初论元素富集成矿的地球化学机理—以岩浆热液矿床的形成为例

元素富集成矿的过程实质上是元素在地球不同圈层和不同相以及不同集合体之间分配的结果。元素的富集起始于地球形成的初期。对于大多数金属成矿元素 ,地壳特别是上地壳是大多数矿石和矿胎的储库 ,地壳丰度是元素富集成矿的物质基础。元素在地质体系演化共存相间的分配是元素富集成矿的关键过程。对于以侵入体为中心的热液矿床的形成 ,岩浆部分熔融、结晶分异、液态分离、挥发分分离以及气液相不混溶等过程能够导致金属元素最终达到矿石级的富集。挥发分则是元素富集成矿的重要制约因素

ON THE GEOCHEMICAL MECHANISMS OF ENRICHMENT AND ORE FORMATION OF ORE METALS

In essence, the enrichment and ore formation of ore metals result from the partitioning of ore metals among different layers, different phases and different aggregates. The enrichment of metals is due to fractionation and accretion of the earth. For most ore metals, the continental crust, especially, the upper continental crust, is the repository of all ores and protores. Therefore, the average crust abundance of metals is the material base for the enrichment of ore metals. The partitioning of ore metals among different phases during the evolution of the geological system constrains the enrichment of ore metals. For the intrusion\|centered hydrothermal ore deposits, the enrichment of metals may result from these constraints including fractionation melting, fractionation crystallization, liquid immiscibility, volatile exsolution, aqueous fluid immiscibility and so on, of which, volatiles are of critical importance for the enrichment and ore formation of ore metals.