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Browsing Research Output by Author "Basson, IJ"

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    Structural controls on mineralisation at the Namib Lead and Zinc Mine, Damara Belt, Namibia
    (Elsevier, 2018-04) Basson, IJ; McCall, M-J; Andrew, J; Daweti, E
    The Namib Lead and Zinc (Pb-Zn) Mine is hosted within the Karibib Formation of the Swakop Group, Damara Sequence. The host marble contains sulphide-rich beds and is locally Pb- and Zn-rich over a strike extent of >100 km. Mining took place in the upper portions of a remobilized MVT or SEDEX orebody, which may occur adjacent to a reactivated major structure. Pb and Zn show locally anomalous copper, tin, indium and fluorine concentrations. Based on the position of gossans, individual orebodies comprise discrete elongate shoots around an antiform and its meso-scale parasitic folds, within calcitic marble. Non-coaxial flattening of the fold-cleavage geometry reflects a series of non-coaxial deformation events, recorded in the Southern Central Zone of the Damara Belt which were superimposed on a NE-SW structural grain and pre-existing fold axial planes. Non-coaxial flattening resulted in further remobilization of sulphides into dilational rhombs which formed from shearing along overlapping axial planar cleavage, in concert with the dilation of banding in the host marble.
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    Structural controls on mineralisation at the Namib Lead and Zinc Mine, Damara Belt, Namibia
    (Elsevier, 2018-04) Basson, IJ; McCall, M-J; Andrew, J; Daweti, E
    The Namib Lead and Zinc (Pb-Zn) Mine is hosted within the Karibib Formation of the Swakop Group, Damara Sequence. The host marble contains sulphide-rich beds and is locally Pb- and Zn-rich over a strike extent of >100 km. Mining took place in the upper portions of a remobilized MVT or SEDEX orebody, which may occur adjacent to a reactivated major structure. Pb and Zn show locally anomalous copper, tin, indium and fluorine concentrations. Based on the position of gossans, individual orebodies comprise discrete elongate shoots around an antiform and its meso-scale parasitic folds, within calcitic marble. Non-coaxial flattening of the fold-cleavage geometry reflects a series of non-coaxial deformation events, recorded in the Southern Central Zone of the Damara Belt which were superimposed on a NE-SW structural grain and pre-existing fold axial planes. Non-coaxial flattening resulted in further remobilization of sulphides into dilational rhombs which formed from shearing along overlapping axial planar cleavage, in concert with the dilation of banding in the host marble.