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Zircon dissolution in a ductile shear zone, Monte Rosa granite gneiss, northern Italy

By T.J. Dempster, J.C. Martin and Z.K. Shipton


The sizes, distributions and shapes of zircon grains within variably deformed granite gneiss from the western Alps have been studied. Zircon shows numerous indicators of a metamorphic response in both the host gneiss and a 5 cm wide continuous ductile shear zone, within which the zircon grain sizes range from <1 µm to >50 µm. However, the very fine grain sizes are virtually absent from grain boundaries. Within this zone, zircons consistently have more rounded and embayed margins, which are interpreted as evidence of dissolution in response to fluid influx during shearing. Zircons are preferentially located near metamorphic muscovite in both the host gneiss and the shear zone and tend to show the poorest crystal shape, indicating that fluids linked to the formation and presence of muscovite may enhance both the crystallization of zircon and its subsequent dissolution. Larger zircon crystals typically show a brittle response to deformation when adjacent to phyllosilicates, with fractures consistently perpendicular to the (001) mica cleavage. The variety of metamorphic behaviour observed for zircon indicates that it may be highly reactive in sub-solidus mid-crustal metamorphic environments

Topics: QE
Publisher: Mineralogical Society
Year: 2008
OAI identifier:
Provided by: Enlighten

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  2. (1980). A preliminary study on the behaviour of brittle minerals in a ductile matrix: example of zircons and feldspars.
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  6. (2007). Coupling of oceanic and continental crust during Eocene eclogite-facies metamorphism: evidence from the Monte Rosa nappe, western Alps. Contributions to Mineralogy and Petrology,
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  8. (2006). Crystal-plastic deformation of zircon: A defect in the assumption of chemical robustness.
  9. (1999). Dating of eclogite-facies zircons: the age of Alpine metamorphism in the Sesia-Lanzo Zone (Western Alps).
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  11. (2008). Early (54.5 Ga) formation of terrestrial crust: Lu-Hf, d 18O, and Ti thermometry results for Hadean zircons.
  12. (1986). Early Alpine eclogite metamorphism in the Penninic Monte RosaGran Paradiso basement nappes of the northwestern Alps.
  13. (1976). Equilibrium-disequilibrium relations in the Monte Rosa granite, western Alps: petrological, Rb-Sr and stable isotope data. Contributions to Mineralogy and Petrology,
  14. (2001). Evidence from detrital zircons for the existence of continental crust and oceans on the Earth4.4 Ga ago.
  15. (2003). Experimental hydrothermal alteration of partially metamict zircon.
  16. (1986). Four zircon ages from one rock: the history of a 3,930 Ma-old granulite from Mount Scones, Enderby Land, Antarctica. Contributions to Mineralogy and Petrology,
  17. (2001). Geochemistry of a talc-kyanite-chloritoid shear zone within the Monte Rosa granite, Val d’Ayas,
  18. (2001). Geology of the Monte Rosa massif: historical review and personal comments.
  19. (1989). Hydrothermal zircons and zircon overgrowths,
  20. (1995). Improving the resolution of single-grain U/Pb dating by the use of zircon extracted from feldspar: Application to the Variscan magmatic cycle in the central Alps.
  21. (1982). Leachability of zircon as a function of alpha dose. Scientific Basis for Radioactive Waste Management,
  22. (2001). Leaching and differential recrystallization of metamict zircon under experimental hydrothermal conditions. Contributions to Mineralogy and Petrology,
  23. (2003). Linking growthof zircon and metamorph ic textures to zircon chemistry: an example from the ultrahigh-temperature granulites of Rogaland
  24. (2006). Low-temperature Zr mobility: An in situ synchrotron-radiation XRF study of the effect of radiation damage in zircon on the element release
  25. (2004). Lu-Hf and U-Pb isotope systematics of zircon from the Storgangen Intrusive Complex, SW Norway; implications for the composition and evolution of Precambrian lower crust in the Baltic shield.
  26. (2001). Metamictization and chemical durability of detrital zircon.
  27. (2001). Metamictization of natural zircon: accumulation versus thermal annealing of radioactivity-induced damage. Contributions to Mineralogy and Petrology,
  28. (2001). Metamorphic evolution of pelitic rocks of the Monte Rosa nappe: Constraints from petrology and single grain monazite age data.
  29. (2000). Metamorphic zircon formation by solid-state recrystallization of protolithigneous zircon.
  30. (2008). Micro-zircon: origin and evolution during metamorphism.
  31. (1999). Nature of the Earth’s earliest crust from hafnium isotopes in single detrital zircons.
  32. (1973). Old lead components in the young Bergell Massif, south-east Swiss Alps. Contributions to Mineralogy and Petrology,
  33. (2001). On the kinematics of shearing near the top of the Monte Rosa nappe and the nature of the Furgg zone in Val Loranco (Antrona valley, N. Italy): tectonometamorphic and paleogeographical consequences:
  34. (1990). On the kinematics of zircon growth and its petrogenetic significance: A cathodoluminescence study. Contributions to Mineralogy and Petrology,
  35. (1970). Polymetamorphism in the Monte Rosa, Western Alps. Eclogae Geologicae Helvetiae,
  36. (2002). Polyphase zircon in ultrahigh-temperature granulites (Rogaland, SW Norway): constraints for Pb diffusion in zircon.
  37. (1997). Rare-earthdiffusion in zircon.
  38. (2001). Response of detrital zircon and monazite, and their U-Pb isotopic systems, to regional metamorphism and host-rock partial melting,
  39. (1995). Self-induced fracture generation in zircon.
  40. (1992). Some observations on the use of zircon U-Pb geochronology in the study of granitic rocks.
  41. (2002). Stability of zircon in a low-grade ultramylonite and its utility for chemical mass balancing: the shear zone at Mie ´ville, Switzerland. Chemical Geology,
  42. (1992). Stability of zircon U-Pb systematics in a greenschist-grade mylonite: An example from the Rockfish Valley Fault Zone,
  43. (1983). Symbols for rock-forming minerals.
  44. (2003). The Composition of Zircon and Igneous and Metamorphic Petrogenesis.
  45. (1995). The Earth’s early evolution.
  46. (1987). The kinematics of gouge deformation.
  47. (1994). The Structure of Metamict Zircon:
  48. (2001). U-Pb SHRIMP geochronology of an amphibolitized eclogite and an orthogneiss from the Furgg zone (Western Alps) and implications for its geodynamic evolution.
  49. (1988). U-Pb zircon and Sm-Nd model ages of high-grade Moldanubian metasediments,
  50. (1978). U/Pb systematics of zircons during dynamic metamorphism: A study from the Brevard Fault Zone: Contributions to Mineralogy and Petrology,
  51. (1963). Uranium-lead isotopic variations in zircons: A case study.
  52. (2002). Vertical stretching and crustal thickening at Nanga Parbat, Pakistan Himalaya: a model for distributed continental deformation during mountain building.
  53. (2001). Zircon and monazite response to prograde metamorphism in the Reynolds Range, central Australia. Contributions to Mineralogy and Petrology,
  54. (2004). Zircon growthin slate.
  55. (2005). Zircon growthin very low grade metasedimentary rocks: evidence for zirconium mobility at ~250ºC. Contributions to Mineralogy and Petrology,
  56. (2003). Zircons from Syros, Cyclades, Greece recrystallization and mobilization of zircon during high pressure metamorphism.
  57. (2001). Zr budgets for metamorphic reactions, and the formation of zircon from garnet breakdown.

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