Pirotte et al., 2023 Internal differentiation and volatile budget of Mercury inferred from the partitioning of heat producing element at highly reduced conditions.pdf
Differentiation; Heat-producing elements; Mercury; Sulfur; Volatility; Astronomy and Astrophysics; Space and Planetary Science
Abstract :
[en] Understanding the behavior of elements under highly reduced conditions is fundamental to explain the differentiation, crust formation, and volatile budget of Mercury. Here we report experiments on a synthetic composition representative of the bulk silicate Mercury (BSM), at pressure up to 3 GPa, temperature up to 1720 °C, and under highly reduced conditions (∼IW − 8 to ∼IW − 1, with IW the iron-wüstite oxygen fugacity buffer). We determined partition coefficients for >30 minor and trace elements between silicate melt, metal melt (Fe–Si), sulfide melt (FeS), and MgS solid sulfides. Based on these results and published literature, we modeled the behavior of heat-producing elements (HPE: U, Th, and K) during Mercury's early differentiation and mantle partial melting and estimated their concentrations in the mantle and crust. We found that U, K and especially Th are principally concentrated in the BSM and did not partition into the core because they are not siderophile elements. Uranium is chalcophile under highly reduced conditions, and so our model suggests that an FeS layer at the core-mantle boundary formed during Mercury's primordial differentiation would likely have incorporated large amounts of U, significantly increasing the Th/U ratio of the BSM. However, this is inconsistent with the chondritic or slightly sub-chondritic Th/U ratios of Mercury's lavas. In addition, the likely presence of mantle sulfides, such as MgS, would have also fractionated U and Th, increasing the mantle Th/U. It is possible to have an FeS layer if Mercury formed under less reduced conditions, or if the building blocks of Mercury had Th/U ratios close to the lower end of chondritic data. If, as suggested by our model, no FeS layer formed during differentiation, it means that the majority of HPE are concentrated in Mercury's thin silicate part. Based on the compatibility of U, Th and K, we also show that surface K/Th and K/U ratios are respectively 2–4 times and 3–6 times lower than expected for initial K/Th and K/U ratios similar to enstatite chondrites, implying that the planet suffered an important volatile loss via mechanisms that remain undetermined.
F.R.S.-FNRS - Fonds de la Recherche Scientifique [BE] FWO - Fonds Wetenschappelijk Onderzoek Vlaanderen [BE] DFG - Deutsche Forschungsgemeinschaft [DE] FRIA - Fonds pour la Formation à la Recherche dans l'Industrie et dans l'Agriculture [BE]
Funding text :
HP was supported by the FRIA -FNRS ( Fonds pour la Formation à la Recherche dans l'Industrie et dans l'Agriculture - Fonds de la Recherche Scientifique) (grant FC 31865). ON acknowledges support from FWO through an Odysseus grant. BC is a Research Associate of the Belgian Fund for Scientific Research-FNRS. C. McCammon is thanked for her help with piston cylinder experiments at BGI. O. Namur acknowledges support from the DFG Core Facility for High-Pressure Research from the German Science Foundation for the high-pressure experiments performed at BGI. We are grateful to Rob Dennen for editing carefully the manuscript. We thank Asmaa Boujibar and an anonymous reviewer for their comments that greatly improved the manuscript. Doris Breuer is acknowledged for handling the manuscript.HP was supported by the FRIA-FNRS (Fonds pour la Formation à la Recherche dans l'Industrie et dans l'Agriculture - Fonds de la Recherche Scientifique) (grant FC 31865). ON acknowledges support from FWO through an Odysseus grant. BC is a Research Associate of the Belgian Fund for Scientific Research-FNRS. C. McCammon is thanked for her help with piston cylinder experiments at BGI. O. Namur acknowledges support from the DFG Core Facility for High-Pressure Research from the German Science Foundation for the high-pressure experiments performed at BGI. We are grateful to Rob Dennen for editing carefully the manuscript. We thank Asmaa Boujibar and an anonymous reviewer for their comments that greatly improved the manuscript. Doris Breuer is acknowledged for handling the manuscript.
Albarède, F., Volatile accretion history of the terrestrial planets and dynamic implications. Nature 461 (2009), 1227–1233.
Anderson, J.D., Colombo, G., Esposito, P.B., Lau, E.L., Trager, G.B., The mass, gravity field, and ephemeris of Mercury. Icarus 71:3 (1987), 337–349.
Anzures, B.A., Parman, S.W., Milliken, R.E., Namur, O., Cartier, C., Wang, S., Effect of sulfur speciation on chemical and physical properties of very reduced mercurian melts. Geochim. Cosmochim. Acta 286 (2020), 1–18.
Ash, M.E., Shapiro, I.I., Smith, W.B., The system of planetary masses: new results show that Pluto's mass cannot be determined reliably from existing data. Science 174:4009 (1971), 551–556.
Barrat, J.A., Zanda, B., Jambon, A., Bollinger, C., The lithophile trace elements in enstatite chondrites. Geochim. Cosmochim. Acta 128 (2014), 71–94.
Bédard, J.H., Partitioning coefficients between olivine and silicate melts. Lithos 83 (2005), 394–419.
Bédard, J.H., Trace element partitioning coefficients between silicate melts and orthopyroxene: parameterizations of D variations. Chem. Geol. 244 (2007), 263–303.
Benkhoff, J., Van Casteren, J., Hayakawa, H., Fujimoto, M., Laakso, H., Novara, M., Ferri, P., Middleton, H.R., Ziethe, R., BepiColombo—comprehensive exploration of mercury: mission overview and science goals. Planet. Space Sci. 58:1–2 (2010), 2–20.
Berndt, J., Liebske, C., Holtz, F., Freise, M., Nowak, M., Ziegenbein, D., Hurkuck, W., Koepke, J., A combined rapid-quench and H-2-membrane setup for internally heated pressure vessels: description and application for water solubility in basaltic melts. Am. Mineral. 87 (2002), 1717–1726.
Berthet, S., Malavergne, V., Righter, K., Melting of the Indarch meteorite (EH4 chondrite) at 1 GPa and variable oxygen fugacity: implications for early planetary differentiation processes. Geochim. Cosmochim. Acta 73:20 (2009), 6402–6420.
Bouhifd, M.A., Gautron, L., Bolfan-Casanova, N., Malavergne, V., Hammouda, T., Andrault, D., Jephcoat, A.P., Potassium partitioning into molten iron alloys at high-pressure: implications for Earth's core. Phys. Earth Planet. Inter. 160:1 (2007), 22–33.
Bouhifd, M.A., Andrault, D., Bolfan-Casanova, N., Hammouda, T., Devidal, J.-L., Metal-silicate partitioning of Pb and U: effects of metal composition and oxygen fugacity. Geochim. Cosmochim. Acta 114 (2013), 13–28.
Boujibar, A., Andrault, D., Bouhifd, M.A., Bolfan-Casanova, N., Devidal, J.L., Trcera, N., Metal–silicate partitioning of sulphur, new experimental and thermodynamic constraints on planetary accretion. Earth Planet. Sci. Lett. 391 (2014), 42–54.
Boujibar, A., Habermann, M., Righter, K., Ross, D.K., Pando, K., Righter, M., Chidester, B.A., Danielson, L.R., U, Th, and K partitioning between metal, silicate, and sulfide and implications for Mercury's structure, volatile content, and radioactive heat production. Am. Mineral. 104 (2019), 1221–1237.
Boukaré, C.E., Parman, S.W., Parmentier, E.M., Anzures, B.A., Production and preservation of sulfide layering in Mercury's mantle. J. Geophys. Res. Planets 124 (2019), 3354–3372.
Bunce, E.J., Martindale, A., Lindsay, S., Muinonen, K., Rothery, D.A., Pearson, J., McDonnell, I., Thomas, C., Thornhill, J., Tikkanen, T., Feldman, C., Huovelin, J., Korpela, S., Esko, E., Lehtolainen, A., Treis, J., Majewski, P., Hilchenbach, M., Väisänen, T., Luttinen, A., Kohout, T., Penttilä, A., Bridges, J., Joy, K.H., Alcacera-Gil, M.A., Alibert, G., Anand, M., Bannister, N., Barcelo-Garcia, C., Bicknell, C., Blake, O., Bland, P., Butcher, G., Cheney, A., Christensen, U., Crawford, T., Crawford, I.A., Dennerl, K., Dougherty, M., Drumm, P., Fairbend, R., Genzer, M., Grande, M., Hall, G.P., Hodnett, R., Houghton, P., Imber, S., Kallio, E., Lara, M.L., Balado Margeli, A., Mas-Hesse, M.J., Maurice, S., Milan, S., Millington-Hotze, P., Nenonen, S., Nittler, L., Okada, T., Ormö, J., Perez-Mercader, J., Poyner, R., Robert, E., Ross, D., Pajas-Sanz, M., Schyns, E., Seguy, J., Strüder, L., Vaudon, N., Viceira-Martín, J., Williams, H., Willingale, D., Yeoman, T., The BepiColombo mercury imaging X-ray spectrometer: science goals, instrument performance and operations. Space Sci. Rev. 216 (2020), 1–38.
Cartier, C., Comportement des terres rares (REE) et des éléments fortement chargés (HSFE) pendant la différenciation précoce de la Terre sous faible fugacité d'oxygène. Sciences de la Terre. 2014, Université Blaise Pascal - Clermont-Ferrand II.
Cartier, C., Wood, B.J., The role of reducing conditions in building Mercury. Elements 15 (2019), 39–45.
Cartier, C., Hammouda, T., Doucelance, R., Boyet, M., Devidal, J.-L., Moine, B., Experimental study of trace element partitioning between enstatite and melt in enstatite chondrites at low oxygen fugacities and 5 GPa. Geochim. Cosmochim. Acta 130 (2014), 167–187.
Cartier, C., Namur, O., Nittler, L.R., Weider, S.Z., Crapster-Pregont, E., Vorburger, A., Frank, E.A., Charlier, B., No FeS layer in Mercury? Evidence from Ti/Al measured by MESSENGER. Earth Planet. Sci. Lett., 534, 2020, 116108.
Chabot, N.L., Drake, M.J., Potassium solubility in metal: the effects of composition at 15 kbar and 1900 C on partitioning between iron alloys and silicate melts. Earth Planet. Sci. Lett. 172:3–4 (1999), 323–335.
Charlier, B., Namur, O., The origin and differentiation of planet Mercury. Elem. Int. Mag. Miner. Geochem. Petrol. 15:1 (2019), 9–14.
Charlier, B., Grove, T.L., Zuber, M.T., Phase equilibria of ultramafic compositions on Mercury and the origin of the compositional dichotomy. Earth Planet. Sci. Lett. 363 (2013), 50–60.
Chen, B., Li, J., Hauck, S.A., Non-ideal liquidus curve in the Fe-S system and Mercury's snowing core. Geophys. Res. Lett., 35(7), 2008.
Condamine, P., Tournier, S., Charlier, B., Médard, E., Triantafyllou, A., Dalou, C., Tissandier, L., Lequin, D., Cartier, C., Füri, E., Burnard, P.G., Demouchy, S., Marrocchi, Y., Influence of intensive parameters and assemblies on friction evolution during piston-cylinder experiments. Am. Mineral. J. Earth Planet. Mater. 107:8 (2022), 1575–1581.
Corgne, A., Keshav, S., Fei, Y., McDonough, W.F., How much potassium is in the Earth's core? New insights from partitioning experiments. Earth Planet. Sci. Lett. 256 (2007), 567–576.
Corgne, A., Keshav, S., Wood, B.J., McDonough, W.F., Fei, Y., Metal–silicate partitioning and constraints on core composition and oxygen fugacity during Earth accretion. Geochim. Cosmochim. Acta 72:2 (2008), 574–589.
Crozaz, G., Lundberg, L.L., The origin of oldhamite in unequilibrated enstatite chondrites. Geochim. Cosmochim. Acta 59 (1995), 3817–3831.
Dauphas, N., Pourmand, A., Hf–W–Th evidence for rapid growth of Mars and its status as a planetary embryo. Nature 473:7348 (2011), 489–492.
Dauphas, N., Nie, N.X., Blanchard, M., Zhang, Z.J., Zeng, H., Hu, J.Y., Meheut, M., Visscher, C., Canup, R., Hopp, T., The extent, nature, and origin of K and Rb depletions and isotopic fractionations in earth, the moon, and other planetary bodies. Planet. Sci. J., 3(2), 2022, 29.
Dickinson, T.L., Lofgren, G.E., McKay, G.A., REE partitioning between silicate liquid and immiscible sulfide liquid: the origin of the negative Eu anomaly in aubrite sulfides. Lunar and Planetary Science Conference XXI, 1990, 284.
Edmund, E., Morard, G., Baron, M.A., Rivoldini, A., Yokoo, S., Boccato, S., Hirose, K., Pakhomova, A., Antonangeli, D., The Fe-FeSi phase diagram at Mercury's core conditions. Nat. Commun., 13(1), 2022, 387.
Evans, L.G., Peplowski, P.N., Rhodes, E.A., Lawrence, D.J., McCoy, T.J., Nittler, L.R., Solomon, S.C., Sprague, A.L., Stockstill-Cahill, K.R., Starr, R.D., Weider, S.Z., Boynton, W.V., Hamara, D.K., Goldsten, J.O., Major-element abundances on the surface of mercury: results from the MESSENGER gamma-ray spectrometer. J. Geophys. Res. Planets, 117(E12), 2012.
Evans, L.G., Peplowski, P.N., McCubbin, F.M., McCoy, T.J., Nittler, L.R., Zolotov, M.Y., Ebel, D.S., Lawrence, D.J., Starr, R.D., Weider, S.Z., Solomon, S.C., Chlorine on the surface of Mercury: MESSENGER gamma-ray measurements and implications for the planet's formation and evolution. Icarus 257 (2015), 417–427.
Genova, A., Goossens, S., Mazarico, E., Lemoine, F.G., Neumann, G.A., Kuang, W., Sabaka, T.J., Hauck, S.A., Smith, D.E., Solomon, S.C., Zuber, M.T., Geodetic evidence that Mercury has a solid inner core. Geophys. Res. Lett. 46:7 (2019), 3625–3633.
Goossens, S., Renaud, J.P., Henning, W.G., Mazarico, E., Bertone, S., Genova, A., Evaluation of recent measurements of Mercury's moments of inertia and tides using a comprehensive Markov chain Monte Carlo method. Planet. Sci. J., 3(2), 2022, 37.
Griffin, W.L., Powell, W.J., Pearson, N.J., O'Reilly, S.Y., GLITTER: data reduction software for laser ablation ICP-MS. Sylvester, P., (eds.) Laser Ablation ICP-MS in the Earth Sciences: Current Practices and Outstanding Issues Mineralogical Association of Canada. Short Course Series, 40, 2008, 308–311.
Hammouda, T., Boyet, M., Frossard, P., Cartier, C., The message of oldhamites from enstatite chondrites. Prog. Earth Planet. Sci. 9:1 (2022), 1–19.
Hauck, S.A., Margot, J.-L., Solomon, S.C., Phillips, R.J., Johnson, C.L., Lemoine, F.G., Mazarico, E., McCoy, T.J., Padovan, S., Peale, S.J., Perry, M.E., Smith, D.E., Zuber, M.T., The curious case of Mercury's internal structure. J. Geophys. Res. Planets 118 (2013), 1204–1220.
Humayun, M., Clayton, R.N., Potassium isotope cosmochemistry: genetic implications of volatile element depletion. Geochim. Cosmochim. Acta 59:10 (1995), 2131–2148.
Ingrao, N.J., Hammouda, T., Boyet, M., Gaborieau, M., Moine, B.N., Vlastelic, I., Bouhifd, M.A., Devidal, J.L., Mathon, O., Testemale, D., Hazemann, J.L., Proux, O., Rare earth element partitioning between sulphides and melt: evidence for Yb2+ and Sm2+ in EH chondrites. Geochim. Cosmochim. Acta 265 (2019), 182–197.
Jantzen, T., Hack, K., Yazhenskikh, E., Müller, M., Evaluation of thermodynamic data and phase equilibria in the system Ca–Cr–Cu–Fe–Mg–Mn–S part I: binary and quasi-binary subsystems. Calphad 56 (2017), 270–285.
Javoy, M., Kaminski, E., Earth's Uranium and Thorium content and geoneutrinos fluxes based on enstatite chondrites. Earth Planet. Sci. Lett. 407 (2014), 1–8.
Kilburn, M.R., Wood, B.J., Metal–silicate partitioning and the incompatibility of S and Si during core formation. Earth Planet. Sci. Lett. 152 (1997), 139–148.
Kiseeva, E.S., Wood, B.J., A simple model for chalcophile element partitioning between sulphide and silicate liquids with geochemical applications. Earth Planet. Sci. Lett. 383 (2013), 68–81.
Kiseeva, E.S., Wood, B.J., The effects of composition and temperature on chalcophile and lithophile element partitioning into magmatic sulphides. Earth Planet. Sci. Lett. 424 (2015), 280–294.
Knibbe, J.S., van Westrenen, W., The interior configuration of planet Mercury constrained by moment of inertia and planetary contraction. J. Geophys. Res. Planets 120 (2015), 1904–1923.
Knibbe, J.S., van Westrenen, W., The thermal evolution of Mercury's Fe–Si core. Earth Planet. Sci. Lett. 482 (2018), 147–159.
Knibbe, J.S., Rivoldini, A., Luginbuhl, S.M., Namur, O., Charlier, B., Mezouar, M., Sifre, D., Berndt, J., Kono, Y., Neuville, D.R., van Westrenen, W., Van Hoolst, T., Mercury's interior structure constrained by density and P-wave velocity measurements of liquid Fe-Si-C alloys. J. Geophys. Res. Planets, 126(1), 2021 e2020JE006651.
Lehner, S.W., Petaev, M.I., Zolotov, M.Y., Buseck, P.R., Formation of niningerite by silicate sulfidation in EH3 enstatite chondrites. Geochim. Cosmochim. Acta 101 (2013), 34–56.
Lodders, K., Fegley, B., The Planetary scientist's Companion. 1998, Oxford University Press on Demand.
Malavergne, V., Tarrida, M., Combes, R., Bureau, H., Jones, J., Schwandt, C., New high-pressure and high-temperature metal/silicate partitioning of U and Pb: implications for the cores of the Earth and Mars. Geochim. Cosmochim. Acta 71 (2007), 2637–2655.
Malavergne, V., Toplis, M.J., Berthet, S., Jones, J., Highly reducing conditions during core formation on Mercury: implications for internal structure and the origin of a magnetic field. Icarus 206 (2010), 199–209.
Malavergne, V., Cordier, P., Righter, K., Brunet, F., Zanda, B., Addad, A., Smith, T., Bureau, H., Surblé, S., Raepsaet, C., Charon, E., Hewins, R.H., How Mercury can be the most reduced terrestrial planet and still store iron in its mantle. Earth Planet. Sci. Lett. 394 (2014), 186–197.
Margot, J.L., Peale, S.J., Jurgens, R.F., Slade, M.A., Holin, I.V., Large longitude libration of Mercury reveals a molten core. Science 316:5825 (2007), 710–714.
Margot, J.L., Hauck, S.A.I., Mazarico, E., Padovan, S., Peale, S.J., Mercury's internal structure. Solomon, S.C., Nittler, L.R., Anderson, B.J., (eds.) Mercury: The View after MESSENGER, 2018, Cambridge University Press, 85–113.
McCoy, T.J., Dickinson, T.L., Lofgren, G.E., Partial melting of the Indarch (EH4) meteorite: a textural, chemical, and phase relations view of melting and melt migration. Meteorit. Planet. Sci. 34 (1999), 735–746.
McCubbin, F.M., Riner, M.A., Vander Kaaden, K.E., Burkemper, L.K., Is Mercury a volatile-rich planet?. Geophys. Res. Lett., 39(9), 2012.
McCubbin, F.M., Vander Kaaden, K.E., Peplowski, P.N., Bell, A.S., Nittler, L.R., Boyce, J.W., Evans, L.G., Keller, L.P., Elardo, S.M., McCoy, T.J., A low O/Si ratio on the surface of Mercury: evidence for silicon smelting?. J. Geophys. Res. Planets 122 (2017), 2053–2076.
McDonough, W.F., The composition of the lower mantle and core. Deep Earth: Physics and Chemistry of the Lower Mantle and Core, 2016, 143–159.
McLennan, S.M., Large-ion lithophile element fractionation during the early differentiation of Mars and the composition of the martian primitive mantle. Meteorit. Planet. Sci. 38 (2003), 895–904.
Mills, N.M., Agee, C.B., Draper, D.S., Metal-silicate partitioning of cesium: implications for core formation. Geochim. Cosmochim. Acta 71 (2007), 4066–4081.
Miozzi, F., Morard, G., Antonangeli, D., Baron, M.A., Pakhomova, A., Clark, A.N., Mezouar, M., Fiquet, G., The Fe-Si-C system at extreme P-T conditions: a possible core crystallization pathway for reduced planets. Geochim. Cosmochim. Acta 322 (2022), 129–142.
Morgan, J.W., Lovering, J.F., Uranium and thorium abundances in chondritic meteorites. Talanta 15:11 (1968), 1079–1095.
Mouser, M.D., Dygert, N., Anzures, B.A., Grambling, N.L., Hrubiak, R., Kono, Y., Shen, G., Parman, S.W., Experimental investigation of Mercury's magma ocean viscosity: implications for the formation of Mercury's cumulate mantle, its subsequent dynamic evolution, and crustal petrogenesis. J. Geophys. Res. Planets, 126(11), 2021 e2021JE006946.
Namur, O., Charlier, B., Silicate mineralogy at the surface of Mercury. Nat. Geosci. 10:1 (2017), 9–13.
Namur, O., Charlier, B., Holtz, F., Cartier, C., McCammon, C., Sulfur solubility in reduced mafic silicate melts: implications for the speciation and distribution of sulfur on Mercury. Earth Planet. Sci. Lett. 448 (2016), 102–114.
Namur, O., Collinet, M., Charlier, B., Grove, T.L., Holtz, F., McCammon, C., Melting processes and mantle sources of lavas on Mercury. Earth Planet. Sci. Lett. 439 (2016), 117–128.
Nittler, L.R., Chabot, N.L., Grove, T.L., Peplowski, P.N., The chemical composition of Mercury. Anderson, B.J., Nittler, L.R., Solomon, S.C., (eds.) Mercury: The View after MESSENGER, 2018, Cambridge University Press, Cambridge, 30–51.
Nittler, L.R., Boujibar, A., Crapster-Pregont, E., Frank, E.A., McCoy, T.J., McCubbin, F.M., Starr, R.D., Vander Kaaden, K.E., Vorburger, A., Weider, S.Z., Heterogeneous distribution of chromium on Mercury. Mercury Curr. Future Sci. Innermost Planet, 2047, 2018, 6095.
Parman, S.W., Parmentier, E.M., Wang, S., Crystallization of mercury's sulfur-rich magma ocean. 47th Annual Lunar and Planetary Science Conference, 2016, March (No. 1903, p. 2990).
Peplowski, P.N., Evans, L.G., Hauck, S.A., McCoy, T.J., Boynton, W.V., Gillis-Davis, J.J., Ebel, D.S., Goldsten, J.O., Hamara, D.K., Lawrence, D.J., McNutt, R.L., Nittler, L.R., Solomon, S.C., Rhodes, E.A., Sprague, A.L., Starr, R.D., Stockstill-Cahill, K.R., Radioactive elements on Mercury's surface from MESSENGER: implications for the planet's formation and evolution. Science 333 (2011), 1850–1852.
Peplowski, P.N., Evans, L.G., Rhodes, E.A., Goldsten, J.O., Hamara, D.K., Head, J.W., Lawrence, D.J., Nittler, L.R., Solomon, S.C., Sprague, A.L., Elemental composition of the surface of mercury from the MESSENGER gamma-ray spectrometer. AGU Fall Meeting Abstracts, 2012, December (Vol. 2012, pp. P31D-05).
Peplowski, P.N., Evans, L.G., Stockstill-Cahill, K.R., Lawrence, D.J., Goldsten, J.O., McCoy, T.J., Nittler, L.R., Solomon, S.C., Sprague, A.L., Starr, R.D., Weider, S.Z., Enhanced sodium abundance in Mercury's north polar region revealed by the MESSENGER Gamma-Ray Spectrometer. Icarus 228 (2014), 86–95.
Peplowski, P.N., Lawrence, D.J., Feldman, W.C., Goldsten, J.O., Bazell, D., Evans, L.G., Head, J.W., Nittler, L.R., Solomon, S.C., Weider, S.Z., Geochemical terranes of Mercury's northern hemisphere as revealed by MESSENGER neutron measurements. Icarus 253 (2015), 346–363.
Peterson, G.A., Johnson, C.L., Jellinek, A.M., Thermal evolution of mercury with a volcanic heat-pipe flux: reconciling early volcanism, tectonism, and magnetism. Science. Advances, 7(40), 2021, eabh2482.
Rivoldini, A., Van Hoolst, T., The interior structure of Mercury constrained by the low-degree gravity field and the rotation of Mercury. Earth Planet. Sci. Lett. 377–378 (2013), 62–72.
Rothery, D.A., Massironi, M., Alemanno, G., Barraud, O., Besse, S., Bott, N., Brunetto, R., Bunce, E., Byrne, P., Capaccioni, F., Capria, M.T., Carli, C., Charlier, B., Cornet, T., Cremonese, G., D'Amore, M., De Sanctis, M.C., Doressoundiram, A., Ferranti, L., Filacchione, G., Galluzzi, V., Giacomini, L., Grande, M., Guzzetta, L.G., Helbert, J., Heyner, D., Hiesinger, H., Hussmann, H., Hyodo, R., Kohout, T., Kozyrev, A., Litvak, M., Lucchetti, A., Malakhov, A., Malliband, C., Mancinelli, P., Martikainen, J., Martindale, A., Maturilli, A., Milillo, A., Mitrofanov, I., Mokrousov, M., Morlok, A., Muinonen, K., Namur, O., Nittler, L.R., Oliveira, J.S., Owens, A., Palumbo, P., Pajola, M., Pegg, D.L., Penttilä, A., Politi, R., Quarati, F., Re, C., Sanin, A., Schulz, R., Stangarone, C., Stojic, A., Tretiyakov, V., Väisänen, T., Varatharajan, I., Weber, I., Wright, J., Wurz, P., Zambon, F., Rationale for BepiColombo Studies of Mercury's Surface and composition. Space Sci. Rev. 216 (2020), 1–46.
Shannon, R.D., Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides. Acta Crystallogr. Sec. A 32 (1976), 751–767.
Shaw, D.M., Trace element fractionation during anatexis. Geochim. Cosmochim. Acta 34:2 (1970), 237–243.
Smith, D.E., Zuber, M.T., Phillips, R.J., Solomon, S.C., Hauck, S.A., Lemoine, F.G., Mazarico, E., Neumann, G.A., Peale, S.J., Margot, J.-L., Johnson, C.L., Torrence, M.H., Perry, M.E., Rowlands, D.D., Goossens, S., Head, J.W., Taylor, A.H., Gravity field and internal structure of Mercury from MESSENGER. Science 336 (2012), 214–217.
Steenstra, E.S., Agmon, N., Berndt, J., Klemme, S., Matveev, S., van Westrenen, W., Depletion of potassium and sodium in mantles of Mars, Moon and Vesta by core formation. Sci. Rep., 8(1), 2018, 7053.
Steenstra, E.S., Trautner, V.T., Berndt, J., Klemme, S., van Westrenen, W., Trace element partitioning between sulfide-, metal- and silicate melts at highly reduced conditions: insights into the distribution of volatile elements during core formation in reduced bodies. Icarus, 335, 2020, 113408.
Steenstra, E.S., Kelderman, E., Berndt, J., Klemme, S., Bullock, E.S., van Westrenen, W., Highly reduced accretion of the Earth by large impactors? Evidence from elemental partitioning between sulfide liquids and silicate melts at highly reduced conditions. Geochim. Cosmochim. Acta 286 (2020), 248–268.
Steinbrügge, G., Dumberry, M., Rivoldini, A., Schubert, G., Cao, H., Schroeder, D.M., Soderlund, K.M., Challenges on Mercury's interior structure posed by the new measurements of its obliquity and tides. Geophys. Res. Lett., 48(3), 2021.
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 59:5 (1995), 991–1002.
Tosi, N., Grott, M., Plesa, A.C., Breuer, D., Thermochemical evolution of Mercury's interior. J. Geophys. Res. Planets 118 (2013), 2474–2487.
van Achterbergh, E., Ryan, C., Jackson, S., Griffin, W., Data reduction software for LA-ICP-MS. Sylvester, P., (eds.) Laser Ablation-ICPMS in the Earth Sciences Mineral Assoc Can Short Course Handbook, vol. 29, 2001, 239–243.
Vander Kaaden, K.E., McCubbin, F.M., The origin of boninites on Mercury: an experimental study of the northern volcanic plains lavas. Geochim. Cosmochim. Acta 173 (2016), 246–263.
Vander Kaaden, K.E., McCubbin, F.M., Turner, A.A., Ross, D.K., Constraints on the abundances of carbon and silicon in Mercury's core from experiments in the Fe-Si-C system. J. Geophys. Res. Planets, 125(5), 2020 e2019JE006239.
Wasson, J.T., Kallemeyn, G.W., Compositions of chondrites. Philos. Trans. R. Soc. Lond. A Math. Phys. Sci. 325:1587 (1988), 535–544.
Weider, S.Z., Nittler, L.R., Starr, R.D., Crapster-Pregont, E.J., Peplowski, P.N., Denevi, B.W., Head, J.W., Byrne, P.K., Hauck Ii, S.A., Ebel, D.S., Solomon, S.C., Evidence for geochemical terranes on Mercury: global mapping of major elements with MESSENGER's X-ray spectrometer. Earth Planet. Sci. Lett. 416 (2015), 109–120.
Wiik, H.B., The chemical composition of some stony meteorites. Geochim. Cosmochim. Acta 9 (1956), 279–289.
Wilbur, Z.E., Udry, A., McCubbin, F.M., vander Kaaden, K.E., DeFelice, C., Ziegler, K., Ross, D.K., McCoy, T.J., Gross, J., Barnes, J.J., Dygert, N., The effects of highly reduced magmatism revealed through aubrites. Meteorit. Planet. Sci. 57:7 (2022), 1387–1420.
Wipperfurth, S.A., Guo, M., Šrámek, O., McDonough, W.F., Earth's chondritic Th/U: negligible fractionation during accretion, core formation, and crust–mantle differentiation. Earth Planet. Sci. Lett. 498 (2018), 196–202.
Wohlers, A., Wood, B.J., A Mercury-like component of early Earth yields uranium in the core and high mantle 142Nd. Nature 520 (2015), 337–340.
Wohlers, A., Wood, B.J., Uranium, thorium and REE partitioning into sulfide liquids: implications for reduced S-rich bodies. Geochim. Cosmochim. Acta 205 (2017), 226–244.
Wood, B.J., Kiseeva, E.S., Trace element partitioning into sulfide: how lithophile elements become chalcophile and vice versa. Am. Mineral. 100 (2015), 2371–2379.
Zolotov, M.Y., Sprague, A.L., Hauck, S.A., Nittler, L.R., Solomon, S.C., Weider, S.Z., The redox state, FeO content, and origin of sulfur-rich magmas on Mercury. J. Geophys. Res. Planets 118 (2013), 138–146.
