Diamonds

how they form where they are

W. L. Griffin*, S. Y. O'Reilly, D. Araujo, J. C. Afonso, Graham Begg

*Corresponding author for this work

    Research output: Chapter in Book/Report/Conference proceedingConference proceeding contribution

    Abstract

    Seismic tomography, lithosphere modeling and trace-element microanalysis of diamonds are providing new insights into the genesis of cratonic diamonds and the tectonic location of kimberlitic magmas. This multidisciplinary approach also helps to understand why these diamonds occur where they do, and how to improve exploration sucess. Cratonic diamonds form by the refertilisation of highly depleted dunite/harzburgite in the deep lithosphere. This process probably involves the oxidation of CH4-bearing fluids and the reduction of Fe in lithospheric rocks. Further refertilisation by silicate melts produces lherzolites, and oxidised fluids that form most fibrous diamonds. A review of data on the alluvial diamonds of Eastern Australia emphasizes how the major Copeton-Bingara population differs from cratonic diamonds, supports their unique subduction origin, and notes some pitfalls for the explorer.

    Original languageEnglish
    Title of host publicationSmart science for exploration and mining
    EditorsP. J. Williams et. al.
    Place of PublicationQLD, Australia
    PublisherJAMES COOK UNIV
    Pages669-671
    Number of pages3
    Volume1 & 2
    ISBN (Print)9780980558685
    Publication statusPublished - 2010
    Event10th Biennial SGA Meeting of the Society for Geology Applied to Mineral Deposits - Townsville, Australia
    Duration: 17 Aug 200920 Aug 2009

    Conference

    Conference10th Biennial SGA Meeting of the Society for Geology Applied to Mineral Deposits
    CountryAustralia
    CityTownsville
    Period17/08/0920/08/09

    Keywords

    • Diamond
    • lithospheric mantle
    • Archean lithosphere
    • subduction diamonds
    • EASTERN AUSTRALIA
    • ALLUVIAL DIAMONDS
    • KAAPVAAL CRATON
    • MANTLE
    • METASOMATISM
    • BINGARA

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