成矿流体运动系统与金质来源和富集机制讨论

DISCUSSION ON GOLD ORIGIN AND RICH MECHANISM OF ORE-FORMING FLUID MOVEMENT

以吉林和山东地区大型、超大型金矿为例 ,从运动学和动力学角度 ,系统研究其成矿作用的起点 (岩石—岩浆—流体间的物理化学作用 )和终点 (矿富集于断裂复合处或交汇部位 ) ,以及成矿流体在运动中的渗透、振荡、气—液态交替、流速的突变及多层次循环流体的萃取、沟通等多方面的共同作用。结果表明 ,巨量金质来源和富集的关键取决于各层次流体循环系统间的沟通 ,地幔富 C-H-O流体循环系统、中—下部地壳富硅流体循环系统、浅—表部 (主体位于浅部地壳和主体位于海底 )富硫流体循环系统3个层次的流体相互沟通、混合 ,导致流体循环持续时间增长 ,萃取围岩有用元素增多 ,成矿元素丰度升高 ,并最终形成金矿集中区。

Gold origin and rich mechanism are the key and core of gold metallization,which determine the formation and distribution of gold deposits.The study of movement and dynamics indicates that origin and rich mechanism can not be regarded only as the starting point of physical chemical factors among rock magma fluid and terminal point of gold deposits in fault superimposition and counter fault,but the study should be made mainly of osmosis,vibration,gas liquid alternate,flowing speed sudden changing,gradations circulatory fluid drawing and joining together and others in Au bearing fluid movement.Gold deposits are formed especially by long range moving mantle fluid,which is more important to gold origin and rich mechanism in moving fluid.The key of giant gold origin and enrichment is the combination of all kinds of gradations of circulation system of Au bearing fluids.The system includes three kinds of gradations:①the C H O bearing fluid in mantle,②the Si bearing fluid in middle lower crust,and ③ the S bearing fluid in shallow surface.Because of the three kinds of fluids linking up and mixing with each other,the time of circulation system of Au bearing fluids gets longer,the quantity of extraction of ore forming elements gets larger,the abundance of gold gets higher,thus forming the gold ore deposit concentrating area.