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冀北银矿床类型、矿床地质地球化学、地史-演化模式及找矿方向 总被引：10，自引：5，他引：5
对冀北１７个银矿床地质调查和５个大一中型银矿床地质、地球化学剖析研究基础上,从银矿床产出的区域地质、矿床地质、控制地质条件、围岩蚀变、矿石类型、成矿机理、成矿时代和成矿物质演化上,确定了冀北银矿床有３个成矿系列,８种矿床类型。提出牛圈子为火山喷气－热泉型银矿床;蔡家营为古喷气－热水沉积变质－热液叠加型铅锌银矿床;银冶岭为层控－热液叠加型铅锌银矿床的新认识,建立了冀北银矿床成矿模式和地史演化的区域成 相似文献
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《矿产与地质》2019,(4)
为了探究尕龙格玛铜多金属矿床成因,选取金属硫化物为研究对象,通过电子探针进行矿物学分析研究。结合矿床地质特征,为该矿床成因提供依据。结果表明:该矿床成矿阶段可划分为火山沉积热液期和中温热液硫化物期,并进一步细分为热水沉积-黄铁矿阶段、石英-黄铁矿阶段、碳酸盐阶段、铜铅锌-硫化物阶段和闪锌矿-碳酸盐阶段等五阶段。不同成矿阶段的黄铁矿标型特征表明其分别具有火山喷流沉积、火山热液改造和岩浆热液等不同成因。该矿床经历了早期火山喷流沉积,形成火山沉积(热液)矿化;中期受较大范围的火山热液充填交代;后期中酸性岩浆侵入引起的中温岩浆热液矿化,沿着断裂构造上侵,在前期矿化体中叠加成矿。 相似文献
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新疆穷布拉克铜矿床成矿模式 总被引：6，自引：0，他引：6
穷布拉克铜矿床地质研究表明，该矿床为火山热液、次火山热液和沉积－改造作用成矿。认为岩浆和成矿物质来源于深部地壳，成矿与火山—次火山作用密切相关，是同一岩浆源分异演化不同阶段的产物，矿床成因属中低温火山—次火山热液型和沉积—改造型矿床，并建立了矿床成矿模式 相似文献
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云南老新街铜矿床地质特征及成因探讨 总被引：2，自引：0，他引：2
龙脖河铜矿带老新街铜矿床位于红河断裂与阿龙古－龙山断裂夹持的红河裂陷槽中。矿体呈层状、似太产出,受层位、岩性和构造控制。 蚀变发育,硅化、黄铁矿化、绿泥石化与矿化关系密切,根据老新街铜矿床的地质特征,探讨了成矿物质来 成矿机制,指出了矿床属于火山沉积－热液叠加改造型层控矿床。 相似文献
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变质矿床成因分类的讨论 总被引：2，自引：0，他引：2
在探讨了变质矿床的定义并结合前人研究的基础上,对变质矿床初步提出了一个新的成因分类方案。该方案共分为五个大类和十三个亚类,并对每个大类和亚类都提出了一些代表性矿床实例。新的变质矿床成因分类方案为：（1）受变质矿床类,分为受变质硅铁质建造沉积矿床、受变质硅铁质建造火山–沉积矿床、受变质其它建造沉积–火山沉积矿床、受变质火成岩改造矿床和受变质细碧角斑质火山喷发沉积矿床五个亚类;（2）区域变质作用变成矿床类,分为变质重结晶型、变质化学反应重组型和变质热液型三个亚类;（3）局部变质作用变成矿床类,分为接触交代夕卡岩矿床、局部接触热变质变成矿床和局部动力变质变成矿床三个亚类;（4）受变质沉积–火山沉积变质热液叠加改造矿床类;（5）混合岩化作用形成矿床类,又分为混合岩化交代型和后期混合岩化热液型两个亚类。 相似文献
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恰夏─铁米尔特多金属矿田已发现黄铁矿型铜矿床、黄铁矿型铜铅锌多金属矿床和构造热液型铜金矿床三种矿化类型，组成矿田的矿床系列。早泥盆世第一次火山活动于近火山口附近形成与喷气热液有关的恰夏黄铁矿型铜矿床；于火山洼地中形成与火山－沉积作用有关的铁米尔特黄铁矿型铜铅锌多金属矿床；褶皱期于构造破碎带中形成构造热液型铜金矿化．区内三种矿床（化）类型具有较大远景． 相似文献
10.
丁－马微细浸染型层控锑－金矿床是在特殊的大地构造背景下的扩张海盆复杂岩相古地理沉积环境中，首先形成金等成矿元素初始富集矿源层，并在沉积成矿作用的基础上，经进一步叠加改造成矿作用，形成具沉积（含火山热液）－构造叠加－地下水循环热液改造成因的矿床。 相似文献
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庐枞盆地中发育一些大中型硫铁矿床,曾长期被认为是与次火山岩有关的中低温热液成因。本文从矿床层控特点、矿体形态产状、矿石沉积组构、矿物组合及其生成顺序、矿化分带、包裹体及同位素地球化学等诸方面,证明它们具显著的火山喷气沉积成因特征,并受到后期热液叠加改造。提出了大鲍庄式陆相火山喷气沉积-热液叠加改造型硫铁矿的成矿模式。 相似文献
13.
宋文霞 《沉积与特提斯地质》2002,22(3):95-99
拨茅山—牛头山铜矿床的的赋矿岩石为中生代的火成岩系。侵入岩一潜火山岩一火山岩构成完整的侵入—喷发系列。该矿床可分为火山气液—沉积铜矿床和斑岩型铜矿床两种类型。在成矿前期，陆相火山岩在湖底发生火山喷气、火山热泉以及火山热水沉积。潜火山岩的侵入，伴有长期热液循环活动，在张性断裂为主的赋矿空间生成与斑岩有关的各类型矿床。 相似文献
14.
华南白垩-第三纪地壳拉张与铀成矿的关系 总被引：65，自引：0，他引：65
华南是中国最重要的铀矿产区之一。按赋矿围岩的不同 ,该区主要产出花岗岩型、火山岩型和碳硅泥岩型 3类铀矿床。铀矿区都分布有比铀成矿超前形成的富铀岩石 ;铀矿床成矿热液中的水主要为大气成因地下水 ,成矿温度约为 1 2 0～ 2 5 0℃ ,成矿热液的δ1 3 C值主要为 - 4‰～ - 8‰ ,表明幔源CO2 参与了成矿作用 ;矿床的N(3 He) /N(4He)为 0 .1 0～ 2 .0 2Ra,显示成矿热液中大量幔源He的存在。这些铀矿床的成矿时代与赋矿围岩的岩性和时代无关 ,都集中在该区地壳受到强烈拉张因而断陷盆地广泛发育并伴有幔源基性岩浆活动 (基性脉岩、玄武岩 )的白垩—第三纪。研究表明 ,白垩—第三纪导致了地幔与地壳表层沟通的地壳拉张 ,把该区 3大类型的铀矿床串联成了一个有机的整体 :(1 )地壳拉张通过控制向大气成因的贫CO2 热液提供铀成矿必不可少的幔源CO2 ,而与铀成矿发生联系 ;(2 )同一机制形成的富CO2 热液浸取同一或不同铀源岩石中的铀并在不同围岩中成矿 ,形成了按赋矿围岩划分的各种矿床类型 (花岗岩型、火山岩型和碳硅泥岩型 )。 相似文献
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块状硫化物矿床(黄铁矿型矿床、黑矿型矿床)与玄武岩-流纹岩建造的相互关系是由矿石与围岩形成的近似性所决定的,更确切地说,是矿石有规律地产在火山岩一定的岩相中。近年来,火山岩系的岩相分析已成为火山岩地区区域地质调查、块状硫化物矿床普查勘探工作中最重要的方法之一。这是因为,一方面岩相分析和古火山恢复方法,可以对火山体、火山岩系的喷发沉积旋回,以及火山岩的层序进行详细的研究,从而较为客观地总结出 相似文献
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The Hatu, Qi-III, and Qi-V gold deposits in the Hatu–Baobei volcanic–sedimentary basin (west Junggar, Xinjiang) represent the proximal, middle, and distal parts of the Hatu gold district, respectively. Orebodies of these deposits mainly consist of Au-bearing quartz veins and altered host rocks with disseminated sulfide minerals. Six types of pyrite in these mines are studied here to illustrate ore-formation processes. Sedimentary pyrite, including framboidal and fine-grained pyrite, occurs in mudstone-bearing sedimentary rocks or altered volcanic–sedimentary rocks. Framboidal pyrite formed during redox changes in sedimentary layers. Hydrothermal pyrite contains five subgroups, from Py1 to Py5. Porous Py1 formed prior to gold mineralization, and is overgrown by Py2 that contains inclusions of sulfide minerals and native gold. Coarser Py3 coexists with arsenopyrite and native gold, and contains the greatest As concentrations. Gold and antimony are also preferentially concentrated in arsenian Py2 and Py3. The Au–As-deficient Py4 and Py5 formed during the post-ore process. There is a negative correlation between the As and S contents in Py1, Py2, and Py3, implying the substitution of sulfur by arsenic. Gold precipitated under relatively reducing condition in framboid- and graphite-bearing tuffaceous rocks. Cesium, Rb, Sr, La, Ce, Au, As, Sb, Cu, and Pb are concentrated in altered host rocks. The Au-bearing quartz veins and disseminated sulfide mineral orebodies were formed via a co-genetic hydrothermal fluid and formed during different stages. The variation of fO2 during fluid/rock interactions, and crystallization of arsenian pyrite were major factors that controlled gold precipitation. 相似文献
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安徽向山地区火山岩层中硬石膏的沉积成因特征及其与硫铁矿的关系 总被引：8，自引：0，他引：8
本文从赋矿地层,含矿层序、容矿岩性、矿石结构构造、矿物组合、生成顺序、地球化学特征以及区域对比等方面,论证了向山地区的硬石膏矿床是在蒸发环境条件下,主要由火山喷气作用提供物质来源,通过沉积作用所形成的特殊膏盐建造,并受到后期岩浆热液的叠加改造。文章还分析了硬石膏形成的地质环境条件。最后阐述了该区硫铁矿与硬石膏的两种成因关系。 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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In northern Chile, between 27 and 33°S, there are numerous deposits where residual petroleum is associated with Cu-(Ag) mineralisation (the most famous being El Soldado). All of these deposits are hosted by Lower Cretaceous volcanic or volcanoclastic facies along the axis of a former backarc basin. This close relationship suggests that the generation, migration and emplacement of hydrocarbons in the Cretaceous volcanic units is a regional process, associated with the evolution of the Cretaceous backarc basin and points to the importance of pyrobitumen as an exploration tool for similar Cu–(Ag) deposits. The present work analyses four small strata-bound copper deposits located along a north–south belt approximately 10 km east of Copiapó in northern Chile. These deposits are typically hosted by pyrobitumen-rich andesitic volcanic to volcanoclastic rocks intercalated with the marine carbonate Pabellón Formation, the youngest formation within the Chañarcillo Group. The strong genetic and spatial relationships between the pyrobitumen-rich lavas and the mineral deposits allow us to define this volcanic belt as the Ocoita-Pabellón Metallotect. Two hydrothermal events can be distinguished based on the mineralogical, textural, fluid inclusion and isotope data of ore and gangue and on the optical properties of residual petroleum. During the early event, petroleum was mobilised from the source rocks into the primary and secondary porosity of the lavas by Fe-rich hydrothermal fluids, which precipitated pyrite as an early sulphide phase. The second event is characterised by Cu-rich hydrothermal fluids, which induced three successive sub-stages of Cu-sulphide precipitation. The hydrothermal fluids chemically and thermally altered the first-stage bitumen, transforming it into pyrobitumen. The present work documents similarities between the Ocoita-Pabellón Metallotect and the El Soldado ore deposit and emphasises important differences. In the El Soldado host rocks, a petroleum reservoir existed prior to the arrival of the mineralising hydrothermal fluids, the framboidal pyrite was formed by assistance of bacteria, the S of the Cu sulphides was inherited from the pyrite, and the fluid source was basin connate-metamorphic brine. In the Ocoita-Pabellón Metallotect, the hydrocarbons were mobilised into the host rocks by hydrothermal fluids; the pyrite is epigenetic, the δ34S values of pyrite and copper sulphides are very different, with distinctive light δ34S signature of Cu sulphides (δ34S between −44.7 and −17.9‰), and the calculated δ18O of hydrothermal fluids indicates the participation of meteoric water in the late phases of the hydrothermal system.
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