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Contributions to Mineralogy and Petrology

, Volume 153, Issue 2, pp 237–250 | Cite as

Diffusion-controlled development of silica-undersaturated domains in felsic granulites of the Bohemian Massif (Variscan belt of Central Europe)

  • Lucie Tajčmanová
  • Jiří Konopásek
  • James A. D. Connolly
Original Paper

Abstract

Plagioclase rims around metastable kyanite crystals appear during decompression of high-pressure felsic granulites from the high-grade internal zone of the Bohemian Massif (Variscan belt of Central Europe). The development of the plagioclase corona is a manifestation of diffusion-driven transfer of CaO and Na2O from the surrounding matrix and results in isolation of kyanite grains from the quartz- and K-feldspar-bearing matrix. This process establishes Si-undersaturated conditions along the plagioclase–kyanite interface, which allow crystallization of spinel during low-pressure metamorphism. The process of the plagioclase rim development is modeled thermodynamically assuming local equilibrium. The results combined with textural observations enable estimation of equilibration volume and diffusion length for Na and Ca that extends ∼400–450 and ∼450–550 μm, respectively, around each kyanite crystal. Low estimated bulk diffusion coefficients suggest that the diffusion rate of Ca and Na is controlled by low diffusivity of Al across the plagioclase rim.

Keywords

Equilibration volume Coronal structures Diffusion Low-pressure granulites Perple_X Bohemian Massif 

Notes

Acknowledgements

This work was financially supported by Charles University Grant Agency (GAUK no. 333/2004/ B-GEO/PrF) and by Project of the Czech Geological Survey and Ministry of Environment (No. 6352). We gratefully acknowledge R. Čopjaková, R.Škoda from Masaryk University in Brno and R. Procházka from Charles University in Prague for operating the microprobe. J. Košler is acknowledged for the ICP-MS measurements. Two anonymous reviewers are thanked for their constructive reviews and T. L. Grove is gratefully thanked for his careful editorial work.

References

  1. Abart R, Kunze K, Milke R, Sperb R, Heinrich W (2004) Silicon and oxygen self diffusion in enstatite polycrystals: the Milke et al. (2001) rim growth experiments revisited. Contrib Mineral Petrol 147(6):633–646CrossRefGoogle Scholar
  2. Ashworth JR (1993) Fluid-absent diffusion kinetics of Al inferred from retrograde metamorphic coronas. Am Mineral 78:331–337Google Scholar
  3. Ashworth JR, Birdi JJ (1990) Diffusion modelling of coronas around olivine in an open system. Geochim Cosmochim Acta 54:2389–2401CrossRefGoogle Scholar
  4. Ashworth JR, Chambers AD (2000) Symplectic reaction in olivine and the controls of intergrowth spacing in symplectites. J Petrol 41(2):285–304CrossRefGoogle Scholar
  5. Berman RG (1990) Mixing properties of Ca–Mg–Fe–Mn garnets. Am Mineral 75:328–344Google Scholar
  6. Brady JB (1977) Metasomatic zones in metamorphic rocks. Geochim Cosmochim Acta 41:113–125CrossRefGoogle Scholar
  7. Brady JB (1983) Intergranular diffusion in metamorphic rocks. Am J Sci 283A:181–200Google Scholar
  8. Brady JB, Yund RA (1983) Interdiffusion of K and Na in alkali feldspar: homogenization experiments. Am Mineral 68:106–111Google Scholar
  9. Christoffersen R, Yund RA, Tullis J (1983) Inter-diffusion of K and Na in alkali feldspars: diffusion couple experiments. Am Mineral 68:1126–1133Google Scholar
  10. Connolly JAD (2005) Computation of phase equilibria by linear programming: a tool for geodynamic modeling and its application to subduction zone decarbonation. Earth Planet Sci Lett 236(1–2):524–541CrossRefGoogle Scholar
  11. Dasgupta S, Sengupta P, Juergen E, Raith M, Bardhan S (1995) Reaction textures in a suite of spinel granulites from the Eastern Ghats Belt, India: evidence for polymetamorphism, a partial petrogenetic grid in the system KFMASH and the roles of ZnO and Fe2O3. J Petrol 36:435–461Google Scholar
  12. Farver JR, Yund RA (1995) Volume and grain boundary diffusion of calcium in natural and hot-pressed calcite aggregates. Contrib Mineral Petrol 118:340–355CrossRefGoogle Scholar
  13. Fisher GW (1973) Nonequilibrium thermodynamics as a model for diffusion-controlled metamorphic processes. Am J Sci 273:897–924CrossRefGoogle Scholar
  14. Fisher GW (1978) Rate laws in metamorphism. Geochim Cosmochim Acta 42:1035–1050CrossRefGoogle Scholar
  15. Fisher GW, Elliott D (1974) Criteria for quasi-steady diffusion and local equilibrium in metamorphism. In: Hofmann AW et al (eds) Geochemical transport and kinetics. Carnegie Inst. Wash. Publ 634, pp 231–241Google Scholar
  16. Holland TJB, Powell R (1998) An internally consistent thermodynamic data set for phases of petrological interest. J Metamorph Geol 16:309–343CrossRefGoogle Scholar
  17. Joesten R (1977) Evolution of mineral assemblage zoning in diffusion metasomatism. Geochim Cosmochim Acta 41:649–670CrossRefGoogle Scholar
  18. Joesten R (1991) Grain-boundary diffusion kinetics in silicate and oxide minerals. In: Ganguly J (ed) Diffusion, atomic ordering, and mass transport. Springer Berlin Heidelberg New York, pp 345–395Google Scholar
  19. Kaur I, Mishin Y, Gust W (1995) Fundamentals of grain boundary and interphase boundary diffusion, 3rd edn. Wiley, ChichesterGoogle Scholar
  20. Keller LM, Abart R, Wirth R, Schmid DW, Kunze K (2006) Enhanced mass transfer through short-circuit diffusion: growth of garnet reaction rims at eclogite facies conditions. Am Mineral 91(7):1024–1038CrossRefGoogle Scholar
  21. Korzhinskii DS (1959) Physico-chemical basis of the analysis of the paragenesis of materials. Consultants Bureau, New York, 142 ppGoogle Scholar
  22. Kretz R (1983) Symbols for rock forming minerals. Am Mineral 68:277–279Google Scholar
  23. Lang HM, Wachter AJ, Peterson VL (2004) Coexisting clinopyroxene/spinel and amphibole/spinel symplectites in metatroctolites from the Buck Creek ultramafic body, North Carolina Blue Ridge. Am Mineral 89(1):20–30Google Scholar
  24. Milke R, Heinrich W (2002) Diffusion-controlled growth of wollastonite rims between quartz and calcite: comparison between nature and experiment. J Metamorph Geol 20:467–480CrossRefGoogle Scholar
  25. Milke R, Wiedenbeck M, Heinrich W (2001) Grain boundary diffusion of Si, Mg, and O in enstatite reaction rims: a SIMS study using isotopically doped reactants. Contrib Mineral Petrol 142:15–26Google Scholar
  26. Möller C (1998) Decompressed eclogites in the Sveconorwegian (–Grenvillian) orogen of SW Sweden: petrology and tectonic implications. J Metamorph Geol 20:641–656CrossRefGoogle Scholar
  27. Mongkoltip P, Ashworth JR (1983) Quantitative estimation of an open-system symplectite-forming reaction: restricted diffusion of Al and Si in coronas around olivine. J Petrol 24:635–661Google Scholar
  28. Nakamura D (2002) Kinetics of decompressional reactions in eclogitic rocks—formation of plagioclase coronas around kyanite. J Metamorph Geol 20:325–333CrossRefGoogle Scholar
  29. Nakamura D, Hirajima T (2000) Granulite-facies overprinting of ultrahigh-pressure metamorphic rocks, northeastern Su–Lu region, eastern China. J Petrol 20:563–582CrossRefGoogle Scholar
  30. Newton RC, Charlu TV, Kleppa OJ (1980) Thermochemistry of high structural state plagioclases. Geochim Cosmochim Acta 44:933–941CrossRefGoogle Scholar
  31. Nichols GT, Berry RF, Green DH (1992) Internally consistent gahnitic spinel–cordierite–garnet equilibria in the FMASHZn system: geothermobarometry and applications. Contrib Mineral Petrol 111:362–377CrossRefGoogle Scholar
  32. Obata M (1994) Material transfer and local equilibria in a zoned kelyphite from a garnet pyroxenite, Ronda, Spain. J Petrol 35(1):271–287Google Scholar
  33. O’Brien PJ (1999) Asymmetric zoning profiles in garnet from HP–HT granulite and implications for volume and grain-boundary diffusion. Mineral Mag 63(2):227–238CrossRefGoogle Scholar
  34. O’Brien PJ, Rötzler J (2003) High-pressure granulites: formation, recovery of peak conditions and implications for tectonics. J Metamorph Geol 21:3–20CrossRefGoogle Scholar
  35. Okay AI (1995) Paragonite eclogites from Dabie Shan, China: re-equilibration during exhumation? J Metamorph Geol 20:449–460CrossRefGoogle Scholar
  36. Powell R, Holland TJB (1999) Relating formulations of the thermodynamics of mineral solid solutions; activity modeling of pyroxenes, amphiboles and micas. Am Mineral 84(1–2):1–14Google Scholar
  37. Schulmann K, Kröner A, Hegner E, Wendt I, Konopásek J, Lexa O, Štípská P (2005) Chronological constraints on the pre-orogenic history, burial and exhumation of deepseated rocks along the eastern margin of Variscan orogen, Bohemian Massif, Czech Republic. Am J Sci 305:407–448CrossRefGoogle Scholar
  38. Stüwe K (1997) Effective bulk composition changes due to cooling: a model predicting complexities in retrograde reaction textures. Contrib Mineral Petrol 129(1):43–52CrossRefGoogle Scholar
  39. Tajčmanová L, Konopásek J, Schulmann K (2006) Thermal evolution of the orogenic lower crust during exhumation within a thickened Moldanubian root of the Variscan belt of Central Europe. J Metamorph Geol 24:119–134CrossRefGoogle Scholar
  40. Thompson JB, Hovis GL (1979) Entropy of mixing in sanidine. Am Mineral 64:57–65Google Scholar
  41. White RW, Powell R, Holland TJB (2001) Calculation of partial melting equilibria in the system Na2O–CaO–K2O–FeO–MgO–Al2O3–SiO2–H2O (NCKFMASH). J Metamorph Geol 19:139–153CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2006

Authors and Affiliations

  • Lucie Tajčmanová
    • 1
    • 2
  • Jiří Konopásek
    • 1
    • 2
  • James A. D. Connolly
    • 3
  1. 1.Institute of Petrology and Structural GeologyCharles UniversityPragueCzech Republic
  2. 2.Czech Geological SurveyPraha 1Czech Republic
  3. 3.Institut für Mineralogie und PetrographieETH-ZentrumZürichSwitzerland

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