Curtin University Homepage
  • Library
  • Help
    • Admin

    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

    Aseismic refinement of orogenic gold systems

    Access Status
    Fulltext not available
    Authors
    Voisey, C.R.
    Willis, D.
    Tomkins, A.G.
    Wilson, C.J.L.
    Micklethwaite, S.
    Salvemini, F.
    Bougoure, J.
    Rickard, William
    Date
    2020
    Type
    Journal Article
    
    Metadata
    Show full item record
    Citation
    Voisey, C.R. and Willis, D. and Tomkins, A.G. and Wilson, C.J.L. and Micklethwaite, S. and Salvemini, F. and Bougoure, J. et al. 2020. Aseismic refinement of orogenic gold systems. Economic Geology. 115 (1): pp. 33-50.
    Source Title
    Economic Geology
    DOI
    10.5382/econgeo.4692
    ISSN
    0361-0128
    Faculty
    Faculty of Science and Engineering
    School
    John de Laeter Centre (JdLC)
    Funding and Sponsorship
    http://purl.org/au-research/grants/arc/LP150100717
    URI
    http://hdl.handle.net/20.500.11937/82053
    Collection
    • Curtin Research Publications
    Abstract

    ©2020 Society of Economic Geologists, Inc.

    Orogenic Au deposits have contributed the majority of Au recovered globally throughout history. However, the mechanism that concentrates Au to extremely high bonanza grades in small domains within these deposits remains enigmatic. The volume of fluid required to provide extreme Au endowments in localized occurrences is not reflected in field observations (e.g., in the extent of quartz veining or hydrothermal alteration). Detailed optical, scanning and transmission electron microscopy, nanoscale secondary ion mass spectrometry, and 3-D neutron tomography have been used to investigate the processes responsible for development of anomalously high grade ore (upward of 3% Au) found in quartz veins at Fosterville gold mine (Victoria, Australia). Distinct textural settings of visible Au include (1) Au concentrated along pressure solution seams associated with wall-rock selvages, (2) as nano- to microscale dusty Au seams parallel to pressure solution seams, and (3) in microscale tension fractures perpendicular to stylolitic seams. The distribution of Au in arsenopyrite and pyrite hosted within pressure solution seams changes as a function of the extent of deformation. Sulfides in highly deformed pressure solution seams exclusively host Au as nano- to micrometer-sized clusters within features associated with corrosion and brittle failure, whereas sulfides in mildly deformed pressure solution seams have Au bound in the crystal structure. It is proposed that Au supersaturation in fluids introduced during seismic periods led to the deposition of abundant Au nanoparticles in quartz-carbonate veins. Subsequent pressure dissolution of vein quartz and carbonate during interseismic intervals allowed for episodic increase in the Au/ quartz ratio and permitted liberation and migration of Au nanoparticles, promoting Au grain growth in favorable textural settings. Galvanic corrosion and brittle fracturing of auriferous sulfides during the interseismic period allowed additional remobilization and/or enrichment of sulfide-hosted Au. Repetition of this mechanism over the time scale of deposit formation acted to concentrate Au within the lodes. This Au ore upgrading model, referred to as “aseismic refinement,” provides a new insight for the genesis of ultrarich Au mineralization and, based on textures reported from many Au deposits, may be a globally significant component in the formation of orogenic Au deposits.

    Related items

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

    • The Nadun Cu-Au mineralization, central Tibet: Root of a high sulfidation epithermal deposit
      Li, J.; Qin, K.; Li, G.; Evans, Noreen; Zhao, J.; Cao, M.; Huang, F. (2016)
      A new high sulfidation epithermal Cu–Au occurrence (Nadun) has been discovered adjacent to the Cretaceous Duolong porphyry Cu–Au deposit within the Bangong–Nujiang metallogenic belt, central Tibet. The Nadun Cu–Au ...
    • Using in situ SHRIMP U-Pb monazite and xenotime geochronology to determine the age of orogenic gold mineralization: An example from the Paulsens Mine, Southern Pilbara Craton
      Fielding, I.; Johnson, S.; Zi, J.; Rasmussen, Birger; Muhling, J.; Dunkley, D.; Sheppard, S.; Wingate, M.; Rogers, J. (2017)
      Paulsens is a mesothermal orogenic gold deposit located in the Wyloo Inlier on the southern margin of the Pilbara craton of Western Australia. Gold occurs in quartz-sulfide veins hosted within a folded and faulted gabbro ...
    • The evolution of a Precambrian arc-related granulite facies gold deposit: Evidence from the Glenburgh deposit, Western Australia
      Roche, L.; Korhonen, F.; Johnson, S.; Wingate, M.; Hancock, E.; Dunkley, Daniel; Zi, Jianwei; Rasmussen, Birger; Muhling, Janet; Occhipiniti, S.; Dunbar, M.; Goldsworthy, J. (2017)
      Gold deposits are rare in upper-amphibolite to granulite facies environments. Known examples commonly attract debate about whether they formed under these conditions or instead represent metamorphosed, metasomatic, or ...
    Advanced search

    Browse

    Communities & CollectionsIssue DateAuthorTitleSubjectDocument TypeThis CollectionIssue DateAuthorTitleSubjectDocument Type

    My Account

    Admin

    Statistics

    Most Popular ItemsStatistics by CountryMost Popular Authors

    Follow Curtin

    • 
    • 
    • 
    • 
    • 

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

    Copyright | Disclaimer | Privacy statement | Accessibility

    Curtin would like to pay respect to the Aboriginal and Torres Strait Islander members of our community by acknowledging the traditional owners of the land on which the Perth campus is located, the Whadjuk people of the Nyungar Nation; and on our Kalgoorlie campus, the Wongutha people of the North-Eastern Goldfields.