与侵入岩有关的金矿体系

与侵入岩有关的金矿体系的主要特点 :1.大地构造位置是会聚板块边缘的内侧。这种部位的大陆岩浆作用往往形成了同时代的碱性、偏铝钙碱性和过铝成分的侵入岩 ;2 .显生宙 ,尤其是海西期和燕山期形成的侵入岩是与侵入岩金矿床有关的最佳侵入岩 ,其中最有利的部位是已知钨、锡矿床产出部位 ;3.成矿母岩是中性到酸性成分的偏铝、次碱性侵入岩 ,介于钛铁矿系列与磁铁矿系列之间 ;4 .成矿流体是富碳的热流体 ;5 .金属组合是 Au与 Bi、W、As、Mo、Te或 Sb组合 ,贱金属含量低 ;6 .硫化物含量低 ,一般低于 5 % ,显示还原性质的矿石矿物组合 ,特征的矿物组成是毒砂和磁黄铁矿 ,缺失磁铁矿和赤铁矿 ;7.除了浅成条件下形成的金矿床 ,该金矿体系的热液蚀变较弱 ,常见的蚀变产物是白云母 -绢云母 -绿泥石 -碳酸盐集合体。

INTRUSION-RELATED GOLD SYSTEMS

The main features of intrusion related gold deposits system are: 1 A tectonic setting is the inboard of convergent plate boundaries,where contiental magmatism commonly formed coeval intrusion of alkalic,metaluminous calcalkalic,and peraluminous compositions; 2 Intrusion formed during the phauerozoic, especially hercynian and yanshanian is best for intrusion related gold system A best location in magmatic provinces for intrusion related gold system is the known tungsten and/or tin deposits 3 Intrusion is metaluminous,subalkalic intrusions of intermediate to felsic composition that lie near the boundary between ilmenite and magnetite series 4 An ore formed fluid is the carbonic hydrothermal fluids 5 A metal assemblage is characterized by variably combinations of gold with Bi,W,As,Mo,Te,or Sb and low concentrations of base metals 6 A low sulfide mineral content commonly <5%Vol,with a reduced ore mineral assemblage,that typically comprises arsenopyrite,pyrrhotite,and pyrite and lacks magnetite or hematite 7.Except the gold formed at hypabyssal condition hydrothermal alteration of the gold deposit system is relatively weak with muscovite sericite chlorite carbonate assemblage as common alteration production