| 焦家金矿床水-岩反应过程及成矿流体组分变化规律 |
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| 引用本文： | 刘亚洲,王恩敬,王偲瑞,郭广军,李大鹏,张炳林.焦家金矿床水-岩反应过程及成矿流体组分变化规律[J].高校地质学报,2018,24(6):907. |
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| 作者姓名： | 刘亚洲 王恩敬 王偲瑞 郭广军 李大鹏 张炳林 |
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| 摘 要： | 在野外和室内岩相学观察的基础上，详细剖析了蚀变-矿化时序，结合热力学数值模拟方法与定量结果，厘定了水-
岩反应过程中矿物的沉淀次序、流体组分的存在形式、迁移行为、浓度变化和矿物形成机制以及组分之间的化学反应，为
进一步研究水-岩反应与金矿化的关系奠定了基础。研究结果显示反应初期K+由流体带入围岩形成钾长石化，随着反应的
进行，H+浓度持续降低而Fe2+和Al3+含量升高，绢云母和石英大量沉淀，钾长石消失；反应后期各类硫化物开始沉淀，石英
持续沉淀贯穿整个反应过程。成矿流体中SO42-，HS-，Fe2+的含量对蚀变矿物组合影响很大；水-岩反应过程中硫酸盐
（SO42-） 减少生成等量的HS-并伴随着含三价铁矿物的沉淀，可能是焦家金矿床硫化物沉淀的一种重要机制。整个反应过程
中溶液pH值持续升高是原岩中Ca，K，Na，Mg等与溶液中H+发生交换反应的结果；同时pH值的升高也会降低金的溶解度
致使金沉淀。上述研究成果对于理解岩石中的矿物共生组合、生成顺序及蚀变分带的成因机制提供了新的依据。
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| 关 键 词： | 水-岩反应过程 水-岩作用机理 热力学模拟 蚀变-矿化 焦家金矿床 |
Water-Rock Interaction in Jiaojia Gold Deposits and Variations of the Ore-Forming Fluid |
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| LIU Yazhou,WANG Enjing,WANG Sirui,GUO Guangjun,LI Dapeng,ZHANG Binglin.Water-Rock Interaction in Jiaojia Gold Deposits and Variations of the Ore-Forming Fluid[J].Geological Journal of China Universities,2018,24(6):907. |
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| Authors: | LIU Yazhou WANG Enjing WANG Sirui GUO Guangjun LI Dapeng ZHANG Binglin |
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| Abstract: | On the basis of detailed analysis of the alteration-mineralization time series of the Jiaojia gold deposit, and the correlative
theory of chemical thermodynamics and chemical reaction, a solid phase titration model of water-rock interaction in Jiaojia gold deposit
is established. In addition, we discussed the precipitation order, existence form, migration behavior, and concentration change of
ore-forming fluid components by using numerical simulation of thermodynamics. we further discussed the relationship between
water-rock interaction and gold mineralization. The results show that the potash feldspathization occurred at the initial stage of the
reaction due to the K+ flow into the surrounding rocks from the fluid, the concentration of Fe2+ and Al3+ increased with the continuous
reduction of H+ concentration along with proceeding of the water-rock interaction. Sericite and quartz heavily precipitated with the
disappearance of potassium feldspar, followed by precipitation of the sulfide minerals. The content of SO42-, HS- and Fe2 + in the
ore-forming fluid has a great influence on the alteration mineral assemblage, the reduction of sulphate (SO42-) and the formation of the
same amount of HS-, which was accompanied by the precipitation of ferric minerals during the process of water-rock reaction. This may
be an important mechanism of sulfide precipitation in Jiaojia gold deposits. The continuous increase of pH value during the whole
reaction process is due to the exchange of Ca, K, Na and Mg in the original rock with H+ in the solution. Also, the increased pH value
reduces the solubility of gold, resulting in Au precipitation. These results provide a new basis for understanding the mineral
assemblage, sequence of formation, and the genetic mechanism of altered zonation |
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| Keywords: | process of water-rock interaction mechanism of water-rock interaction thermodynamic simulation alteration-mineralization Jiaojia gold deposit |
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