贵州太平洞金矿床流体包裹体特征及流体不混溶机制

太平洞金矿床是兴仁-安龙金矿带灰家堡金矿区的重要卡林型金矿之一。流体包裹体研究证明,石英-黄铁矿阶段(Ⅰ)、石英-黄铁矿-毒砂阶段(Ⅱ)、石英-方解石-雄黄阶段(Ⅲ)的包裹体类型丰富,以气液水两相包裹体、CO₂-H₂O包裹体和纯液相水包裹体为主,CO₂两相包裹体、纯气相有机质包裹体和有机质-H₂O包裹体次之,偶见气液有机质包裹体。由Ⅰ→Ⅱ→Ⅲ阶段,气液水包裹体均一温度(200～260℃→180～240℃→100～160℃)呈现逐渐降低的趋势。在Ⅰ阶段的石英中,只在局部偶见到CO₂-H₂O包裹体和气液两相水包裹体共生;在Ⅱ阶段的石英中,纯液相水包裹体、气液两相盐水包裹体、CO₂-H₂O包裹体、CO₂包裹体及纯气相有机质包裹体共存,它们共生在同一平面中且气液两相盐水包裹体和CO₂-H₂O包裹体测温数据相差不大,说明当时捕获的是不均匀成矿流体,它是由含有机质的成矿流体经历了CO₂-低盐度水的不混溶作用形成的。因而认为,太平洞金矿床中成矿早期流体不混溶作用不明显,主成矿阶段流体的不混溶作用是导致金矿质沉淀的重要原因。     

Reconciling fluid inclusion types,fluid processes,and fluid sources in skarns: an example from the Bismark Deposit,Mexico

The Bismark deposit (8.5 Mt at 8% Zn, 0.5% Pb, 0.2% Cu, and 50 g/t Ag) located in northern Mexico is an example of a stock-contact skarn end member of a continuum of deposit types collectively called high-temperature, carbonate-replacement deposits. The deposit is hosted by massive sulfide within altered limestone adjacent to the Bismark quartz monzonite stock (~42 Ma) and the Bismark fault. Alteration concurrently developed in both the intrusion and limestone. The former contains early potassic alteration comprising K-feldspar and biotite, which was overprinted by kaolinite-rich veins and alteration and later quartz, sericite, and pyrite with minor sphalerite and chalcopyrite. Prograde exoskarn alteration in the limestone consists of green andradite and diopside, and transitional skarn comprising red-brown andradite, green hedenbergite and minor vesuvinite, calcite, fluorite, and quartz. The main ore stage post-dates calc-silicate minerals and comprises sphalerite and galena with gangue pyrite, pyrrhotite, calcite, fluorite, and quartz. The entire hydrothermal system developed synchronously with faulting. Fluid inclusion studies reveal several distinct temporal, compositional, and thermal populations in pre-, syn- and post-ore quartz, fluorite, and calcite. The earliest primary fluid inclusions are coexisting vapor-rich (type 2A) and halite-bearing (type 3A; type 3B contain sylvite) brine inclusions (32 to >60 total wt% salts) that occur in pre-ore fluorite. Trapping temperatures are estimated to have been in excess of 400 °C under lithostatic pressures of ~450 bar (~1.5 km depth). Primary fluid inclusions trapped in syn-ore quartz display critical to near critical behavior (type 1C), have moderate salinity (8.4 to 10.9 wt% NaCl equiv.) and homogenization temperatures (Th) ranging from 351 to 438 °C. Liquid-rich type 1A and 1B (calcite-bearing) inclusions occur as primary to secondary inclusions predominantly in fluorite and show a range in Th (104–336 °C) and salinity (2.7–11.8 wt% NaCl equiv.), which at the higher Th and salinity ranges overlap with type 1C inclusions. Oxygen isotope analysis was carried out on garnet, quartz, and calcite (plus carbon isotopes) in pre-, syn-, post-ore, and peripheral veins. Pre-ore skarn related garnets have a δ¹⁸O_mineral range between 3.9 and 8.4‰. Quartz from the main ore stage range between 13.6 and 16.0‰. Calcite from the main ore stage has δ¹³C values of –2.9 to –5.1‰ and δ¹⁸O values of 12.3 to 14.1‰, which are clearly distinct from post-ore veins and peripheral prospects that have much higher δ¹⁸O (16.6–27.3‰) and δ¹³C (1.3–3.1‰) values. Despite the numerous fluid inclusion types, only two fluid sources can be inferred, namely a magmatic fluid and an external fluid that equilibrated with limestone. Furthermore, isotopic data does not indicate any significant mixing between the two fluids, although fluid inclusion data may be interpreted otherwise. Thus, the various fluid types were likely to have formed from varying pressure–temperature conditions through faulting during exsolution of magmatic fluids. Late-stage hydrothermal fluid activity was dominated by the non-magmatic fluids and was post-ore.     

The composition and role of the fluid in migmatites: a fluid inclusion study of the Front Range rocks

Monophase negative-crystal shaped CO₂ inclusions occurring isolated, in small clusters, or in well-healed intragranular fractures are common in the leucosome quartz of the 1700m.y.-old migmatites from the east-central Colorado Front Range. They are, however, quite rare in the mafic selvage and paleosome (host rock) quartz. The mode of occurrence suggests that these are the earliest inclusions to form. In addition to the difference in abundance of the inclusions, there is a difference in CO₂-density distribution between migmatitic zones. The temperatures of homogenization for the leucosome inclusions range and +l°C from –67° C to +20° C with two maxima (at –21° C) while those for the paleosome and selvage inclusions are –37° C to +20° C with a single maximum at + 5° C. These differences between the migmatitic zones which occur on the scale of a few centimeters suggest that the formation of these inclusions was related to the migmatization process. The densities corresponding to the Th maxima are appropriate for the P-T conditions for migmatization estimated from the mineral geobarometer/geothermometer. These inclusions must contain nearly pure CO₂, as their final melting temperatures (–56.5° to –57.2° C) are very close to that of the triple point of CO₂. Their composition also was confirmed by Raman spectroscopic analyses.It has been proposed by other workers that CO₂ fluid in the inclusions could form from an H₂O-CO₂ fluid when H₂O is partitioned into the silicate melt. Such partitioning should result in some early H₂O-rich inclusions: H₂O must be released as the melt crystallizes. As found in migmatites from other areas, most aqueous inclusions in the Front Range rocks are obviously much younger than the early CO₂ ones. However, early H₂O-rich fluid may still be preserved, at least in three ways: (A) in rare, isolated or clustered inclusions within quartz inclusions in feldspar; (B) as inclusions in microcline porphyroblasts; (C) in hydrous alteration products of feldspar. (A) contain dilute fluids, 1 to 6 wt% NaCl equivalent. The densities of (A) as well as those of the early CO₂ inclusions found in the quartz inclusions in feldspar are appropriate for the range of P — T conditions estimated for migmatization. These early inclusions must have been preserved because of protected environment. Inclusions (B), found to contain H₂O (and possibly CO₂) by infrared analyses, must be early because they are absent from recrystallized grains. (B) and (C) are much more common in the leucosome than in the other zones suggesting that they are related to migmatization process. The concentration of early CO₂ inclusions in the leucosome is consistent with the model of migmatization in which fluid concentration in the leucosome was a cause of melting.     

Effects of fluid production on fluid flow during regional and contact metamorphism

Numerical and analytical models of fluid flow that account for fluid production during prograde regional and contact metamorphism show that expulsion of metamorphic fluids dominates the convective flux when crustal permeabilities are less than 0.1–100 μD, depending primarily on the rate of fluid production. When this is the case, fluid circulation is limited or prevented, fluid pressures are elevated above hydrostatic values, and flow throughout most of the model is up and away from the region of maximum fluid production. Fluid circulation is predicted to occur where permeability is high, in dry rocks, or after rates of fluid production decrease as peak temperatures are reached. Large changes in the pattern of flow and influx of externally derived fluids may thus occur in metamorphic terranes when dehydration wanes or ceases and cooling begins. Inclusion of an impermeable horizon in the models further inhibits fluid circulation. Earlier, shallow hydrothermal models and interpretations based on the Rayleigh number may be inappropriate for characterizing fluid flow during prograde metamorphism at depth because they do not account for fluid production.     

火成岩中的超临界流体晶及其研究意义

流行火成岩理论中,岩浆被默认为自然熔体,因而火成岩中的矿物晶体都形成于熔体的结晶作用,可称为熔体晶。许多证据表明,火成岩中也可以含有从超临界流体析出的晶体,被称为超临界流体晶(文中简称为流体晶)。根据三个典型实例分析,流体晶既可以从超临界流体直接析出,类似于从热液析出晶体的过程;也可以由超临界流体浓缩产生的熔体结晶形成。不管是哪一种晶出方式,流体晶产生的前提都是岩浆达到流体过饱和态;而满足这一前提的基本条件则是透岩浆流体过程和岩浆快速上升。结合前人关于熔体流体平衡条件的研究进展,以及熔体黏度对挥发分含量和岩浆上升速度对熔体黏度的依赖,发现透岩浆流体过程与岩浆上升过程之间具有耦合关系,这种关系可以用来阐明岩浆系统行为非线性变化的原因。流体晶的研究具有重要意义,可用于：(1)提供一种研究岩浆系统流体条件的新途径;(2)揭示岩浆系统偏离理想态的程度;(3)为反演岩浆系统动力学过程提供新的约束;(4)为识别致矿侵入体和评估侵入体的找矿潜力提供新的矿物学标志;(5)理解火成岩理论中一些长期得不到解决的问题,如岩浆中挥发分溶解度问题、冻结岩浆的活化问题、岩浆成矿专属性问题。     

流体包裹体组合对测温数据有效性的制约及数据表达方法

本文探讨流体包裹体组合（FIA）的原理及其对包裹体测温数据有效性的制约以及数据的表达方法。流体包裹体组合指的是一组同时被捕获的流体包裹体,其同时性的依据是岩相学关系而不是测温数据的相似性。如果根据岩相学关系建立了一个FIA,且这个FIA内的包裹体测温数据很一致,那么这些包裹体可能属于均一捕获且在捕获后未受破坏,这些包裹体的测温数据是有效的。在进行数据汇总或统计时,应取整个FIA内所有包裹体的平均值为代表,而不应将每个包裹体的数据都列入。如果同一FIA内包裹体的测温数据变化很大,那么这些包裹体可能属于非均一捕获或在捕获后遭受了显著改变（如卡脖子、拉伸）。这种情况下包裹体的测温数据是无效的,不应纳入数据汇总或统计。在很多情况下,一组包裹体是否属于同时捕获是很难确定的,因此不能严格地用FIA的方法来判定数据的有效性。但是,FIA的原理还是可以提供一些制约的。例如,如果相邻包裹体显示相似的测温数据,那么这些包裹体可能属于均一捕获且无显著捕获后变化。各个包裹体的数据都应纳入数据汇总及统计,但要注意不要将数据点过分集中在某个小区域。反之,如果相邻包裹体的测温数据相差很大,就要怀疑是不是非均一捕获、捕获后破坏,或不同期次包裹体叠加。详细的包裹体测温“填图”,结合与已知FIA数据的比较,可能可以解决这种多解性问题。     

Characteristics and Applications of Fluid Inclusions in the Eogene System of the Biyang Depression—I.A Fluid Inclusion Study

Presented in this paper are the rypes,salinities,homogenization temperatures and organic components of fluid inclusions formed at the four stages of diagenetic authigenesis in the Eogene of the Biyang Depression.The results of cooling experiments on fluid inclusions were used to determine the fluid system and composition of saline aqueous solution in each of the stages .The homogenization temperatures of saline aqueous solution inclusions and hydrocarbon organic inclu-sions have been corrected by two approaches ,and the trapping temperatures and pressures of fluid inclusions at each of the stages have been obtained.This strdy has shed light on the physicochemistry and evolution of diagenetic fluids.The diagentic fluid system is a system which was transformed from a chloride-bearing to a carbonate-bearing system along with the diagenic evolu-tion.The decrease of diagenetic temperature at Stage III of diagenetic authigenesis suggests that the depression would have experiences uplifting at that time.The fluorescent characteristics of fluid inclusions indicate the varieties of organic components in fluid inclusions both in time and in space.     

Late-Variscan fluid migration at the Variscan thrust front of Eastern Belgium: numerical modelling of the palaeothermal and fluid flow field

Modelling of the palaeothermal field at the Variscan thrust front in eastern Belgium indicates significant temperature modifications by late-Variscan palaeofluids migrating from internal to peripheral parts of the orogen. A detailed set of calibration data (chlorite geothermometry, microthermometry, organic rank) gives evidence of temporary palaeotemperature variations at the Variscan thrust front obviously connected to the migration of hot, low saline palaeofluids. These thermal events likely enhanced organic maturation (vitrinite reflectance, conodont alteration) of Devonian and Carboniferous sediments, which accumulated long before the Variscan orogeny occurred. Numerical simulation (2D Finite Element method) of the palaeothermal field includes coupled heat transport by thermal conduction and fluid flow. Palaeothermal scenarios yield successive palaeotemperatures (200–300°C), which are indicated by the control data, due to relatively short-term fluid ascent along the detachment and the imbricate thrust front. The simulated flow velocities are up to tens of metre per year lasting several thousand years (non-steady-state solution). In the scenarios modelled, these thermal events occur in a realm of enhanced bulk temperatures due to elevated basal heat flow densities (90 mW m⁻²) and an additional burial depth of some kilometres. The simulated temperature enhancement due to fluids ascending at the Variscan thrust front is several tens degrees. The scenarios demonstrate long-distance fluid migration during or after deformation of the Palaeozoic basin and its effect on the palaeothermal field.     

含油气盆地中热流体活动的流体包裹体依据

为寻找含油气盆地中热流体活动的证据,根据国内外含油气盆地中与热流体有关的包裹体的对比研究,阐述了流体包裹体宿主矿物产状、形貌特点及均一温度实测值高异常等特征。研究表明,脉体矿物多数是与热流体活动有关的包裹体的宿主矿物,有些碎屑矿物成岩愈合微裂隙中的包裹体也与热流体活动有关。沸腾包襄体反映了油气成藏与热流体的脉动式活动密切相关。流体包裹体的均一温度高异常是由热流体活动所导致的。因此,流体包裹体研究对识别古热流活动具有重要的指示意义。     

淘金冲金矿成矿流体地球化学和矿床成因研究

包裹体地球化学和氢氧同位素研究结果表明，淘金冲金矿床成矿溶液为中低温，中压，弱碱性和还原性的Ｃａ－Ｍｇ－Ｃ－Ｓ体系，成矿液早期以变质水为主，中晚期则以建造水为主（大气降水来源），明显具混合成因特点，其矿成因类型属受地下水改造成因的层控金矿或特征的“江南型”金矿。     

强成膜性护壁冲洗液体系的研究与应用

强成膜性护壁冲洗液体系是地质调查项目"重点成矿带钻探冲洗液关键技术研究与示范"项目的研究成果之一,是以强成膜性护壁剂GCMJ-2为主要处理剂而配制的一种护壁冲洗液体系。该冲洗液体系主要针对松散破碎地层及强水敏性地层的钻探施工中遇到的难题,具有强成膜性、抑制性和胶结性。通过在宁夏银川盆地第四系环境科学钻探、新疆黄土钻探以及四川若尔盖湖泊科学钻探中应用,该体系显示出较强的护壁和护心效果:孔壁稳定、取心质量好,有效地保证了项目的顺利实施。     

涠西南地区岩石特性及钻井液技术研究

北部湾盆地涠西南油田群是南海西部重要的原油产区，同时油田群紧邻众多国家级自然保护区，属于环境敏感区域。针对北部湾盆地涠西南地区环保要求，以及涠洲组和流沙港组钻井过程经常出现井壁失稳导致的憋卡、起下钻阻卡等问题，开展了涠西南地区地层泥页岩特性及环保钻井液技术研究。通过地层岩石黏土矿物分析、孔喉结构分析以及理化性能评价，明确了涠西南地区泥页岩井壁失稳的机理；提出以类油基的水溶性复合基基液为核心，构建了一套具有油基钻井液工程特性和水基钻井液环保特性的新型环保防塌钻井液技术，并进行了相关的现场应用。现场应用显示：应用井与邻井相比，12-1/4″井段阻卡划眼时间减少，井径扩大率大幅度降低，并且在128 h的长时间浸泡过程中没有复杂情况产生，有效地解决了涠洲组、流沙港组易失稳地层的井壁稳定问题；同时，钻井液环保性能达到一级海域环保要求，可以替代目前应用的油基钻井液体系，解决了海上使用油基钻井液存在配制成本高、含油钻屑需全回收及环境危害隐患大等技术难题。该研究对于涠西南油田环保、井壁失稳和钻井液技术发展具有较高的理论价值和借鉴意义。     

Ion probe and fluid inclusion evidence for co-seismic fluid infiltration in a crustal detachment

We have investigated the geochemical pattern of fluid infiltration in the extensional detachment of Tinos Island (Cyclades, Greece). Ion microprobe O-isotope analyses and fluid inclusion studies have been conducted in strain fringes developing around pyrite blasts in the mylonite of the shear zone. Micro-scale traverses in quartz and calcite fibres show that δ¹⁸O increases from 17–18 to 20–21‰ in 1 mm towards the blast, drops of 3‰ in ∼200 μm, then rises again in the direction of growth. δ¹⁸O variations are interpreted as transient influxes of exotic fluids into the shear zone between periods of closed system buffering by the host rock. Fluid inclusions trapped in the fibres show fluctuating salinities (0–4 wt% NaCl eq.) and densities that reflect drops of the pore pressure from lithostatic (λ=1) to hydrostatic (λ=0.4) values during fringe growth. Isotopic and microthermometric data are consistent with models of seismic pumping developed for compressive shear zones. We therefore suggest that co-seismic pore pressure variations developed suction forces sufficient to drive large-scale fluid migration in the Tinos detachment, as in convergent tectonic settings.     

透岩浆流体成矿体系

根据透岩浆流体成矿理论,熔浆体系与含矿流体体系可以看作是两个相互独立的地质体系,它们因相互需要而耦合在一起形成一个复杂的混合体系。当熔浆与流体发生解耦时,可以在不同的边界条件下发生不同类型的成矿作用。因此,可以将透岩浆流体成矿体系进一步划分成正岩浆成矿体系、接触带成矿体系、远程热液成矿体系和火山热液成矿体系。如果熔浆具有很强的流体圈闭能力,所有的含矿流体都将被封存在岩浆体内,并随着岩浆的固结而析出成矿物质,形成正岩浆矿床。当岩浆具有较高的渗透率且含矿流体逸出岩浆体时,如果岩浆的直接围岩具有较强的捕获成矿物质的能力,即发生接触带成矿作用。否则,含矿流体将在岩浆热驱动下远离岩浆体,形成远程热液矿床。如果有利的流体通道直达岩浆体,含矿流体甚至可以喷出地表或其附近,形成火山热液矿床或水底喷流沉积矿床。这种理论分析似乎与许多成矿事实相吻合,可以有效地指导区域成矿预测和矿床勘探。     

Transmantle fluid flows and plume genesis

A mantle plume formation model based on possible migration of fluid in the plastic mantle as subvertical isolated cavities-fractures is offered. Excessive pressure (EP) proportional to the vertical size of the cavity and the difference in fluid and rock densities appears in such cavities under plasticity conditions. The excess of the EP value over rock hardness results in ??fluid fracturing?? (by analogy with hydrofracturing) in the ??head?? and, due to the cavity volume stability, in collapse of the fracture tail providing its movement upwards. Gas emission from the Earth??s core is accompanied by its accumulation at the boundary between the core and the mantle as fluid lenses, which having attained a critical size break through the mantle and migrate to the surface. In fact, a relatively stable fluid flow is created in the mantle heating it up and interacting with it. The flow stops down in the hard lithosphere base and spreads laterally initiating mantle metamorphism and melting accompanied by the formation of magmatic reservoirs massively intruding and flowing out when the critical height is attained.     

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。     

Syndeformational fluid trapping in quartz: determining the pressure-temperature conditions of deformation from fluid inclusions and the formation of pure CO2 fluid inclusions during grain-boundary migration

Abstract Observations and microthermometric data on fluid inclusions from a terrane that underwent deformation following peak metamorphic conditions show that grain-boundary migration recrystallization favours the entrapment of carbonic inclusions whereas microfracturing during brittle deformation favours the infiltration and eventual entrapment of aqueous fluids. Our results imply that pure CO₂ fluid inclusions in metamorphic rocks are likely to be the residue of deformation-recrystallization process rather than representing a primary metamorphic fluid.
Where the temperature of deformation can be deduced by other means, the densities of fluid inclusions trapped during recrystallization, which we call recrystallization-primary fluid inclusions, can be used to constrain the ambient pressure during deformation. Using these constraints, the data imply that the post-metamorphic Hercynian exhumation in Sardinia brought rocks at 300° C to within 3km of the surface. This conclusion is similar to that described for the rapidly uplifted Southern Alps in New Zealand.     

Characterization and recovery of the halophiles in the fluid inclusions in halite

正1 Introduction It is the focus of geology and biology that the creature preserved in the geological history and the organic evolution.The creature preserved in geological history by these things:sedimentary,frozen earth,chrysophoron and evaporation salt.Evaporation salt can preserve the microbe