Phase equilibria of ultramafic compositions on Mercury and the origin of the compositional dichotomy

Crustal composition; Magma ocean; MESSENGER; Planetary formation; Volcanism; Crystallography; Igneous rocks; Magnesium; Melting; Mineralogy; Minerals; Olivine; Phase equilibria; Reflection; Silica; Silicates; Structural geology; Surfaces; Volcanoes; Mercury (metal); Mercury (planet)

Abstract :

[en] Measurements of major element ratios obtained by the MESSENGER spacecraft using x-ray fluorescence spectra are used to calculate absolute element abundances of lavas at the surface of Mercury. We discuss calculation methods and assumptions that take into account the distribution of major elements between silicate, metal, and sulfide components and the potential occurrence of sulfide minerals under reduced conditions. These first compositional data, which represent large areas of mixed high-reflectance volcanic plains and low-reflectance materials and do not include the northern volcanic plains, share common silica- and magnesium-rich characteristics. They are most similar to terrestrial volcanic rocks known as basaltic komatiites. Two compositional groups are distinguished by the presence or absence of a clinopyroxene component. Melting experiments at one atmosphere on the average compositions of each of the two groups constrain the potential mineralogy at Mercury's surface, which should be dominated by orthopyroxene (protoenstatite and orthoenstatite), plagioclase, minor olivine if any, clinopyroxene (augite), and tridymite. The two compositional groups cannot be related to each other by any fractional crystallization process, suggesting differentiated source compositions for the two components and implying multi-stage differentiation and remelting processes for Mercury. Comparison with high-pressure phase equilibria supports partial melting at pressure <10. kbar, in agreement with last equilibration of the melts close to the crust-mantle boundary with two different mantle lithologies (harzburgite and lherzolite). Magma ocean crystallization followed by adiabatic decompression of mantle layers during cumulate overturn and/or convection would have produced adequate conditions to explain surface compositions. The surface of Mercury is not an unmodified quenched crust of primordial bulk planetary composition. Ultramafic lavas from Mercury have high liquidus temperatures (1450-1350. °C) and very low viscosities, in accordance with the eruption style characterized by flooding of pre-existing impact craters by lava and absence of central volcanoes. © 2012 Elsevier B.V.

Disciplines :

Earth sciences & physical geography

Author, co-author :

Charlier, Bernard ; Université de Liège - ULiège > Département de géologie > Pétrologie, géochimie endogènes et pétrophysique

Grove, T. L.; Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, United States

Zuber, M. T.; Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, United States

Title :

Phase equilibria of ultramafic compositions on Mercury and the origin of the compositional dichotomy

Publication date :

2013

Journal title :

Earth and Planetary Science Letters

ISSN :

0012-821X

eISSN :

1385-013X

Publisher :

Elsevier, Netherlands

Volume :

363

Pages :

50-60

Peer reviewed :

Peer Reviewed verified by ORBi

Available on ORBi :

since 12 November 2014

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Bibliography

Aitken B.G., Echeverría L.M. Petrology and geochemistry of komatiites and tholeiites from Gorgona Island, Colombia. Contrib. Mineral. Petrol. 1984, 86:94-105.
Andersen O. The system anorthite-forsterite-silica. Am. J. Sci. 1915, 39:407-454.
Armstrong J.T. Citzaf-a package of correction programs for the quantitative electron microbeam X-ray analysis of thick polished materials, thin-films, and particles. Microbeam Anal. 1995, 4:177-200.
Arndt N.T., Nisbet E.G. Komatiites 1982, George Allen and Unwin, London, pp. 526.
Berthet S., Malavergne V., Righter K. Melting of the Indarch meteorite (EH4 chondrite) at 1GPa and variable oxygen fugacity: implications for early planetary differentiation processes. Geochim. Cosmochim. Acta 2009, 73:6402-6420.
Blewett D.T., Lucey P.G., Hawke B.R., Ling G.G., Robinson M.S. A comparison of mercurian reflectance and spectral quantities with those of the Moon. Icarus 1997, 129:217-231.
Brown S.M., Elkins-Tanton L.T. Compositions of Mercury's earliest crust from magma ocean models. Earth Planet. Sci. Lett. 2009, 286:446-455.
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 2008, 72:574-589.
De Wit M.J., Ashwal L.D. Convergence towards divergent models of greenstone belts. Greenstone Belts. Oxford Monograph on Geology and Geophysics 1997, vol. 35:ix-xvii. Oxford University Press.
Delano J.W. Pristine lunar glasses: criteria, data, and implications. J. Geophys. Res. 1986, 91:D201-D213.
Denevi B.W., et al. The evolution of Mercury's crust: a global perspective from MESSENGER. Science 2009, 324:613-618.
Elkins-Tanton L.T., Parmentier E.M., Hess P.C. Magma ocean fractional crystallization and cumulate overturn in terrestrial planets: implications for Mars. Meteorit. Planet. Sci. 2003, 38:1753-1771.
Evans L.G., et al. Major-element abundances on the surface of Mercury: results from the MESSENGER Gamma-Ray Spectrometer. J. Geophys. Res. 2012, 117:E00L07.
Fan J., Kerrich R. Geochemical characteristics of aluminum depleted and undepleted komatiites and HREE-enriched low-Ti tholeiites, western Abitibi greenstone belt: a heterogeneous mantle plume-convergent margin environment. Geochim. Cosmochim. Acta 1997, 61:4723-4744.
Fassett C.I., Kadish S.J., Head J.W., Solomon S.C., Strom R.G. The global population of large craters on Mercury and comparison with the Moon. Geophys. Res. Lett. 2011, 38:L10202.
Fassett C.I., et al. Large impact basins on Mercury: global distribution, characteristics, and modification history from MESSENGER orbital data. J. Geophys. Res. 2012, 117:E00L08.
Filiberto J., Dasgupta R. Fe2+-Mg partitioning between olivine and basaltic melts: applications to genesis of olivine-phyric shergottites and conditions of melting in the Martian interior. Earth Planet. Sci. Lett. 2011, 304:527-537.
Giordano D., Russell J.K., Dingwell D.B. Viscosity of magmatic liquids: a model. Earth Planet. Sci. Lett. 2008, 271:123-134.
Grove T.L. Use of FePt alloys to eliminate the iron loss problem in 1atm gas mixing experiments: theoretical and practical considerations. Contrib. Mineral. Petrol. 1981, 78:298-304.
Grove T.L. Corrections to expressions for calculating mineral components in "Origin of calc-alkaline series lavas at medicine lake volcano by fractionation, assimilation and mixing" and "Experimental petrology of normal MORB near the kane fracture zone: 22°-25°N, mid-atlantic ridge". Contrib. Mineral. Petrol. 1993, 114:422-424.
Grove T.L., Parman S.W. Thermal evolution of the Earth as recorded by komatiites. Earth Planet. Sci. Lett. 2004, 219:173-187.
Gudfinnsson G.H., Presnall D.C. Melting behaviour of model lherzolite in the system CaO-MgO-Al2O3-SiO2-FeO at 0.7-2.8GPa. J. Petrol. 2000, 41:1241-1269.
Head J.W., et al. Flood volcanism in the northern high latitudes of Mercury revealed by MESSENGER. Science 2011, 333:1853-1856.
Head J.W., et al. Volcanism on Mercury: evidence from the first MESSENGER flyby. Science 2008, 321:69-72.
Hess P.C., Parmentier E.M. A model for the thermal and chemical evolution of the Moon's interior: implications for the onset of mare volcanism. Earth Planet. Sci. Lett. 1995, 134:501-514.
Hollings P., Kerrich R. Trace element systematics of ultramafic and mafic volcanic rocks from the 3Ga North Caribou greenstone belt, northwestern Superior Province. Precambrian Res. 1999, 93:257-279.
Keil K. Mineralogical and chemical relationships among enstatite chondrites. J. Geophys. Res. 1968, 73:6945-6976.
Kerber L., et al. The global distribution of pyroclastic deposits on Mercury: the view from MESSENGER flybys 1-3. Planet. Space Sci. 2011, 59:1895-1909.
Kushiro I. Determination of liquidus relations in synthetic silicate systems with electron probe analysis: the system forsterite-diopside-silica at 1atm. Am. Mineral. 1972, 57:1260-1271.
Larimer J.W., Ganapathy R. The trace element chemistry of CaS in enstatite chondrites and some implications regarding its origin. Earth Planet. Sci. Lett. 1987, 84:123-134.
Lawrence D.J., et al. Identification and measurement of neutron-absorbing elements on Mercury's surface. Icarus 2010, 209:195-209.
Le Bas M.J. IUGS reclassification of the high-Mg and picritic volcanic rocks. J. Petrol. 2000, 41:1467-1470.
Li J., Agee C.B. Geochemistry of mantle-core differentiation at high pressure. Nature 1996, 381:686-689.
Liu T.-C., Presnall D.C. Liquidus phase relationships on the join anorthite-forsterite-quartz at 20kbar with applications to basalt petrogenesis and igneous sapphirine. Contrib. Mineral. Petrol. 1990, 104:735-742.
Longhi J., Boudreau A.E. The orthoenstatite liquidus field in the system forsterite-diopside-silica at one atmosphere. Am. Mineral. 1980, 65:563-573.
Longhi J., Pan V. A reconnaisance study of phase boundaries in low-alkali basaltic liquids. J. Petrol. 1988, 29:115-147.
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 2010, 206:199-209.
McClintock W.E., et al. Spectroscopic observations of Mercury's surface reflectance during MESSENGER's first Mercury flyby. Science 2008, 321:62-65.
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. 1999, 34:735-746.
McCubbin F.M., Riner M.A., Vander Kaaden K.E., Burkemper L.K. Is Mercury a volatile-rich planet?. Geophys. Res. Lett. 2012, 39:L09202.
Michel N.C., Hauck II S.A., Solomon S.C., Phillips R.J., Roberts J.H., Zuber M.T., 2012. Implications of MESSENGER observations for mantle convection of Mercury. In: Proceedings of the 43rd Lunar Planetary Science Conference, p.1671.
Nittler L.R., et al. The major-element composition of Mercury's surface from MESSENGER x-ray spectrometry. Science 2011, 333:1847-1850.
Osborn E.F., Tait D.B. The system diopside-forsterite-anorthite. Am. J. Sci. Bowen Volume 1952, 413-433.
Papike J.J., Ryder G., Shearer C.K. Lunar samples. Rev. Mineral. Geochem. 1998, 36(5.1-5):234.
Parman S.W., Grove T.L., Dann J.C. The production of Barberton komatiites in an Archean subduction sone. Geophys. Res. Lett. 2001, 28:2513-2516.
Peplowski P.N., et al. Radioactive elements on Mercury's surface from MESSENGER: implications for the planet's formation and evolution. Science 2011, 333:1850-1852.
Polat A., Kerrich R., Wyman D.A. Geochemical diversity in oceanic komatiites and basalts from the late Archean Wawa greenstone belts, Superior Province, Canada: trace element and Nd isotope evidence for a heterogeneous mantle. Precambrian Res. 1999, 94:139-173.
Presnall D.C., et al. Liquidus phase relations on the join diopside-forsterite-anorthite from 1atm to 20kbar: their bearing on the generation and crystallization of basaltic magma. Contrib. Mineral. Petrol. 1978, 66:203-220.
Presnall D.C., Dixon J.R., O'Donnell T.H., Dixon S.A. Generation of mid-ocean ridge tholeiites. J. Petrol. 1979, 20:3-35.
Prockter L.M., et al. Evidence for young volcanism on Mercury from the third MESSENGER flyby. Science 2010, 329:668-671.
Rava B., Hapke B. An analysis of the Mariner 10 color ratio map of mercury. Icarus 1987, 71:397-429.
Riner M.A., Lucey P.G., Desch S.J., McCubbin F.M. Nature of opaque components on Mercury: insights into a Mercurian magma ocean. Geophys. Res. Lett. 2009, 36:L02201.
Riner M.A., McCubbin F.M., Lucey P.G., Talyor G.J., Gillis-Davis J.J. Mercury surface composition: integrating petrologic modeling and remote sensing data to place constraints on FeO abundance. Icarus 2010, 209:301-313.
Riner M.A., Lucey P.G., McCubbin F.M., Taylor G.J. Constraints on Mercury's surface composition from MESSENGER neutron spectrometer data. Earth Planet. Sci. Lett. 2011, 308:107-114.
Robinson M.S., Lucey P.G. Recalibrated Mariner 10 color mosaics: implications for Mercurian volcanism. Science 1997, 275:197-200.
Robinson M.S., et al. Reflectance and color variations on Mercury: regolith processes and compositional heterogeneity. Science 2008, 321:66-69.
Rothery D., et al. Mercury's surface and composition to be studied by BepiColombo. Planet. Space Sci. 2010, 58:21-39.
Schlemm C., et al. The X-Ray spectrometer on the MESSENGER spacecraft. Space Sci. Rev. 2007, 131:393-415.
Sen G., Presnall D.C. Liquidus phase relationships on the join anorthite-forsterite-quartz at 10kbar with applications to basalt petrogenesis. Contrib. Mineral. Petrol. 1984, 85:404-408.
Smith J.V. Crystal structure and stability of the MgSiO3 polymorphs: physical properties and phase relations of Mg,Fe pyroxenes. Miner. Soc. Amr. Spec. 1969, Paper 2:3-29.
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 2012, 336:214-217.
Solomatov V.S. Fluid dynamics of a terrestrial magma ocean. Origin of the Earth and Moon 2000, 323-338. University of Arizona Press, Phoenix. R.M. Canup, K. Righter (Eds.).
Sprague A.L., et al. Spectral emissivity measurements of Mercury's surface indicate Mg- and Ca-rich mineralogy, K-spar, Na-rich plagioclase, rutile, with possible perovskite, and garnet. Planet. Space Sci. 2009, 57:364-383.
Strom R.G., Trask N.J., Guest J.E. Tectonism and volcanism on Mercury. J. Geophys. Res. 1975, 80:2478-2507.
Taylor G.J., Scott E.R.D. Mercury. Treatise on Geochemistry 2003, 477-485. Pergamon, Oxford. D.H. Heinrich, K.T. Karl (Eds.).
Viljoen M.J., Viljoen R.P. The geology and geochemistry of the lower ultramafic unit of the Onverwacht Group and a proposed new class of igneous rocks. Geol. Soc. S. Afr. Spec. Publ. 1969, 2:55-86.
Wadhwa M. Redox conditions on small bodies, the Moon and Mars. Rev. Mineral. Geochem. 2008, 68:493-510.
Weng Y.-H., Presnall D.C. The system diopside-forsterite-enstatite at 5.1GPa: a ternary model for melting of the mantle. Can. Mineral. 2001, 39:299-308.
Wasson J.T. The building stones of the planets. Mercury 1988, 622-650. The University of Arizona Press, Tucson. F. Vilas, C.R. Chapman, M.S. Matthews (Eds.).
Weider S.Z., Nittler L.R., Starr R.D., McCoy T.J., Stockstill-Cahill K.R., Byrne P.K., Denevi B.W., Head J.W., Solomon S.C. Chemical heterogeneity on Mercury's surface revealed by the MESSENGER X-Ray Spectrometer. J. Geophys. Res. 2012, 117:E00L05.
Yasuda M., Kitamura M., Morimoto N. Electron microscopy of clinoenstatite from a boninite and a chondrite. Phys. Chem. Miner. 1983, 9:192-196.
Yoder H.S. Generation of Basaltic Magma 1976, National Academy of Science, Washington, DC, p. 278.
Zolotov M.Y. On the chemistry of mantle and magmatic volatiles on Mercury. Icarus 2011, 212:24-41.