Abstract
The Hyde-Macraes Shear Zone has hydrothermal alteration that occurred under lower greenschist facies retrogression conditions, so that alteration reactions were subtle and mainly confined to accessory minerals. Mineralisation mainly involved replacement of silicate minerals by sulphide minerals and silicification. Gold is largely encapsulated in pyrite and arsenopyrite that occur as porphyroblasts in shears and with fine grained replacement quartz in veins. Scheelite was emplaced in veins and associated variably silicified breccias. Gold and scheelite introduction was accompanied by formation of minor boulangerite, chalcopyrite, sphalerite, and galena.
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References
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Craw, D., MacKenzie, D. (2016). Mineralogy and Paragenesis. In: Macraes Orogenic Gold Deposit (New Zealand). SpringerBriefs in World Mineral Deposits. Springer, Cham. https://doi.org/10.1007/978-3-319-35158-2_5
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DOI: https://doi.org/10.1007/978-3-319-35158-2_5
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