Br diffusion in phonolitic melts: Comparison with fluorine and chlorine diffusion

Abstract Bromine diffusion was measured in two natural phonolitic melts: (1) a K2O-rich (~10 wt%) one synthesized from the white pumice phase of the 79 AD eruption of Vesuvius (Italy), and (2) a Na2O-rich (~10 wt%) one corresponding to the most differentiated melt of the 12 000 BC eruption of the Laacher See (Germany). Experiments were performed at 0.5 and 1.0 GPa, 1250 to 1450 °C, at anhydrous and hydrous (2.65 ± 0.35 wt% of dissolved water) conditions. Experiments conducted with the diffusion-couple technique in the piston cylinder were performed with only bromine diffusing and with the simultaneous diffusion of a halogen mixture (F, Cl, Br) to evaluate the interactions between the halogens during diffusion. The diffusion profiles of Br were measured by X-ray fluorescence using synchrotron radiation microprobe (SYXRF), ID18F, at the European Synchrotron Radiation Facility (ESRF, France). Bromine diffusion displays Arrhenian behavior under anhydrous conditions that is similar when it diffuses alone and when it diffuses with F and Cl. The Br diffusion coefficients range between 2 × 10–12 m2/s at 1250 °C and 1.5 × 10–11 m2/s at 1450 °C for the Na-rich melt and between 3 × 10–12 m2/s at 1250 °C and 2.5 × 10–11 m2/s at 1450 °C for the K-rich melt, at 1.0 GPa. Although Br mobility is independent of F and Cl in anhydrous phonolitic melts, its behavior may be dependent on the dominant alkali in the melt, as previously observed for Cl, but not F. For hydrous experiments, although the data are scattered, the Br diffusivity increases slightly with water and the Na/K ratio seems to influence Br diffusivity. Similarly to noble gases, halogen diffusivity at a given temperature in the phonolitic melts appears related to the ionic porosity of the silicate structure. Compared to basaltic melt, Br diffusivities are approximately one order of magnitude lower in the Na-phonolite melt, because of the difference of the pre-exponential factor. Br mobility appears to be decoupled from melt viscosity, considering the results here.

[1]  J. Hazemann,et al.  New insights on Br speciation in volcanic glasses and structural controls on halogen degassing , 2020, American Mineralogist.

[2]  D. Dingwell,et al.  Diffusion of F and Cl in dry rhyodacitic melt , 2019, American Mineralogist.

[3]  T. Roberts,et al.  Advances in Bromine Speciation in Volcanic Plumes , 2018, Front. Earth Sci..

[4]  D. Pyle,et al.  The role of melt composition on aqueous fluid vs. silicate melt partitioning of bromine in magmas , 2018, Earth and Planetary Science Letters.

[5]  J. Touret.  The role of halogens in terrestrial and extraterrestrial geochemical processes. Surface, crust and mantle , 2018, International Geology Review.

[6]  D. Garbe‐Schönberg,et al.  Combined LA-ICP-MS microanalysis of iodine, bromine and chlorine in fluid inclusions , 2018 .

[7]  S. Yoshimura.  Chlorine diffusion in rhyolite under low-H2O conditions , 2018 .

[8]  K. Koga,et al.  Halogens in Terrestrial and Cosmic Geochemical Systems: Abundances, Geochemical Behaviors, and Analytical Methods , 2018 .

[9]  R. Bodnar,et al.  Halogen Geochemistry of Ore Deposits: Contributions Towards Understanding Sources and Processes , 2018 .

[10]  A. Aiuppa,et al.  Halogens in Mafic and Intermediate-Silica Content Magmas , 2018 .

[11]  G. Eby,et al.  A new set of standards for in–situ measurement of bromine abundances in natural silicate glasses: Application to SR-XRF, LA-ICP-MS and SIMS techniques , 2017 .

[12]  I. Kantor,et al.  Bromine speciation in hydrous silicate melts at high pressure , 2015 .

[13]  B. Mysen,et al.  In-situ measurements of fluorine and chlorine speciation and partitioning between melts and aqueous fluids in the Na2O-Al2O3-SiO2-H2O system , 2015 .

[14]  D. R. Neuville,et al.  Incorporation et rôle des halogènes dans les silicates vitreux et fondus , 2015 .

[15]  M. Marks,et al.  Halogen variations in alkaline rocks from the Upper Rhine Graben (SW Germany): Insights into F, Cl and Br behavior during magmatic processes , 2014 .

[16]  B. Schmidt,et al.  Fluorine and chlorine diffusion in phonolitic melt , 2013 .

[17]  G. Boudon,et al.  Behavior of halogens during the degassing of felsic magmas , 2010 .

[18]  D. Baker.  Erratum to: Chemical interdiffusion of dacite and rhyolite: anhydrous measurements at 1 atm and 10 kbar, application of transition state theory, and diffusion in zoned magma chambers , 1990, Contributions to Mineralogy and Petrology.

[19]  D. Baker,et al.  F and Cl diffusion in phonolitic melts: Influence of the Na/K ratio , 2009 .

[20]  D. Baker,et al.  Halogen diffusion in magmatic systems: Our current state of knowledge , 2009 .

[21]  A. Aiuppa,et al.  Halogens in volcanic systems , 2009 .

[22]  B. Vivo,et al.  The partitioning behavior of Cl, S, and H2O in aqueous vapor- ± saline-liquid saturated phonolitic and trachytic melts at 200 MPa , 2009 .

[23]  J. Vigneresse.  Evaluation of the chemical reactivity of the fluid phase through hard-soft acid-base concepts in magmatic intrusions with applications to ore generation , 2009 .

[24]  D. L. Bryce,et al.  Chlorine, Bromine, and Iodine Solid-State NMR Spectroscopy , 2009 .

[25]  D. Dingwell,et al.  Viscosity of magmatic liquids: A model , 2008 .

[26]  D. Baker.  The fidelity of melt inclusions as records of melt composition , 2008 .

[27]  Hélène Balcone-Boissard.  Le comportement des éléments halogènes au cours du dégazage des magmas en relation avec leur chimie et le style éruptif , 2008 .

[28]  D. Baker,et al.  Halogen diffusion in a basaltic melt , 2007 .

[29]  P. Richet,et al.  Silicate glasses and melts : properties and structure , 2005 .

[30]  D. Baker.  Piston-cylinder calibration at 400 to 500 MPa: A comparison of using water solubility in albite melt and NaCl melting , 2004 .

[31]  G. Cody,et al.  Solubility mechanisms of fluorine in peralkaline and meta-aluminous silicate glasses and in melts to magmatic temperatures 1 1 Associate editor: F. J. Ryerson , 2004 .

[32]  K. Hirose,et al.  Solubilities of nitrogen and noble gases in silicate melts under various oxygen fugacities: implications for the origin and degassing history of nitrogen and noble gases in the earth , 2004 .

[33]  U. Platt,et al.  Detection of bromine monoxide in a volcanic plume , 2003, Nature.

[34]  N. Métrich,et al.  An experimental study of bromine behaviour in water-saturated silicic melts , 2003 .

[35]  Koen Janssens,et al.  ID18F: a new micro-x-ray fluorescence end-station at the european synchrotron radiation facility (ESRF): preliminary results , 2001 .

[36]  H. Keppler,et al.  Volcanic degassing of bromine and iodine: experimental fluid/melt partitioning data and applications to stratospheric chemistry , 2000 .

[37]  Q. Zeng,et al.  Fluoride sites in aluminosilicate glasses: High-resolution 19F NMR results , 2000 .

[38]  R. Garcia,et al.  Stratospheric ozone destruction: The importance of bromine relative to chlorine , 1999 .

[39]  E. Stolper,et al.  An Experimental Study of Water and Carbon Dioxide Solubilities in Mid-Ocean Ridge Basaltic Liquids. Part I: Calibration and Solubility Models , 1995 .

[40]  J. Webster,et al.  Solubilities of sulfur, noble gases, nitrogen, chlorine, and fluorine in magmas , 1994 .

[41]  A. K. V. Groos,et al.  DIFFUSION OF CHLORINE IN GRANITIC MELTS , 1994 .

[42]  E. Stolper,et al.  Noble gas solubilities in silicate melts and glasses: New experimental results for argon and the relationship between solubility and ionic porosity , 1993 .

[43]  D. Baker.  Chemical interdiffusion of dacite and rhyolite: anhydrous measurements at 1 atm and 10 kbar, application of transition state theory, and diffusion in zoned magma chambers , 1990 .

[44]  J. Webster,et al.  Partitioning of F and Cl between magmatic hydrothermal fluids and highly evolved granitic magmas , 1990 .

[45]  H. Shinohara,et al.  Partition of chlorine compounds between silicate melt and hydrothermal solutions: I. Partition of NaCl-KCl , 1989 .

[46]  J. Webster,et al.  Partitioning of lithophile trace elements between H 2 O and H 2 O + CO 2 fluids and topaz rhyolite melt , 1989 .

[47]  R. Luth.  Raman spectroscopic study of the solubility mechanisms of F in glasses in the system CaO-CaF 2 -SiO 2 , 1988 .

[48]  G. Lux.  The behavior of noble gases in silicate liquids: Solution, diffusion, bubbles and surface effects, with applications to natural samples , 1987 .

[49]  S. Wofsy,et al.  Reductions of Antarctic ozone due to synergistic interactions of chlorine and bromine , 1986, Nature.

[50]  B. Mysen,et al.  Iron-bearing silicate melts: Relations between pressure and redox equilibria , 1985 .

[51]  R. Lowry,et al.  Structural controls and mechanisms of diffusion in natural silicate melts , 1985 .

[52]  R. Lowry,et al.  Tracer diffusion of some alkali, alkaline-earth and transition element ions in a basaltic and an andesitic melt, and the implications concerning melt structure , 1982 .

[53]  D. Manning.  The effect of fluorine on liquidus phase relationships in the system Qz-Ab-Or with excess water at 1 kb , 1981 .

[54]  A. Jambon,et al.  Lithium diffusion in silicate glasses of albite, orthoclase, and obsidian composition: An ion-microprobe determination , 1978 .

[55]  John Crank,et al.  The Mathematics Of Diffusion , 1956 .

[56]  V. G. Smith,et al.  a Mathematical Analysis of Solute Redistribution during Solidification , 1955 .

[57]  J. Howell,et al.  Diffusion in Solids , 1984, Materials Science Forum.