Abstract
The Moon is thought to have formed from debris ejected by a giant impact with the early ‘proto’-Earth1 and, as a result of the high energies involved, the Moon would have melted to form a magma ocean. The timescales for formation and solidification of the Moon can be quantified by using 182Hf–182W and 146Sm–142Nd chronometry2,3,4, but these methods have yielded contradicting results. In earlier studies3,5,6,7, 182W anomalies in lunar rocks were attributed to decay of 182Hf within the lunar mantle and were used to infer that the Moon solidified within the first ∼60 million years of the Solar System. However, the dominant 182W component in most lunar rocks reflects cosmogenic production mainly by neutron capture of 181Ta during cosmic-ray exposure of the lunar surface3,7, compromising a reliable interpretation in terms of 182Hf–182W chronometry. Here we present tungsten isotope data for lunar metals that do not contain any measurable Ta-derived 182W. All metals have identical 182W/184W ratios, indicating that the lunar magma ocean did not crystallize within the first ∼60 Myr of the Solar System, which is no longer inconsistent with Sm–Nd chronometry8,9,10,11. Our new data reveal that the lunar and terrestrial mantles have identical 182W/184W. This, in conjunction with 147Sm–143Nd ages for the oldest lunar rocks8,9,10,11, constrains the age of the Moon and Earth to Myr after formation of the Solar System. The identical 182W/184W ratios of the lunar and terrestrial mantles require either that the Moon is derived mainly from terrestrial material or that tungsten isotopes in the Moon and Earth’s mantle equilibrated in the aftermath of the giant impact, as has been proposed to account for identical oxygen isotope compositions of the Earth and Moon12.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 51 print issues and online access
$199.00 per year
only $3.90 per issue
Buy this article
- Purchase on Springer Link
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
References
Canup, R. M. & Asphaug, E. Origin of the Moon in a giant impact near the end of the Earth’s formation. Nature 412, 708–712 (2001)
Nyquist, L. E. et al. Sm-146–Nd-142 formation interval for the lunar mantle. Geochim. Cosmochim. Acta 59, 2817–2837 (1995)
Kleine, T., Palme, H., Mezger, K. & Halliday, A. N. Hf–W chronometry of lunar metals and the age and early differentiation of the Moon. Science 310, 1671–1674 (2005)
Rankenburg, K., Brandon, A. D. & Neal, C. R. Neodymium isotope evidence for a chondritic composition of the Moon. Science 312, 1369–1372 (2006)
Lee, D. C., Halliday, A. N., Leya, I., Wieler, R. & Wiechert, U. Cosmogenic tungsten and the origin and earliest differentiation of the Moon. Earth Planet. Sci. Lett. 198, 267–274 (2002)
Lee, D. C., Halliday, A. N., Snyder, G. A. & Taylor, L. A. Age and origin of the moon. Science 278, 1098–1103 (1997)
Leya, I., Wieler, R. & Halliday, A. N. Cosmic-ray production of tungsten isotopes in lunar samples and meteorites and its implications for Hf–W cosmochemistry. Earth Planet. Sci. Lett. 175, 1–12 (2000)
Borg, L. E. et al. Isotopic studies of ferroan anorthosite 62236: A young lunar crustal rock from a light rare-earth-element-depleted source. Geochim. Cosmochim. Acta 63, 2679–2691 (1999)
Carlson, R. W. & Lugmair, G. W. The age of ferroan anorthosite 60025: oldest crust on a young Moon? Earth Planet. Sci. Lett. 90, 119–130 (1988)
Norman, M. D., Borg, L. E., Nyquist, L. E. & Bogard, D. D. Chronology, geochemistry, and petrology of a ferroan noritic anorthosite clast from Descartes breccia 67215: Clues to the age, origin, structure, and impact history of the lunar crust. Meteorit. Planet. Sci. 38, 645–661 (2003)
Nyquist, L. et al. Feldspathic clasts in Yamato-86032: Remnants of the lunar crust with implications for its formation and impact history. Geochim. Cosmochim. Acta 70, 5990–6015 (2006)
Pahlevan, K. & Stevenson, D. J. Equilibration in the aftermath of the lunar-forming giant impact. Earth Planet. Sci. Lett. 262, 438–449 (2007)
Leya, I., Wieler, R. & Halliday, A. N. The influence of cosmic-ray production on extinct nuclide systems. Geochim. Cosmochim. Acta 67, 529–541 (2003)
Kleine, T., Mezger, K., Palme, H., Scherer, E. & Münker, C. Early core formation in asteroids and late accretion of chondrite parent bodies: Evidence from 182Hf–182W in CAIs, metal-rich chondrites and iron meteorites. Geochim. Cosmochim. Acta 69, 5805–5818 (2005)
Shearer, C. K. & Papike, J. J. Magmatic evolution of the Moon. Am. Mineral. 84, 1469–1494 (1999)
Palme, H. & Wänke, H. A unified trace-element model for the evolution of the lunar crust and mantle. Proc. Lunar Sci. Conf. 6th 1179–1202 (1975)
Shearer, C. K. & Newsom, H. E. W–Hf isotope abundances and the early origin and evolution of the Earth–Moon system. Geochim. Cosmochim. Acta 64, 3599–3613 (2000)
Righter, K. & Shearer, C. K. Magmatic fractionation of Hf and W: Constraints on the timing of core formation and differentiation in the Moon and Mars. Geochim. Cosmochim. Acta 67, 2497–2507 (2003)
Solomatov, V. S. in Origin of the Earth and Moon (eds Canup, R. M. & Righter, K.) 323–338 (Lunar and Planetary Institute, Houston, TX, 2000)
Newsom, H. E. et al. The depletion of W in the bulk silicate Earth: constraints on core formation. Geochim. Cosmochim. Acta 60, 1155–1169 (1996)
Palme, H. & Rammensee, W. The significance of W in planetary differentiation processes: Evidence from new data on eucrites. Proc. 12th Lunar Planet. Sci. Conf. 949–964 (1981)
Allègre, C. J., Dupre, B. & Lewin, E. Thorium uranium ratio of the Earth. Chem. Geol. 56, 219–227 (1986)
Rocholl, A. & Jochum, K. P. Th, U and other trace elements in carbonaceous chondrites: Implications for the terrestrial and solar-system Th/U ratios. Earth Planet. Sci. Lett. 117, 265–278 (1993)
Jacobsen, S. B. The Hf–W isotopic system and the origin of the Earth and Moon. Annu. Rev. Earth Planet. Sci. 33, 531–570 (2005)
Boyet, M. & Carlson, R. W. 142Nd evidence for early (>4.53 Ga) global differentiation of the silicate Earth. Science 309, 576–581 (2005)
Allègre, C. J., Manhes, G. & Gopel, C. The age of the Earth. Geochim. Cosmochim. Acta 59, 1445–1456 (1995)
Kleine, T., Mezger, K., Palme, H., Scherer, E. & Münker, C. The W isotope evolution of the bulk silicate Earth: constraints on the timing and mechanisms of core formation and accretion. Earth Planet. Sci. Lett. 228, 109–123 (2004)
Nimmo, F. & Agnor, C. B. Isotopic outcomes of N-body accretion simulations: Constraints on equilibration processes during large impacts from Hf/W observations. Earth Planet. Sci. Lett. 243, 26–43 (2006)
Wiechert, U. et al. Oxygen isotopes and the moon-forming giant impact. Science 294, 345–348 (2001)
Kleine, T., Mezger, K., Palme, H., Scherer, E. & Münker, C. The W isotope composition of eucrites metal: Constraints on the timing and cause of the thermal metamorphism of basaltic eucrites. Earth Planet. Sci. Lett. 231, 41–52 (2005)
Acknowledgements
We thank the Curation and Analysis Planning Team for Extraterrestrial Materials (CAPTEM), NASA curatorial staff; G. Lofgren for supplying the Apollo lunar samples; L. Borg and A. Brandon for reviews; and F. Nimmo and J. Van Orman for discussions. This research was supported by a EU Marie Curie postdoctoral fellowship to T. Kleine.
Author information
Authors and Affiliations
Corresponding author
Supplementary information
Supplementary Information
The file contains Supplementary Notes including descriptions of: the lunar metals, the analytical methods, the cosmogenic effects on W isotope ratios in lunar samples and the Hf/W fractionation in the crystallizing lunar magma ocean. It also contains Supplementary Table 1 summarizing the calculated cosmogenic corrections for the data presented in the main text, as well as Supplemental Figure 1 illustrating the two stage model age of the lunar mantle. (PDF 250 kb)
Rights and permissions
About this article
Cite this article
Touboul, M., Kleine, T., Bourdon, B. et al. Late formation and prolonged differentiation of the Moon inferred from W isotopes in lunar metals. Nature 450, 1206–1209 (2007). https://doi.org/10.1038/nature06428
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1038/nature06428
This article is cited by
-
Detection of apatite in ferroan anorthosite indicative of a volatile-rich early lunar crust
Nature Astronomy (2024)
-
Moon’s high-energy giant-impact origin and differentiation timeline inferred from Ca and Mg stable isotopes
Communications Earth & Environment (2023)
Comments
By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.