• Login
    View Item 
    •   Home
    • Theses & Dissertations
    • 2014 - Mines Theses & Dissertations
    • View Item
    •   Home
    • Theses & Dissertations
    • 2014 - Mines Theses & Dissertations
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Browse

    All of Mines RepositoryCommunitiesPublication DateAuthorsTitlesSubjectsThis CollectionPublication DateAuthorsTitlesSubjects

    My Account

    Login

    Mines Links

    Arthur Lakes LibraryColorado School of Mines

    Statistics

    Display Statistics

    Mineralogy and geochemistry of carbonaceous mudstone as a vector to ore: a case study at the Lagunas Norte high-sulfidation gold deposit, Peru

    • CSV
    • RefMan
    • EndNote
    • BibTex
    • RefWorks
    Thumbnail
    Name:
    Hanneman_mines_0052N_316.zip
    Size:
    16.68Mb
    Format:
    Unknown
    Description:
    Data
    Download
    Thumbnail
    Name:
    Hanneman_mines_0052N_10403.pdf
    Size:
    11.95Mb
    Format:
    PDF
    Description:
    Thesis
    Download
    Author
    Hanneman, Harry
    Advisor
    Monecke, Thomas
    Date issued
    2014
    Date submitted
    2014
    Keywords
    Lagunas Norte
    high-sulfidation
    exploration vectors
    siliciclastic host rocks
    mudstone alteration
    epithermal gold
    Mudstone -- Peru
    Mineralogy -- Peru
    Geochemistry -- Peru
    Sedimentology -- Peru
    Hydrothermal alteration -- Peru
    Metallogeny -- Peru
    Geology -- Peru
    
    Metadata
    Show full item record
    URI
    http://hdl.handle.net/11124/358
    Abstract
    The Lagunas Norte Au deposit in the Alto Chicama district of Peru is a ~14 Moz high-sulfidation epithermal deposit that is hosted by an atypical host-rock succession for this deposit type. Approximately 80% of the ore body is contained in the Lower Cretaceous Chimu Formation, which is composed of quartz arenite with interbedded carbonaceous mudstone, siltstone, and coal seams. The remainder of the ore is hosted by the Miocene volcanic rocks of the Calipuy Group, forming an irregular and thin veneer on the deformed sedimentary rocks of the basement. The host rock succession of the Lagunas Norte deposit has been affected by widespread hydrothermal alteration. The alteration is cryptic within most of sedimentary rocks as the quartz arenite was largely inert to alteration by the strongly acidic fluids. Vuggy textures associated with residual quartz alteration can only be recognized in the overlying Miocene volcanic rocks. However, the present study shows that mudstone of the Chimu Formation records acid-type alteration due to its originally high clay mineral content. The mineralogy of the mudstone broadly changes from residual quartz to quartz-alunite-pyrophyllite-kaolinite/dickite to illite-smectite away from the deposit. Mineralogical changes are paralleled by notable variations in the whole-rock major and trace element composition of the mudstone, allowing the definition of a set of alteration vectors to ore. Textural evidence suggests that alteration of the host rocks at Lagunas Norte predated precious metal mineralization. Residual quartz formed during the early acidic alteration is overgrown by later euhedral quartz that is texturally associated with the ore minerals. Fluid inclusion data suggest that the euhedral quartz and associated ore minerals formed from a low-temperature, low-salinity liquid. This liquid infiltrated the previously altered host rock succession, forming the sulfide ore zones of the epithermal deposit. Subsequent supergene weathering resulted in deep oxidation of the ore body.
    Rights
    Copyright of the original work is retained by the author.
    Collections
    2014 - Mines Theses & Dissertations

    entitlement

     
    DSpace software (copyright © 2002 - 2023)  DuraSpace
    Quick Guide | Contact Us
    Open Repository is a service operated by 
    Atmire NV
     

    Export search results

    The export option will allow you to export the current search results of the entered query to a file. Different formats are available for download. To export the items, click on the button corresponding with the preferred download format.

    By default, clicking on the export buttons will result in a download of the allowed maximum amount of items.

    To select a subset of the search results, click "Selective Export" button and make a selection of the items you want to export. The amount of items that can be exported at once is similarly restricted as the full export.

    After making a selection, click one of the export format buttons. The amount of items that will be exported is indicated in the bubble next to export format.