METALLOGENIC CHARACTERISTICS OF GOLD AND COPPER DEPOSITS IN MESOZOIC VOLCANIC-MAGMATIC AREA IN NORTHEASTERN YANBIAN

The Mesozoic continental volcanic fault basin in the northeast area of Yanbian is located in Yanbian synclinorium of Yanbian eugeosyncline folding zone.Since Mesozoic, faults with different directions, strong volcanic activities and frequent magma intrusions have been developing in this area.There are occurred many copper polymetal deposits which are genetically related to Mesozoic volcanic-magmatic activity.The mineralized alteration can be commonly found,forming the famous Wufeng-Xiaoxinancha post-magmatic epithermal type of Au-Cu-polymetal mineralized belt striking E-W.The Mesozoic volcanic-magmatic rocks of the area resulted from the underthrust of the Pacific plate which made the intense extension of continental margin and upward intrusion of upper mantle magma accompanied by mineralization.Au,Au-Cu or Cu-Au polymetal deposits formed in favourable places of inner and outer contact zone in magmatic body.From distal to proximal, metallogenic zoning is Au, Ag→Au, Cu, Ag→Cu, Au,Pb,Zn→Cu(Mo,Au) The mineralization shows a process from low temperature to high temperature and from low sulphur to high sulphur.