中文摘要:岩浆在其放气作用过程中能向地表释放出大量的金属元素,如Cu、Mo、Au,如果存在适当的富集机制,从岩浆熔体中释放出来的成矿元素在一定的地质环境中聚集并沉淀就能够形成工业矿体。岩浆液态不混溶作用是导致分散于岩浆熔体中的成矿元素有效富集并最终形成工业矿体的重要机制。在封闭体系中,随岩浆结晶作用的进行,挥发性组分会在残余岩浆中不断聚集并最终析出而形成岩浆热液。F和B因易与Si、Al、Na、K等造岩元素结合而倾向于固定在熔体结构中,并在结晶作用发生时进入矿物晶格中,因此不易从岩浆熔体中析出而进入流体中。蚀变与矿化是两个独立的地质作用,尽管矿化与蚀变相伴生,但成矿作用的发生与否与蚀变作用没有本质上的联系。
Abstract:Through convection, hydrothermal system derived from magmatic fluids causes the diffusion of large proportion of heat from the depth of the earth to the surface. At the same time, these fluids transport metals, forming a very important class of ore deposit, namely hydrothermal deposits. Porphyry copper and molybdenum deposits, for example, provide more than half of these metals for the world. Magmatic fluids serve as the major source for many components in hydrothermal deposits. These components consisting of metallogenic elements and their carriers find their ways to and eventually get concentrated in magmatic fluids. Under low pressure (e.g. in a volcanic environment), some ore-forming elements such as Cu, Au, Mo and S might get concentrated in magmatic fluids, which, in turn, can form economic deposits once the proper mechanism for metallic concentration comes into being. In addition, the immiscibility of magmatic liquids might cause the separation of the magmatic system into two immiscible parts: silicate melt and fluids, with the latter being enriched in ore-forming elements and volatiles. In this paper, the foltowing points are emphatically pointed out: (l) ore-forming elements in hydrothermal deposits are derived directly from magma; (2) magmatic fluids play a leading role in the formation of hydrothermal deposits; (3) magmatic liquid immiscibility seems to be an important factor causing ore-forming elements to be separated from silicate melt and get concentrated; (4) though closely associated with mineralization, alteration is not the cause responsible for the ore-forming process.
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基金项目:国家教委留学回国人员资助费资助
引用文本:
朱永峰,艾永富,赵永超.1995.关于岩浆热液矿床形成的几个问题——以斑岩型矿床为例[J].矿床地质,14(4):380~384.1995.Some problems concerning the formation of magmatic hyrrothermal deposits[J].Mineral Deposits14(4):380~384
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