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Structure and thermal history of the H-chondrite parent asteroid revealed by thermochronometry


Our Solar System formed 4.6 billion years ago from the collapse of a dense core inside an interstellar molecular cloud. The subsequent formation of solid bodies took place rapidly. The period of <10 million years over which planetesimals were assembled can be investigated through the study of meteorites1,2,3. Although some planetesimals differentiated and formed metallic cores like the larger terrestrial planets, the parent bodies of undifferentiated chondritic meteorites experienced comparatively mild thermal metamorphism that was insufficient to separate metal from silicate4,5. There is debate about the nature of the heat source6,7,8,9 as well as the structure and cooling history of the parent bodies10,11,12. Here we report a study of 244Pu fission-track and 40Ar–39Ar thermochronologies of unshocked H chondrites, which are presumed to have a common, single, parent body. We show that, after fast accretion, an internal heating source (most probably 26Al decay8,9,10,13) resulted in a layered parent body6 that cooled relatively undisturbed: rocks in the outer shells reached lower maximum metamorphic temperatures and cooled faster than the more recrystallized and chemically equilibrated rocks from the centre, which needed 160 Myr to reach 390K.

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Figure 1: Onion-shell model for undifferentiated ordinary chondrite parent asteroids6. A celestial body that is internally heated (probably by the decay energy from short-lived 26Al) reaches higher maximum metamorphic temperatures in its centre, resulting in higher petrologic types (numbers shown) that cool slower than in the outer layers, which in turn results in lower petrologic types with faster cooling.
Figure 2: Correlation between cooling ages and metamorphic grade.
Figure 3: Integrated cooling curves for all H chondrites where complete chronological information is available.


  1. Chen, J. H. & Wasserburg, G. J. The isotopic composition of uranium and lead in Allende inclusions and meteoritic phosphates. Earth Planet. Sci. Lett. 5, 15–21 (1981)

    Google Scholar 

  2. Allègre, C. J., Manhès, G. & Göpel, C. The age of the Earth. Geochim. Cosmochim. Acta 59, 1445–1456 (1995)

    Article  ADS  Google Scholar 

  3. Lugmair, G. W. & Galer, S. J. G. Age and isotopic relationships among the angrites Lewis Cliff 86010 and Angra dos Reis. Geochim. Cosmochim. Acta 56, 1673–1694 (1992)

    Article  ADS  CAS  Google Scholar 

  4. van Schmus, W. R. & Wood, J. A. A chemical-petrologic classification for the chondritic meteorites. Geochim. Cosmochim. Acta 31, 747–765 (1967)

    Article  ADS  CAS  Google Scholar 

  5. Dodd, R. T. Metamorphism of the ordinary chondrites: a review. Geochim. Cosmochim. Acta 33, 161–203 (1969)

    Article  ADS  CAS  Google Scholar 

  6. Herndon, J. M. & Herndon, M. A. Aluminium-26 as a planetoid heat source in the early solar system. Meteoritics 12, 459–465 (1977)

    Article  ADS  CAS  Google Scholar 

  7. Wood, J. A. & Pellas, P. in The Sun in Time (eds Sonett, C. P., Giampapa, M. S. & Matthews, M. S.) 741–760 (Univ. of Arizona Press, Tucson, 1991)

    Google Scholar 

  8. Lee, T., Papanastassiou, D. A. & Wasserburg, G. W. Demonstration of 26Mg excess in Allende and evidence for 26Al. Geophys. Res. Lett. 3, 109–112 (1976)

    Article  ADS  CAS  Google Scholar 

  9. Knodlseder, J., Cervino, M., Le Duigou, J. M., Meynet, G., Schaerer, D. & von Ballmoos, P. Gamma-ray line emission from OB associations and young open clusters–II. The Cygnus region. Astron. Astrophys. 390, 945–960 (2002)

    Article  ADS  Google Scholar 

  10. Miyamoto, M., Fujii, N. & Takeda, H. Ordinary chondrite parent body: an internal heating model. In Proc. Lunar Planet. Sci. Conf. 12B, 1145–1152 (1981)

    ADS  Google Scholar 

  11. Scott, E. R. D. & Rajan, R. S. Metallic minerals, thermal histories and parent bodies of some xenolithic, ordinary chondrite meteorites. Geochim. Cosmochim. Acta 45, 53–67 (1981)

    Article  ADS  CAS  Google Scholar 

  12. Grimm, R. E. Penecontemporaneous metamorphism, fragmentation, and reassembly of ordinary chondrite parent bodies. J. Geophys. Res. 90(B2), 2022–2028 (1985)

    Article  ADS  Google Scholar 

  13. Zinner, E. & Göpel, C. Aluminum-26 in H4 chondrites: implications for its production and its usefulness as a fine-scale chronometer for early solar system events. Meteoritics Planet. Sci. 37, 1001–1013 (2002)

    Article  ADS  CAS  Google Scholar 

  14. Wood, J. A. The cooling rates and parent planets of several iron meteorites. Icarus 3, 429–459 (1964)

    Article  ADS  CAS  Google Scholar 

  15. Taylor, G. J., Maggiore, P., Scott, E. R. D., Rubin, A. E. & Keil, K. Original structures, and fragmentation and reassembly histories of asteroids: evidence from meteorites. Icarus 69, 1–13 (1987)

    Article  ADS  CAS  Google Scholar 

  16. Jordan, J., Kirsten, T. & Richter, H. 129I/127I: a puzzling early solar system chronometer. Z. Naturforsch. 35(a), 145–170 (1980)

    ADS  Google Scholar 

  17. Cherniak, D., Lanford, W. A. & Ryerson, F. J. Lead diffusion in apatite and zircon using ion implantation and Rutherford backscattering techniques. Geochim. Cosmochim. Acta 55, 1663–1673 (1991)

    Article  ADS  CAS  Google Scholar 

  18. Göpel, C., Manhès, G. & Allègre, C. J. U–Pb systematics of phosphates from equilibrated ordinary chondrites. Earth Planet. Sci. Lett. 121, 153–171 (1994)

    Article  ADS  Google Scholar 

  19. Pellas, P., Fieni, C., Trieloff, M. & Jessberger, E. K. The cooling history of the Acapulco meteorite as recorded by the 244Pu and 40Ar–39Ar chronometers. Geochim. Cosmochim. Acta 61, 3477–3501 (1997)

    Article  ADS  CAS  Google Scholar 

  20. Turner, G., Enright, M. C. & Cadogan, P. H. The early history of chondrite parent bodies inferred from 40Ar–39Ar ages. Proc. Lunar Planet. Sci. Conf. 9, 989–1025 (1978)

    ADS  Google Scholar 

  21. Lavielle, B., Marti, K., Pellas, P. & Perron, C. Search for extinct 248Cm in the early Solar System. Meteoritics 27, 382–386 (1992)

    Article  ADS  CAS  Google Scholar 

  22. Steiger, R. H. & Jäger, E. Subcommission on Geochronology: convention on the use of decay constants in geo- and cosmochronology. Earth Planet. Sci. Lett. 36, 359–362 (1977)

    Article  ADS  CAS  Google Scholar 

  23. Renne, P. R. 40Ar/39Ar age of plagioclase from Acapulco meteorite and the problem of systematic errors in cosmochronology. Earth Planet. Sci. Lett. 175, 13–26 (2000)

    Article  ADS  CAS  Google Scholar 

  24. Begemann, F. et al. Call for an improved set of decay constants for geochronological use. Geochim. Cosmochim. Acta 65, 111–121 (2001)

    Article  ADS  CAS  Google Scholar 

  25. Trieloff, M., Jessberger, E. K. & Fiéni, C. Comment on ‘40Ar/39Ar age of plagioclase from Acapulco meteorite and the problem of systematic errors in cosmochronology’ by Paul R. Renne. Earth Planet. Sci. Lett. 190, 267–269 (2001)

    Article  ADS  CAS  Google Scholar 

  26. Brazzle, R. H., Pravdivtseva, O. V., Meshik, A. P. & Hohenberg, C. M. Verification and interpretation of the I–Xe chronometer. Geochim. Cosmochim. Acta 63, 739–760 (1999)

    Article  ADS  CAS  Google Scholar 

  27. Pravec, P. & Harris, A. W. Fast and slow rotation of asteroids. Icarus 148, 12–20 (2000)

    Article  ADS  Google Scholar 

  28. Pellas, P. & Storzer, D. Mesures des taux de refroidissement des chondrites ordinaires à partir des traces de fission du plutonium 244 enregistrées dans les cristaux détecteurs. C. R. Acad. Sci. III D 280, 225–228 (1975)

    ADS  CAS  Google Scholar 

  29. Trieloff, M., Deutsch, A. & Jessberger, E. K. The age of the Kara impact structure, Russia. Meteoritics Planet. Sci. 33, 361–372 (1998)

    Article  ADS  CAS  Google Scholar 

  30. Schaeffer, G. A. & Schaeffer, O. A. 40Ar–39Ar ages of lunar rocks. Proc. Lunar Planet. Sci. Conf. 8, 2253–2300 (1977)

    ADS  CAS  Google Scholar 

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We thank B. Dominik for mineral separation, A. Bouikine and E. Korotchantseva for assisting in 40Ar–39Ar analyses, and D. Stöffler for shock-stage classification of some H chondrites. We appreciate discussions with J.A. Wood, E. Anders and T. Althaus, and support from R. Altherr, T. Kirsten and K. Mauersberger at various stages of this study. M.T., E.K.J. and J.H. acknowledge support from the Deutsche Forschungsgemeinschaft.Author contributions P.P. provided the motivation for this research by his enthusiastic work on 244Pu fission-track studies.

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Correspondence to Mario Trieloff.

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Trieloff, M., Jessberger, E., Herrwerth, I. et al. Structure and thermal history of the H-chondrite parent asteroid revealed by thermochronometry. Nature 422, 502–506 (2003).

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