Movatterモバイル変換

[0]ホーム
URL:

Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Advertisement

Nature
  • Article
  • Published:

Moon-forming impactor as a source of Earth’s basal mantle anomalies

Naturevolume 623, pages95–99 (2023)Cite this article

Subjects

Abstract

Seismic images of Earth’s interior have revealed two continent-sized anomalies with low seismic velocities, known as the large low-velocity provinces (LLVPs), in the lowermost mantle1. The LLVPs are often interpreted as intrinsically dense heterogeneities that are compositionally distinct from the surrounding mantle2. Here we show that LLVPs may represent buried relics of Theia mantle material (TMM) that was preserved in proto-Earth’s mantle after the Moon-forming giant impact3. Our canonical giant-impact simulations show that a fraction of Theia’s mantle could have been delivered to proto-Earth’s solid lower mantle. We find that TMM is intrinsically 2.0–3.5% denser than proto-Earth’s mantle based on models of Theia’s mantle and the observed higher FeO content of the Moon. Our mantle convection models show that dense TMM blobs with a size of tens of kilometres after the impact can later sink and accumulate into LLVP-like thermochemical piles atop Earth’s core and survive to the present day. The LLVPs may, thus, be a natural consequence of the Moon-forming giant impact. Because giant impacts are common at the end stages of planet accretion, similar mantle heterogeneities caused by impacts may also exist in the interiors of other planetary bodies.

This is a preview of subscription content,access via your institution

Access options

Access through your institution

Access Nature and 54 other Nature Portfolio journals

Get Nature+, our best-value online-access subscription

9,800 Yen / 30 days

cancel any time

Subscription info for Japanese customers

We have a dedicated website for our Japanese customers. Please go tonatureasia.com to subscribe to this journal.

Buy this article

  • Purchase on SpringerLink
  • Instant access to full article PDF

Prices may be subject to local taxes which are calculated during checkout

Fig. 1: Schematic diagram illustrating the giant-impact origin of the LLVPs.
Fig. 2: Density profiles of the TMM and the BSE as a function of pressure.
Fig. 3: The formation of LLVP-like thermochemical piles from intrinsically dense TMM.

Similar content being viewed by others

Data availability

All data and parameters are available in the main text or the supplementary materials. The data that support the findings of this study are also available athttps://doi.org/10.6084/m9.figshare.24013776.v1. Source data are provided with this paper.

Code availability

The author’s modified 2D Citcom code used in this study is available fromhttps://figshare.com/projects/Yuan_Li_2022_NG/129185. The GIZMO code is made available athttp://www.tapir.caltech.edu/~phopkins/Site/GIZMO.html. SWIFT is publicly available athttp://swiftsim.com. WoMa is publicly available athttps://github.com/srbonilla/WoMa, or the Python module can be installed directly with pip (https://pypi.org/project/woma/).

References

  1. Garnero, E. J., McNamara, A. K. & Shim, S. H. Continent-sized anomalous zones with low seismic velocity at the base of Earth’s mantle.Nat. Geosci.9, 481–489 (2016).

    Article CAS ADS  Google Scholar 

  2. Labrosse, S., Hernlund, J. W. & Coltice, N. A crystallizing dense magma ocean at the base of the Earth’s mantle.Nature450, 866–869 (2007).

    Article CAS PubMed ADS  Google Scholar 

  3. Canup, R. M. & Asphaug, E. Origin of the Moon in a giant impact near the end of the Earth’s formation.Nature412, 708–712 (2001).

    Article CAS PubMed ADS  Google Scholar 

  4. Kokubo, E. & Ida, S. Orbital evolution of protoplanets embedded in a swarm of planetesimals.Icarus114, 247–257 (1995).

    Article ADS  Google Scholar 

  5. Cameron, A. G. W. & Ward, W. R. The origin of the Moon.Abstr. Lunar Planet. Sci. Conf.7, 120–122 (1976).

    ADS  Google Scholar 

  6. Ringwood, A. E. Volatile and siderophile element geochemistry of the Moon: a reappraisal.Earth Planet. Sci. Lett.111, 537–555 (1992).

    Article CAS ADS  Google Scholar 

  7. Nie, N. X. & Dauphas, N. Vapor drainage in the protolunar disk as the cause for the depletion in volatile elements of the Moon.Astrophys. J.884, L48 (2019).

    Article CAS ADS  Google Scholar 

  8. Lee, C. T. A. et al. Upside-down differentiation and generation of a primordial lower mantle.Nature463, 930–933 (2010).

    Article CAS PubMed ADS  Google Scholar 

  9. Christensen, U. R. & Hofmann, A. W. Segregation of subducted oceanic crust in the convecting mantle.J. Geophys. Res.99, 19867–19884 (1994).

    Article CAS ADS  Google Scholar 

  10. Williams, C. D., Mukhopadhyay, S., Rudolph, M. L. & Romanowicz, B. Primitive helium is sourced from seismically slow regions in the lowermost mantle.Geochem. Geophys. Geosyst.20, 4130–4145 (2019).

    Article CAS ADS  Google Scholar 

  11. Mukhopadhyay, S. Early differentiation and volatile accretion recorded in deep-mantle neon and xenon.Nature486, 101–104 (2012).

    Article CAS PubMed ADS  Google Scholar 

  12. Desch, S. J. & Robinson, K. L. A unified model for hydrogen in the Earth and Moon: no one expects the Theia contribution.Chemie der Erde79, 125546 (2019).

    Article ADS  Google Scholar 

  13. Pepin, R. O. & Porcelli, D. Origin of noble gases in the terrestrial planets.Rev. Mineral. Geochem.47, 191–246 (2002).

    Article CAS  Google Scholar 

  14. Burke, K., Steinberger, B., Torsvik, T. H. & Smethurst, M. A. Plume generation zones at the margins of large low shear velocity provinces on the core–mantle boundary.Earth Planet. Sci. Lett.265, 49–60 (2008).

    Article CAS ADS  Google Scholar 

  15. Will, P., Busemann, H., Riebe, M. E. I. & Maden, C. Indigenous noble gases in the Moon’s interior.Sci. Adv.8, 1–9 (2022).

    Article  Google Scholar 

  16. Stewart, S. et al. The shock physics of giant impacts: key requirements for the equations of state.AIP Conf. Proc.2272, 080003 (2020).

    Article  Google Scholar 

  17. Kegerreis, J. A., Eke, V. R., Massey, R. J., Sandnes, T. D. & Teodoro, L. F. A. Immediate origin of the Moon as a post-impact satellite.Astrophys. J. Lett.937, L40 (2022).

    Article ADS  Google Scholar 

  18. Deng, H. et al. Enhanced mixing in Giant Impact simulations with a new Lagrangian method.Astrophys. J.870, 127 (2019).

    Article CAS ADS  Google Scholar 

  19. Deng, H. et al. Primordial Earth mantle heterogeneity caused by the Moon-forming Giant Impact?Astrophys. J.887, 211 (2019).

    Article CAS ADS  Google Scholar 

  20. Cottaar, S. & Lekic, V. Morphology of seismically slow lower-mantle structures.Geophys. J. Int.207, 1122–1136 (2016).

    Article ADS  Google Scholar 

  21. Kegerreis, J. A. et al. Planetary giant impacts: convergence of high-resolution simulations using efficient spherical initial conditions and SWIFT.Mon. Not. R. Astron. Soc.487, 5029–5040 (2019).

    Article CAS ADS  Google Scholar 

  22. Deguen, R., Landeau, M. & Olson, P. Turbulent metal–silicate mixing, fragmentation, and equilibration in magma oceans.Earth Planet. Sci. Lett.391, 274–287 (2014).

    Article CAS ADS  Google Scholar 

  23. Dauphas, N., Burkhardt, C., Warren, P. H. & Fang-Zhen, T. Geochemical arguments for an Earth-like Moon-forming impactor.Philos. Trans. R. Soc. A372, 20130244 (2014).

    Article ADS  Google Scholar 

  24. Pahlevan, K., Stevenson, D. J. & Eiler, J. M. Chemical fractionation in the silicate vapor atmosphere of the Earth.Earth Planet. Sci. Lett.301, 433–443 (2011).

    Article CAS ADS  Google Scholar 

  25. Meier, M. M. M., Reufer, A. & Wieler, R. On the origin and composition of Theia: constraints from new models of the Giant Impact.Icarus242, 316–328 (2014).

    Article CAS ADS  Google Scholar 

  26. Robinson, K. L. et al. Water in evolved lunar rocks: evidence for multiple reservoirs.Geochim. Cosmochim. Acta188, 244–260 (2016).

    Article CAS ADS  Google Scholar 

  27. Connolly, J. A. D. Computation of phase equilibria by linear programming: a tool for geodynamic modeling and its application to subduction zone decarbonation.Earth Planet. Sci. Lett.236, 524–541 (2005).

    Article CAS ADS  Google Scholar 

  28. Connolly, J. A. D. The geodynamic equation of state: what and how.Geochem. Geophys. Geosyst.10, 1–19 (2009).

    Article  Google Scholar 

  29. Stixrude, L. & Lithgow-Bertelloni, C. Thermodynamics of mantle minerals – II. Phase equilibria.Geophys. J. Int.184, 1180–1213 (2011).

    Article CAS ADS  Google Scholar 

  30. Nakajima, M. & Stevenson, D. J. Melting and mixing states of the Earth’s mantle after the Moon-forming impact.Earth Planet. Sci. Lett.427, 286–295 (2015).

    Article CAS ADS  Google Scholar 

  31. Gurnis, M. The effects of chemical density differences on convective mixing in the Earth’s mantle.J. Geophys. Res., Solid Earth91, 11407–11419 (1986).

    Article  Google Scholar 

  32. Tackley, P. J. inThe Core‐Mantle Boundary Region (eds Gurnis, M., Wysession, M. E., Knittle, E. & Buffet, B. A.) 231–253 (American Geophysical Union, 1998).

  33. Nakagawa, T., Tackley, P. J., Deschamps, F. & Connolly, J. A. D. The influence of MORB and harzburgite composition on thermo-chemical mantle convection in a 3-D spherical shell with self-consistently calculated mineral physics.Earth Planet. Sci. Lett.296, 403–412 (2010).

    Article CAS ADS  Google Scholar 

  34. Gu, T., Li, M., McCammon, C. & Lee, K. K. M. Redox-induced lower mantle density contrast and effect on mantle structure and primitive oxygen.Nat. Geosci.9, 723–727 (2016).

    Article CAS ADS  Google Scholar 

  35. Yuan, Q. & Li, M. Instability of the African large low-shear-wave-velocity province due to its low intrinsic density.Nat. Geosci.15, 334–339 (2022).

    Article CAS ADS  Google Scholar 

  36. McNamara, A. K. & Zhong, S. Thermochemical structures beneath Africa and the Pacific Ocean.Nature437, 1136–1139 (2005).

    Article CAS PubMed ADS  Google Scholar 

  37. O’Neill, C., Marchi, S., Zhang, S. & Bottke, W. Impact-driven subduction on the Hadean Earth.Nat. Geosci.10, 793–797 (2017).

    Article ADS  Google Scholar 

  38. Hernlund, J. W. & Houser, C. On the statistical distribution of seismic velocities in Earth’s deep mantle.Earth Planet. Sci. Lett.265, 423–437 (2008).

    Article CAS ADS  Google Scholar 

  39. Lei, W. et al. Global adjoint tomography – model GLAD-M25.Geophys. J. Int.223, 1–21 (2020).

    Article ADS  Google Scholar 

  40. Elkins-Tanton, L. T. Magma oceans in the inner Solar System.Annu. Rev. Earth Planet. Sci.40, 113–139 (2012).

    Article CAS ADS  Google Scholar 

  41. Abe, Y. Thermal and chemical evolution of the terrestrial magma ocean.Phys. Earth Planet. Inter.1, 27–39 (1997).

    Article ADS  Google Scholar 

  42. Solomatov, V. S. inTreatise on Geophysics 1st edn, Vol. 9 (ed. Schubert, G.) 91–119 (Elsevier, 2007).

  43. Maurice, M. et al. Onset of solid-state mantle convection and mixing during magma ocean solidification.J. Geophys. Res., Planets122, 577–598 (2017).

    Article ADS  Google Scholar 

  44. Boukaré, C. E., Parmentier, E. M. & Parman, S. W. Timing of mantle overturn during magma ocean solidification.Earth Planet. Sci. Lett.491, 216–225 (2018).

    Article ADS  Google Scholar 

  45. Labrosse, S., Morison, A., Deguen, R. & Alboussière, T. Rayleigh–Bénard convection in a creeping solid with melting and freezing at either or both its horizontal boundaries.J. Fluid Mech.846, 5–36 (2018).

    Article MathSciNet CAS MATH ADS  Google Scholar 

  46. Agrusta, R. et al. Mantle convection interacting with magma oceans.Geophys. J. Int.220, 1878–1892 (2020).

    Article CAS ADS  Google Scholar 

  47. Morison, A., Labrosse, S., Deguen, R. & Alboussière, T. Timescale of overturn in a magma ocean cumulate.Earth Planet. Sci. Lett.516, 25–36 (2019).

    Article CAS ADS  Google Scholar 

  48. Becker, T. W., Kellogg, J. B. & O’Connell, R. J. Thermal constraints on the survival of primitive blobs in the lower mantle.Earth Planet. Sci. Lett.171, 351–365 (1999).

    Article CAS ADS  Google Scholar 

  49. Lock, S. J., Bermingham, K. R., Parai, R. & Boyet, M. Geochemical constraints on the origin of the Moon and preservation of ancient terrestrial heterogeneities.Space Sci. Rev.216, 1–46 (2020).

    Article  Google Scholar 

  50. Ballmer, M. D., Lourenço, D. L., Hirose, K., Caracas, R. & Nomura, R. Reconciling magma-ocean crystallization models with the present-day structure of the Earth’s mantle.Geochem. Geophys. Geosyst.18, 2785–2806 (2017).

    Article CAS ADS  Google Scholar 

  51. Maas, C. & Hansen, U. Dynamics of a terrestrial magma ocean under planetary rotation: a study in spherical geometry.Earth Planet. Sci. Lett.513, 81–94 (2019).

    Article CAS ADS  Google Scholar 

  52. Williams, C. D. & Mukhopadhyay, S. Capture of nebular gases during Earth’s accretion is preserved in deep-mantle neon.Nature565, 78–81 (2019).

    Article CAS PubMed ADS  Google Scholar 

  53. Mundl-Petermeier, A. et al. Temporal evolution of primordial tungsten-182 and3He/4He signatures in the Iceland mantle plume.Chem. Geol.525, 245–259 (2019).

    Article CAS ADS  Google Scholar 

  54. Li, M., McNamara, A. K. & Garnero, E. J. Chemical complexity of hotspots caused by cycling oceanic crust through mantle reservoirs.Nat. Geosci.7, 366–370 (2014).

    Article CAS ADS  Google Scholar 

  55. Mulyukova, E., Steinberger, B., Dabrowski, M. & Sobolev, S. V. Survival of LLSVPs for billions of years in a vigorously convecting mantle: replenishment and destruction of chemical anomaly.J. Geophys. Res., Solid Earth120, 3824–3847 (2015).

    Article ADS  Google Scholar 

  56. Jackson, M. G. et al. Ancient helium and tungsten isotopic signatures preserved in mantle domains least modified by crustal recycling.Proc. Natl Acad. Sci. USA117, 30993–31001 (2020).

    Article CAS PubMed PubMed Central ADS  Google Scholar 

  57. Brown, J. M. & Shankland, T. J. Thermodynamic parameters in the Earth as determined from seismic profiles.Geophys. J. R. Astron. Soc.66, 579–596 (1981).

    Article MATH ADS  Google Scholar 

  58. Stacey, F. D. A thermal model of the earth.Phys. Earth Planet. Inter.15, 341–348 (1977).

    Article ADS  Google Scholar 

  59. Canup, R. M., Barr, A. C. & Crawford, D. A. Lunar-forming impacts: high-resolution SPH and AMR-CTH simulations.Icarus222, 200–219 (2013).

    Article ADS  Google Scholar 

  60. Hosono, N., Saitoh, T. R., Makino, J., Genda, H. & Ida, S. The Giant Impact simulations with density independent smoothed particle hydrodynamics.Icarus271, 131–157 (2016).

    Article ADS  Google Scholar 

  61. Reinhardt, C. & Stadel, J. Numerical aspects of Giant Impact simulations.Mon. Not. R. Astron. Soc.467, 4252–4263 (2017).

    Article ADS  Google Scholar 

  62. Ruiz-Bonilla, S. et al. Dealing with density discontinuities in planetary SPH simulations.Mon. Not. R. Astron. Soc.512, 4660–4668 (2022).

    Article CAS ADS  Google Scholar 

  63. Hosono, N. & Karato, S. The influence of equation of state on the Giant Impact simulations.J. Geophys. Res., Planets127, 1–18 (2022).

    Article  Google Scholar 

  64. Hosono, N. et al. Unconvergence of very-large-scale Giant Impact simulations.Publ. Astron. Soc. Jpn69, 1–11 (2017).

    Article  Google Scholar 

  65. Meier, T., Reinhardt, C. & Stadel, J. G. The EOS/resolution conspiracy: convergence in proto-planetary collision simulations.Mon. Not. R. Astron. Soc.1816, 1806–1816 (2021).

    Article ADS  Google Scholar 

  66. Raskin, C. & Owen, J. M. Examining the accuracy of astrophysical disk simulations with a generalized hydrodynamical test problem.Astrophys. J.831, 26 (2016).

    Article ADS  Google Scholar 

  67. Gabriel, T. S. J. & Allen-Sutter, H. Dependencies of mantle shock heating in pairwise accretion.Astrophys. J. Lett.915, L32 (2021).

    Article ADS  Google Scholar 

  68. Frontiere, N., Raskin, C. D. & Owen, J. M. CRKSPH – a conservative reproducing kernel smoothed particle hydrodynamics scheme.J. Comput. Phys.332, 160–209 (2017).

    Article MathSciNet MATH ADS  Google Scholar 

  69. Rosswog, S. Astrophysical smooth particle hydrodynamics.New Astron. Rev.53, 78–104 (2009).

    Article CAS ADS  Google Scholar 

  70. Schaller, M. et al. SWIFT: SPH with inter-dependent fine-grained tasking. InAstrophysics Source Code Library, ascl-1805 (2018).

  71. Ruiz-Bonilla, S., Eke, V. R., Kegerreis, J. A., Massey, R. J. &Teodoro, L. F. A. The effect of pre-impact spin on the Moon-forming collision.Mon. Not. R. Astron. Soc.2870, 2861–2870 (2021).

    ADS  Google Scholar 

  72. Canup, R. M. Forming a Moon with an Earth-like composition via a giant impact.Science338, 1052–1056 (2012).

    Article CAS PubMed PubMed Central ADS  Google Scholar 

  73. Hopkins, P. F. A new class of accurate, mesh-free hydrodynamic simulation methods.Mon. Not. R. Astron. Soc.450, 53–110 (2015).

    Article CAS ADS  Google Scholar 

  74. Thompson, S. L. & Lauson, H. S.Improvements in the Chart D Radiation—Hydrodynamic Code. III. Revised Analytic Equation of State. Sandia Report SC-RR-71 0174 (1972).

  75. Melosh, H. J. A hydrocode equation of state for SiO2.Meteorit. Planet. Sci.42, 2079–2098 (2007).

    Article CAS ADS  Google Scholar 

  76. Fiquet, G. et al. Melting of peridotite to 140 gigapascals.Science329, 1516–1518 (2010).

    Article CAS PubMed ADS  Google Scholar 

  77. Andrault, D. et al. Solidus and liquidus profiles of chondritic mantle: implication for melting of the Earth across its history.Earth Planet. Sci. Lett.304, 251–259 (2011).

    Article CAS ADS  Google Scholar 

  78. Abe, Y. inEvolution of the Earth and Planets (eds Takahashi, E., Jeanloz, R. & Rubie, D.) 41–54 (American Geophysical Union, 1993).

  79. Miyazaki, Y. & Korenaga, J. On the timescale of magma ocean solidification and its chemical consequences: 2. Compositional differentiation under crystal accumulation and matrix compaction.J. Geophys. Res., Solid Earth124, 3399–3419 (2019).

    Article CAS ADS  Google Scholar 

  80. Nomura, R. et al. Spin crossover and iron-rich silicate melt in the Earth’s deep mantle.Nature473, 199–202 (2011).

    Article CAS PubMed ADS  Google Scholar 

  81. Andrault, D. et al. Solid–liquid iron partitioning in Earth’s deep mantle.Nature487, 354–357 (2012).

    Article CAS PubMed ADS  Google Scholar 

  82. Moresi, L. N. & Solomatov, V. S. Numerical investigation of 2D convection with extremely large viscosity variations.Phys. Fluids7, 2154–2162 (1995).

    Article MATH ADS  Google Scholar 

  83. Farrell, K. A. O. & Lowman, J. P. Emulating the thermal structure of spherical shell convection in plane-layer geometry mantle convection models.Phys. Earth Planet. Inter.182, 73–84 (2010).

    Article ADS  Google Scholar 

  84. Tackley, P. J. & King, S. D. Testing the tracer ratio method for modeling active compositional fields in mantle convection simulations.Geochem. Geophys. Geosyst.4, 1–15 (2003).

    Article  Google Scholar 

  85. Schaller, M. et al. Swift: a modern highly-parallel gravity and smoothed particle hydrodynamics solver for astrophysical and cosmological applications. Preprint athttp://arxiv.org/abs/2305.13380 (2023).

  86. Hirth, G. & Kohlstedt, D. L. Water in the oceanic upper mantle: implications for rheology, melt extraction and the evolution of the lithosphere.Earth Planet. Sci. Lett.144, 93–108 (1996).

    Article CAS ADS  Google Scholar 

  87. Dziewonski, A. M. & Anderson, D. L. Preliminary reference Earth model.Phys. Earth Planet. Inter.25, 297–356 (1981).

    Article ADS  Google Scholar 

Download references

Acknowledgements

We thank M. Gurnis, D. Stevenson, R. Canup, P. Olson, S. Stewart, M. Zolotov, T. Becker, M. Jackson, S.-H. Shim, D. Grady, R. Shi and S. Yuan for their support, discussions and insights. The numerical models were performed on the Agave cluster at Arizona State University. Any use of trade, firm or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. This work is supported by National Science Foundation grants EAR-1849949, EAR-1855624 and EAR-2216564. Q.Y. acknowledges support from the O. K. Earl Postdoctoral Fellowship at Caltech. T.S.J.G. recognizes support from the U.S. Geological Survey, Astrogeology Science Center. J.A.K. acknowledges support from a NASA Postdoctoral Program Fellowship, administered by Oak Ridge Associated Universities. Y.M. acknowledges a Stanback Postdoctoral Fellowship from the Caltech Center for Comparative Planetary Evolution. V.R.E. is supported by Science and Technology Facilities Council (STFC) grant ST/T000244/1. The MFM giant-impact simulations were performed on the Piz Daint supercomputer of the Swiss Nation Supercomputing Centre and the local cluster of the Shanghai Astronomical Observatory. The research in this paper made use of the SWIFT open-source simulation code70,85, v.0.9.0. This work used the DiRAC@Durham facility managed by the Institute for Computational Cosmology on behalf of the STFC DiRAC High-Performance Computing Facility (www.dirac.ac.uk). The equipment was funded by capital funding from the Department for Business, Energy and Industrial Strategy via STFC capital grants ST/K00042X/1, ST/P002293/1, ST/R002371/1 and ST/S002502/1, Durham University and STFC operations grant ST/R000832/1. DiRAC is part of the National e-Infrastructure.

Author information

Authors and Affiliations

  1. School of Earth and Space Exploration, Arizona State University, Tempe, AZ, USA

    Qian Yuan, Mingming Li, Steven J. Desch, Byeongkwan Ko & Edward J. Garnero

  2. Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA

    Qian Yuan, Yoshinori Miyazaki & Paul D. Asimow

  3. Department of Earth and Environmental Sciences, Michigan State University, East Lansing, MI, USA

    Byeongkwan Ko

  4. Shanghai Astronomical Observatory, Chinese Academy of Sciences, Shanghai, China

    Hongping Deng

  5. U.S. Geological Survey, Astrogeology Science Center, Flagstaff, AZ, USA

    Travis S. J. Gabriel

  6. NASA Ames Research Center, Moffett Field, CA, USA

    Jacob A. Kegerreis

  7. Institute for Computational Cosmology, Department of Physics, Durham University, Durham, UK

    Vincent Eke

Authors
  1. Qian Yuan
  2. Mingming Li
  3. Steven J. Desch
  4. Byeongkwan Ko
  5. Hongping Deng
  6. Edward J. Garnero
  7. Travis S. J. Gabriel
  8. Jacob A. Kegerreis
  9. Yoshinori Miyazaki
  10. Vincent Eke
  11. Paul D. Asimow

Contributions

Q.Y. and E.J.G. conceptualized the initial idea. Q.Y., M.M.L. and E.J.G. designed the study. Q.Y. performed and analysed the geodynamic models with supervision from M.M.L. S.J.D. constrained the impact scenario and provided the composition of Theia. B.K. and Q.Y. computed the thermodynamic and seismic calculations. H.P.D., J.A.K. and V.R.E. performed the impact simulations and analysed the results. T.S.J.G. performed independent verifications of the SPH results and consulted on the SPH numerics. Y.M. developed the thermal evolution model. P.D.A. examined the fragmentation, dilution effect and magma mixing associated with the impact. All authors contributed to the writing and editing of the manuscript.

Corresponding author

Correspondence toQian Yuan.

Ethics declarations

Competing interests

The authors declare no competing interests.

Peer review

Peer review information

Nature thanks Stéphane Labrosse and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

Additional information

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Extended data figures and tables

Extended Data Fig. 1 Entropy profile (blue, in Jkg−1K−1) of mantle material in the post-impact Earth for our impact model using the meshless finite mass (MFM) method18.

The red curve shows the liquidus of forsterite16 and the rheological transition of the mantle was marked by the orange curve where the melt fraction above that depth becomes larger than 40%42,86.

Source data

Extended Data Fig. 2 Phase diagrams of the bulk silicate Earth (a), Theia_1 (b), Theia_2 (c) and Theia_3 (d) with geotherm from ref.57.

The FeO contents of Theia are 13 wt% (Theia_1), 15 wt% (Theia_2), and 17 wt% (Theia_3), respectively. Phase equilibria were calculated using Perple_X27,28 with thermodynamic data from ref.29. St: stishovite, Fp: ferropericlase, Ring: ringwoodite, Wad: wadsleyite, Ol: olivine, Cpx: clinopyroxene, Brg: bridgmanite, Gt: garnet, CaPv: davemaoite.

Source data

Extended Data Fig. 3 Phase diagrams of the bulk silicate Earth (a), Theia_1 (b), Theia_2 (c) and Theia_3 (d) with geotherm from ref.58.

The FeO contents of Theia are 13 wt% (Theia_1), 15 wt% (Theia_2), and 17 wt% (Theia_3), respectively. Phase equilibria were calculated using Perple_X27,28 with thermodynamic data from ref.29. Fp: ferropericlase, Wad: wadsleyite, Ol: olivine, Cpx: clinopyroxene, Brg: bridgmanite, Gt: garnet, CaPv: davemaoite.

Source data

Extended Data Fig. 5 One numerical experiment showing that dense TMM sinks to the CMB before upper mantle materials mix with lower mantle materials.

a-d, Snapshots of the temperature fields (a, c) and compositional fields (b, d) at 0.00 Myr (a-b) and 27.36 Myr (c-d). At t = 0.00, random TMM blobs are placed in the lower mantle (b). After 27.36 Myr, the TMM blobs reach the CMB (d) whereas there is little mixing between the upper mantle and lower mantle (c).

Source data

Extended Data Table 1 The depth of layer boundary and the enclosing mass of Theia mantle material below the boundary for the canonical Moon-forming giant impact simulations from ref.19
Extended Data Table 2 Results from the MFM simulations with updated versions of the ANEOS equations of state16
Extended Data Table 3 Results from the SPH simulations
Extended Data Table 4 Major elemental compositions of the mantle of Theia and proto-Earth, and the bulk silicate Earth (BSE) (wt%) used in our thermodynamic modeling
Extended Data Table 5 Physical parameters for mantle convection models
Extended Data Table 6 Full list of performed mantle convection models

Supplementary information

Supplementary Video 1

A canonical giant-impact simulation using the MFM method shows the preservation of a mostly solid lower layer in Earth’s mantle after the impact. Model evolution spans 13.1 h after the giant impact, and the entropy unit is MJ K−1 kg−1.

Supplementary Video 2

A canonical giant-impact simulation using the SPH method, highlighting the preservation of a mostly solid lower layer in Earth’s mantle after the impact event. Entropy unit is kJ K−1 kg−1.

Supplementary Video 3

Reference case of a successful mantle convection model showing that the random spheres of solid TMM in the lower layer of Earth’s mantle quickly descend to the lowermost mantle and are later shaped into isolated thermochemical piles (large low-velocity provinces in the models) by mantle convection after Earth’s history.

Supplementary Video 4

Mantle convection in case 2 showing that a less dense TMM will be mostly entrained away in the background mantle.

Supplementary Video 5

Mantle convection in case 3 showing that the 3.5% denser TMM can sink and survive Earth’s 4.5 Gyr convective history.

Supplementary Video 6

Mantle convection in case 4 showing that a TMM with an end-member density of 5% can still sink and survive Earth’s 4.5 Gyr convective history as isolated thermochemical piles.

Supplementary Video 7

Mantle convection in case 5 showing that a half-sized TMM will not be able to survive Earth’s 4.5 Gyr convective history.

Supplementary Video 8

Mantle convection in case 6 showing that a TMM enriched in radioactive elements can sink and survive Earth’s 4.5 Gyr convective history.

Supplementary Video 9

Mantle convection in case 7 showing that a higher temperature-dependent viscosity does not affect our convection results.

Supplementary Video 10

Mantle convection in case 8 showing that a periodic side-boundary condition does not affect our numerical results.

Supplementary Video 11

Mantle convection in case 9 showing that a different initial temperature does not affect our convection results.

Rights and permissions

Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Yuan, Q., Li, M., Desch, S.J.et al. Moon-forming impactor as a source of Earth’s basal mantle anomalies.Nature623, 95–99 (2023). https://doi.org/10.1038/s41586-023-06589-1

Download citation

This article is cited by

Comments

Commenting on this article is now closed.

  1. Kumon Tokumaru

    https://uploads.disquscdn.c...

    I think the Kalahari Desert is one of the possible Giant Impact locations.

  2. Boxer Puppy Spot

    This study on the Moon-forming impactor's role in creating basal mantle anomalies provides valuable insights into Earth's geological history. The research sheds light on the complex processes that shaped our planet, deepening our understanding of its evolution. Impressive work! 👏🌍🌕

Access through your institution
Buy or subscribe

Associated content

Collection

Constraints on mantle heterogeneity

Advertisement

Search

Advanced search

Quick links

Nature Briefing

Sign up for theNature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox.Sign up for Nature Briefing
[8]ページ先頭
©2009-2025 Movatter.jp