共查询到20条相似文献，搜索用时 15 毫秒
1.
滇东南老君山锡-钨-锌-铟多金属矿集区含矿矽卡岩成因研究 总被引：2，自引：2，他引：0
滇东南老君山矿集区广泛分布的矽卡岩是本区锡-钨-锌-铟多金属矿床的主要赋存围岩。长期以来,该区含矿矽卡岩的成因争议较大,由此也制约了对该区锡钨多金属成矿规律的认识。本文以区内代表性的都龙和南秧田矿区含矿矽卡岩为研究对象,在对其地质特征详细研究的基础上,运用电子探针和ICP-MS分别测定了上述两个矿区含矿矽卡岩的矿物成分、微量和稀土元素组成,探讨了它们和多金属矿床的成岩成矿机制的关系。结果表明,区内同时存在与地层产状一致的"层状"含矿矽卡岩和明显切割层理的穿层含矿矽卡岩。都龙矿区含矿矽卡岩富Fe、贫Al,主要矿物端元成分为钙铁榴石(And_(52-69)Gro_(28-45)Spe_(1-4))、钙铁辉石(Di_(11-41)Hd_(51-73)Jo_(0-28))和铁阳起石等,从干矽卡岩到退化蚀变阶段,形成环境由酸性的弱还原环境向偏碱性的相对氧化环境变化。南秧田矿区含矿矽卡岩富Mg、Al,贫Fe,主要矿物端元成分为钙铝榴石(Gro_(82-89)Alm_(7-13)And_(2-5))、透辉石(Di_(55-81)Hd_(18-42)Jo_(0-5))和透闪石(阳起石)等,形成于相对还原的环境。都龙和南秧田矿区含矿矽卡岩与花岗岩都显示出相似的、LREE相对富集的右倾型稀土配分模式,多具有中等-弱Eu负异常,与典型的热液交代成因矽卡岩特征相似。综合分析认为,该区含矿矽卡岩主要形成于燕山晚期花岗岩浆热液与围岩的交代作用,"层状"矽卡岩可能是热液沿层间构造、岩相突变带等有利位置进行交代的结果。 相似文献
2.
3.
Fluid inclusions in skarns (carbonate replacement deposits) 总被引：7，自引：0，他引：7
T. A. P. KWAK 《Journal of Metamorphic Geology》1986,4(4):363-384
Abstract Fluid inclusions in ore skarn minerals reflect the physiochemical nature of the solutions present during the skarn-forming process. Because of the dense nature of skarn minerals and the dynamic processes operative during skarn genesis, sufficient primary fluid inclusions are usually present. Ore skarn solutions, as opposed to metamorphic skarn or ore vein solutions, have much higher CaCl2 contents and usually very high formation temperatures (>500°C) and salinities (>40 wt % T.D.S.). Temperatures and salinities generally decrease away from the solution source, both in time and space. The gradients found at greater distances from the source in distal (far from contact) skarns tend to be less (e.g. 210–350°C) for a particular skarn stage to that in proximal (near contact) skarns (e.g. 400–650°C). This information is useful for delineating the parts of such a hydrothermal system. Temperatures also tend to decrease with time, which is reflected by the superimposition of various overprinting, retrograde mineral stages. In a few areas (e.g. Naica, Mexico) intermittent boiling of ore solutions occurs, periodically elevating both temperatures and salinities, but commonly boiling only occurs early in skarn genesis just after an early, commonly lower temperature, phase. Most fluid inclusions represent a mix of‘exhaust’or reacted solutions with minor unreacted or new (pre-) ore solution components. Limited data on the distribution of elements present in fluid inclusions that do not normally take part in skarn genesis (Na, K and Cl) indicate that their proportions reflect the nature of the associated pluton. High KC1 contents are found in skarns adjacent to high K granitoids, whereas high NaCl contents are found in skarns adjacent to calcic granitoids. In many examples, daughter minerals present in minor proportions in opened fluid inclusion cavities reflect the metal characteristics of the ore solution. Small rare-earth metal, tungsten, zinc and copper daughter(?) minerals have been identified. The temperature and (or) salinity data for skarns of different metal or geological type is not particularly useful to delineate whether a skarn locality is part of a more complex, as yet unexplored system. Solutions in Pb–Zn skarns tend to be lower-temperature (150–400°C) and more dilute (<30 wt % T.D.S.) than in other skarn types, but exceptions occur. 相似文献
4.
Fluid metasomatic genesis of stratiform skarn in the Suoerkuduke Cu-Mo deposit,East Junggar,NW China
Stratiform skarns associated with ore deposits are widespread in the north of East Junggar, particularly in the Suoerkuduke Cu-Mo deposit. The Suoerkuduke stratiform and stratoid skarns are hosted by Devonian intermediate-mafic volcanic and pyroclastic rocks, mainly andesite, andesitic porphyry and tuffaceous sandstone, without carbonate or calcareous rocks. The skarns consist of dominant andradite-grossular, epidote, diopside-hedenbergite and minor actinolite, quartz, magnetite and metallic sulfides. The garnet and epidote composition, especially Fe3 + and Al contents, is largely a function of the bulk composition and physicochemical environment (particularly fO2) during crystallization. Such mineralogy indicates a relatively oxidizing environment and medium acidity of solution during skarnization.The Suoerkuduke skarns are distinct from typical contact metasomatic skarn in wall rock, as no carbonate or calcareous rocks were found, and differ in the distribution patterns of skarn zonation in that gradually weakened skarn zones are not quite symmetrically distributed on both sides of the alteration center (a garnet skarn). Abundant remnants of andesite, andesitic porphyry and tuffaceous sandstone in the weakened skarn zone indicate that the protolith of the skarn is andesite, andesitic porphyry and tuffaceous sandstone. Magmatic water, meteoric and seawater are involved in skarn alteration. Moyite and granitic porphyry are not coeval with skarn, and their emplacement resulted in the hornfelization of wall rock instead of skarnization, and themselves keep away from skarn alteration. Therefore, there was probably a huge batholith supplying magmatic fluid for skarn formation. Mass balance estimates suggest that hydrothermal fluid must contribute a portion of Ca and Fe to ensure sufficient supply for skarn formation in the absence of local carbonate and calcareous rocks. In conclusion, the stratiform skarns in the Suoerkuduke are products of intermediate-mafic volcanic and pyroclastic rocks metasomatised by hydrothermal fluid that probably leached calcareous wall rock during ascent. 相似文献
5.
矽卡岩矿床的研究现状 总被引：11，自引：0，他引：11
本文评述了矽卡岩矿床类型划分、矽卡岩形成的物理化学条件、成矿流体以及矿物成分与矿化关系的某些进展。镁矽卡岩形成于各种深度,而钙矽卡岩则形成于较浅和较低温的环境;限制矽卡岩形成的主要参数是ＣＯ＿２、深度以及岩浆期后诸元素的活度（如Ｍｇ￣（２＋）、Ｃａ￣（２＋）…）、ｐＨ和Ｅ＿ｈ值。当前已应用非平衡热力学去研究矽卡岩成岩成矿过程。接触交代带中存在两种流体,一种来自岩浆,另一种是天水循环来源;同位素资料提供水／岩反应的信息,而Ｓ、Ｐｂ、Ｓｒ等同位素资料提供矿质来源的标志。矽卡岩矿物如辉石、石榴石的化学成分与矿化关系密切,可以指示矿化类型。文中总结了矽卡岩型金矿特点,其蹄、铋矿物及退化蚀变是重要的找矿标志。含矿流体及成矿动力学是今后研究的重要方向。 相似文献
6.
渗滤脉状矽卡岩成岩过程的计算机模拟 总被引：3，自引：0，他引：3
用多相多组分平衡分析了个旧锡矿区渗滤脉矽卡岩形成的机理，以该理论为基础设计的计算机程序模拟了这类矽卡岩脉的成岩过程。结果表明，花岗岩饱和热液成分不同，碳酸盐岩类型不同，通过模拟可以得到不同类型的矽卡岩及脉状矽卡岩的对称状矿物分带。 相似文献
7.
哈萨克斯坦萨亚克大型铜矿田中, 矽卡岩型矿床的矿体赋存于石炭系灰岩与花岗岩类的接触带上, 矿体及其周围发育大量矽卡岩。矽卡岩矿物主要由石榴子石、辉石、绿帘石、绿泥石等组成, 矿石矿物主要发育黄铜矿、斑铜矿、黄铁矿、磁黄铁矿、辉钴矿等。萨亚克矽卡岩型矿床成矿作用分为5个阶段: 透辉石-石榴子石矽卡岩阶段、石榴子石矽卡岩阶段、绿帘石-磁铁矿阶段、石英-硫化物阶段和碳酸盐阶段。电子探针分析结果表明, 矿区矽卡岩属典型的钙质矽卡岩。 其中石榴子石发育3种类型, 均属钙铝-钙铁榴石固溶体系列, 自早期透辉石-石榴子石矽卡岩阶段至晚期石榴子石矽卡岩阶段, 由钙铁榴石向钙铝-钙铁榴石转变, 并且钙铁-钙铝榴石与矿化关系最为密切。其中具环带结构的石榴子石中钙铁与钙铝含量随环带呈韵律性变化, 表明生长过程中成分具震荡性变化, 形成于不完全封闭的平衡条件, 指示流体的多期次多阶段性; 辉石以透辉石为主; 绿帘石属绿帘石族中绿帘石范畴; 磁铁矿TFeO含量高, 与其他氧化物成分呈负相关关系。石英硫化物阶段早期发育黄铜矿-黄铁矿-磁黄铁矿-白铁矿、黄铜矿-辉钴矿矿物组合; 晚期为主要矿化阶段, 发育大量致密块状黄铜矿。黄铜矿显示贫硫富铜、铁特征; 黄铁矿为亏硫型; 磁黄铁矿属贫钴富镍型。矽卡岩矿物共生组合及石榴子石成分演化等矿物学特征显示, 成矿过程中随着温度及氧逸度的降低, 成矿热液由弱碱性向酸性演化, 伴随热液在接触带的中和作用, 以黄铜矿为主的金属硫化物富集沉淀。 相似文献
8.
9.
10.
The skarn type copper deposits are widespread in the Jiurui district in the Middle-Lower Yangtze River metallogenic belt. This paper reports a detailed study on mineral chemistry, and H, O, S and Pb isotopic compositions on skarn silicate and sulfide minerals in the three major skarn dominant deposits (Wushan, Dongleiwan and Dengjiashan). The Wushan skarn deposit is characterized with prograde garnet-dominated and clinopyroxene limited skarns with average andradite content of 83% and hedenbergite content of 10%, whereas the Dongleiwan and Dengjiashan deposits are featured with retrograde skarn alteration with abundant hydrous minerals such as epidote and chlorite. The garnet and clinopyroxene compositions show 59% andradite and 15% hedenbergite for the Dongleiwan skarns, and 43% and 22% for the Dengjiashan skarns respectively. The pistacite components (Ps value) defined as Fe3 +/(Fe3 ++ Al) and Fe3 +/Fe2 + value of epidote are 0.12 and 1.63 for the Wushan skarns, 0.30 and 32.73 for the Dongleiwan skarns, and 0.17 and 42.85 for the Dengjiashan skarns. It is suggested that the prograde skarn mineralization in the three deposits was all formed in a relatively oxidizing environment, with the Wushan showing the highest oxidation potential and the Dengjiashan having the least oxidation potential. However, in the retrograde skarns, the Dongleiwan and Dengjiashan deposits show higher oxidation potential than that of Wushan. The three deposits show similar sulfur isotopic compositions of − 2.9 to + 1.4‰ and similar lead isotopic compositions with 206Pb/204Pb, 207Pb/204Pb and 208Pb/204Pb ratios of 17.900 to 18.205, 15.538 to 15.649 and 38.170 to 39.025, respectively. All the three deposits should have similar magmatic origin for the ore-forming materials based on their S and Pb isotopes. The oxygen isotopic compositions of the prograde and retrograde fluids in the three deposits show some differences, with δ18OFluid values of + 8.13‰ and + 7.81‰ for the Wushan, + 6.47‰ and + 2.33‰ for the Dongleiwan, and + 8.27‰ and + 4.43‰ for the Dengjiashan. But the hydrogen isotopic compositions are similar for the prograde (− 65 to − 31‰) and retrograde (− 64 to − 33‰) fluids. Therefore, the fluid origins and evolution may be different in each deposit. The hydrothermal fluids for the prograde skarns in all three deposits were likely derived from magmatic–hydrothermal sources, but the Dongleiwan and Dengjiashan show a higher proportion of meteoric water input in the retrograde stage. Considering the similar average prograde temperatures (574 to 560 °C) as calculated from coexisting garnet–clinopyroxene pairs, and similar retrograde temperatures (281 to 246 °C) as calculated from chlorite chemistry for the three deposits, we suggest that the trigger for deposition of sulfide ores in the Wushan garnet-dominated skarn deposit was mainly caused by system cooling with temperature drop along with magmatic intrusion and crystallization process. The Dongleiwan and Dengjiashan skarn deposits constitute a well developed retrograde skarn system with abundant epidote, chlorite, quartz and calcite, which probably caused by fluid mixing of high-temperature saline magmatic–hydrothermal fluids with cooler, oxidizing and dilute meteoric water. 相似文献
11.
矽卡岩岩浆对中国北方某些矽卡岩型矿床形成的制约——来自包裹体激光拉曼分析证据 总被引：4，自引：1，他引：3
本文将报道中国北方主要矽卡岩型矿床矿物熔融包裹体和流体-熔融包裹体的激光拉曼分析结果。研究目的是确认这些矿化矽卡岩矿物是否含熔融包裹体和流体-熔融包裹体,获取有关它们相态特征和相组成以及它们的分布状况(是局部的、偶然性的,还是广泛的)的信息。文章对邯邢铁矿、蒙库铁矿和杨家杖子钼矿等9个矿床12块标本中石榴石、辉石和方解石或白云石中23个包裹体进行了共聚焦激光拉曼光谱仪分析。拉曼分析结果表明,所研究的矽卡岩矿物均含熔融包裹体和/或流体-熔融包裹体,它们是岩浆矽卡岩的直接证据。结合本文激光拉曼分析结果、地质背景和其他地区岩浆矽卡岩矿物包裹体测温学研究,对所研究矽卡岩的形成机制和岩浆矽卡岩对中国北方某些矽卡岩型矿床的制约进行了讨论。认为含有熔融包裹体和/或流体-熔融包裹体的矿化矽卡岩系岩浆成因,其分布范围广泛,规模不小。中国北方某些矽卡岩型矿床的时空分布和规模受控于该地区分布的岩浆矽卡岩。希望本文有助于拓宽矽卡岩型矿床成矿规律研究和深部找矿勘探的思路。 相似文献
12.
江西永平铜矿矽卡岩矿物特征及其地质意义 总被引：4，自引：3，他引：1
永平铜矿含矿岩石主要为绿帘石透辉石石榴石矽卡岩,这种岩石类型是与斑岩体有关的矽卡岩铜矿的典型赋矿岩石。通过对这一主要赋矿矽卡岩的研究,我们发现石榴石生长分为两个阶段:(1)早期石榴石:主要分布在石榴石颗粒核部,XAdr=1.0,主要以钙铁榴石为主,说明早期流体中可能含有较多的铁,是在较氧化条件下形成的;(2)晚期石榴石,沿石榴石裂隙重新成核或者在靠近流体通道的早期石榴石表面生长,出现震荡环带,XAdr=0.46~0.99,为钙铁-钙铝石榴石系列。石榴石发生变化的期间也形成新的矿物,如绿帘石、萤石、方解石和石英等。共存石榴石和绿帘石矿物中存在Fe3+-Al3+之间的替代,说明流体的氧逸度、组分浓度或aFe3+/aAl3+可能发生了变化。金属矿物也可能是在这一阶段形成的。永平铜矿矽卡岩从接触带到大理岩空间上有分带现象。从岩体到围岩的变化趋势为:石榴石含量减少,颜色存在红棕色-棕色-棕绿色-黄绿色-浅黄色的变化趋势;矿石品位降低,这与石榴石中Al2O3含量的变化较一致。我们认为这种变化是含矿热液对早期矽卡岩进行再交代改造的结果,表现为石榴石和绿帘石中Fe3+-Al3+含量的变化,并将Cu等金属沉淀下来。根据矽卡岩矿物的这些特征,在矿床勘探时,可依据棕色石榴石来追踪主矿体的位置。 相似文献
13.
The Nanling Range in South China hosts numerous world-class W–Sn deposits and some Fe deposits. The Mesozoic Tengtie Fe skarn deposit in the southern Nanling Range is contemporaneous with the regional Sn mineralization. The deposit is composed of numerous ore bodies along the contacts between the late Paleozoic or Mesozoic carbonate rocks and the Yanshanian Lianyang granitic complex. Interaction of the magma with hosting dolomitic limestone and limestone formed calcic (Ca-rich) and magnesian (Mg-rich) skarns, respectively. The Tengtie deposit has a paragenetic sequence of the prograde stage of anhydrous skarn minerals, followed by the retrograde stage of hydrous skarn minerals, and the final sulfide stage. Magnetite in the prograde and retrograde skarn stages is associated with diopside, garnet, chlorite, epidote, and phlogopite, whereas magnetite of the final stage is associated with chalcopyrite and pyrite. Massive magnetite ores crosscut by quartz and calcite veins are present mainly in the retrograde skarn stage. Laser ablation ICP-MS was used to determine trace elements of magnetite from different stages. Some magnetite grains have unusually high Ca, Na, K, and Si, possibly due to the presence of silicate mineral inclusions. Magnetite of the prograde stage has the highest Co contents, but that of the sulfide stage is extremely poor in Co which partitions in sulfides. Magnetite of magnesian skarns contains more Mg, Mn, and Al than that of calcic skarns, attributed to the interaction of the magma with compositionally different host rocks. Magnetite from calcic and magnesian skarns contains 6–185 ppm Sn and 61–1246 ppm Sn, respectively. The high Sn contents are not due to the presence of cassiterite inclusions which are not identified in magnetite. Instead, we believe that Sn resides in the magnetite structure. Regionally, intensive Mesozoic Sn mineralization in South China indicates that concurrent magmatic–hydrothermal fluids may be rich in Sn and contribute to the formation of high-Sn magnetite. Our study demonstrates that trace elements of magnetite can be a sensitive indicator for the skarn stages and wall-rock compositions, and as such, trace elemental chemistry of magnetite can be a potentially powerful fingerprint for sediment provenance and regional mineralization. 相似文献
14.
对安徽新桥矿床进行系统的野外地质调查和矿相学研究发现,层状矿体中的胶状黄铁矿交代矽卡岩磁铁矿矿体,为探讨层状硫化物矿床是早期沉积成因还是岩浆热液成因提供了新的地质约束。对铜陵矿集区内的新桥矿床层状菱铁矿矿体和凤凰山矽卡岩型矿体中的菱铁矿开展了Fe同位素组成的对比研究,结果显示：新桥矿床菱铁矿与典型低温热液脉型矿床和沉积铁矿中的菱铁矿在Fe同位素组成特征上有所不同,而与凤凰山矽卡岩型矿床中的菱铁矿更为接近;新桥矿床中胶状黄铁矿和菱铁矿相对于磁铁矿富集Fe的轻同位素,表明磁铁矿不是过去认为的由胶状黄铁矿和菱铁矿矿胚层经热液改造形成,而是与典型的岩浆热液有关。新桥矿区层状硫化物矿体和矽卡岩型矿体中,近岩体矽卡岩和最早形成的金属矿物磁铁矿比岩体更为富集Fe的轻同位素,而赋矿围岩比岩体更为富集Fe的重同位素。同时,不同矿化阶段形成的含铁矿物和不同空间位置的硫化物中的Fe同位素组成呈现出时空分带现象,Fe同位素组成的时空演化特征与流体出溶、流体演化非常一致,并且符合同位素分馏的基本理论,表明层状硫化物矿体和矽卡岩型矿体具有相同的成矿物质来源,为同一流体体系演化的产物。新桥矿区岩相学的研究结果和Fe同位素组成特征均表明,新桥层状硫化物矿床不是海西期喷流沉积成矿作用的产物,而是燕山期热液成矿作用的产物,为一个典型的热液成因矿床。 相似文献
15.
新疆蒙库铁矿床稀土元素地球化学及对铁成矿作用的指示 总被引：16，自引：4，他引：16
新疆富蕴县蒙库大型铁矿呈层状、似层状、透镜状赋存于下泥盆统康布铁堡组变质火山-沉积岩系中.矿体中发育矽卡岩,但矽卡岩并不产在侵入岩接触带上.绿帘石、石榴石和矿石的稀土配分模式具有相似性,均为轻稀土富集,正铕异常,基本上无铈异常,暗示它们之间存在成因联系.石榴石稀土配分模式呈折线型,具有明显的正铕异常,石榴石流体包裹体中熔融包裹体、熔流包裹体和气液包裹体共存,表明石榴石矽卡岩具有岩浆成因和热液成因的特征,形成于晶体 熔体 流体三相共存的岩浆-热液过渡阶段.矿床地质特征、矽卡岩矿物和矿石稀土特征表明蒙库铁矿为矽卡岩型矿床. 相似文献
16.
小柳沟钨钼(铜)矿床位于北祁连西段镜铁山_朱龙关裂谷带内,矿化主要产于长城系朱龙关群碳酸盐岩及基性火山岩中,它是一个与花岗质岩石有关的斑岩_矽卡岩_石英脉型矿床。其中,钨矿化主要为矽卡岩型,钼矿化主要为斑岩型。小柳沟花岗质岩石主要由二长花岗岩和花岗闪长岩组成,与成矿作用关系密切的为二长花岗岩。文章以小柳沟花岗质岩石中的主要造岩矿物和矽卡岩中的石榴子石为对象,利用电子探针对其矿物学特征进行研究。结果表明,小柳沟花岗质岩石的成岩物质主要来源于地壳,并有地幔物质的加入,岩体形成于较高氧逸度环境〔(logfO2Ni_NiO〕,是钨钼(铜)矿形成的有利条件。小柳沟矽卡岩中的石榴子石属于钙铝榴石_钙铁榴石系列,以钙铝榴石为主,矽卡岩属于交代成因的钙矽卡岩,主要形成于还原环境。石榴子石环带的核部相对富Al,边部相对富Fe,暗示成矿流体温度降低、氧逸度和p H值升高。矿物成分分析表明,石榴子石的Mn/Fe比值和矿化金属类型之间存在一定联系。硫化物的硫同位素显示,S可能来源于岩浆热液,结合前人的研究成果,认为小柳沟钨钼矿床的钨可能来源于岩浆及地层,钼主要来源于岩浆。 相似文献
17.
含金夕卡岩矿床产出构造环境和地质地球化学评价标志 总被引：10，自引：0，他引：10
近十几年来,含金夕卡岩矿床的勘查与研究在国内外取得了很大的进展,发现了一批大型矿床,从而引人注目。含金夕卡岩矿床主要集中分布于环太平洋成矿带,按其产出构造环境可分为三类,即中（新）生代褶皱带、古生代褶皱带和地盾（台）区。控矿地层主要为石炭—二叠系和三叠系碳酸盐岩,次为第三系和寒武系等。有关岩浆岩大多为浅成钙碱性中酸性侵入岩,属Ⅰ型;时代以燕山期和喜山期为主,少数为华力西期、加里东期和印支期。含金夕卡岩绝大多数为钙夕卡岩,只有少数属镁夕卡岩,又可进一步划分为还原型和氧化型。金属矿物组合的特征是常有砷化物、铋化物和碲化物存在,Ｃｕ,Ａｕ,Ａｇ,Ａｓ,Ｂｉ,Ｔｅ,Ｃｏ和Ｓｅ等元素组合是含金夕卡岩特征性的地球化学标志。矿床（田）常具明显的交代矿化分带,并可构成一定成矿系列,其综合交代矿化分带模式,自岩体向碳酸盐围岩方向依次为：Ｃｕ（Ｍｏ）→Ｃｕ（Ｆｅ）→Ｃｕ（Ａｕ）→Ａｕ→Ａｕ（Ｐｂ,Ｚｎ,Ａｇ）。矿物共生组合和流体包裹体研究表明,夕卡岩矿物形成于６８０～３２０℃,盐度为ｗ（ＮａＣｌ）＝５９５％～１８６％,金的沉淀发生在夕卡岩期后的退化热液交代阶段,大致相当于温度为３５０～１５３℃,盐度ｗ（ＮａＣｌ）＝２４％～? 相似文献
18.
青海西部祁漫塔格地区主要矽卡岩铁多金属矿床成矿地质背景和矿化蚀变特征 总被引：8，自引：2，他引：6
青海西部祁漫塔格地区矽卡岩铁多金属矿床分布广泛,目前已成为中国西部最重要和最有找矿潜力的矽卡岩铁多金属成矿带.在大地构造上,该地区属东昆仑造山带;成矿主要与印支期(204～237Ma)闪长岩、花岗闪长岩和二长花岗岩有关;控矿地层包括蓟县系狼牙山组大理岩、硅质岩,奥陶系-志留系滩间山群大理岩、碎屑岩、硅质岩、中-基性火山岩和石炭系结晶灰岩、碎屑岩等.区内发育3类矽卡岩,即钙矽卡岩、镁矽卡岩和锰质矽卡岩,以前者为主.钙矽卡岩常伴生Fe、Cu、Mo(Pb,Zn)矿化,镁矽卡岩主要伴生Fe矿化,锰质矽卡岩则伴生Pb、Zn(Ag)矿化;矿石矿物组合多种多样,矿化具有一定的分带性.内接触带侵入岩广泛发育钾长石化,与矽卡岩类型一起构成该类矿床的重要找矿标志之一. 相似文献
19.
20.
Lin Wenwei 《《地质学报》英文版》1990,64(3):299-308
On the basis of geological studies of skarn deposits in China and by using thermodynamic models of thesolid solution, the coexisting clinopyroxene-garnet pair in skarn deposits has been analysed and a coexistingclinopyroxene-garnet acidometer developed. They can be used to estimate the medium condition under whichthe skarn was formed. The research on the acidity for the formation of various metallic skarn deposits in Chinasuggests that skarns endowed with dissimilar types of mineralization and occurring in diverse environments dif-fer in the acidity conditions for their formation and in the trend of acidity variation of ore-bearing fluid. This,coupled with the study of oxygen fugacity of coexisting minerals, makes it possible to establish the oxygenfugacity-acidity facies of skarn deposits, which reflect the close genetic relationship between the metallizationand the formation of skarn. 相似文献