The decay of short-lived iodine (I) and plutonium (Pu) results in xenon (Xe) isotopic anomalies in the mantle that record Earth’s earliest stages of formation1,2,3,4,5,6,7,8. Xe isotopic anomalies have been linked to degassing during accretion2,3,4, but degassing alone cannot account for the co-occurrence of Xe and tungsten (W) isotopic heterogeneity in plume-derived basalts9,10 and their long-term preservation in the mantle. Here we describe measurements of I partitioning between liquid Fe alloys and liquid silicates at high pressure and temperature and propose that Xe isotopic anomalies found in modern plume rocks (that is, rocks with elevated 3He/4He ratios) result from I/Pu fractionations during early, high-pressure episodes of core formation. Our measurements demonstrate that I becomes progressively more siderophile as pressure increases, so that portions of mantle that experienced high-pressure core formation will have large I/Pu depletions not related to volatility. These portions of mantle could be the source of Xe and W anomalies observed in modern plume-derived basalts2,3,4,9,10. Portions of mantle involved in early high-pressure core formation would also be rich in FeO11,12, and hence denser than ambient mantle. This would aid the long-term preservation of these mantle portions, and potentially points to their modern manifestation within seismically slow, deep mantle reservoirs13 with high 3He/4He ratios.
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Allègre, C. J., Staudacher, T., Sarda, P. & Kurz, M. Constraints on evolution of Earth’s mantle from rare gas systematics. Nature 303, 762–766 (1983)
Mukhopadhyay, S. Early differentiation and volatile accretion recorded in deep-mantle neon and xenon. Nature 486, 101–104 (2012)
Peto, M. K., Mukhopadhyay, S. & Kelley, K. A. Heterogeneities from the first 100 million years recorded in deep mantle noble gases from the Northern Lau Back-arc Basin. Earth Planet. Sci. Lett. 369/370, 13–23 (2013)
Caracausi, A., Avice, G., Burnard, P. G., Füri, E. & Marty, B. Chondritic xenon in the Earth’s mantle. Nature 533, 82–85 (2016)
Moreira, M., Kunz, J. & Allegre, C. Rare gas systematics in popping rock: isotopic and elemental compositions in the upper mantle. Science 279, 1178–1181 (1998)
Holland, G. & Ballentine, C. J. Seawater subduction controls the heavy noble gas composition of the mantle. Nature 441, 186–191 (2006)
Tucker, J. M., Mukhopadhyay, S. & Schilling, J. G. The heavy noble gas composition of the depleted MORB mantle (DMM) and its implications for the preservation of heterogeneities in the mantle. Earth Planet. Sci. Lett. 355/356, 244–254 (2012)
Parai, R. & Mukhopadhyay, S. The evolution of MORB and plume mantle volatile budgets: constraints from fission Xe isotopes in Southwest Indian Ridge basalts. Geochem. Geophys. Geosyst. 16, 719–735 (2015)
Rizo, H. et al. Preservation of Earth-forming events in the tungsten isotopic composition of modern flood basalts. Science 352, 809–812 (2016)
Mundl, A. et al. Tungsten-182 heterogeneity in modern ocean island basalts. Science 356, 66–69 (2017)
Rubie, D. C. et al. Heterogeneous accretion, composition and core–mantle differentiation of the Earth. Earth Planet. Sci. Lett. 301, 31–42 (2011)
Frost, D. J., Mann, U., Asahara, Y. & Rubie, D. C. The redox state of the mantle during and just after core formation. Phil. Trans. R. Soc. Lond. 366, 4315–4337 (2008)
French, S. W. & Romanowicz, B. Broad plumes rooted at the base of the Earth’s mantle beneath major hotspots. Nature 525, 95–99 (2015)
Kurz, M. D., Jenkins, W. J. & Hart, S. R. Helium isotopic systematics of oceanic islands and mantle heterogeneity. Nature 297, 43–47 (1982)
Kleine, T. et al. Hf–W chronology of the accretion and early evolution of asteroids and terrestrial planets. Geochim. Cosmochim. Acta 73, 5150–5188 (2009)
Walter, M. J. & Thibault, Y. Partitioning of tungsten and molybdenum between metallic liquid and silicate melt. Science 270, 1186–1189 (1995)
Cottrell, E., Walter, M. J. & Walker, D. Metal–silicate partitioning of tungsten at high pressure and temperature: implications for equilibrium core formation in Earth. Earth Planet. Sci. Lett. 281, 275–287 (2009)
Wade, J., Wood, B. J. & Tuff, J. Metal–silicate partitioning of Mo and W at high pressures and temperatures: evidence for late accretion of sulphur to the Earth. Geochim. Cosmochim. Acta 85, 58–74 (2012)
Sleep, N. H. Gradual entrainment of a chemical layer at the base of the mantle by overlying convection. Geophys. J. Int. 95, 437–447 (1988)
Armytage, R. M., Jephcoat, A. P., Bouhifd, M. A. & Porcelli, D. Metal–silicate partitioning of iodine at high pressures and temperatures: implications for the Earth’s core and 129* Xe budgets. Earth Planet. Sci. Lett. 373, 140–149 (2013)
Ma, Z. Thermodynamic description for concentrated metallic solutions using interaction parameters. Metall. Mater. Trans. B 32, 87–103 (2001)
Fiquet, G. et al. Melting of peridotite to 140 gigapascals. Science 329, 1516–1518 (2010)
Walter, M. J. & Cottrell, E. Assessing uncertainty in geochemical models for core formation in Earth. Earth Planet. Sci. Lett. 365, 165–176 (2013)
Wang, Z. & Becker, H. Ratios of S, Se and Te in the silicate Earth require a volatile-rich late veneer. Nature 499, 328–331 (2013)
Jackson, M., Shirey, S., Hauri, E., Kurz, M. & Rizo, H. Peridotite xenoliths from the Polynesian Austral and Samoa hotspots: implications for the destruction of ancient 187Os and 142Nd isotopic domains and the preservation of Hadean 129Xe in the modern convecting mantle. Geochim. Cosmochim. Acta 185, 21–43 (2016)
Wood, B. J., Walter, M. J. & Wade, J. Accretion of the Earth and segregation of its core. Nature 441, 825–833 (2006)
Rudge, J. F., Kleine, T. & Bourdon, B. Broad bounds on Earth’s accretion and core formation constrained by geochemical models. Nat. Geosci. 3, 439–443 (2010)
Chambers, J. E. & Wetherill, G. W. Making the terrestrial planets: N-body integrations of planetary embryos in three dimensions. Icarus 136, 304–327 (1998)
McNamara, A. K. & Zhong, S. Thermochemical structures beneath Africa and the Pacific Ocean. Nature 437, 1136–1139 (2005)
Jackson, M., Konter, J. & Becker, T. Primordial helium entrained by the hottest mantle plumes. Nature 542, 340–343 (2017)
Thibault, Y. & Walter, M. J. The influence of pressure and temperature on the metal-silicate partition coefficients of nickel and cobalt in a model C1 chondrite and implications for metal segregation in a deep magma ocean. Geochim. Cosmochim. Acta 59, 991–1002 (1995)
Du, Z. et al. Using stepped anvils to make even insulation layers in laser-heated diamond-anvil cell samples. Rev. Sci. Instrum. 86, 095103 (2015)
Akahama, Y. & Kawamura, H. Pressure calibration of diamond anvil Raman gauge to 310 GPa. J. Appl. Phys. 100, 043516 (2006)
Prescher, C. & Prakapenka, V. B. DIOPTAS: a program for reduction of two-dimensional X-ray diffraction data and data exploration. High Press. Res. 35, 223–230 (2015)
Andrault, D. et al. Thermal pressure in the laser-heated diamond-anvil cell: an X-ray diffraction study. Eur. J. Mineral. 10, 931–940 (1998)
Tange, Y., Nishihara, Y. & Tsuchiya, T. Unified analyses for P–V–T equation of state of MgO: a solution for pressure-scale problems in high P–T experiments. J. Geophys. Res. Solid Earth 114 (B3), (2009)
Fischer, R. A. et al. High pressure metal–silicate partitioning of Ni, Co, V, Cr, Si, and O. Geochim. Cosmochim. Acta 167, 177–194 (2015)
Du, Z. & Lee, K. K. High-pressure melting of MgO from (Mg, Fe) O solid solutions. Geophys. Res. Lett. 41, 8061–8066 (2014)
Hirschmann, M. M., Baker, M. B. & Stolper, E. M. The effect of alkalis on the silica content of mantle-derived melts. Geochim. Cosmochim. Acta 62, 883–902 (1998)
Liu, J., Li, J. & Ikuta, D. Elastic softening in Fe7C3 with implications for Earth’s deep carbon reservoirs. J. Geophys. Res. Solid Earth 121, 1514–1524 (2016)
Basu, S., Lahiri, A. K. & Seetharaman, S. Activity of iron oxide in steelmaking slag. Metall. Mater. Trans. B 39, 447–456 (2008)
Japan Society for the Promotion of Science (JSPS) and the Nineteenth Committee on Steelmaking. JSPS Steelmaking Data Sourcebook 273–297 (Gordon and Breach Science Publishers, 1988)
Wade, J. & Wood, B. Core formation and the oxidation state of the Earth. Earth Planet. Sci. Lett. 236, 78–95 (2005)
Ohnishi, S., Kuwayama, Y. & Inoue, T. Melting relations in the MgO–MgSiO3 system up to 70 GPa. Phys. Chem. Mineral. 44, 1–9 (2017)
Kilburn, M. & Wood, B. Metal–silicate partitioning and the incompatibility of S and Si during core formation. Earth Planet. Sci. Lett. 152, 139–148 (1997)
Rubie, D. C., Gessmann, C. K. & Frost, D. J. Partitioning of oxygen during core formation on the Earth and Mars. Nature 429, 58–61 (2004)
Dalou, C., Hirschmann, M. M., von der Handt, A., Mosenfelder, J. & Armstrong, L. S. Nitrogen and carbon fractionation during core–mantle differentiation at shallow depth. Earth Planet. Sci. Lett. 458, 141–151 (2017)
Li, Y., Dasgupta, R., Tsuno, K., Monteleone, B. & Shimizu, N. Carbon and sulfur budget of the silicate Earth explained by accretion of differentiated planetary embryos. Nat. Geosci. 9, 781–785 (2016)
Pepin, R. O. & Porcelli, D. Xenon isotope systematics, giant impacts, and mantle degassing on the early Earth. Earth Planet. Sci. Lett. 250, 470–485 (2006)
Kendrick, M. et al. Seawater cycled throughout Earth's mantle in partially serpentinized lithosphere. Nat. Geosci. 10, 222–228 (2017)
Touboul, M., Puchtel, I. S. & Walker, R. J. Tungsten isotopic evidence for disproportional late accretion to the Earth and Moon. Nature 520, 530–533 (2015)
Kruijer, T. S., Kleine, T., Fischer-Gödde, M. & Sprung, P. Lunar tungsten isotopic evidence for the late veneer. Nature 520, 534–537 (2015)
Heber, V. S., Brooker, R. A., Kelley, S. P. & Wood, B. J. Crystal-melt partitioning of noble gases (helium, neon, argon, krypton, and xenon) for olivine and clinopyroxene. Geochim. Cosmochim. Acta 71, 1041–1061 (2007)
Smye, A. J. et al. Noble gases recycled into the mantle through cold subduction zones. Earth Planet. Sci. Lett. 471, 65–73 (2017)
Bali, E., Keppler, H. & Audetat, A. The mobility of W and Mo in subduction zone fluids and the Mo–W–Th–U systematics of island arc magmas. Earth Planet. Sci. Lett. 351/352, 195–207 (2012)
Matsuda, J. & Nagao, K. Noble gas abundances in a deep sea sediment core from eastern equatorial Pacific. Geochem. J. 20, 71–80 (1986)
Staudacher, T. & Allegre, C. J. Recycling of oceanic crust and sediments—the noble gas subduction barrier. Earth Planet. Sci. Lett. 89, 173–183 (1988)
Chavrit, D. et al. The contribution of hydrothermally altered ocean crust to the mantle halogen and noble gas cycles. Geochim. Cosmochim. Acta 183, 106–124 (2016)
Kendrick, M. A ., Honda, M. & Vanko, D. A. Halogens and noble gases in Mathematician Ridge meta-gabbros, NE Pacific: implications for oceanic hydrothermal root zones and global volatile cycles. Contrib. Mineral. Petrol. 170, 43 (2015)
Kendrick, M. A., Scambelluri, M., Honda, M. & Phillips, D. High abundances of noble gas and chlorine delivered to the mantle by serpentinite subduction. Nat. Geosci. 4, 807–812 (2011)
König, S., Münker, C., Schuth, S. & Garbe-Schönberg, D. Mobility of tungsten in subduction zones. Earth Planet. Sci. Lett. 274, 82–92 (2008)
Harper, C. L. & Jacobsen, S. B. Evidence for 182Hf in the early Solar System and constraints on the timescale of terrestrial accretion and core formation. Geochim. Cosmochim. Acta 60, 1131–1153 (1996)
Arevalo, R. & McDonough, W. F. Tungsten geochemistry and implications for understanding the Earth’s interior. Earth Planet. Sci. Lett. 272, 656–665 (2008)
O’Brien, D. P., Walsh, K. J., Morbidelli, A., Raymond, S. N. & Mandell, A. M. Water delivery and giant impacts in the ‘Grand Tack’ scenario. Icarus 239, 74–84 (2014)
Matsuda, J. et al. Noble gas partitioning between metal and silicate under high pressures. Science 259, 788–790 (1993)
Sudo, M., Ohtaka, O. & Matsuda, J. Noble gas partitioning between metal and silicate under high pressures: the case of iron and peridotite. In Noble Gas Geochemistry and Cosmochemistry (ed. Matsuda, J. ) 217–227 (Terra Scientific, 1994)
Bouhifd, M., Jephcoat, A. P., Heber, V. S. & Kelley, S. P. Helium in Earth’s early core. Nat. Geosci. 6, 982–986 (2013)
Chidester, B. A., Rahman, Z., Righter, K. & Campbell, A. J. Metal–silicate partitioning of U: implications for the heat budget of the core and evidence for reduced U in the mantle. Geochim. Cosmochim. Acta 199, 1–12 (2017)
Herzberg, C. et al. Nickel and helium evidence for melt above the core–mantle boundary. Nature 493, 393–397 (2013)
Moussallam, Y. et al. The impact of degassing on the oxidation state of basaltic magmas: a case study of Kiīlauea volcano. Earth Planet. Sci. Lett. 450, 317–325 (2016)
McDonough, W. F. & Sun, S. S. The composition of the Earth. Chem. Geol. 120, 223–253 (1995)
Cottaar, S. & Lekic, V. Morphology of seismically slow lower-mantle structures. Geophys. J. Int. 207, 1122–1136 (2016)
Dauphas, N. & Pourmand, A. Hf–W–Th evidence for rapid growth of Mars and its status as a planetary embryo. Nature 473, 489–492 (2011)
Portions of this work were performed at GeoSoilEnviroCARS (The University of Chicago, Sector 13), the Advanced Photon Source, Argonne National Laboratory. GeoSoilEnviroCARS is supported by the National Science Foundation—Earth Sciences (EAR-1128799) and the Department of Energy—GeoSciences (DE-FG02-94ER14466). This research used resources of the Advanced Photon Source, a US Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under contract number DE-AC02-06CH11357. We acknowledge the support provided by C. Prescher, E. Greenberg, and V. Prakapenka during the experiments conducted at GSECARS and in data reduction. We acknowledge E. Bullock and S. Vitale for their assistance with the electron microscopy, electron microprobe analysis, and focused ion beam recovery. We thank T. Gooding for his assistance in preparing the piston cylinder experiments for analysis. We acknowledge discussions with R. Fischer, R. Parai, S. Parman, J. Tucker and M. Nakajima during the development of the manuscript. C.R.M.J., N.R.B. and Z.D. acknowledge fellowship support from the Carnegie Institution for Science, and C.R.M.J. additionally acknowledges fellowship support from the Smithsonian Institution. The research was also supported by NSF grants to C.R.M.J. (EAR-1725315), to E.C. (EAR-0738654) and to Y.F. (EAR-1447311).
The authors declare no competing financial interests.
Reviewer Information Nature thanks G. Avice and the other anonymous reviewer(s) for their contribution to the peer review of this work.
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Extended data figures and tables
Extended Data Figure 1 Parameterization of I partitioning between liquid Fe alloy and silicate liquid.
a, Partitioning of I plotted against the O content (atomic) of metal phases. Oxygen content of the metal is the first parameter identified in the stepwise fitting approach. Higher O contents of metal are associated with greater partitioning of I into metal over silicate. b, Partitioning of I corrected to O-free metal plotted against S content of metal. The S content of the metal is the second parameter identified in the stepwise fitting approach. c, Partitioning of I corrected to O- and S-free metal plotted against P/T. The P/T term is the third parameter identified in the stepwise fitting approach. d, A comparison of observed and predicted I partitioning. I partitioning is predicted using equation (1) (R2 = 0.86). e–h, Covariance plots of parameterization. ‘Intercept’ refers to the constant term in equation (1).
a, A comparison of I partition coefficients determined in piston cylinder (PC) experiments and the I partition coefficient predicted from equation (1). Piston cylinder data are corrected to remove the effect of S and to the O contents of metal predicted along the mantle liquidus of ref. 22, allowing a direct comparison to the DAC data model. Upper-limit partition coefficients are consistent with the lower end of the uncertainty envelope. The difference in measured I partitioning coefficients in the piston cylinder series suggests that I partitioning is redox sensitive. b, Measured partition coefficients in piston cylinder series are corrected to ΔIW-1.3 and offset in pressure for clarity. Error bars and the uncertainty envelope are 2σ.
Extended Data Figure 3 Calculated concentration of MSEs in plume mantle as a function of the pressure of core–mantle equilibrium.
W (a), Ni (b), and Co (c) concentrations in plume mantle all increase with increasing core–mantle equilibrium pressure. Results are normalized to the calculated concentration of MORB MSEs. MORB MSE concentrations are calculated using the average P–T–X conditions that satisfy BSE [W] and [FeO] (Supplementary Table 4). Temperatures are assumed to follow the mantle liquidus of ref. 22. FeO abundances are calculated following ref. 11. W partitioning is from ref. 18. Ni and Co partitioning are from ref. 37. Plume mantle data points are plotted only for P–T–X conditions that satisfy W and Xe isotopic constraints (see Methods subsection ‘Calculation of W and Xe isotopic anomalies resulting from discrete stages of core formation’).
a, Secondary electron (SE) image of the DAC_I_EXP5 spot 4 silicate shows evidence of vesiculation in the area that was analysed. b, C map showing no obvious concentration of C local to vesiculation. The dark material in the lower left corner of a is diamond. Scale bar is 1 μm.
a, Si–Fe exchange coefficient plotted against inverse temperature. Data from this study (circles) are corrected for S–O–C interactions with silicon. Squares are from the compilation of ref. 37 corrected from O–C interactions with silicon. b, (Mg+Fe)/Si ratios of the silicate phase from this study (circles) and ref. 44 (squares) plotted against pressure. Symbols are grouped for Mg#, with darker symbols corresponding to lower Mg#. The offset of lower Mg# silicates within a pressure range to higher (Mg+Fe)/Si ratios and the similar pressure slopes within Mg# groupings support the accuracy of our pressure calculations.
Extended Data Figure 6 Secondary electron image and EDS maps of experiment DAC_I_EXP9 spot 4 showing I mobility.
The sequence of images shows the nature and distribution of I-rich materials that are mobilized to the surface of heating spots after storage in desiccators. a, Map of I distribution. I-rich materials are concentrated along the left and right edges of the heating spot, within isolated regions of the metal and silicate phases, and surrounding the Fe alloy phase. b, Map of Fe distribution. The metallic phase is mantled by Fe-rich and I-rich material. This material is also rich in C and O (not shown). The I-rich material that is present along the edges of the heating spot is also enriched in Fe, C and O. c, Secondary electron image. I-rich materials are positive relief features. Images are 20 μm wide.
Extended Data Figure 7 Parent–daughter ratio variations required to account for Xe isotopic variability between plume and MORB mantle.
a, Closure ages plotted against initial 129I/244Pu ratios. Closure ages are calculated using 129Xe*/136XePu ratios from ref. 8 and equation (12). The MORB mantle 129I/244Pu ratio is fixed and derived from estimates for the bulk silicate Earth from refs 49 and 50. The grey shading delineates I–Pu–Xe closure ages that are equal to or less than that determined for MORB mantle. Vertical lines in the grey shaded area are fractional depletions of the I/Pu in plume mantle relative to MORB mantle, ordered sequentially. The ratios denote the fractional depletion of the I/Pu ratio for plume mantle relative to initial MORB mantle. An approximately 3× lower I/Pu ratio for plume mantle results in equal closure ages for MORB and plume mantle. b, Closure ages plotted against the ratio of radiogenic components for 129Xe/130Xe within MORB and plume mantle. The upper edge of the grey shaded area delineates the upper limit of MORB mantle I–Pu–Xe closure. Left and right edges delineate the uncertainty on the ratio of radiogenic components observed in MORB and plume mantle. Curves are calculations for the ratio of radiogenic components of 129Xe/130Xe (denoted ‘–R’, see equation (13)), assuming different fractional depletions of the I/Xe ratio in plume mantle relative to initial MORB mantle (see fractions plotted along edge of graph). These calculations assume a MORB mantle closure age of 61 million years (Ma).
This table contains metadata associated with diamond anvil cell experiments. (XLSX 28 kb)
This table contains metadata associated with piston cylinder experiments. (XLSX 19 kb)
This table contains the fitting parameters for equation 1. (XLSX 14 kb)
This table contains modelling parameters. (XLSX 19 kb)
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Jackson, C., Bennett, N., Du, Z. et al. Early episodes of high-pressure core formation preserved in plume mantle. Nature 553, 491–495 (2018) doi:10.1038/nature25446
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