Oxygen reservoirs in the early solar nebula inferred from an Allende CAI

Science

Volumn 282, Issue 5388, 1998, Pages 452-455

  Young, Edward D ^a   Russell, Sara S ^b  

^a UNIVERSITY OF OXFORD   (United Kingdom)

^b DEPARTMENT OF LIFE SCIENCES   (United Kingdom)

Author keywords

[No Author keywords available]

Indexed keywords

ALUMINUM; CALCIUM; OXYGEN; OXYGEN 18;

ASTRONOMY; LASER; PRIORITY JOURNAL; RESERVOIR; REVIEW;

METEOROIDS; OXYGEN; OXYGEN ISOTOPES; SOLAR SYSTEM;

EID: 0032538396     PISSN: 00368075     EISSN: None     Source Type: Journal    
DOI: 10.1126/science.282.5388.452     Document Type: Review

References (40)

1. Roughly 70 to 80% by mass of each of the terrestrial planets is composed of a silicate mantle. These mantles are composed of 48% by mass oxygen [H. Wänke and G. Dreibus, Philos. Trans. R. Soc. London A 325, 545 (1988); K. Lodders and B. Fegley Jr., Icarus 126, 373 (1997)]. The abundant OC meteorites are composed mainly of silicates and oxides, suggesting that the same is true for much of the asteroid belt (30).
2. Roughly 70 to 80% by mass of each of the terrestrial planets is composed of a silicate mantle. These mantles are composed of 48% by mass oxygen [H. Wänke and G. Dreibus, Philos. Trans. R. Soc. London A 325, 545 (1988); K. Lodders and B. Fegley Jr., Icarus 126, 373 (1997)]. The abundant OC meteorites are composed mainly of silicates and oxides, suggesting that the same is true for much of the asteroid belt (30).
3. A. P. Boss, Astrophys. J. 417, 351 (1993).
4. _, ibid. 469, 906 (1996); J. N. Cuzzi, A. R. Dobrovolskis, J. M. Champney, Icarus 106, 102 (1993).
5. _, ibid. 469, 906 (1996); J. N. Cuzzi, A. R. Dobrovolskis, J. M. Champney, Icarus 106, 102 (1993).
6. A. C. Cameron, Meteoritics 30, 133 (1995).
7. -1 and persisted for several million years (4). For a canonical disk mass and assuming that the sole source of accretion was the disk, material within 2 AU would have been consumed every 80,000 years during this interval.
8. C. J. Allègre, C. Manhès, C. Göpel, Geochim. Cosmochim. Acta 59, 1445 (1995). The Pb-Pb date for inclusion USNM 3576-1 was reported as sample A1/7 in their study.
9. R. N. Clayton, L. Grossman, T. K. Mayeda, Science 182, 485 (1973).
10. 18O are defined in an analogous fashion.
11. R. N. Clayton, N. Onuma, L. Grossman, T. K. Mayeda, Earth Planet. Sci. Lett. 34, 209 (1977).
12. R. N. Clayton, Annu. Rev. Earth Planet. Sci. 21, 115 (1993).
13. 16O. Homogeneity in Earth's initial oxygen reservoir is supported by lack of deviations from the average TF curve [F. Robert, A. Rejou-Michel, M. Javoy, Earth Planet. Sci. Lett. 108, 1 (1992)]. The relation between the average TF curve and other rocky bodies of the solar system is summarized in (37).
14. 16O. Homogeneity in Earth's initial oxygen reservoir is supported by lack of deviations from the average TF curve [F. Robert, A. Rejou-Michel, M. Javoy, Earth Planet. Sci. Lett. 108, 1 (1992)]. The relation between the average TF curve and other rocky bodies of the solar system is summarized in (37).
15. Recent studies of "space weathering" of asteroids (30) suggest that the dominance of OCs among the stony meteorites reflects the profusion of this material in the asteroid inner main belt and, by inference, in the protoplanetary inner solar system.
16. 18O of 5.8 per mil. These data suggest an accuracy of ±0.2 per mil or better and a precision of between ±0.1 and ±0.3 per mil at the time inclusion USNM 3576-1 was analyzed.
17. 18O of -30 per mil (9).
18. 18O) - 3.4 [R. N. Clayton and T. K. Mayeda, Earth Planet. Sci. Lett. 67, 151 (1984)].
19. Characteristic x-ray maps and backscattered electron images reveal the presence of localized patches of submicron alteration in otherwise pristine melilite throughout inclusion USNM 3576-1.
20. E. D. Young, D. W. Coutts, D. Kapitan, Geochim. Cosmochim. Acta, in press.
21. T. K. Mayeda, R. N. Clayton, H. Nagasawa, Lunar Planet. Sci. Conf. XVII, 526 (1986).
22. 16O alone, yielding a slope of 1.00 on a three-isotope plot.
23. 16O enrichment of CAIs relative to other rocky components of the solar system.
24. 16O enrichment of CAIs relative to other rocky components of the solar system.
25. I. Jabeen, M. Kusakabe, T. Nakamura, K. Nagao, Meteorit. Planet. Sci. 33, A76 (1998); K. D. McKeegan, L. A. Leshin, G. J. MacPherson, ibid., p. A102.
26. I. Jabeen, M. Kusakabe, T. Nakamura, K. Nagao, Meteorit. Planet. Sci. 33, A76 (1998); K. D. McKeegan, L. A. Leshin, G. J. MacPherson, ibid., p. A102.
27. N. Onuma, R. N. Clayton, T. K. Mayeda, Geochim. Cosmochim. Acta 36, 169 (1972).
28. E. D. Young, H. Nagahara, B. O. Mysen, D. M. Audet, ibid., in press.
29. S. S. Russell et al., ibid. 62, 689 (1998).
30. 18O of +5.7 per mil in 36 hours, whereas the outer edge of the molten sphere is shifted by +17.2 per mil in 15 min. The smaller oxygen diffusivities of O in solid pyroxene and spinel make preservation of heavy isotope enrichment in their evaporative residues unlikely.
31. F. J. Ryerson and K. D. McKeegan, Geochim. Cosmochim. Acta 58, 3713 (1994).
32. S. Yoneda and L. Grossman, ibid. 59, 3413 (1995).
33. D. S. Ebel and L. Grossman, Lunar Planet. Sci. Conf. XXIX (1998) [CD-ROM]; J. M. Allen, L. Grossman, A. M. Davis, I. D. Hutcheon, ibid. IX, 1209 (1978).
34. D. S. Ebel and L. Grossman, Lunar Planet. Sci. Conf. XXIX (1998) [CD-ROM]; J. M. Allen, L. Grossman, A. M. Davis, I. D. Hutcheon, ibid. IX, 1209 (1978).
35. Large differences in temperature could be sustained for no more than a few tens of seconds because length scales for thermal diffusion in mineral materials are comparable to the size of the CAI over this time scale; either heating was on the order of a second, or kinetic barriers must have existed if partial melting was confined to the rim of the inclusion and mantles surrounding fassaite.
36. C. R. Chapman, Meteorit. Planet. Sci. 31, 699 (1996).
37. R. N. Clayton, N. Onuma, T. K. Mayeda, Earth Planet. Sci. Lett. 30, 10 (1976).
38. D. D. Clayton, Astrophys. J. 334, 191 (1988).
39. _ and K. Liffman, ibid. 346, 531 (1989).
40. Funding was provided by an award from the National Environment Research Council, UK. USNM 3576-1 was supplied by J. Arden.