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The effect of feldspar on quartz-H2O−CO2 dihedral angles at 4 kbar, with consequences for the behaviour of aqueous fluids in migmatites

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Abstract

An investigation was made of the effect of trace amounts of feldspar (Na and/or K) on dihedral angles in the quartz-H2O−CO2 system at 4 kbar and 450–1050°C. Quartz-quartz-H2O dihedral angles in feldspar-bearing quartz aggregates are observed to be the same as those in pure quartz aggregates at temperatures below 500°C. Above this temperature, they decrease with increasing temperature until the solidus. The final angle at the inception of melting is about 65° for microcline-quartz-H2O and microcline-albite-quartz-H2O, and much less than 60° (the critical value for formation of grain-edge fluid channels in an isotropic system) for the albite-quartz-H2O system. CO2 was observed to produce a constant quartz-quartz-fluid dihedral angle of 97° in feldspar-bearing quartz aggregates at all temperatures studied. Also examined were the dihedral angles for the two co-existing supersolidus fluids in quartz aggregates. In all systems the quartz-volatile fluid angle is greater than 60°, whereas the quartz-melt angle is lower than 60°. Both supersolidus angles decrease with increasing temperature. The transition from nonconnected to connected porosity with increasing temperature observed in the quartz-albite-H2O system some tens of degrees below the solidus (termed a permeability transition), if a common feature of rocks near their melting points, will play an important role in controlling the permeability of high-grade rocks to aqueous fluids.

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References

  • Ashworth JR (1976) Petrogenesis of migmatites in the Huntly-Portsoy area, north-east Scotland. Mineral Mag 40:661–682

    Article  Google Scholar 

  • Boettcher AL, Wyllie PJ (1969) Phase relationships in the system NaAlSiO2−SiO2−H2O to 35 kilobars pressure. Am J Sci 267:875–909

    Google Scholar 

  • Brenan JM, Watson EB (1988) Fluids in the lithosphere, 2. Experimental constraints on CO2 transport in dunite and quartzite at elevated P-T conditions with implications for mantle and crustal decarbonation processes. Earth Planet Sci Lett 91:141–158

    Article  Google Scholar 

  • Bulau JR (1982) Intergranular fluid distribution in olivine-liquid basalt systems. PhD dissertation, Yale University, New Haven. Connecticut

  • Clemens JD (1984) Water contents of silicic to intermediate magmas. Lithos 17:273–287

    Article  Google Scholar 

  • Cooper RF, Kohlstedt DL (1982) Interfacial energies in the olivine-basalt system. In: Akimoto S, Manghanani MH (eds) High pressure research in geophysics. Advances in Earth and Planetary Sciences. Centre for Academic Publications, Tokyo pp 217–228

    Google Scholar 

  • Farver JR, Yund RA (1992) Oxygen diffusion in a fine-grained quartz aggregate with wetted and non-wetted microstructures. J Geophys Res 97:14017–14029

    Article  Google Scholar 

  • Harker D, Parker ER (1945) Grain shape and grain growth. Trans Am Soc Met 34:156–195

    Google Scholar 

  • Holness MB (1992) Equilibrium dihedral angles in the system quartz-CO2−H2O−NaCl at 800°C and 1–15 kbar: the effects of pressure and fluid composition on the permeability of quartzites. Earth Planet Sci Lett 114:171–184

    Article  Google Scholar 

  • Holness MB (1993) Temperature and pressure dependence of quartz-aqueous fluid dihedral angles: the control of adsorbed H2O on the permeability of quartzites. Earth Planet Sci Lett 117:363–377

    Article  Google Scholar 

  • Holness MB, Graham CM (1991) Equilibrium dihedral angles in the system H2O−CO2−NaCl-calcite, and implications for fluid flow during metamorphism. Contrib Mineral Petrol 108:368–383

    Article  Google Scholar 

  • Holness MB, Graham CM (1994) P-T-X effects on equilibrium carbonate-H2O−CO2−NaCl dihedral angles: constraints on carbonate permeability and the role of deformation during fluid infiltration. Contrib Mineral Petrol, in press

  • Johannes W (1984) Beginning of melting in the granite system Qz−Or−Ab−An−H2O. Contrib Mineral Petrol 86:264–273

    Article  Google Scholar 

  • Johannes W (1988) What controls partial melting in migmatites? J Metamorphic Geol 6:451–465

    Article  Google Scholar 

  • Jurewicz SR, Watson EB (1984) Distribution of partial melt in a felsic system: the importance of surface energy. Contrib Mineral Petrol 85:25–29

    Article  Google Scholar 

  • Jurewicz SR, Watson EB (1985) The distribution of partial melt in a granitic system: the application of liquid phase sintering theory. Geochim Cosmochim Acta 49:1109–1121

    Article  Google Scholar 

  • Laporte D (1991) Partial melting and melt segregation: textural constraints. Terra Abstracts 4:26

    Google Scholar 

  • Laporte D, Provost A (1993) Grain-scale distribution of melts in partially molten crustal sources: the importance of anisotropy of solid-liquid interfacial energies on wetting angles. Terra Abstracts 5:519

    Google Scholar 

  • Lee VW, Mackwell SJ, Brantley SL (1991) The effect of fluid chemistry on wetting textures in novaculite. J Geophys Res 96:10 023–10037

    Google Scholar 

  • Luth WC, Jahns RH, Tuttle OF (1964) The granite system at pressures of 4 to 10 kbars. J Geophys Res 69:759–773

    Article  Google Scholar 

  • Maaløe S (1992) Melting and diffusion processes in closed-system migmatization. J Metamorphic Geol 10:503–516

    Article  Google Scholar 

  • Manning DAC (1981) The effect of fluorine on liquidus phase relationships in the system Qz-Ab-Or with excess water at 1 kbar. Contrib Mineral Petrol 76:206–216

    Article  Google Scholar 

  • Mchnert KR, Büsch W (1982) The initial stage of migmatite formation. Neues Jahrb Mineral Abh 145:211–238

    Google Scholar 

  • Newton RC, Smith JV, Windley BF (1980) Carbonic metamorphism, granulites and crustal growth. Nature 288:45–50

    Article  Google Scholar 

  • Powell R (1983) Processes in granulite facies metamorphism. In: Atherton MP, Gribble CD (eds) Migmatites melting and metamorphism. Shiva, Nantwich, pp 127–141

    Google Scholar 

  • Powell R, Downes J (1990) Garnet porphyroblast-bearing leucosomes in metapelites: mechanisms, phase diagrams, and an example from Broken Hill, Australia. In: Ashworth JR, Brown M (eds). High-temperature metamorphism and crustal anatexis. pp 105–123

  • Riegger OK, Van Vlack L (1960) Dihedral angle measurement. Trans Metall Soc AIME 218:933–935

    Google Scholar 

  • Shaw HR (1963) The four-phase curve sanidine-quartz-liquid-gas between 500 and 4000 bars. Am Mineral 48:883–896

    Google Scholar 

  • Smith CS (1948) Grains, phases, and interfaces: an interpretation of microstructure. Trans Metall Soc AIME 175:15–51

    Google Scholar 

  • Stevens G, Clemens JD (1993) Fluid-absent melting and the roles of fluids in the lithosphere: a slanted summary? Chem Geol 108:1–17

    Article  Google Scholar 

  • Stickels CA, Hücke EE (1964) Measurement of dihedral angles. Trans Metall Soc AIME 230:795–801

    Google Scholar 

  • Watson EB, Brenan JM (1987) Fluids in the lithosphere, I. Experimentally-determined wetting characteristics of CO2−H2O fluids and their implications for fluid transport, host rock physical properties, and fluid inclusion formation. Earth Planet Sci Lett 85:497–515

    Article  Google Scholar 

  • Wilks SS (1962) Mathematical statistics. Wiley, New York.

    Google Scholar 

  • Wyllie PJ, Tuttle OF (1964) Experimental investigation of silicate systems containing two volatile components. Part III. The effects of SO3, P2O5, HCl, and Li2O, in addition to H2O, on the melting temperatures of albite and granite. Am J Sci 262:930–939

    Google Scholar 

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  1. Department of Geology and Geophysics, University of Edinburgh, King's Buildings, West Mains Road, EH9 3JW, Edinburgh, UK

    Marian B. Holness

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  1. Marian B. Holness
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Holness, M.B. The effect of feldspar on quartz-H2O−CO2 dihedral angles at 4 kbar, with consequences for the behaviour of aqueous fluids in migmatites. Contr. Mineral. and Petrol. 118, 356–364 (1995). https://doi.org/10.1007/s004100050020

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  • DOI: https://doi.org/10.1007/s004100050020

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