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American Mineralogist

Journal of Earth and Planetary Materials

Ed. by Baker, Don / Xu, Hongwu


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Volume 101, Issue 6

Issues

Cu diffusion in a basaltic melt

Peng Ni
  • Corresponding author
  • Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, Michigan 48109-1005, U.S.A
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/ Youxue Zhang
  • Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, Michigan 48109-1005, U.S.A
  • Other articles by this author:
  • De Gruyter OnlineGoogle Scholar
Published Online: 2016-06-03 | DOI: https://doi.org/10.2138/am-2016-5544

Abstract

Recent studies suggest a potential role of diffusive transport of metals (e.g., Cu, Au, PGE) in the formation of magmatic sulfide deposits and porphyry-type deposits. However, diffusivities of these metals are poorly determined in natural silicate melts. In this study, diffusivities of copper in an anhydrous basaltic melt (<10 ppm H2O) were measured at temperatures from 1298 to 1581 °C, and pressures of 0.5, 1, and 1.5 GPa. Copper diffusivities in anhydrous basaltic melt at 1 GPa can be described as: DCubasalt=exp[(14.12±0.50)11813±838T]

where DCubasalt is the diffusivity in m2/s, T is the temperature in K, and errors are given at 1σ level. A fitting of all experimental data considering the pressure effect is: DCubasalt=exp[(13.59±0.81)(12153±1229)+(620±241)PT]

where P is the pressure in GPa, which corresponds to a pre-exponential factor D0 = (1.25 ×÷ 2.2)×10–6 m2/s, an activation energy Ea = 101 ± 10 kJ/mol at P = 0, and an activation volume Va = (5.2 ± 2.0)×10–6 m3/mol.

The diffusivity of copper in basaltic melt is high compared to most other cations, similar to that of Na. The high copper diffusivity is consistent with the occurrence of copper mostly as Cu+ in silicate melts at or below NNO. Compared to the volatile species, copper diffusivity is generally smaller than water diffusivity, but about one order of magnitude higher than sulfur and chlorine diffusivities. Hence, Cu partitioning between a growing sulfide liquid drop and the surrounding silicate melt is roughly in equilibrium, whereas that between a growing fluid bubble and the surrounding melt can be out of equilibrium if the fluid is nearly pure H2O fluid. Our results are the first copper diffusion data in natural silicate melts, and can be applied to discuss natural processes such as copper transport and kinetic partitioning behavior in ore formation, as well as copper isotope fractionation caused by evaporation during tektite formation.

Key words: Copper diffusivity; kinetics; kinetic fractionation; copper isotope fractionation

References cited

  • Alletti, M., Baker, D.R., and Freda, C. (2007) Halogen diffusion in a basaltic melt. Geochimica et Cosmochimica Acta, 71, 3570–3580.Web of ScienceGoogle Scholar

  • Baker, D.R., and Watson, E.B. (1988) Diffusion of major and trace elements in compositionally complex Cl- and F-bearing silicate melts. Journal of Non-Crystalline Solids, 102, 62–70.Google Scholar

  • Behrens, H., and Hahn, M. (2009) Trace element diffusion and viscous flow in potassium-rich trachytic and phonolitic melts. Chemical Geology, 259, 63–77.Web of ScienceGoogle Scholar

  • Candela, P.A., and Holland, H.D. (1984) The partitioning of copper and molybdenum between silicate melts and aqueous fluids. Geochimica et Cosmochimica Acta, 48, 373–380.Google Scholar

  • Crank, J. (1975) The Mathematics of Diffusion. Clarendon Press, Oxford, U.K.Google Scholar

  • Freda, C., Baker, D.R., and Scarlato, P. (2005) Sulfur diffusion in basaltic melts. Geochimica et Cosmochimica Acta, 69, 5061–5069.Web of ScienceGoogle Scholar

  • Giordano, D., and Dingwell, D. (2003) Viscosity of hydrous Etna basalt: implications for Plinian-style basaltic eruptions. Bulletin of Volcanology, 65, 8–14.Google Scholar

  • Huber, C., Bachmann, O., Vigneresse, J.L., Dufek, J., and Parmigiani, A. (2012) A physical model for metal extraction and transport in shallow magmatic systems. Geochemistry, Geophysics, Geosystems, 13, Q08003.Google Scholar

  • Hui, H., Zhang, Y., Xu, Z., and Behrens, H. (2008) Pressure dependence of the speciation of dissolved water in rhyolitic melts. Geochimica et Cosmochimica Acta, 72, 3229–3240.Web of ScienceGoogle Scholar

  • Lodders, K. (2003) Solar System abundances and condensation temperatures of the elements. The Astrophysical Journal, 591, 1220.Google Scholar

  • Lowry, R.K., Reed, S.J.B., Nolan, J., Henderson, P., and Long, J.V.P. (1981) Lithium tracer-diffusion in an alkali-basaltic melt–-an ion-microprobe determination. Earth and Planetary Science Letters, 53, 36–40.Google Scholar

  • Lowry, R.K., Henderson, P., and 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. Contributions to Mineralogy and Petrology, 80, 254–261.Google Scholar

  • Moynier, F., Beck, P., Jourdan, F., Yin, Q.Z., Reimold, U., and Koeberl, C. (2009) Isotopic fractionation of zinc in tektites. Earth and Planetary Science Letters, 277, 482–489.Google Scholar

  • Moynier, F., Koeberl, C., Beck, P., Jourdan, F., and Telouk, P. (2010) Isotopic fractionation of Cu in tektites. Geochimica et Cosmochimica Acta, 74, 799–807.Google Scholar

  • Mungall, J.E. (2002a) Kinetic controls on the partitioning of trace elements between silicate and sulfide liquids. Journal of Petrology, 43, 749–768.Google Scholar

  • Mungall, J.E. (2002b) Empirical models relating viscosity and tracer diffusion in magmatic silicate melts. Geochimica et Cosmochimica Acta, 66, 125–143.Google Scholar

  • Nadeau, O., Williams-Jones, A.E., and Stix, J. (2010) Sulphide magma as a source of metals in arc-related magmatic hydrothermal ore fluids. Nature Geoscience, 3, 501–505.Google Scholar

  • Nadeau, O., Stix, J., and Williams-Jones, A.E. (2013) The behavior of Cu, Zn and Pb during magmatic–hydrothermal activity at Merapi volcano, Indonesia. Chemical Geology, 342, 167–179.Web of ScienceGoogle Scholar

  • Naldrett, A.J. (1989) Magmatic Sulfide Deposits. Oxford University Press, U.K.Google Scholar

  • Ni, H., and Zhang, Y. (2008) H2O diffusion models in rhyolitic melt with new high pressure data. Chemical Geology, 250, 68–78.Web of ScienceGoogle Scholar

  • Ni, P., Zhang, Y., Simon, A., and Gagnon, J. (2015) Cu and Fe diffusion in rhyolitic melts during chalcocite “dissolution”. Goldschmidt Abstracts, 2269.Google Scholar

  • Pearce, N.J., Perkins, W.T., Westgate, J.A., Gorton, M.P., Jackson, S.E., Neal, C.R., and Chenery, S.P. (1997) A compilation of new and published major and trace element data for NIST SRM 610 and NIST SRM 612 glass reference materials. Geostandards Newsletter, 21, 115–144.Google Scholar

  • Ripley, E.M., and Brophy, J.G. (1995) Solubility of copper in a sulfur-free mafic melt. Geochimica et Cosmochimica Acta, 59, 5027–5030.Google Scholar

  • Rudnick, R.L., and Gao, S. (2014) Composition of the continental crust. Treatise on Geochemistry, 2nd ed., p. 1–51.Google Scholar

  • Shannon, R.T. (1976) Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides. Acta Crystallographica, A32, 751–767.Google Scholar

  • Simon, A.C., Pettke, T., Candela, P.A., Piccoli, P.M., and Heinrich, C.A. (2006) Copper partitioning in a melt–vapor–brine–magnetite–pyrrhotite assemblage. Geochimica et Cosmochimica Acta, 70, 5583–5600.Google Scholar

  • Singer, D.A. (1995) World class base and precious metal deposits; a quantitative analysis. Economic Geology, 90, 88–104.Google Scholar

  • von der Gonna, G., and Russel, C. (2000) Diffusivity of various polyvalent elements in a Na2O·2SiO2 glass melt. Journal of Non-Crystalline Solids, 261, 204–210.Google Scholar

  • Walter, L.S. (1967) Tektite compositional trends and experimental vapor fractionation of silicates. Geochimica et Cosmochimica Acta, 31, 2043–2063.Google Scholar

  • Wang, H., Xu, Z., Behrens, H., and Zhang, Y. (2009) Water diffusion in Mount Changbai peralkaline rhyolitic melt. Contributions to Mineralogy and Petrology, 158, 471–484.Google Scholar

  • Williams, T.J., Candela, P.A., and Piccoli, P.M. (1995) The partitioning of copper between silicate melts and two-phase aqueous fluids: an experimental investigation at 1 kbar, 800 °C and 0.5 kbar, 850 °C. Contributions to Mineralogy and Petrology, 121, 388–399.Google Scholar

  • Zajacz, Z., and Halter, W. (2009) Copper transport by high temperature, sulfur-rich magmatic vapor: Evidence from silicate melt and vapor inclusions in a basaltic andesite from the Villarrica volcano (Chile). Earth and Planetary Science Letters, 282, 115–121.Web of ScienceGoogle Scholar

  • Zajacz, Z., Halter, W.E., Pettke, T., and Guillong, M. (2008) Determination of fluid/melt partition coefficients by LA-ICPMS analysis of co-existing fluid and silicate melt inclusions: controls on element partitioning. Geochimica et Cosmochimica Acta, 72, 2169–2197.Web of ScienceGoogle Scholar

  • Zhang, Y. (2008) Geochemical Kinetics. Princeton University Press, New Jersey.Google Scholar

  • Zhang, Y. (2010) Diffusion in minerals and melts: theoretical background. Reviews in Mineralogy and Geochemistry, 72, 5–59.Web of ScienceGoogle Scholar

  • Zhang, Y. (2015) Toward a quantitative model for the formation of gravitational magmatic sulfide deposits. Chemical Geology, 391, 56–73.Web of ScienceGoogle Scholar

  • Zhang, Y., and Ni, H. (2010) Diffusion of H, C, and O components in silicate melts. Reviews in Mineralogy and Geochemistry, 72, 171–225.Google Scholar

  • Zhang, Y., Ni, H., and Chen, Y. (2010) Diffusion data in silicate melts. Reviews in Mineralogy and Geochemistry, 72, 311–408.Google Scholar

About the article

Received: 2015-08-26

Accepted: 2016-02-16

Published Online: 2016-06-03

Published in Print: 2016-06-01


Citation Information: American Mineralogist, Volume 101, Issue 6, Pages 1474–1482, ISSN (Online) 1945-3027, ISSN (Print) 0003-004X, DOI: https://doi.org/10.2138/am-2016-5544.

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© 2016 by Walter de Gruyter Berlin/Boston.

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