热液成矿分带的溶解—沉淀波结构

热液成矿分带是一种输运－反应问题，热液成矿分带基本属于渗滤交代分带性质，它是溶解－沉淀波在可渗透介质中形成和传播的结果。本文应用物理化学流体动力学中的渗滤与溶解－沉淀反应耦合过程理论研究的溶解－沉淀波的结构特征，并进一步应用多组分耦合系统动力学中的相干原理揭示其形成的动力学机制，最后提出了一种热流成矿分带理论，对热液成矿分带问题的性质、热液成矿分带的本质和热液成矿分带的结构特征与形成机制提出了新认     

金矿床成因研究的若干问题

金矿在矿流体的来泊是金矿庆成因研究的内容。对传统的成矿流体认识进行了评述,强调了渗滤热液在金成矿中的作用,金沉淀的机制除流体温,压的降低外,流体的混合作用及流体与围岩的反应是更为重要的因素。     

金矿床成因研究的若干问题

金矿成矿流体的来源是金矿床成因研究的重要内容.对传统的成矿流体认识进行了评述,强调了渗滤热液在金成矿中的作用.金沉淀的机制除流体温、压的降低外,流体的混合作用及流体与围岩的反应是更为重要的因素.     

试论铀成矿的热渗滤机制

本文应用热渗滤作用理论,对部分产出在花岗岩体外接触带沉积围岩中的热液铀矿床的形成机制作出合理的解释。在分析热渗滤作用特点及部分岩石热渗滤系数并详细对比了天然岩石中五种存在形成H_2O的物理化学性质的基础上,作者认为参与热渗滤作用的主要是存在于矿物颗粒表面和岩石微裂隙中的结合水(薄膜水和分子结合水)。位于热渗滤带的富铀地层中的H_2O及溶解于其中的铀在热渗滤作用下将朝岩体接触带的增温方向迁移。与传统的概念相反,作者指出。成矿溶液是从矿物粒间和岩石微裂隙朝成矿断裂构造方向运移,尔后在物化条件急剧变化的地段沉淀并逐步富集形成具有工业价值的铀矿床。     

碳酸盐溶解,沉淀控制下的反应—迁移模型研究

以碳酸盐岩中方解石，白云石和石膏的溶解和沉淀化学反应为基础，阐述了反应模型和水流模型，建立了化学动力学方程－水流方向的关系，并且采用解法－数值法混合解法求解济南岩溶区的反应－模型，计算该区的化学反应速率常数和水动力参数。     

碳酸盐溶解、沉淀控制下的反应－迁移模型研究

以碳酸盐岩中方解石、白云石和石膏的溶解和沉淀化学反应为基础，阐述了反应模型和水流模型，建立了化学动力学方程－水流方程的关系，并且采用解析法－数值法混合解法求解济南岩溶区的反应－迁移模型，计算该区的化学反应速率常数和水动力参数     

含矿流体混合反应与成矿作用的动力平衡模拟研究

本文在约定热液体系中成矿元素成矿速率(成矿过程中单位时间内单位体积所合成矿元素重量的变化)的基础上。借助于物质-热-化学-成矿四重全耦合的研究思路，构建了均匀热液体系、层状热液体系、岩浆侵入热液体系下成矿元素的迁移、富集、溶解与沉淀作用数值模型。模拟结果表明；(1)硫化物(H2S)和硫酸盐(SO42-)流体的混合反应是成矿热液体系中铅、锌、铁成矿元素成矿的重要控制因素；(2)均匀介质、岩浆侵入或地质构造的存在，对成矿元素在成矿流体运移的速度、流线、温度分布和成矿元素的溶解与沉淀分布都有着各自的特征．不同的成矿环境或成矿背景制约了成矿元素的迁移与富集以及矿体的产出定位。暗示成矿环境及成矿速率对热液体系中成矿元素的沉淀与溶解具重要作用；成矿流体的混合反应是成矿作用发生的重要机制之一。在成矿理论研究中必须充分考虑不同地质构造因素的约束。     

热液成矿分带的径向对称性

热液成矿分带是普遍存在的规律。在研究银山和铜厂等具体矿床分带规律的基础上,总结出热液成矿分带具有径向对称性,并且用自孤子理论研究了其内在机制,指出热液矿床是活性扩散系统中的自孤子,给出了热液成矿自孤子的定义。用静态径向对称自孤子模型对热液成矿分带的径向对称性进行了描述和分析,得出了一些定性的认识,它们对更深入地研究热液成矿分带的动力学机制和成矿地球化学过程具有一定的意义。     

多重水力断裂的分形扩张

应用复杂性理论对于赣南脉钨矿床的著名“五层楼”式形态垂直分带进行研究 ,获得如下结果。 (1 )赣南脉钨矿床的“五层楼”式形态垂直分带是“多重水力断裂分形扩张”的结果。脉钨矿床的控矿多重断裂是一种以水力断裂为主导的热致与流体驱动断裂构造。脉钨矿床的自组织临界性是多重分形扩张之源 ,而中观破裂尖端周围流体静力学应力场梯度最大区则是分形扩张的驱动力。多重水力断裂的发生和发展是一种分形扩张过程 ,其演化服从串级“崩塌间断平衡”的时空分形生长动力学 ,与地震的Omori余震律相类似。 (2 )脉钨矿床“三环一帽”式的成矿地球化学分带是一种多组分成矿溶液的渗滤、溶解沉淀波结构 ,是成矿反应扩散系统中化学波的时空同步化传播而形成的目标斑图 ,是近平衡地质介质内 ,通过外界的“短暂局部激发”、继之以构造、岩浆和成矿脉动作用等“局部中断”而形成的径向对称、嵌套球状、远离平衡的局域化耗散结构 ,即脉动型自孤子。 (3)赣南脉钨矿床是近平衡区域地质背景中远离平衡的局域化耗散结构。赣南钨矿集区是复合自孤子的群集体。它们是在构造、岩浆多期次脉动条件下 ,来自①矿源层部分熔融的“区域提纯”、②岩浆期后成矿热液输运反应和③含钨地层、岩石淋滤交代的成矿物质 ,通过岩浆和热液孤     

华南加里东期金矿床的基本特征

文章分析了安徽月山矿田夕卡岩型矿床形成过程中水岩作用的类型和特征。估算和讨论了水岩作用过程中的质量－体积变化和动力学问题。结论认为：水岩作用对流体成矿系统中夕卡岩和蚀变矿化作用的发生、发展，成矿流体的形成，成矿物质的富集，矿床定位等具有重要意义；水岩作用的水岩比值（W／R）小于0．1；夕卡岩和矿化蚀变分带是开放体系一系列溶解沉淀波反应前锋发生水岩反应后矿物和元素组合的时空分离的结果。     

Dissolution Precipitation Wave Structure of Hydrothermal Ore Zoning

Ｄｉｓｓｏｌｕｔｉｏｎ　Ｐｒｅｃｉｐｉｔａｔｉｏｎ　Ｗａｖｅ　Ｓｔｒｕｃｔｕｒｅ　ｏｆＨｙｄｒｏｔｈｅｒｍａｌ　Ｏｒｅ　Ｚｏｎｉｎｇ￥ＹｕＣｈｏｎｇｗｅｎ（ＦａｃｕｌｔｙｏｆＥａｒｔｈＳｃｉｅｎｃｅｓ，ＣｈｉｎａＵｎｉｖｅｒｓｉｔｙｏｆＧｅｏｓｃｉｅ...     

地球化学作用下饱和-非饱和介质水力-传质-传热耦合模型

地球化学作用是影响岩土类多孔介质中流体流动、传质、传热的重要因素之一。基于Fredlund所提出的非饱和土四相理论,将地球化学作用所产生的溶解/沉淀视为一个独立相,在一定的假设基础上,利用溶质浓度对介质孔隙度、含水率进行修正,从而建立起传质过程与介质水力性质之间的关系,改进了传统模型中传质过程与流体密度、黏度之间单一的耦合关系;并以此为基础建立了考虑地球化学作用下饱和-非饱和介质中多组分、多相流体渗流场-浓度场-温度场耦合的数学模型。通过在实验室内对反应性煤矸石进行渗透实验的结果对笔者所建模型进行了验证,结果表明：综合考虑溶解作用时所测点处渗流速度与未考虑耦合作用的结果相比增大0.58倍;单独考虑溶解/沉淀相时,所测点处渗流速度与未考虑密度耦合作用时的结果相比增大0.44倍。水流的实际渗透速度与在使用考虑溶解/沉淀相计算模型时的结果吻合较好。     

流体的沸腾和混合在热液成矿中的意义

讨论了流体沸腾和混合在热液成矿中的重要作用及研究进展。成矿汉体的降温可能不是许多金属矿物沉淀的最有效机制；流体的沸腾作用对浅成热液帮床，斑岩铜钼等矿床中矿物的沉淀作用很大，造成的矿化具有强度大，品位富及垂向分带较发育的特征，同时因其影响范围小，作用时间短，限制了它的作用的发挥。     

Incipient Stage of Ore Formation Process of the Kamioka Zn-Pb Ore Deposit in the Hida Metamorphic Belt, Central Japan: Leaching and Precipitation of Clinopyroxene

Abstract: Boundaries between the cpx Zn-Pb ores of the Kamioka ore deposit and host clinopyroxene granitoid in the Hida metamorphic belt were examined to decipher the incipient stage of ore formation process. The boundaries are characterized by the compositional zoning of relic clinopyroxene with outward increase of XMg from 0. 5 to 0. 75 in the host rocks, and by the incline of XMg towards the ores, passing through the boundaries, reaching up to 0. 95. In the ores, relic clinopyroxene is rimmed by hedenbergite. Both clinopyroxenes show compositional zoning with outward decrease and increase of XMg and MnO, down to 0. 02 and to 3. 2 wt%, respectively. The presence of high magnesian clinopyroxene can be explained if hydrothermal fluid flow had leached hedenbergite component of relic clinopyroxene. The incline of XMg of clinopyroxene toward the ores was attributed to the degree of dissolution of clinopyroxene, and thus the total amounts of fluid to have passed. The outward decrease of XMg of clinopyroxenes in the ores was due to crystal-fluid fractionation during precipitation. These mineralogical changes at the boundaries indicate the time-integrated phenomena of hydrothermal ore forming process. Firstly, leaching of ore components by infiltrating fluid proceeded in host rocks, and enhanced the formation of a fluid channel. The condition of fluid changes through the fluid channel in P-T space, and hence ore forming minerals precipitate at a remote place from the leaching one. This in turn caused the physicochemical change of fluid condition anyhow, and accelerated the precipitation of the minerals. This leaching-precipitation sequence appears a basic process of hydrothermal ore-forming system, and characterizes the incipient stage of ore formation process of the Kamioka Zn-Pb ore deposit. Compositional zoning of clinopyroxenes defines Z-shaped compositional trend in the Di–Hd–Jo diagram, each arm of which corresponds to the leaching and the precipitation stages, and the secondary dissolution of precipitated clinopyroxene.     

Numerical Modelling of Geochemical Behaviour of Fluoride in the Shallow Groundwater Systems

The Xingtai piedmont plain in Hebei Province is a representative area in northern China where endemic fluorosis is serious and shallow high-F ground water is distributed. In this paper, the area is selected as a typical study area, and on the basis of large amounts of field work and the experiments, through groundwater geochemical modelling and by applying the theory and method of the coupled model of hydrodynamic transport and chemical reactions in a multicomponent system, the author performed numerical modelling of the geochemical behaviour of fluoride in a shallow groundwater system, quantitatively studied the hydrodynamic transport and chemical reaction of fluorine migration, transformation and concentration in a water-heterogeneous unsaturated soil system under the conditions of meteoric water infiltration and quantitatively determined the speciation of fluorine and the saturation state and dissolution/precipitation trend of various solid precipitates in shallow high-F groundwater, thus deepening t     

热质输运-反应体系的石英溶解与沉淀的模拟研究

介质中热质输运-反应体系对于热质成矿、污物迁移等十分重要。这里利用热质流体输运动力学模型与石英溶解与沉淀的化学动力学模型,以及多孔介质的本构关系,建立了一个热质输运、反应动力学藕合模型。并使用此模型研究了局部的温度变化和颗粒半径不均一分布对研究区域内温度场和浓度场的变化情况,其结论是它们之间的耦合可能打破系统的平衡,驱使系统长时间持续进行流体输运-反应动力学过程。     

The influence of coupled physical swelling and chemical reactions on deformable geomaterials

Coupled thermo‐hydro‐mechanical‐chemical modelling has attracted attention in past decades due to many contemporary geotechnical engineering applications (e.g., waste disposal, carbon capture and storage). However, molecular‐scale interactions within geomaterials (e.g., swelling and dissolution/precipitation) have a significant influence on the mechanical behaviour, yet are rarely incorporated into existing Thermal‐Hydro‐Mechanical‐Chemical (THMC) frameworks. This paper presents a new coupled hydro‐mechanical‐chemical constitutive model to bridge molecular‐scale interactions with macro‐physical deformation by combining the swelling and dissolution/precipitation through an extension of the new mixture‐coupling theory. Entropy analysis of the geomaterial system provides dissipation energy, and Helmholtz free energy gives the relationship between solids and fluids. Numerical simulation is used to compare with the selected recognized models, which demonstrates that the swelling and dissolution/precipitation processes may have a significant influence on the mechanical deformation of the geomaterials.     

Deformation-induced garnet zoning

Compositional zoning patterns in garnet porphyroblasts from kyanite-bearing samples of the Devonian Littleton Formation, north-central Massachusetts, reveal complex patterns of growth that are related to multiple deformation and metamorphic events. Garnet porphyroblasts exhibit asymmetrical and irregular zoning patterns in X_Mn, X_Ca and Fe/(Fe + Mg). Zoning reversals in Mn and Fe/(Fe + Mg) and patch distribution in Ca appear to occur around the boundaries of the textural zones. Also, the compositions of the garnet at the textural boundaries are variable for all traverses. These observations suggest that the garnet zoning was not only modified from diffusion processes, but was also influenced by pre-existing microfabrics through the effects of preferential dissolution and resorption in partial disequilibrium. Relationships between chemical and textural truncations indicate that the zoning patterns of garnet were strongly modified from preferential dissolution and precipitation during the development of successive foliations that occurred in zones of high strain/stress (cleavage seams) and zones of low strain/stress, respectively.