3D modeling of the Ashanti Belt, southwest Ghana: Evidence for a litho-stratigraphic control on gold occurrences within the Birimian Sefwi Group

S. Perrouty, Mark Lindsay, Mark Jessell, L. Aillères, R. Martin, Y. Bourassa

    Research output: Contribution to journalArticle

    36 Citations (Scopus)

    Abstract

    A three-dimensional model of the gold-rich Paleoproterozoic Ashanti Greenstone Belt has been built with a "hybrid" geological modeling method using Geomodeller and Gocad, then inverted using VPmg software. The model helps to identify the main regional-scale controls leading to abundant gold mineralization in the southeast of the belt by highlighting the lithological distribution and geometry of geological structures. The three-dimensional geological model shows that 85% of gold occurrences in the Ashanti Greenstone Belt are proximal to a specific tholeiitic metabasaltic horizon "BV1". This result is noteworthy given that the relatively thin, 300. m thick, BV1 layer represents only 10%, by volume, of the modeled Sefwi Group stratigraphy. A map of distance between the topography and the BV1 layer is produced and identifies areas showing a high probability to host gold deposits in the southeast of the Ashanti Belt. Possible structural controls performed by the BV1 tholeiitic metabasaltic rocks on the location of gold occurrences are discussed, and we hypothesize that the BV1 layer acted as a mineralization trap or source of gold. Both hypotheses agree with examples from the literature and explain the observed distribution of the mineralized sites. © 2014 Elsevier B.V.
    Original languageEnglish
    Pages (from-to)252-264
    JournalOre Geology Reviews
    Volume63
    DOIs
    Publication statusPublished - 2014

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    Birrimian
    Gold
    gold
    modeling
    greenstone belt
    Gold deposits
    Stratigraphy
    mineralization
    structural control
    Topography
    geological structure
    Rocks
    stratigraphy
    topography
    Geometry
    software
    geometry
    rock

    Cite this

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    title = "3D modeling of the Ashanti Belt, southwest Ghana: Evidence for a litho-stratigraphic control on gold occurrences within the Birimian Sefwi Group",
    abstract = "A three-dimensional model of the gold-rich Paleoproterozoic Ashanti Greenstone Belt has been built with a {"}hybrid{"} geological modeling method using Geomodeller and Gocad, then inverted using VPmg software. The model helps to identify the main regional-scale controls leading to abundant gold mineralization in the southeast of the belt by highlighting the lithological distribution and geometry of geological structures. The three-dimensional geological model shows that 85{\%} of gold occurrences in the Ashanti Greenstone Belt are proximal to a specific tholeiitic metabasaltic horizon {"}BV1{"}. This result is noteworthy given that the relatively thin, 300. m thick, BV1 layer represents only 10{\%}, by volume, of the modeled Sefwi Group stratigraphy. A map of distance between the topography and the BV1 layer is produced and identifies areas showing a high probability to host gold deposits in the southeast of the Ashanti Belt. Possible structural controls performed by the BV1 tholeiitic metabasaltic rocks on the location of gold occurrences are discussed, and we hypothesize that the BV1 layer acted as a mineralization trap or source of gold. Both hypotheses agree with examples from the literature and explain the observed distribution of the mineralized sites. {\circledC} 2014 Elsevier B.V.",
    author = "S. Perrouty and Mark Lindsay and Mark Jessell and L. Aill{\`e}res and R. Martin and Y. Bourassa",
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    doi = "10.1016/j.oregeorev.2014.05.011",
    language = "English",
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    3D modeling of the Ashanti Belt, southwest Ghana: Evidence for a litho-stratigraphic control on gold occurrences within the Birimian Sefwi Group. / Perrouty, S.; Lindsay, Mark; Jessell, Mark; Aillères, L.; Martin, R.; Bourassa, Y.

    In: Ore Geology Reviews, Vol. 63, 2014, p. 252-264.

    Research output: Contribution to journalArticle

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    AU - Lindsay, Mark

    AU - Jessell, Mark

    AU - Aillères, L.

    AU - Martin, R.

    AU - Bourassa, Y.

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