从克拉克值到元素的地球化学性质或行为再到成矿作用

From Clark Values to Elemental Geochemical Properties or Behaviors, and to Mineralization

克拉克值→第一类反作用→元素丰度→第二类反作用→…→进一步富集成矿的机制构成了一个完整的化学成矿过程链。克拉克值的影响通过质量作用定律可以深入到成矿作用的各个方面,但仍然只是一种必要非充分的成矿条件,因元素而异的地球化学性质或行为将产生两种"反作用":①成矿作用是元素在地球不同圈层和不同相以及不同集合体之间多次分配的结果,一旦分配完成,各级元素丰度有望重新成为最主要成矿约束因素之一,丰度比值则体现了元素分配(异)行为的量化特征;②诸如离子电位、赋存状态等元素本身固有的性质或行为亦产生反作用,可通过固定"性质"谈"丰度"认识其成矿学意义。对于最终将工作于远离平衡态条件下的成矿系统,进一步富集的机制另将成为决定性控矿因素。

We believe that Clark values→Reaction I→elemental abundance→Reaction II→…→mechanism of further enrichment and mineralization makes a successive chain for chemical mineralization.Although,elemental abun-dance may exert significant influence on every aspect during metallogenesis in the light of Mass Action Law,it is still a necessary,but not sufficient,condition for mineralization.At the same time,elemental geochemical proper-ties or behaviors may exert two different forms of reactions on the abundance constrains：First,the enrichment and the ore formation of ore metals,in essence,result from the partitioning of ore metals among different layers,dif-ferent phases and different aggregates of the Earth,but once the partition is done and a new phase generates,ele-mental abundance at various levels will play a fundamental role in the ore-genesis again,while ratio of abundance plays as a quantitative indicator for elemental differentiation or partition behaviors;Second,there is the reaction of elemental inherent geochemical properties or behaviors,such as elemental existence form,ionization potential and so on,therefore,to further understand the metallogenic significance of Clark valuer is to compare a fixed set of ele-mental properties with their abundances.Besides,as to the ore-forming system unavoidably far from equilibrium state,mechanism of further enrichment and mineralization may play an irreplaceable and decisive role in the final metallogenesis.