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浙江八面山特大型萤石矿床的沉积成矿特征 总被引：4，自引：0，他引：4
八面山萤石矿床是近年来发现的特大型萤石矿床,通过成矿地质背景,矿体与矿石特征,容矿岩系岩石化学组成特征,岩石与矿石稀土元素特征,钐—钕同位素特征等研究,探讨了矿床的沉积成矿特点。结果充分说明,八面山萤石矿床是一个以沉积为主,后经热液改造的特大型萤石矿床。依据上述分析数据,同时结合容矿围岩和矿体的地质特征,可以推测, 八面山萤石矿床是寒武系沉积岩作为矿源层,为萤石矿床的形成提供了必要的物源。后期岩浆作用只是对部分矿体进行了不同程度的改造,局部形成了构造带中的陡倾斜脉状矿体。 相似文献
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浙江八面山特大型萤石矿床成因研究 总被引：11，自引：5，他引：6
通过成矿地质背景,矿体地质特征,矿石特征,矿床稀土元素,流体包裹体地球化学,氢氧同位素地球化学特征等研究,认为八面山萤石矿床,按矿体赋存于岩体与灰岩接触带、灰岩层间及构造破碎带;岩石有细粒及粗粒-巨晶两类;矿床成矿温度主要集中在120°～240°之间;氢氧同位素特征反应成矿流体具有多来源多成因的特征;成矿物质Ca主要来源于寒武系中的灰岩与泥质灰岩,F主要来源于寒武系泥质灰岩,部分可能为岩浆热液从地表深部携带而来,萤石矿床成矿流体水具有多源性;成矿流体具有大气降水,变质水和岩浆水共同混合作用的结果,在岩浆侵入热源的作用下,三种水混合后被加热,形成了成矿溶液的重要载体。研究认为八面山萤石矿床是受地层-岩体-断裂共同控制"三位一体"的中低温热液成因矿床。 相似文献
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浙西北岩前高氟岩体地球化学特征及其与新类型萤石矿床成矿关系 总被引：4，自引：0，他引：4
浙江八面山特大型萤石矿田属新类型矿床。矿体特征研究表明,其赋存形式及矿石特征与一般萤石矿床不同,具独特性。本文通过岩石学及地球化学特征表明,浙西北岩前岩体富含挥发分,属高氟高硅、贫钙低钛低磷、钙碱性、准铝质一弱过铝质（铝饱和指数ASI：0．96～1．17）岩石。岩浆来源较复杂,既有壳源,也有壳幔混合源,岩浆分异作用强烈。稀土元素分析结果表明,岩体稀土元素含量较高,轻重稀土比值较小（2．24—3．52）,Eu亏损明显（8Eu=0．01—0．03）,轻重稀土分馏较弱。研究还表明,岩前岩体并非过去认为的S型花岗岩,而具有A型花岗岩的特征。矿田萤石矿体与岩前岩体在空间、时间上关系密切,岩体不仅为萤石成矿提供了氟源,侵位形成的构造还为新类型萤石矿提供了赋矿空间。 相似文献
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浙江八面山萤石矿床流体包裹体地球化学研究 总被引：2，自引：1，他引：1
八面山萤石矿床流体包裹体可分为三大类型:Ⅰ气液包裹体,Ⅱ气体包裹体,Ⅲ含子矿物的多相包裹体;矿床成矿温度变化不大,主要集中在120～240°C之间。细粒条带状萤石矿石包裹体温度变化在115～250℃之间;巨晶块状萤石矿石和石英脉型萤石矿石包裹体温度集中在135～170℃之间。萤石矿床流体包裹体以低盐度成矿流体为主。成矿过程中起作用的成矿流体为KCl-H2O体系和CO2-CaF2-H2O体系,成矿溶液的离子类型属K+-Ca2+-HCO--F-型,KCl-H2O体系反映岩浆期后热液作用的结果,而CO2-CaF2-H2O体系可能反映了寒武纪矿源层成矿体系。通过包裹体研究,认为八面山萤石矿床是受地层-岩体-层间断裂共同控制"三位一体"的热液成因矿床。 相似文献
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西天山阿希浅成低温热液金矿床剥蚀改造过程探讨 总被引：1，自引：0，他引：1
阿希金矿床是新疆西天山成矿带上与晚古生代火山岩有关的典型浅成低温热液型金矿床。矿区包括热液成因和沉积成因2种类型的金矿体。其中,热液成因金矿体明显受近南北向断裂控制,并遭受一定的剥蚀改造,矿体空间形态变化特征及黄铁矿热电性标型特征显示矿床南段比北段剥蚀程度高,矿体金品位和厚度质量参数空间分布特征显示矿体具有向北侧伏特征;沉积底砾岩型金矿体角度不整合于热液成因矿体之上,其含矿砾石类型和稀土元素分布特征与热液型矿体基本一致,为热液型矿体遭受剥蚀并在北东部阿恰勒河组中沉积的产物。基于以上认识,并结合矿床的形成、产状变化特征、区域构造地质演化等资料的深入分析,建立了阿希浅成低温热液型金矿床的剥蚀改造模式。 相似文献
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北一、南六矿体是海南石碌铁矿床最主要的2个铁矿体,赋矿围岩同为二透岩,铁矿石主要为赤铁矿加少量磁铁矿.研究两矿体赋矿围岩和富铁矿石的地球化学特征,比较其物质组成差异性,可以为本矿床深部和外围找矿提供有用信息.研究表明,北一、南六2个矿体二透岩、富铁矿的主量元素、微量元素及稀土元素配分曲线差异明显;北一矿体二透岩除CaO和Co含量低于南六矿体样品外,其余氧化物及微量元素含量均高于南六矿体样品;北一矿体二透岩及富铁矿有Eu弱负异常,南六矿体二透岩及富铁矿Eu正异常;所有样品均表现Ce的弱负异常和轻稀土相对亏损、重稀土相对富集的特征.研究结果表明两矿体成矿环境或受后期热液影响不同. 相似文献
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茂租铅锌矿床位于扬子地台西南缘,是滇东北矿集区内的一个大型矿床,矿体主要呈似层状产于震旦系灯影组白云岩中;矿石矿物以闪锌矿为主,次为方铅矿;脉石矿物主要为白云石、方解石和萤石。本文对该矿床中与铅锌矿密切共生的团块状白云石、方解石和萤石以及围岩灯影组白云岩的REE地球化学特征和C、O、Sr同位素进行了对比研究。结果表明:团块状白云石和方解石的稀土配分模式、C同位素和Sr同位素比值与围岩灯影组白云岩比较接近,表明形成团块状白云石和方解石的成矿流体主要来源于围岩灯影组白云岩的溶解;但这两种矿物的稀土总量ΣREE高于灯影组白云岩,说明成矿流体除了主要由围岩提供REE外,还有部分其他富含REE流体的加入。萤石则具有LREE亏损和分配曲线相对平缓的稀土配分模式特征,表明萤石形成于成矿的晚阶段,有更多的外部流体的加入。团块状白云石、方解石和萤石表现出明显的Eu正异常,且团块状白云石和方解石的O同位素低于灯影组白云岩,反映了存在较高温度的流体活动,这3种脉石矿物是由高温热液流体形成的。灯影组白云岩和3种脉石矿物都具有明显的Ce负异常,说明成矿流体可能主要来源于地层循环水,继承了围岩的Ce负异常特征。方解石和萤石的Sr同位素比值高于围岩震旦系灯影组白云岩和峨眉山玄武岩,但小于基底岩石昆阳群和会理群,说明成矿流体主要由赋矿围岩等沉积地层中的循环流体与流经了基底岩石的深部流体混合形成。 相似文献
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班康姆铜金矿床是近年来发现的大型铜金矿床,矿体主要赋存于中基性火山岩之中,其微量元素特征、玄武岩类的Ti-Zr-Y、Ti-Zr判别图、花岗岩类在Nb-Y(A)、Rb-(Y+Ta)判别图均表明成矿构造环境为岛弧环境,火山岩属于中钾钙碱性系列.岩浆岩稀土总量较低,标准化模式曲线均为略富集轻稀土的平坦型,Eu几乎不存在异常,说明火山岩、侵入岩为同源不同期的产物,岩浆热液来源于地幔或下地壳,热液活动划分为火山喷发期、热液叠加期,其成矿物质来源于安山岩,矿(化)体受NNE断裂构造、岩浆岩控制,矿床类型为与岩浆岩密切相关的复合型热液矿床. 相似文献
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XU Zhaowen LU Xiancai LING Hongfei LU Jianjun JIANG Shoyong NIE Guiping HUANG Shunsheng HUA Ming State Key Laboratory of Mineral Deposit Research Department of Earth Sciences Nanjing University Hankou Roa Nanjing Jiangsu Geological Survey of Jiangsu Province Nanjing Jiangsu 《《地质学报》英文版》2005,79(3):405-413
1 Introduction The region of the middle-lower reach of the Yangtze River is an important mineralized belt of Fe, Cu, Au, S and other elements, with a series of sedimentary-hydrothermal diplogenetic mineral deposits (Xu and Zhu, 1978; Liu et al., 1984; Gu and Xu, 1986; Gu et al., 1993, 2000; Zhai et al., 1992). Some geologists thought that the Carboniferous massive sulfide exhalative sediment was the basis of the late diplogenetic mineralization (Gu and Xu, 1986; Gu et al., 1993, 2000); o… 相似文献
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赞坎铁矿石西昆仑成矿带近年来新发现的一处超大型铁矿床,矿区内广泛出露古元古代布伦阔勒变质岩层,矿体主要赋存于布伦阔勒岩群角闪斜长片岩和黑云石英片岩内部,部分产于霏细岩与黑云石英片岩接触带内。矿床由Ⅰ~Ⅶ号矿体组成,其中Ⅰ号和Ⅲ号矿体为主要矿体。根据矿石组构、矿物共生关系等特征,成矿过程可划分为早期沉积期、中期变质期及晚期岩浆热液期3个成矿期,其中,岩浆热液期可进一步划分为矽卡岩阶段、热液改造阶段和硫化物阶段。早期沉积期磁铁矿呈微细粒他形晶结构,被变质期石英颗粒包裹,以较低含量的TFeO、MgO、MnO和较高含量的TiO2、Al2O3为特征;中期变质期磁铁矿分布于条带状矿石内,他形晶粒状结构,与早期相比,TFeO、MgO、MnO等含量相对升高而TiO2、Al2O3等含量相对降低;晚期岩浆热液期矽卡岩阶段磁铁矿分布于块状矿石内,自形晶粒状结构,以相对富TFeO、MgO、MnO而贫TiO2、Al2O3为特征;晚期热液改造阶段磁铁矿分布于浸染状矿石中,半自形-自形粒状结构、交代残余结构为主,TFeO、Al2O3、TiO2、MnO等含量变化较大。认为赞坎铁矿是沉积变质型铁矿床,遭受后期岩浆热液作用交代改造。 相似文献
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会泽水槽子铜矿床及成因探讨 总被引：3，自引：0，他引：3
水槽子铜矿的成因与湖泊沼泽相含煤碎屑岩建造紧密相关，多个呈似层状、透镜状的矿体，均赋存于该沉积序列中。成岩期即为主成矿期，后期含矿热液叠加使局部变富或构成工业矿体。系统的工程揭控显示：含矿层位卷入了后期构造挤压变形，但并没有破坏矿体形成的原始踪迹。矿床成因应属（沉积）层控热液叠加矿床类型。最后，笔者提出在该区寻找同类矿床的新思路与找矿方向。 相似文献
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柴北缘地区的两类块状硫化物矿床——Ⅰ. 锡铁山式SEDEX型铅锌矿床 总被引：16，自引：2，他引：14
作者以连续的两篇文章综述了柴北缘地区的加里东造山带中产出的两类不同的块状硫化物矿床,这就是喷流沉积(SEDEX)型Pb-Zn矿床和火山岩容矿的块状硫化物(VHMS)型Cu-S矿床.认为它们在成矿后的造山过程中受到过不同程度和不同成矿作用的改造,使之兼有后生矿床的特征.锡铁山Pb-Zn矿床的主体是属于以沉积岩为容矿岩石的喷流沉积(SEDEX)型矿床.它的含矿岩系形成于早奥陶世[(486±13) Ma]弧后盆地环境中,并在加里东期碰撞造山过程中发生了强烈的北东-南西向斜向挤压缩短,导致喷流沉积成矿作用形成的原始铅-锌-黄铁矿层,后期遭受了强烈的构造改造,从而在一定程度上使矿体的空间分布受到后期构造的控制.此外,该矿床也程度不大地受到过后期热液改造.为更加显示它的地区性特色和强烈的后期改造,作者建议将其称为"锡铁山式SEDEX型铅锌矿床".在该式矿床的勘查过程中,既要注重研究同生成矿作用对矿体的控制,也要重视研究后期构造对含矿层和矿体的破坏和改造. 相似文献
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PENGRunmin ZHAIYusheng 《《地质学报》英文版》2004,78(2):534-547
Most ore-forming characteristics of the Langshan-Zha‘ertaishan hydrothermal exhalation belt, which consists of the Dongshengmiao, Huogeqi, Tanyaokou and Jiashengpan large-superlarge Zn-Pb-Cu-Fe sulfide deposits, are most similar to those of Mesoproterozoic SEDEX-type provinces of the world. The characteristics include: (1) All deposits of this type in the belt occur in third-order fault-basins in the Langshan-Zha‘ertaishan aulacogen along the northern margin of the North China Platform; (2) these deposits with all their orebodies hosted in the Mesoproterozoic impure dolomite-marble and carbonaceous phyllite (or schists) have an apparent stratabound nature; ores display laminated and banded structures, showing clear depositional features; (3) there is some evidence of syn-sedimentary faulting, which to a certain extent accounts for the temporal and spatial distribution and the size of the orebodies in all deposits and the formation of intrabed conglomerates and breccias; (4) they show lateral and vertical zonation of sulfides; (5) The Cu/(Pb Zn Cu) ratio of the large and thick Pb Zn Cu orebodies gradually decreases from bottom to top; and (6) barite is interbedded with pyrites and sometimes with sphalerite. However, some characteristics such as the Co/Ni radio of the pyrites, the volcanism, for example, of the Langshan-Zha‘ertalshan metallogenic belt, are different from those of the typical SEDEX deposits of the world. The meta-basic volcanic rock in Huogeqi, the sodic bimodal volcanic rocks in the Dongshengmiao and potassic bimodal-volcanic rocks with blastoporphyfitic and blasto-glomeroporphyritic texture as well as blasto-amygdaloidal structure in the Tanyaokou deposits have been discovered in the only ore-bearing second formation of the Langshan Group in the past 10 years. The metallogeny of some deposits hosted in the Langshan Group is closely related to syn-sedimentary volcanism based on the following facts: most of the lead isotopes in sphalerite, galena, pyrite, pyrrhotite and chalcopyrite plot on both sides of the line for the mantle or between the lines for the mantle and lower crust in the lead isotope composition diagram; cobalt content of some pyrites samples is much higher than the nickel content (Co/Ni= 11.91-12.19). Some volcanic blocks and debris have been picked out from some pyritic and pyrrhotitic ores. All Zn-Pb-Cu-Fe sulfide orebodies in these deposits occur in the strata overlying metamorphic volcanic rocks in the only ore-bearing second formation. In the Jiashengpan deposit that lacks syn-sedimentary volcanic rocks in the host succession only Pb and Zn ores occur without Cu ore, but in the Dongshengmiao, Tanyaokou and Huogeqi deposits with syn-sedimentary volcanic rocks in the host succession Cu ores occur. This indicates a relatively higher ore-forming temperature. The process of synsedimentary volcanic eruption directly supplied some ore-forming elements, and resulted in secular geothermal anomaly favorable for the circulation of a submarine convective hydrothermal system, which accounts for the precipitation of deep mineralizing fluids exhaling into anoxidic basins along the syn-sedimentary fault system in the Langshan-Zha‘ertai rift. The Dongshengmiao, Tanyaokou, and Huogeqi deposits hosted in the Langshan Group appear to be a transitional type of mineral deposit between SEDEX and VMS-types but with a bias towards SEDEX, while the Jiashengpan deposit hosted in the Zha‘ertai Group is of a characteristic SEDEX type. This evidence, together with other new discoveries of Mesoproterozoic volcanic rocks and the features of lithogeny and metallogeny of the Bayun Obo deposit in the neighborhood emphasize the diversity, complexity and uniqueness of the Mesoproterozoic Langshan-Zha‘ertal-Bayun Obo ore belt. 相似文献
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Qiuming Pei Shouting Zhang Ken‐ichiro Hayashi Liang Wang Huawen Cao Yu Zhao Xinkai Hu Kairui Song Weiwei Chao 《Resource Geology》2019,69(2):148-166
The recently discovered Xiaobeigou fluorite deposit is situated in the southern part of the Southern Great Xing'an Range metallogenic belt. Fluorite‐bearing veins are rather common over the whole area. So far, 11 mineralized veins have been delineated at the Xiaobeigou deposit. Orebodies of the deposit are mainly hosted in Permian and Jurassic volcano‐sedimentary rocks. The orebodies in this mining district exhibit a well‐developed vertical zonation: from top to bottom, the orebodies can be divided into upper, central, and lower zones. The central zone is the most important part for mining operations, and it shows lateral zonation of fluorite mineralization. Rare earth element (REE) contents of the investigated samples are relatively low (less than 30.2 ppm). Furthermore, the REE contents of the fluorite grains from early to late ore stages exhibit a decreasing trend. All the fluorite samples show no or slightly positive Eu anomalies. Three types of fluid inclusions (FIs) are distinguished in the quartz and fluorite samples, including pure‐liquid single‐phase (PL‐type), liquid‐rich two‐phase (L‐Type), and vapor‐rich two‐phase (V‐type) FIs. The FIs hosted in early‐stage quartz were homogenized at 159.5–260.7°C (mainly 160–240°C); their salinities range from 0.18 to 1.22 wt.% NaCl eqv. The FIs hosted in early‐stage fluorite yield slightly lower homogenization temperatures of 144.4–266.8°C (peaking at 140–220°C), which correspond to salinities of 0.18–0.88 wt.% NaCl eqv. Homogenization temperatures and salinities for the late stage are 132.5–245.8°C (mainly 160–180°C) and 0.18–1.40 wt.% NaCl eqv., respectively. Laser Raman spectroscopy of FIs shows that both the vapor and liquid compositions of the inclusions are dominated by H2O. The H–O isotopic compositions at Xiaobeigou suggest that the ore‐forming fluids are predominantly of meteoric water origin. The Xiaobeigou deposit can be classified as a typical low‐temperature hydrothermal vein‐type fluorite deposit. Combined with regional data, we infer that the fluorite mineralization occurred during the Late Mesozoic in an extensional setting. 相似文献
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Huanzhang Lu 《中国地球化学学报》1983,2(1):45-57
The Fankou Pb-Zn ore deposit occurs in Devonian and Carboniferous carbonate rocks. This deposit was thought to be a hydrothermal ore deposit related to a granite, but the present research suggests it is a stratabound, stratiform mineral deposit. As a result of geological studies, primary sedimentary and later replacement features were found. Part of some ore bodies are concordant with the host rocks, but most are discordant lenses and veins in the carbonate rocks. Thus there are two types of ores, primary sedimentary and later replacement. The replacement type is very common. Isotopic studies indicate that most of the Pb and S are of sedimentary origin, but part of Pb is of radioactive origin, possibly introduced during later replacement. A regional geochemical survey indicates that the Pb and Zn contents of the Fankou region are respectively 1.5 and 3 times the primary sedimentary type. Gas-liquid fluid inclusions were found in the replacement type ore but not in the primary sedimentary type. The fluid which replaced the primary sedimentary rocks had temperatures of 100–200°C, with a salinity of 3–6 wt. % NaCl equiv. Under the action of such fluid the original sedimentary rocks were replaced to form the present ore deposit. 相似文献