Neoproterozoic phyllites and metsandstones, unconformably overlain by Devonian to Carboniferous shallow marine sediments with minor limestone, containing Fe, Mn, Pb, Zn & Cu mineralization on limestone-sandstone contacts. Following Triassic tectonism, these were intruded by Jurassic granites and composite stocks, and related volcanics, followed by an extensive Cretaceous volcanic suite controlled by a major NE trending deep fault zone.
Copper-gold mineralization in the Zijinshan district is developed within the 125 ±4 Ma Shimaoshan volcanics and related intrusives in a small fault bounded volcanic basin where the dacitic volcanic dome complex was formed. Dacitic porphyry occurs in a pipe like intrusion in the centre of the basin, surrounded by dacitic volcanic breccia, tuff and lava. A system of circular and radial faults and fissures, developed around the dacite porphyry pipe, are typically filled by hydrothermal breccias and veins.
Ref.:
- http://www.portergeo.com.au/database/mineinfo.asp?mineid=mn622
