Curtin University Homepage
  • Library
  • Help
    • Log in

    espace - Curtin’s institutional repository

    JavaScript is disabled for your browser. Some features of this site may not work without it.
    View Item 
    • espace Home
    • espace
    • Curtin Research Publications
    • View Item
    • espace Home
    • espace
    • Curtin Research Publications
    • View Item

    Quantitative characterization of plastic deformation of zircon and geological implications

    19978_downloaded_stream_496.pdf (6.752Mb)
    Access Status
    Open access
    Authors
    Reddy, Steven
    Timms, Nicholas Eric
    Pantleon, W.
    Trimby, P.
    Date
    2007
    Type
    Journal Article
    
    Metadata
    Show full item record
    Abstract

    The deformation-related microstructure of an Indian Ocean zircon hosted in a gabbro deformed at amphibolitegrade has been quantified by electron backscatter diffraction. Orientation mapping reveals progressive variations in intragrain crystallographic orientations that accommodate 20 of misorientation in the zircon crystal. These variations are manifest by discrete low-angle (<4) boundaries that separate domains recording no resolvable orientation variation. The progressive nature of orientation change is documented by crystallographic pole figures which show systematic small circle distributions, and disorientation axes associated with 0.5-4 disorientation angles, which lie parallel to rational low index crystallographic axes. In the most distorted part of the grain (area A), this is the [100] crystal direction. A quaternion analysis of orientation correlations confirms the [100] rotation axis inferred by stereographic inspection, and reveals subtle orientation variations related to the local boundary structure. Microstructural characteristics and orientation data are consistent with the lowangle boundaries having a tilt boundary geometry with dislocation line [100]. This tilt boundary is most likely to have formed by accumulation of edge dislocations associated with a <001> {100} slip system. Analysis of the energy associated with these dislocations suggest they are energetically more favourable than TEM verified <010>{100} slip. Analysis of minor boundaries in area A indicates deformation by either [010] (001) edge, or [100](100) and [001](100) screw dislocations. In other parts of the grain, [110] cross slip on (111), (111) and (112) planes seems likely. These data provide the first detailed microstructural analysis of naturally deformed zircon and indicate ductile crystal-plastic deformation of zircon by the formation and migration of dislocations into low-angle boundaries. Minimum estimates of dislocation density in the low-angle boundaries are of the order of ~3.1010 cm-2. This value is sufficiently high to have a marked effect on the geochemical behaviour of zircon, via enhanced bulk diffusion and increased dissolution rates. Therefore, crystal plasticity in zircon may have significant implications for the interpretation of radiometric ages, isotopic discordance and trace element mobility during high-grade metamorphism and melting of the crust.

    Citation
    Reddy, S.M. and Timms, N.E. and Pantleon, W. and Trimby, P.. 2007. Quantitative characterization of plastic deformation of zircon and geological implications. Contributions to Mineralogy and Petrology 153: 625-645.
    Source Title
    Contributions to Mineralogy and Petrology
    DOI
    10.1007/s00410-006-0174-4
    Faculty
    Department of Applied Geology
    Division of Resources and Environment
    Remarks

    The original publication is available at http://www.springerlink.com

    The link to this article is:

    http://dx.doi.org/10.1007/s00410-006-0174-4

    URI
    http://hdl.handle.net/20.500.11937/35049
    Collection
    • Curtin Research Publications

    Related items

    Showing items related by title, author, creator and subject.

    • Inclusion-localised crystal-plasticity, dynamic porosity, and fast-diffusion pathway generation in zircon
      Timms, Nicholas Eric; Reddy, Steven; FitzGerald, J.; Green, L.; Muhling, J. (2011)
      A population of oscillatory zoned, igneous zircon grains in a Javanese andesite contains fluid and mineral inclusions (up to 10 μm across) trapped during zircon growth. Orientation contrast imaging and orientation mapping ...
    • Enhanced diffusion of Uranium and Thorium linked to crystal plasticity in zircon
      Timms, Nicholas Eric; Kinny, Peter; Reddy, Steven (2006)
      The effects of crystal-plasticity on the U-Th-Pb system in zircon is studied by quantitative microstructural and microchemical analysis of a large zircon grain collected from pyroxenite of the Lewisian Complex, Scotland. ...
    • Crystal-plastic deformation of zircon: A defect in the assumption of chemical robustness
      Reddy, Steven; Timms, Nicholas Eric; Kinny, Peter; Buchan, Craig; Trimby, P.; Blake, K. (2006)
      Orientation contrast imaging and quantitative electron backscatter diffraction analysis of a zircon collected from an Indian Ocean gabbro reveal intragrain crystallographic misorientations (up to 14°) and low-angle ...
    Advanced search

    Browse

    Communities & CollectionsIssue DateAuthorsTitlesSubjectsDocument TypesThis CollectionIssue DateAuthorsTitlesSubjectsDocument Types

    My Account

    Log in

    Statistics

    Most Popular ItemsStatistics by CountryMost Popular Authors

    Connect with Curtin

    • 
    • 
    • 
    • 
    • 
    • 
    • 

    CRICOS Provider Code: 00301JABN: 99 143 842 569TEQSA: PRV12158