The geology of the Rosebery ore deposit

摘要: The stratiform pyritic Zn-Pb-Cu and barite ore deposit at Rosebery is contained in a small shale lens within pyroclastic rocks (the Primrose Pyroclastics) which form part of the Mt. Read Volcanic Group -an extensive belt silicic volcanic Cambrian age. The Pyroclastics consist vitric, crystal lithic tuffs, breccias, shale·lenses quartz-sericitechlorite schists derived from rocks. contain probable ignimbrites therefore may have been deposited on land. They are overlain to east by massive lavas Mt, Black Volcanics. On the, west Pyroclastics flanked appear intertongue with consisting shale, quartz-wacke, greywacke conglomerate dolomitic siltstone. rocks, particularly formations, area,have undergone low-grade regional metamorphism that has·produced mineral assemblages lower greenschist facies together schistose fabrics. In Mine area detailed stratigraphic sequence is: pyroclastics (vitric, tuff), black slate, host rock ( siltstone tuff bands), Barite orebody, rock, Z.n-Pb sulphide orebody an Fe-Cu-rich basal zone, footwall schists, footwall (crystal tuff). contact between underlying slate or host appears, -ion part, be disconformity. footwall schists below thei Zn-Pb possibly represent zone wallrock alteration.i A post-ore basaltic dike corelated the Jurassic dole ritei interest because it contains probable rheomorphic galena-chalcopyrite veinlets.