成矿流体及成矿机制

根据成矿流体样品——流体包裹体研究资料，目前已知的成矿流体主要有下列四种类型：（１）硅酸盐熔融体＋Ｍ（金属）；（２）Ｈ２Ｏ＋ＮａＣｌ＋Ｍ；（３）Ｈ２Ｏ＋ＣＯ２＋Ｍ；（４）Ｈ２Ｏ＋有机质＋Ｍ。这里所说的Ｈ２Ｏ，实际上是含有一定溶质的盐水；ＣＯ２则还包含有ＣＨ４、ＣＯ、Ｎ２、Ｈ２、Ｈ２Ｓ等等其它组分。不同的矿种、不同成因的矿床与一定种类的成矿流体有关，也就是说，成矿流体具有一定成矿专属性。通过成矿流体研究，我们认为成矿作用主要有下述几种形成机制：（１）不同种类流体混合成矿机制；（２）单一流体不混溶分离成矿机制；（３）流体＋有机质成矿机制；（４）水—岩交换成矿机制；（５）流体物－化条件改变成矿机制。

ORE FORMING FLUID AND MINERALIZA TION MECHANISM

According to the data of fluid inclusions, as the sample of ore forming solution, there are several types of ore forming fluid. Up to now we have known: (1) Silicate melt + M(metals), (2) H 2O + NaCl + M, (3) H 2O + CO 2 + M, (4) H 2O + Organic matter + M. In the (2), (3), (4) H 2O consist of Na +, K +, Ca 2+ , Mg 2+ … and Cl -, F -, SO 4 2- , HCO 3 -… and so on. CO 2 also may include a few CH 4,CO,N 2,H 2,H 2S. Different metals and ore genesis are related to a certain type of ore forming fluids. That is to say, some mineralizations are originated from the same type of ore forming fluids. By studying the base of ore forming fluids several mineralization models have been recognized:(1)Mineralization mechanism of two or more fluids mixed.(2)Mineralization mechanism of sole fluid immiscibility.(3)Mineralization mechanism of mixed organic and salt bearing solution.(4)Mineralization mechanism of water rock action.(5)Mineralization mechanism of changing physical chemical conditions.