流体包裹体研究对成矿流体动力学模式的制约（英文）

热液矿床的形成既包括地球化学过程也包括流体动力学过程,后者主要研究成矿流体的驱动力、流动方向、速度及持续时间。流体及金属的来源,金属在热液中的溶解度及溶解机制,以及矿石的沉淀机制等可以通过多种地球化学手段来研究,而流体动力学过程的确定相对比较困难。流体包裹体分析不仅可以为成矿地球化学过程,而且可为流体动力学过程提供制约,因为流体包裹体研究所得到的流体P-V-T-X性质与流体流动、热传导及质量迁移等控制方程直接相关。本文阐述流体包裹体与流体动力学研究的理论关系,流体包裹体研究对已有成矿流体动力学模式的贡献,以及未来的研究方向。从流体包裹体研究得出的流体压力状态为岩浆热液及造山型成矿系统的超压驱动模式提供了关键的证据。流体包裹体均一温度及其分布为沉积盆地成矿流体动力学模式提供了重要的制约。流体包裹体研究在揭示流体混合及流体相分离等重要成矿过程方面提到了至关重要的作用,但它们在研究流体混合及多相流体流动的物理过程方面的潜力有待进一步开发。精心设计的流体包裹体研究有可能应用于古流体流动数值模型的调试。     

流体包裹体在矿床研究中的作用

流体包裹体分析是现代矿床学研究的一个重要手段,对矿床类型的划分及成矿流体成分、温度、压力的研究有着重要的作用.在矿质沉淀的主要机制中,流体相分离及流体混合的主要证据来自流体包裹体;对金属在气相中的搬运的认识,也主要来自包裹体研究.成矿流体成分对认识金属在热液中的搬运方式起着重要作用,流体温度和压力数据是成矿流体动力学模式的重要制约.     

成矿流体中金的沉淀机理研究述评

成矿流体中金的沉淀机理是金地球化学的一个重要研究领域。建立在现代实验地球化学和络合物化学等理论基础上，热液成矿流体中金的迁移形式研究已经取得很大进展。结合矿床地球化学、流体包裹体地球化学等的研究，对金的沉淀机理已提出了许多假说，如沸腾作用、不同流体的混合作用、流体不混溶作用、热液蚀变等等。一方面，受成矿地质环境的制约，不同矿床类型和不同成矿环境，金的沉淀机理可能不同；另一方面，不同沉淀机理还有各自不完善之处，需要更深入地研究。而成矿实验地球化学、计算机模拟等可以发挥重要作用。     

陕南勉宁略地区铜厂铜矿包裹体地球化学特征研究

本文研究陕南勉宁略地区铜厂铜矿三个成矿阶段的包裹体地球化学特征，包括包裹体均－温度，压力，成分，盐度，流体的Ｈ、Ｏ和Ｃ同位素等及含矿热液的物理化学参计算，探讨了成矿过程中各成矿阶段流体的性质及其来源。     

云南墨江金矿床的同位素地球化学及成因探讨

墨江金矿的同位素地球化学特征,成矿元素组合和包裹体成分表明：成矿物质主要来源于金厂蚀变超基性岩体,成矿热液是深源流体,岩浆水和大气降水混合的产物。成矿期深部富矿化剂流体沿断裂上升并与地下水混合,从侵入体及围岩中淋滤出了成矿物质。在迁移过程中,随着地球化学条件的改变,金在有利部位沉淀富集形成矿床。墨江金矿床属混合热液改造型矿床。     

矿床地球化学应用

稳定同位素方法已成为现代地球科学研究的重要手段之一，稳定同位素体系的理论模式及其地球化学应用是国际上地球化学研究的前沿方向之一。本文概括了热液体系内成矿地球化学过程引起稳定同位素组成变化的定量理论模式，包括热液矿物之间的同位素平衡的判断、热液去气和矿物沉淀的储库效应、二元混合与矿床成因等。这些模型对于确定成矿温度、鉴定成矿流体源区和推测成矿地球化学机理提供了更为合理的同位素数据定量解释基础。     

太行山金矿成矿流体温压地球化学研究

该文研究了太行山硫化物-石英脉型金矿的含矿石英中流体包裹体的温压地球化学特征,结果表明,太行山金矿成矿流体从高温向低温演化,流体从早期的岩浆热液向晚期的混合热液方向变化。流体从岩浆中分离后迅速发生的由减压作用造成的流体不混溶作用是金矿成矿的重要控制因素。     

河南西峡石板沟金矿成矿流体地球化学及矿床成因讨论

石板沟金矿是近年在豫西南发现的一个剪切带容矿的脉状金矿。根据流体包裹体地球化学研究,分析了矿床成矿流体地球化学特征,讨论了金的沉淀机制和矿床成因。构造蚀变岩型金矿的形成主要与热液蚀变作用有关,石英脉型金矿的形成,则可能主要与岩浆热液与变质热液的混合作用有关。矿质主要源自晋宁期岩浆岩,成矿流体和热能主要来自海西期花岗岩。矿床为剪切带容矿的中低温热液金矿床。     

墨江金矿成矿流体的形成演化机制

笔者利用矿物流体包裹体、稳定同位素、微量元素和稀土元素地球化学等手段，研究了墨江金矿成矿流体的地球化学特征，成矿物质来源和形成演化机制。研究结果表明，墨江金矿为中低温热液金矿床，成矿流体属于中性－弱碱性的钠质溶液，其中的水为大气降和岩浆水混合成因，矿化剂主要来源于深部，金主要来源于海西期超基性岩和志留系金厂组浅变质岩。     

江西德兴铜厂斑岩铜矿成矿物质来源的再认识——来自流体包裹体的证据

本文从江西德兴斑岩铜矿铜厂矿床的流体包裹体研究出发,讨论了矿床成矿物质来源与矿床成因。矿床中流体包裹体分为6类,即富液包裹体、富气包裹体、含石盐多相包裹体、含CO2多相包裹体以及熔体包裹体和熔体-流体包裹体。富气包裹体、含石盐多相包裹体和熔体与熔体-流体包裹体代表了成矿早期岩浆热液的特征。在这些包裹体中发现黄铜矿等金属矿物,表明成矿金属主要源自岩浆。含石盐多相包裹体和富气包裹体与矿体关系不甚密切,但其中所含有的金属矿物特别是黄铜矿,暗示早期来自岩浆的热液流体金属含量较高,形成于大气降水与岩浆热液混合之前。成矿中晚期大气降水流体在冷却和稀释岩浆流体方面对于矿床的形成作出了一定贡献,但是来自围岩的大气降水可能并没有向成矿体系提供大量金属。     

http://www.sciencedirect.com/science/article/pii/S1674987111000387

Fluid flow is an integral part of hydrothermal mineralization,and its analysis and characterization constitute an important part of a mineralization model.The hydrodynamic study of mineralization deals with analyzing the driving forces,fluid pressure regimes,fluid flow rate and direction,and their relationships with localization of mineralization.This paper reviews the principles and methods of hydrodynamic studies of mineralization,and discusses their significance and limitations for ore deposit studies and mineral exploration. The driving forces of fluid flow may be related to fluid overpressure,topographic relief,tectonic deformation, and fluid density change due to heating or salinity variation,depending on specific geologic environments and mineralization processes.The study methods may be classified into three types,megascopic(field) observations, microscopic analyses,and numerical modeling.Megascopic features indicative of significantly overpressured (especially lithostatic or supralithostatic) fluid systems include horizontal veins,sand injection dikes,and hydraulic breccias.Microscopic studies,especially microthermometry of fluid inclusions and combined stress analysis and microthermometry of fluid inclusion planes(FIPs) can provide important information about fluid temperature,pressure,and fluid-structural relationships,thus constraining fluid flow models.Numerical modeling can be carried out to solve partial differential equations governing fluid flow, heat transfer,rock deformation and chemical reactions,in order to simulate the distribution of fluid pressure, temperature,fluid flow rate and direction,and mineral precipitation or dissolution in 2D or 3D space and through time.The results of hydrodynamic studies of mineralization can enhance our understanding of the formation processes of hydrothermal deposits,and can be used directly or indirectly in mineral exploration.     

成矿流体动力学的原理、研究方法及应用

流体流动是热液成矿作用不可或缺的一部分,其研究是建立成矿模式的重要组成部分。成矿流体动力学主要研究流体流动的驱动力、压力状态、流速、流动方向以及它们与矿床定位的关系。文中总结了成矿流体动力学的基本原理和方法,并对其在成矿作用研究和矿产勘查上的重要性和局限性进行了讨论。流体流动的驱动力可以是流体的超压、地势差、构造变形以...     

流体包裹体与金矿床的成矿及勘探评价

金矿床矿石和脉石矿物中的流体包裹体是封存在这些矿物中的热液样品,它可以提供含金成矿流体的温度、盐度、压力、密度、成分以及热液来源和成矿时代等信息.本文对中深脉状、浅成低温热液型、卡林型、斑岩型和矽卡岩型金矿床中的流体包裹体特征作了探讨,提出流体包裹体岩相学、均一温度、爆裂温度及气相成分等是金矿床勘探评价直观而有效的方法.     

The relative effects of deformation and thermal advection on fluid pathways in basin-related mineralization

The migration of basinal brines into basement material has been proposed as a means of scouring or leaching metals for subsequent ore deposition. Here we address this issue by numerically examining competing processes, namely deformation, fluid flow and thermal gradients, to describe potential fluid pathways leading to enrichment of metals and ore deposition. Stable convective fluid patterns may be established across the cover/basement interfaces if permeability contrasts are minimized, however, at the onset of extensional deformation these convective patterns quickly collapse. On cessation of the deformation, convection cells again develop, which are oscillatory with time. Input to the thermal budget from a radiogenic heat source suggests that basinal fluids can be drawn down around the margins of granite intrusions and fluid mixing processes may take place due to small and localised convective patterns. Fluid migration from basin into basement and back is highly likely given the right conditions, however, the rate and extent of fluid flow are determined by thermal and deformation processes.     

初论稀有金属矿床研究的一些重要进展

稀有金属矿是重要的战略性储备资源,其成矿机制和成矿作用研究也一直受到了国际上的广泛关注。本文从矿床类型特征、岩浆岩、碳酸岩体与稀有金属矿化的关系、矿床成矿流体与成矿机制和成矿年代学等4个方面,对近年来的研究进展进行了简要的论述。稀有金属矿床以花岗岩型和花岗伟晶岩型为主,与稀有金属矿化有关的岩体的地球化学组成可以有效指示稀有金属矿化趋势,锆石常具有特殊的化学组成特征(高Th/U比值(1~10)、Y/Ho20、Sm/Nd0.5、Nb/Y0.08和Hf2wt%)。流体不混溶作用在稀有金属矿床,尤其是伟晶岩型矿床的成矿流体中常见,成矿多经历了从岩浆-热液多个阶段,流体成分较复杂,除B、F等外,最近还发现了较少见的碳酸盐矿物,其成矿机制值得深入研究。     

流体不混溶性和流体包裹体

大多数流体包裹体是捕获于均匀体系,但有一部分包裹体捕获自非均匀体系(不混溶体系)。在自然界存在着许多不混溶的过程,这包括基性岩浆和酸性岩浆之间,岩浆与热液,岩浆与CO₂,盐水溶液与CO₂等。液体的不混溶性对于成矿作用十分重要,这方面有3个典型的例子,第一个是金矿的成矿作用与NaCl-H₂O-CO₂体系流体的不混溶有着重大的关系;第二个例子是斑岩铜矿;第三个例子是伟晶岩,发现在伟晶岩演化和成矿作用中存在着岩浆和热液的不混溶作用。实际上不混溶的大部分证据是从流体包裹体的研究中获得的。现在的问题是如何来确定哪些包裹体是从不混溶过程中捕获的。这种捕获于不混溶过程中的流体包裹体怎么来确定他的T_h和成分。这种捕获于不混溶过程中的流体包裹体怎么与"卡脖子"拉伸作用"中捕获的包裹体和捕获自均匀体系的流体包裹体相区分。     

Nature and source of the ore-forming fluids associated with orogenic gold deposits in the Dharwar Craton

Neoarchean orogenic gold deposits, associated with the greenstone-granite milieus in the Dharwar Craton include(1) the famous Kolar mine and the world class Hutti deposit;(2) small mines at HiraBuddini, Uti, Ajjanahalli, and Guddadarangavanahalli;(3) prospects at Jonnagiri; and(4) old mining camps in the Gadag and Ramagiri-Penakacherla belts. The existing diametric views on the source of ore fluid for formation of these deposits include fluids exsolved from granitic melts and extracted by metamorphic devolatilization of the greenstone sequences. Lode gold mineralization occurs in structurally controlled higher order splays in variety of host rocks such as mafic/felsic greenstones, banded iron formations, volcaniclastic rocks and granitoids. Estimated metamorphic conditions of the greenstones vary from lower greenschist facies to mid-amphibolite facies and mineralizations in all the camps are associated with distinct hydrothermal alterations. Fluid inclusion microthermometric and Raman spectroscopic studies document low salinity aqueous-gaseous(H_2O + CO_2 ± CH_4 + NaCl) ore fluids,which precipitated gold and altered the host rocks in a narrow P-T window of 0.7-2.5 kbar and 215-320℃. While the calculated fluid O-and C-isotopic values are ambiguous, S-isotopic compositions of pyrite-precipitating fluid show distinct craton-scale uniformity in terms of its reduced nature and a suggested crustal sulfur source.Available ages on greenstone metamorphism, granitoid plutonism and mineralization in the Hutti Belt are tantamount, making a geochronology-based resolution of the existing debate on the metamorphic vs.magmatic fluid source impossible. In contrast, tourmaline geochemistry suggests involvement of single fluid in formation of gold mineralization, primarily derived by metamorphic devolatilization of mafic greenstones and interlayered sedimentary rocks, with minor magmatic contributions. Similarly, compositions of scheelite, pyrite and arsenopyrite point toward operation of fault-valves that caused pressure fluctuation-induced fluid phase separation, which acted as the dominant process of gold precipitation,apart from fluid-rock sulfidation reactions. Therefore, results from geochemistry of hydrothermal minerals and those from fluid inclusion microthermometry corroborate in constraining source of ore fluid,nature of gold transport(by Au-bisulfide complex) and mechanism of gold ore formation in the Dharwar Craton.     

Geological,geochemical, stable isotope,and fluid inclusion characteristics of epithermal gold mineralization,Velvet District,Nevada

Gold mineralization in the Velvet District occurs in an eastward dipping sequence of late Tertiary rhyolitic ash-flow tuffs, flows, and tuffaceous sediments in northwestern Nevada. Minor gold and silver concentrations are associated with irregular zones of brecciation, argillic alteration, and quartz veining along north-northeast trending normal faults. Reaction of mineralizing fluids with wallrock produced an argillic alteration assemblage of illite, mixed-layer clays, smectite, and kaolinite. Illite alteration and highest gold concentrations appear to be associated with zones of high water/rock ratios. Kaolinite, smectite, alunite, and opal are postulated to have formed during a steam-dominated episode of alteration.Fluid inclusion studies indicate that the quartz veins were deposited in the temperature range 230 to 280°C from fluids which had salinities equivalent to 0.2–0.8 weight percent NaCl. δ ¹⁸O of quartz veins varies from ?2.5 to $\text{+6.7 ‰}$ and indicates that the ore fluid must have been Tertiary meteroric water. Stable isotope data appear to define a zone of concentrated fluid flow and potential subsurface mineralization in the southeastern part of the district. Fluid inclusion and isotope studies can be used in combination with more standard geochemical, geophysical, and geological information to provide site-specific targets for epithermal metal concentrations.