Contributions to Mineralogy and Petrology

, Volume 164, Issue 4, pp 715–729 | Cite as

Intracrystalline microstructures in alkali feldspars from fluid-deficient felsic granulites: a mineral chemical and TEM study

  • Lucie TajčmanováEmail author
  • Rainer Abart
  • Richard Wirth
  • Gerlinde Habler
  • Dieter Rhede
Original Paper


Samples of essentially “dry” high-pressure felsic granulites from the Bohemian Massif (Variscan belt of Central Europe) contain up to 2-mm-large perthitic alkali feldspars with several generations of plagioclase precipitates in an orthoclase-rich host. The first generation takes the form of lenses homogeneous in size, whereas the size of a second generation of very thin albite-rich precipitates is more variable with comparatively high aspect ratios. In the vicinity of large kyanite, garnet or quartz inclusions, the first generation of plagioclase precipitates is significantly less abundant, the microstructure is coarser than in the remainder of the perthitic grain and the host is a tweed orthoclase. The first generation of precipitates formed at around 850 °C during the high-pressure stage (16–18 kbar) of metamorphism. Primary exsolution was followed by primary coarsening of the plagioclase precipitates, which still took place at high temperatures (850–700 °C). The coarsening was pronounced due to the access of fluids in the outer portions of the perthitic alkali feldspar and in more internal regions around large inclusions. The second generation of albite-rich precipitates was formed at around 570 °C. TEM investigations revealed that the interfaces between the second-generation plagioclase lamellae and the orthoclase-rich host are coherent or semi-coherent. During late evolutionary stages of the perthite, albite linings were formed at phase boundaries, and the perthitic microstructure was partially replaced by irregularly shaped precipitates of pure albite with incoherent interfaces. The albitization occurred below 400 °C and was linked to fluid infiltration in the course of deuteric alteration. Based on size-distribution analysis, it is inferred that the precipitates of the first generation were most probably formed by spinodal decomposition, whereas the precipitates of the second generation rather were formed by nucleation and growth.


Bohemian Massif High-pressure granulites Perthite Nucleation and growth Size distribution Spinodal decomposition 



We are grateful to J. Franěk for providing such interesting samples. The Alexander von Humboldt Foundation is thanked for its financial support of L.T. during her research stay at the Free University of Berlin. SEM–FIB work at the University of Vienna was funded by the Austrian Science Fund (FWF) project number I471-N19. I. Parsons and one anonymous reviewer are thanked for their very constructive reviews and T.L. Grove for his careful editorial work.


  1. Abart R, Petrishcheva E, Wirth R, Rhede D (2009a) Exsolution by spinodal decomposition II: perthite formation during slow cooling of anatexites from Ngoronghoro, Tanzania. Am J Sci 309:450–475CrossRefGoogle Scholar
  2. Abart R, Petrishcheva E, Kässner S, Milke R (2009b) Perthite microstructure in magmatic alkali feldspar with oscillatory zoning; Weinsberg Granite, Upper Austria. Miner Petrol 97:251–263CrossRefGoogle Scholar
  3. Ardell AJ (1972) The effect of volume fraction on particle coarsening: theoretical considerations. Acta Metall 20:66–71Google Scholar
  4. Ardell AJ, Ozolins V (2005) Trans-interface diffusion-controlled coarsening. Nat Mater 4:309–316CrossRefGoogle Scholar
  5. Balluffi RW, Allen SM, Carter WC (2005) Kinetics of materials ISBN: 9780471246893 Baker and Taylor (USA)Google Scholar
  6. Baronnet A (1982) Ostwald ripening in solution. The case of calcite and mica. Estudios G eologicos (Madrid) 38:185–198Google Scholar
  7. Baronnet A (1984) Growth kinetics ofthe silicates. A review of basic concepts. Fortschr Mineral 62:187–232Google Scholar
  8. Benisek A, Dachs E, Kroll H (2010) A ternary feldspar-mixing model based on calorimetric data: development and application. Contrib Mineral Petrol 160:327–337CrossRefGoogle Scholar
  9. Brown WL, Parsons I (1984a) Exsolution and coarsening mechanisms and kinetics in an ordered cryptoperthite series. Contrib Mineral Petrol 86:3–18CrossRefGoogle Scholar
  10. Brown WL, Parsons I (1984b) The nature of potassium feldspar, exsolution microtextures and development of dislocations as a function of composition in perthitic alkali feldspars. Contrib Mineral Petrol 86:335–341CrossRefGoogle Scholar
  11. Brown WL, Parsons I (1988) Zoned ternary feldspars in the Klokken intrusion: exsolution textures and mechanisms. Contrib Mineral Petrol 98:444–454CrossRefGoogle Scholar
  12. Brown WL, Parsons I (1989) Alkali feldspars: ordering rates, phase transformations and behaviour diagrams for igneous rocks. Mineral Mag 53:25–42CrossRefGoogle Scholar
  13. Brown WL, Parsons I (1993) Storage and release of elastic strain energy the driving force for low temperature reactivity and alteration of alkali feldspars. In: Boland JN, Fitz Gerald JD (eds) Defects and processes in the solid state geoscience applications. The McLaren volume (Developments in petrology 14). Elsevier, Amsterdam, pp 267–290Google Scholar
  14. Brown WL, Willaime C (1974) An explanation of exsolution orientations and residual strain in cryptoperthites. In: MacKenzie WS, Zussman J (eds) The feldspars. Manchester University Press, Manchester, pp 440–459Google Scholar
  15. Cahn JW (1968) Spinodal decomposition. Trans Metall Soc AIME 242:166–180Google Scholar
  16. Cahn JW, Hilliard JE (1958) Free energy of a non-uniform system. I. Interfacial free energy. J Chem Phys 28:258–267CrossRefGoogle Scholar
  17. Cahn JW, Hilliard JE (1959) Free energy of a non-uniform system. III. Nucleation in a two-component incompressible Guid. J Chem Phys 31:688–699CrossRefGoogle Scholar
  18. Eberl DD, Drits VA, Srodon J (1998) Deducing growth mechanisms for minerals from the shapes of crystal size distributions. Am J Sci 298:499–533CrossRefGoogle Scholar
  19. Eberl DD, Kile DE, Drits VA (2002) On geological interpretations of crystal size distributions: constant vs. proportionate growth. Am Mineral 87:1235–1241Google Scholar
  20. Evangelakakis C, Kroll H, Voll G, Wenk HR, Meisheng H, Koepcke J (1993) Low-temperature coherent exsolution in alkali feldspars from high-grade metamorphic rocks of Sri Lanka. Contrib Mineral Petrol 114:519–532CrossRefGoogle Scholar
  21. Fiala J, Matějovská O, Vaňková V (1987) Moldanubian granulites: source material and petrogenetic considerations. Neues Jahrb Mineral Abh 157:133–165Google Scholar
  22. Finger F, Cooke R, Janoušek V, Konzett J, Pin C, Roberts MP, Tropper P (2003) Petrogenesis of the south Bohemian granulites: the importance of crystal–melt relationships. J Czech Geol Soc 48:44–45Google Scholar
  23. Fitz Gerald FD, McLaren AC (1982) The microstructures of microcline from some granitic rocks and pegmatites. Contrib Mineral Petrol 80:219–229CrossRefGoogle Scholar
  24. Fitz Gerald JD, Parsons I, Cayzer N (2006) Nanotunnels and pull-aparts: defects of exsolution lamellae in alkali feldspars. Am Mineral 91:772–783CrossRefGoogle Scholar
  25. Franěk J, Schulman K, Lexa O (2006) Kinematic and rheological model of exhumation of high pressure granulites in the Variscan orogenic root: example of the Blanský les granulite, Bohemian Massif, Czech Republic. Mineral Petrol 86:253–276CrossRefGoogle Scholar
  26. Franěk J, Schulmann K, Lexa O, Ulrich S, Štípská P, Haloda J, Týcová P (2011) Origin of felsic granulite microstructure by heterogeneous decomposition of alkali feldspar and extreme weakening of orogenic lower crust during the Variscan orogeny. J Metamorph Geol 29:103–130CrossRefGoogle Scholar
  27. Fuhrman ML, Lindsley DH (1988) Ternary-feldspar modeling and thermometry. Am Mineral 73:201–215Google Scholar
  28. Garvie LAJ (2010) Can electron energy-loss spectroscopy (EELS) be used to quantify hydrogen in minerals from the O K edge? Am Mineral 95:92–97CrossRefGoogle Scholar
  29. Hartmann K, Wirth R, Markl G (2008) P-T-X-controlled element transport through granulite-facies ternary feldspar from Lofoten, Norway. Contrib Mineral Petrol 156:359–375CrossRefGoogle Scholar
  30. Higgins M (2000) Measurement of crystal size distributions. Am Mineral 85:1105–1116Google Scholar
  31. Jakeš P (1997) Melting in high-P region—case of Bohemian granulites. Acta Univ Carol Geol 41:113–125Google Scholar
  32. Janoušek V, Holub FV (2007) The causal link between HP–HT metamorphism and ultrapotassic magmatism in collisional orogens: case study from the Moldanubian Zone of the Bohemian Massif. Proc Geol Assoc 118:75–86CrossRefGoogle Scholar
  33. Janoušek V, Finger F, Roberts M, Frýda J, Pin C, Dolejš D (2004) Deciphering the petrogenesis of deeply buried granites: whole-rock geochemical constraints on the origin of largely undepleted felsic granulites from the Moldanubian Zone of the Bohemian Massif. Trans R Soc Edinb Earth Sci 95:141–159CrossRefGoogle Scholar
  34. Janoušek V, Gerdes A, Vrána S, Finger F, Erban V, Friedel G, Braithwaite CJ (2006) Low-pressure granulites of the Lisov Massif, Southern Bohemia: visean metamorphism of Late Devonian plutonic arc rocks. J Petrol 47:705–744CrossRefGoogle Scholar
  35. Klimenkov M, Möslang A, Lindau R (2008) EELS analysis of complex precipitates in PM 2000 steel. Eur Phys J Appl Phys 42:293–303CrossRefGoogle Scholar
  36. Kotková J, Harley SL (1999) Formation and evolution of high-pressure leucogranulites: experimental constraints and unresolved issues. Phys Chem Earth Part A: Solid Earth Geodesy 24:299–304CrossRefGoogle Scholar
  37. Kretz R (1983) Symbols for rock forming minerals. Am Mineral 68:277–279Google Scholar
  38. Lee MR, Parsons I (1997) Dislocation formation and albitization in alkali feldspars from the Shap granite. Am Mineral 82:557–570Google Scholar
  39. Lifshitz IM, Slyozov VV (1961) The kinetics of precipitation from supersaturated solid solutions. J Phys Chem Solids 19:35–50CrossRefGoogle Scholar
  40. Marsh BD (1988) Crystal Size distribution (CSD) in rocks and kinetics and dynamics of crystallization. 1. Theory. Contrib Mineral Petrol 99:277–291CrossRefGoogle Scholar
  41. Mazzini A, Nermoen A, Krotkiewski M, Podladchikov Y, Planke S, Svensen H (2009) Strike-slip faulting as a trigger mechanism for overpressure release through piercement structures. Implications for the Lusi mud volcano, Indonesia. Marine Petrol Geol 26:1751–1765Google Scholar
  42. Nauman EB, He DQ (2001) Nonlinear diffusion and phase separation. Chem Eng Sci 56:1999–2018CrossRefGoogle Scholar
  43. Norberg N, Neusser G, Wirth R, Harlov D (2011) Microstructural evolution during experimental albitization of K-rich alkali feldspar. Contrib Mineral Petrol 162:531–546CrossRefGoogle Scholar
  44. Nord GL, McCallister RH (1979) Kinetics and mechanism of decomposition in WozsEnrrFsaac linopyroxene. Geologic Society of America Abstracts with Programs 11:488Google Scholar
  45. Ostwald W (1900) Ueber die vermeintliche Isomerie des roten und gelben Quecksilberoxyds und die Oberflaechenspannung fester Koerper. Z Phys Chem 34:495–503Google Scholar
  46. Owen DC, McConnell JDC (1974) Spinodal unmixing in alkali feldspar. In MacKenzie WS, Zussman J (eds) The Feldspars, Proceedings of a NATO Advanced Study Institute, Manchester University Press, Manchester pp 424–439Google Scholar
  47. Parsons I, Brown WL (1983) A TEM and microprobe study of a two-perthite alkali gabbro: implications for the ternary feldspar system. Contrib Mineral Petrol 81:1–12CrossRefGoogle Scholar
  48. Parsons I, Brown WL (1984) Feldspars and the thermal history of igneous rocks. In: Brown WL (ed) Feldspars and feldspathoids: structure, properties and occurrences. NATO ASI Series C, Reidel Publishing Co, Dordrecht, pp 317–371Google Scholar
  49. Parsons I, Lee M (2009) Mutual replacement reactions in alkali feldspars I: microtextures and mechanisms. Contrib Mineral Petrol 157:641–661CrossRefGoogle Scholar
  50. Parsons I, Thompson P, Lee MR, Cayzer N (2005) Alkali feldspar microtextures as provenance indicators in siliciclastic rocks and their role in feldspar dissolution during transport and diagenesis. J Sediment Res 75:921–942CrossRefGoogle Scholar
  51. Parsons I, Fitz Gerald JD, Lee JKW, Ivanic T, Golla-Schindler U (2010) Time–temperature evolution of microtextures and contained fluids in a plutonic alkali feldspar during heating. Contrib Mineral Petrol 160:155–180CrossRefGoogle Scholar
  52. Prior DJ, Boyle AP, Brenker F, Cheadle MC, Day A, Lopez G, Peruzzo L, Potts GJ, Reddy S, Spiess R, Timms NE, Trimby P, Wheeler J, Zetterström L (1999) The application of electron backscatter diffraction and orientation contrast imaging in the SEM to textural problems in rocks. Am Mineral 84:1741–1759Google Scholar
  53. Putnis A (2002) Mineral replacement reactions: from macroscopic observations to microscopic mechanisms. Mineral Mag 66:689–708CrossRefGoogle Scholar
  54. Putnis A (2009) Mineral replacement reactions. Rev Mineral Geochem 70:87–124CrossRefGoogle Scholar
  55. Randle V (1992) Microtexture Determination and its Applications. The Institute of Materials, London 174:29Google Scholar
  56. Randle V, Engler O (2000) Introduction to texture analysis: macrotexture, microtexture and orientation mapping. CRC, LondonGoogle Scholar
  57. Schmid DW, Abart R, Podladchikov YY, Milke R (2009) Matrix rheology effects on reaction rim growth II: coupled diffusion and creep model. J Metamorph Geol 27:83–91CrossRefGoogle Scholar
  58. Schulmann K, Kroener 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
  59. Schulmann K, Lexa O, Štípská P, Racek M, Tajčmanová L, Konopásek J, Edel JB, Peschler A, Lehman J (2008) Vertical extrusion and horizontal channel flow of orogenic lowercrust: key exhumation mechanisms in large hot orogens? J Metamorph Geol 26:273–297CrossRefGoogle Scholar
  60. Štípská P, Powell R, White RW, Baldwin JA (2010) Using calculated chemical potential relationships to account for coronas around kyanite: an example from the Bohemian Massif. J Metamorph Geol 28:97–116CrossRefGoogle Scholar
  61. Suess FE (1912) Die Moravischen Fenster und ihre Beziehung zum Grundgebirge des Hohen Gesenkes. Akademie der Wissenschaften, Denkschrift Matematisch-Naturwissenschaftliche Klasse 88:541–631Google Scholar
  62. 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
  63. Tajčmanová L, Soejono I, Konopásek J, Košler J, Kloetzli U (2010) Structural position of high-pressure felsic to intermediate granulites from NE Moldanubian zone (Bohemian Massif). J Geol Soc Lond 167:329–345CrossRefGoogle Scholar
  64. Tajčmanová L, Abart R, Neusser G, Rhede D (2011) Growth of decompression plagioclase rims around metastable kyanite from high-pressure felsic granulites (Bohemian Massif). J Metamorph Geol 29:1003–1018CrossRefGoogle Scholar
  65. Teran AV, Bill A, Bergmann RB (2010) Time-evolution of grain size distributions in random nucleation and growth crystallization processes. Phys Rev B 81:075319-19CrossRefGoogle Scholar
  66. Wagner C (1961) Theorie der Alterung von Niederschlägen durch Umlösen (Ostwald Reifung). Zeitschrift Elektrochemie 65:581–591Google Scholar
  67. Walker FDL, Lee MR, Parsons I (1995) Micropores and micropermeable texture in alkali feldspars: geochemical and geophysical implications. Mineral Mag 59:505–534CrossRefGoogle Scholar
  68. Weinbruch S, Styrsa V, Mueller WF (2003) Exsolution and coarsening in iron-free clinopyroxene during isothermal annealing. Geochim Cosmochim Acta 67:5071–5082CrossRefGoogle Scholar
  69. Weinbruch S, Styrsa V, Dirsch T (2006) The size distribution of exsolution lamellae in iron-free clinopyroxene. Am Mineral 91:551–559CrossRefGoogle Scholar
  70. Wirth R (1997) Water in minerals detectable by electron energy-loss spectroscopy EELS. Phys Chem Minerals 24:561–568CrossRefGoogle Scholar
  71. Wirth R (2004) Focused ion beam (FIB): a novel technology for advanced application of micro- and nanoanalysis in geosciences and applied mineralogy. Eur J Miner 16:863–876CrossRefGoogle Scholar
  72. Wirth R (2009) Focused ion beam (FIB) combined with SEM and TEM: advanced analytical tools for studies of chemical composition, microstructure and crystal structure in geomaterials on a nanometre scale. Chem Geol 261:217–229CrossRefGoogle Scholar
  73. Yund RA (1984) Coherent exsolution in the alkali feldspars. In: Hofmann AW, Giletti BJ, Yoder HS Jr, Yund RA (eds) Geochemical transport and kinetics. Carnegie Institution of Washington publication 634:173–183Google Scholar

Copyright information

© Springer-Verlag 2012

Authors and Affiliations

  • Lucie Tajčmanová
    • 1
    • 2
    Email author
  • Rainer Abart
    • 3
  • Richard Wirth
    • 4
  • Gerlinde Habler
    • 3
  • Dieter Rhede
    • 4
  1. 1.Department of Earth SciencesSwiss Federal Institute of TechnologyZurichSwitzerland
  2. 2.Czech Geological SurveyPrague 1Czech Republic
  3. 3.Department of Lithospheric ResearchUniversity of ViennaWienAustria
  4. 4.Deutsches GeoForschungsZentrumPotsdamGermany

Personalised recommendations