Abstract
The Earth’s uppermost asthenosphere is generally associated with low seismic wave velocity and high electrical conductivity. The electrical conductivity anomalies observed from magnetotelluric studies have been attributed to the hydration of mantle minerals, traces of carbonatite melt, or silicate melts. We report the electrical conductivity of both H2O-bearing (0–6 wt% H2O) and CO2-bearing (0.5 wt% CO2) basaltic melts at 2 GPa and 1,473–1,923 K measured using impedance spectroscopy in a piston-cylinder apparatus. CO2 hardly affects conductivity at such a concentration level. The effect of water on the conductivity of basaltic melt is markedly larger than inferred from previous measurements on silicate melts of different composition. The conductivity of basaltic melts with more than 6 wt% of water approaches the values for carbonatites. Our data are reproduced within a factor of 1.1 by the equation log σ = 2.172 − (860.82 − 204.46 w 0.5)/(T − 1146.8), where σ is the electrical conductivity in S/m, T is the temperature in K, and w is the H2O content in wt%. We show that in a mantle with 125 ppm water and for a bulk water partition coefficient of 0.006 between minerals and melt, 2 vol% of melt will account for the observed electrical conductivity in the seismic low-velocity zone. However, for plausible higher water contents, stronger water partitioning into the melt or melt segregation in tube-like structures, even less than 1 vol% of hydrous melt, may be sufficient to produce the observed conductivity. We also show that ~1 vol% of hydrous melts are likely to be stable in the low-velocity zone, if the uncertainties in mantle water contents, in water partition coefficients, and in the effect of water on the melting point of peridotite are properly considered.
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References
Angell CA (1991) Relaxation in liquids, polymers and plastic crystals–strong/fragile patterns and problems. J Non-Cryst Solids 131–133:13–31
Arcay D, Tric E, Doin M-P (2005) Numerical simulations of subduction zones: effect of slab dehydration on the mantle wedge dynamics. Phys Earth Planet Inter 149:133–153
Archie GE (1942) The electrical resistivity log as an aid in determining some reservoir characteristics. Trans Am Inst Min Metall Pet Eng 146:54–62
Baba K, Chave AD, Evans RL, Hirth G, Mackie RL (2006) Mantle dynamics beneath the East Pacific Rise at 17°S: insights from the Mantle Electromagnetic and Tomography (MELT) experiment. J Geophys Res 111:B02101. doi:10.1029/2004JB003598
Barsoukov E, Macdonald JR (2005) Impedance spectroscopy. Wiley, New Jersey
Behrens H, Kappes R, Heitjans P (2002) Proton conduction in glass–an impedance and infrared spectroscopic study on hydrous BaSi2O5 glass. J Non-Cryst Solids 306:271–281
Behrens H, Zhang Y, Xu Z (2004) H2O diffusion in dacitic and andesitic melts. Geochim Cosmochim Acta 68:5139–5150
Bell DR, Rossman GR, Moore RO (2004) Abundance and partitioning of OH in a high-pressure magmatic system: megacrysts from the Monastery kimberlite, South Africa. J Petrol 45:1539–1564
Brasse H, Eydam D (2008) Electrical conductivity beneath the Bolivian Orocline and its relation to subduction processes at the South American continental margin. J Geophys Res 113:B07109. doi:10.1029/2007JB005142
Brasse H, Kapinos G, Mütschard L, Alvarado GE, Worzewski T, Jegen M (2009) Deep electrical resistivity structure of northwestern Costa Rica. Geophys Res Lett 36:L02310. doi:10.1029/2008GL036397
Brearley M, Montana A (1989) The effect of CO2 on the viscosity of silicate liquids at high pressure. Geochim Cosmochim Acta 53:2609–2616
Brooker RA, Kohn SC, Holloway JR, McMillan PF (2001) Structural controls on the solubility of CO2 in silicate melts. Part I: bulk solubility data. Chem Geol 174:225–239
Cervantes P, Wallace PJ (2003) Role of H2O in subduction-zone magmatism: new insights from melt inclusions in high-Mg basalts from central Mexico. Geology 31:235–238
Constable S (2006) SEO3: a new model of olivine electrical conductivity. Geophys J Int 166:435–437
Dingwell DB, Webb SL (1990) Relaxation in silicate melts. Eur J Mineral 2:427–449
Dixon JE, Stolper E, Delaney JR (1988) Infrared spectroscopic measurements of CO2 and H2O in Juan de Fuca Ridge basaltic glasses. Earth Planet Sci Lett 90:87–104
Ernsberger FM (1980) The role of molecular water in the diffusive transport of protons in glasses. Phys Chem Glasses 21:146–149
Evans RL, Hirth G, Baba K, Forsyth D, Chave A, Mackie R (2005) Geophysical evidence from the MELT area for compositional controls on oceanic plates. Nature 437:249–252
Falloon TJ, Green DH, Danyushevsky LV, McNeill AW (2008) The composition of near-solidus partial melts of fertile peridotite at 1 and 1.5 GPa: implications for the petrogenesis of MORB. J Petrol 49:591–613
Fulcher GS (1925) Analysis of recent measurements of the viscosity of glasses. J Am Ceram Soc 8:339–355
Gaetani GA, Grove TL (1998) The influence of water on melting of mantle peridotite. Contrib Mineral Petrol 131:323–346
Gaillard F (2004) Laboratory measurements of electrical conductivity of hydrous and dry silicic melts under pressure. Earth Planet Sci Lett 218:215–228
Gaillard F, Iacono-Marziano G (2005) Electrical conductivity of magma in the course of crystallization controlled by their residual liquid composition. J Geophys Res 110:B06204. doi:10.1029/2004JB003282
Gaillard F, Schmidt B, Mackwell S, McCammon C (2003) Rate of hydrogen-iron redox exchange in silicate melts and glasses. Geochim Cosmochim Acta 67:2427–2441
Gaillard F, Malki M, Iacono-Marziano G (2008) Carbonatite melts and electrical conductivity in the asthenosphere. Science 322:1363–1365
Giordano D, Dingwell DB (2003) Viscosity of hydrous Etna basalt: implications for Plinian-style basaltic eruptions. Bull Volcanol 65:8–14
Glover PWJ, Hole MJ, Pous J (2000) A modified Archie’s law for two conducting phases. Earth Planet Sci Lett 180:369–383
Green DH, Hibberson WO, HStC O’Neill (2008) Clarification of the influence of water on mantle wedge melting. Geochim Cosmochim Acta 72:A325
Grove TL, Parman SW, Bowring SA, Price RC, Baker MB (2002) The role of an H2O-rich fluid component in the generation of primitive basaltic andesites and andesites from the Mt. Shasta region, N California. Contrib Mineral Petrol 142:275–396
Grove TL, Chatterjee N, Parman SW, Medard E (2006) The influence of H2O on mantle wedge melting. Earth Planet Sci Lett 249:74–89
Hashin Z, Shtrikman S (1962) A variational approach to the theory of the effective magnetic permeability of multiphase materials. J Appl Phys 33:3125–3131
Haven Y, Verkerk B (1965) Diffusion and electrical conductivity of sodium ions in sodium silicate glasses. Phys Chem Glasses 6:38–45
Heinemann I, Frischat GH (1993) The sodium transport mechanism in Na2O·2SiO2 glass determined by the Chemla experiment. Phys Chem Glasses 34:255–260
Hirschmann MM (2010) Partial melt in the oceanic low velocity zone. Phys Earth Planet Int 179:60–71
Hirschmann MM, Tenner T, Aubaud C, Withers AC (2009) Dehydration melting of nominally anhydrous mantle: the primacy of partitioning. Phys Earth Planet Inter 176:54–68
Hodges FN (1974) The solubility of H2O in silicate melts. Carnegie Inst Wash Yearb 73:251–255
Ingrin J, Blanchard M (2006) Diffusion of hydrogen in minerals. Rev Mineral Geochem 62:291–320
Karato S-I (2006) Remote sensing of hydrogen in Earth’s mantle. Rev Mineral Geochem 62:343–375
Kawakatsu H, Kumar P, Takei Y, Shinohara M, Kanazawa T, Araki E, Suyehiro K (2009) Seismic evidence for sharp lithosphere-asthenosphere boundaries of oceanic plates. Science 324:499–502
Khitarov NI, Slutsky AB, Pugin VA (1970) Electrical conductivity of basalts at high T-P and phase transitions under upper mantle conditions. Phys Earth Planet Inter 3:334–342
Kohn SC, Grant KJ (2006) The partitioning of water between nominally anhydrous minerals and silicate melts. Rev Mineral Geochem 62:231–241
Konschak A (2008) CO2 in Silikatschmelzen. Ph.D. Dissertation, Universität Bayreuth
Kushiro I (1972) Effect of water on the composition of magmas formed at high pressures. J Petrol 13:311–334
Lange RA, Carmichael ISE (1987) Densities of Na2O–K2O-CaO-MgO-FeO-Fe2O3-Al2O3-TiO2-SiO2 liquids: new measurements and derived partial molar properties. Geochim Cosmochim Acta 51:2931–2946
Liu X, O’Neill HSC, Berry AJ (2006) The effect of small amounts of H2O, CO2 and Na2O on the partial melting of spinel lherzolite in the system CaO-MgO-Al2O3-SiO2 ± H2O ± CO2 ± Na2O at 1.1 GPa. J Petrol 47:409–434
Lowrie W (1997) Fundamentals of geophysics. Cambridge University Press, Cambridge, UK p 206
Lowry RK, Henderson P, Nolan J (1982) Tracer diffusion of some alkali, alkaline-earth and transition element ions in a basaltic and an andesitic melt, and the implications concerning melt structure. Contrib Mineral Petrol 80:254–261
Manning CE (2004) The chemistry of subduction-zone fluids. Earth Planet Sci Lett 223:1–16
Michael P (1995) Regionally distinctive sources of depleted MORB: evidence from trace elements and H2O. Earth Planet Sci Lett 131:301–320
Mierdel K, Keppler H, Smyth JR, Langenhorst F (2007) Water solubility in aluminous orthopyroxene and the origin of Earth’s asthenosphere. Science 315:364–368
Mungall JE (2002) Empirical models relating viscosity and tracer diffusion in magmatic silicate melts. Geochim Cosmochim Acta 66:125–143
Murase T, McBirney AR (1973) Properties of some common igneous rocks and their melts at high temperatures. Geol Soc Am Bull 84:3563–3592
Ni H, Zhang Y (2008) H2O diffusion models in rhyolitic melt with new high pressure data. Chem Geol 250:68–78
Ni H, Liu Y, Wang L, Zhang Y (2009a) Water speciation and diffusion in haploandesitic melts at 743–873 K and 100 MPa. Geochim Cosmochim Acta 73:3630–3641
Ni H, Behrens H, Zhang Y (2009b) Water diffusion in dacitic melt. Geochim Cosmochim Acta 73:3642–3655
Ni H, Keppler H, Manthilake MAGM, Katsura T (2011) Electrical conductivity of dry and hydrous NaAlSi3O8 glasses and liquids at high pressures. Contrib Mineral Petrol 161. doi:10.1007/s00410-011-0608-5
Ochs FA, Lange RA (1997) The partial molar volume, thermal expansivity, and compressibility of H2O in NaAlSi3O8 liquid: new measurements and an internally consistent model. Contrib Mineral Petrol 129:155–165
Ohlhorst S, Behrens H, Holtz F (2001) Compositional dependence of molar absorptivities of near-infrared OH- and H2O bands in rhyolitic to basaltic glasses. Chem Geol 174:5–20
Pfeiffer T (1998) Viscosities and electrical conductivities of oxidic glass-forming melts. Solid State Ionics 105:277–287
Poe BT, Romano C, Nestola F, Smyth JR (2010) Electrical conductivity anisotropy of dry and hydrous olivine at 8 GPa. Phys Earth Planet Inter 181:103–111
Pommier A, Gaillard F, Pichavant M, Scaillet B (2008) Laboratory measurements of electrical conductivities of hydrous and dry Mount Vesuvius melts under pressure. J Geophys Res 113:B05205. doi:10.1029/2007JB005269
Pommier A, Gaillard F, Malki M, Pichavant M (2010a) Methodological re-evaluation of the electrical conductivity of silicate melts. Am Mineral 95:284–291
Pommier A, Gaillard F, Pichavant M (2010b) Time-dependent changes of the electrical conductivity of basaltic melts with redox state. Geochim Cosmochim Acta 74:1653–1671
Presnall DC, Simmons CL, Porath H (1972) Changes in electrical conductivity of a synthetic basalt during melting. J Geophys Res 77:5665–5672
Saal AE, Hauri EH, Langmuir CH, Perfit MR (2002) Vapour undersaturation in primitive mid-ocean-ridge basalt and the volatile content of Earth’s upper mantle. Nature 419:451–455
Salters VJM, Hart SR (1989) The hafnium paradox and the role of garnet in the source of mid-ocean-ridge basalts. Nature 342:420–422
Salters VJM, Stracke A (2004) Composition of the depleted mantle. Geochem Geophys Geosys 5:Q05B07. doi: 10.1029/2003GC000597
Shaw HR (1963) Obsidian-H2O viscosities at 1000 and 2000 bars in the temperature range 700° to 900°C. J Geophys Res 68:6337–6343
Shen Y, Forsyth DW (1995) Geochemical constraints on initial and final depths of melting beneath mid-ocean ridges. J Geophys Res 100:2211–2237
Sisson TW, Layne GD (1993) H2O in basalt and basaltic andesite glass inclusions from four subduction-related volcanoes. Earth Planet Sci Lett 117:619–635
Soyer W, Unsworth M (2006) Deep electrical structure of the northern Cascadia (British Columbia, Canada) subduction zone: implications for the distribution of fluids. Geology 34:53–56
The MELT Seismic Team (1998) Imaging the deep seismic structure beneath a mid-ocean ridge: the MELT experiment. Science 280:1215–1218
Tyburczy JA, Waff HS (1983) Electrical conductivity of molten basalt and andesite to 25 kilobars pressure: geographical significance and implications for charge transport and melt structure. J Geophys Res 88:2413–2430
van Keken PE, Kiefer B, Peacock SM (2002) High-resolution models of subduction zones: implications for mineral dehydration reactions and the transport of water into the deep mantle. Geochem Geophys Geosys 3:1056. doi:10.1029/2001GC000256
Waff HS, Weill DF (1975) Electrical conductivity of magmatic liquids: effects of temperature, oxygen fugacity and composition. Earth Planet Sci Lett 28:254–260
Wang D, Mookherjee M, Xu Y, Karato S-I (2006) The effect of water on the electrical conductivity of olivine. Nature 443:977–980
Watson EB (1979) Diffusion of cesium ions in H2O-saturated granitic melt. Science 205:1259–1260
Whittington A, Richet P, Holtz F (2000) Water and the viscosity of depolymerized aluminosilicate melts. Geochim Cosmochim Acta 64:3725–3736
Workman RK, Hart SR (2005) Major and trace element composition of the depleted MORB mantle (DMM). Earth Planet Sci Lett 231:53–72
Xu Y, Poe BT, Shankland TJ, Rubie DC (1998) Electrical conductivity of olivine, wadsleyite, and ringwoodite under upper-mantle conditions. Science 280:1415–1418
Yamashita S, Kitamura T, Kusakabe M (1997) Infrared spectroscopy of hydrous glasses of arc magma compositions. Geochem J 31:169–174
Yoshino T, Matsuzaki T, Yamashita S, Katsura T (2006) Hydrous olivine unable to account for conductivity anomaly at the top of the asthenosphere. Nature 443:973–976
Yoshino T, Laumonier M, McIsaac E, Katsura T (2010) Electrical conductivity of basaltic and carbonatite melt-bearing peridotites at high pressures: implications for melt distribution and melt fraction in the upper mantle. Earth Planet Sci Lett 295:593–602
Zhang Y, Ni H (2010) Diffusion of H, C, and O components in silicate melts. Rev Mineral Geochem 72:171–225
Zhang Y, Stolper EM (1991) Water diffusion in basaltic melts. Nature 351:306–309
Zhang Y, Stolper EM, Wasserburg GJ (1991) Diffusion of water in rhyolitic glasses. Geochim Cosmochim Acta 55:441–456
Zhang Y, Ni H, Chen Y (2010) Diffusion data in silicate melts. Rev Mineral Geochem 72:311–408
Acknowledgments
We thank Hubert Schulze and Uwe Dittmann for sample preparation and Sven Linhardt for assistance in the conductivity experiments. Constructive reviews by F. Gaillard, A. Pommier, and an anonymous referee improved the manuscript. Discussions with B. Poe were beneficial.
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Ni, H., Keppler, H. & Behrens, H. Electrical conductivity of hydrous basaltic melts: implications for partial melting in the upper mantle. Contrib Mineral Petrol 162, 637–650 (2011). https://doi.org/10.1007/s00410-011-0617-4
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DOI: https://doi.org/10.1007/s00410-011-0617-4