin, and J. T. Wasson, Oxygen isotopes in R-chondrite magnetite and olivine: Links between R chondrites and ordinary chondrites, Geochim. Cosmochim. Acta, 64, 3897–3911, 2000.

    Article  Google Scholar 

  9. Grossman, J. N. and A. J. Brearley, The onset of metamorphism in ordinary and carbonaceous chondrites, Meteoritics & Planetary Sci., 40, 87–122, 2005.

    Article  Google Scholar 

  10. Hsu, W., Mn−Cr systematics of pallasites, Geochem. J., 39, 311–316, 2005.

    Article  Google Scholar 

  11. Hua, X., G. R. Huss, S. Tachibana, and T. G. Sharp, Oxygen, silicon, and Mn−Cr isotopes of fayalite in the Kaba oxidized CV3 chondrite: Constraints for its formation history, Geochim. Cosmochim. Acta, 1333–1348, 2005.

    Google Scholar 

  12. Ito, M. and J. Ganguly, Diffusion kinetics of Cr in olivine and 53Mn−53Cr thermo-chronology of early solar system objects, Geochim. Cosmochim. Acta, 70, 799–809, 2006.

    Article  Google Scholar 

  13. Kallemeyn, G.W., A. E. Rubin, and J. T. Wasson, The compositional classification of chondrites 7. The R chondrite group, Geochim. Cosmochim Acta, 60, 2243–2256, 1996.

    Article  Google Scholar 

  14. Kita, N., H. Nagahara, S. Togashi, and Y. Morishita, A short duration of chondrule formation in the solar nebula: Evidence from 26Al in Semarkona ferromagnesian chondrules, Geochim. Cosmochim. Acta, 64, 3913–3922, 2000.

    Article  Google Scholar 

  15. Krot, A. N., A. J. Brearley, M. Petaev, G. W. Kallemeyn, D. W. G. Sears, P. Benoit, I. D. Hutcheon, M. E. Zolensky, and K. Keil, Evidence for low temperature growth of fayalite and hedenbergite in MacAlpine Hills 88107, an ungrouped carbonaceous chondrites related to the CM-CO clan, Meteoritics & Planetary Sci., 35, 1365–1386, 2000.

    Article  Google Scholar 

  16. Lugmair, G.W. and A. Shukolyukov, Early solar system timescales according to 53Mn−53Cr systematics, Geochim. Cosmochim. Acta, 62, 2863–2886, 1998.

    Article  Google Scholar 

  17. Nakagawa, Y., C. Hayashi, and K. Nakazawa, Accumulation of planetesimals in the solar nebula, Icarus, 54, 361–376, 1983.

    Article  Google Scholar 

  18. Nyquist, L., L. Lindstrom, D. Mittlefehldt, C.-Y. Shih, H. Weismann, S. Wentworth, and R. Martinez, Manganese-chromium formation intervals for chondrules from the Bishumpur and Chainpur meteorites, Meteoritics & Planetary Sci., 36, 911–938, 2001.

    Article  Google Scholar 

  19. Rubin, A. and G. W. Kallemeyn, Pecora Escarpment 91002: A member of the new Rumuruti (R) chondrite group, Meteoritics, 29, 255–264, 1994.

    Article  Google Scholar 

  20. Schultz, L. and H. W. Weber, The irradiation history of Rumurutichondrites, 26th Symp. Ant. Met. p.128, 2001.

    Google Scholar 

  21. Schultz, L., H. W. Weber, and L. Franke, Rumuruti chondrites: Noble gases, exposure ages, pairing, and parent body history, Meteoritics & Planetary Sci., 40, 557–571, 2005.

    Article  Google Scholar 

  22. Schulze, H., A. Bischoff, H. Palme, B. Spettel, D. Dreibus, and J. Otto, Mineralogy and chemistry of Rumuruti: The first meteorite fall of the new R chondrite group, Meteoritics, 29, 275–286, 1994.

    Article  Google Scholar 

  23. Sugiura, N. and H. Hoshino, Mn−Cr chronology of five IIIAB iron meteorites, Meteoritics & Planet. Sci., 38, 117–144, 2003.

    Article  Google Scholar 

  24. Sugiura, N., A. Miyazaki, and K. Yanai, Widespread magmatic activities on the angrite parent body at 4562 Ma ago, Earth Planets Space, 57, e13–e16, 2005.

    Article  Google Scholar 

  25. Turner, G., M. C. Enright, and P. H. Cadogan, The early history of chondrites parent bodies inferred from 40Ar-39Ar ages, Proc. 9th Lunar Planet. Sci. Conf., pp. 989–1025, 1978.

    Google Scholar 

  26. Weisberg, M. K., M. Prinz, H. Kojima, K. Yanai, R. N. Clayton, and T. K. Mayeda, The Carlisle Lakes-type chondrites: A new grouplet with high δ17O and evidence for nebula oxidation, Geochim. Cosmochim. Acta, 55, 2657–2669, 1991.

    Article  Google Scholar 

  27. Yomogida, K. and T. Matsui, Physical-properties of ordinary chondrites, J. Geophys. Res., 88, 9513–9533, 1983.

    Article  Google Scholar 

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Correspondence to Naoji Sugiura.

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Sugiura, N., Miyazaki, A. Mn−Cr ages of Fe-rich olivine in two Rumuruti (R) chondrites. Earth Planet Sp 58, 689–694 (2006). https://doi.org/10.1186/BF03351966

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Key words

  • Age
  • chondrites
  • olivine
  • Mn
  • Cr