江西省铅山地区硅灰石矿地质特征及找矿远景     

徐铅山  毛奀坤  华嵘辉  毛光水 《火山地质与矿产》2009,(2):119-125

铅山地区除金属矿产外,非金属矿产也较多,其中硅灰石矿分布广泛。铅山硅灰石矿赋存于燕山早期侵入形成的葛仙山花岗岩体的外接触带400~500 m范围的下二叠统栖霞组含燧石灰岩和中厚层状夹硅质条带灰岩及硅质页岩、石英砂岩中。矿体多呈透镜状、囊状、不规则条带状等产出,矿体走向长50~100 m,厚度2~30 m。矿石中主要矿物为硅灰石、石英、方解石,硅灰石含量一般60%~70%,矿石化学成分主要为S iO2和C aO。区内燧石灰岩提供了硅灰石形成的硅钙质组合、中深成岩浆岩为钙硅化学合成硅灰石提供了反应热能,属层控热变质交代型矿床。区内同类型硅灰石矿化普遍,具有较好的成矿潜力。  相似文献   

茅口晚期黔中台沟相锰矿地质特征及控矿条件   总被引：9，自引：3，他引：6  

刘平  廖友常  韩忠华  杨光龙  樊正烈 《贵州地质》2005,22(1):31-38

依据地层学的对比研究,云南格学、贵州水城——纳雍和遵义的锰矿均产于中二叠统茅口晚期黔中台沟相带的茅口组第二段,它们在同一成矿地质背景下,其矿床地质特征相似,物质来源相同,具有一定亲缘关系的可比性。该区(带)的锰矿,主要受被动大陆边缘强烈拉张及同生沉积断裂作用,茅口晚期黔中台沟相带和基性火山喷发活动,以及硅灰泥锰矿组合等条件的严格控制。  相似文献   

福建建阳江墩金矿床地质特征及找矿标志     

江里跃 《福建地质》2005,24(3):154-159

建阳江墩金矿呈脉状-（长）透镜状,赋存于矿化蚀变体内或其边缘,与金矿形成关系密切的矿化蚀变体产于下元古界麻源群大金山组上段变质岩系的F6断裂蚀变带中.共发现表内金矿体9个,表外金矿体3个,规模较小,品位较高.初步认为矿床类型属于与变质热液有关的构造蚀变岩型金矿床.  相似文献   

第二深度空间的找矿、勘探和开发利用——深部找矿浅议   总被引：2，自引：0，他引：2       下载免费PDF全文

赵建光  陈强春  李剑  谢文安 《地质找矿论丛》2009,24(1):11-14,46

我国中东部地区已进入深部找矿新阶段,研究并建立深部找矿勘查模型,总结深部矿床的示踪标志和其探测的有效新技术、新方法、新理论与新进展等,对于迎接第二深度空间的找矿、勘探和开发利用意义重大。  相似文献   

福建政和湖屯铅锌矿地质特征及找矿远景浅析     

张文瑞 《福建地质》2009,28(3):181-187

湖屯铅锌矿主要产于中-晚元古代变质岩基底与火山岩接触部位或“天窗”内外,矿体呈脉状、透镜状、似层状,受变质岩层位与后期断裂构造控制,矿床成因类型为海底火山喷发-沉积变质（热液改造）块状硫化物型和构造蚀变岩型硫化物矿床。区内异常范围大,浓度高,成矿条件好。  相似文献   

Nickeloan pyrite from Prangenhaus quarry, Niederberg area, Germany—A short communication     

Udo Harms 《Chemie der Erde / Geochemistry》2009,69(3):279-285

The mineral chemistry of two nickeloan pyrite samples from the Prangenhaus quarry, Wülfrath, is presented. Sample PRH 5: main zone=4.32-9.7 wt% Ni (0.089-0.202 atoms per formula unit (a.p.f.u.)), 0.21-1.31 wt% Co (0.004-0.027 a.p.f.u.); rim zone=11.76-22.38 wt% Ni (0.244-0.466 a.p.f.u. ), 1.35-8.16 wt% Co (0.028-0.168 a.p.f.u.). Sample PRH 6: 6.75-11.33 wt% Ni (0.139-0.234 a.p.f.u.), 0.86-2.46 wt% Co (0.018-0.051 a.p.f.u.). Estimated Fe/Ni and Fe/Co ratios of the hydrothermal fluids forming the nickeloan pyrite point to very local fluctuations in the chemistry of the ore forming fluids in the Prangenhaus quarry. The presence of nickeloan pyrite indicates formation temperatures below 137 °C, which is in accordance with earlier findings of formation temperatures for sphalerite (60-130 °C) in the Niederberg area.  相似文献   

云南金顶超大型铅锌矿区的构造格架与控矿构造问题讨论     

刘俊来  王安建  翟云峰  夏浩然  曹殿华  高兰  修群业 《地质学报》2009,83(10):1376-1387

金顶铅锌矿床是一个以沉积岩(灰岩与砂岩)为寄主岩石的超大型铅锌矿床。本文在对矿区构造和矿床基本特点研究的基础上,重点阐述了两种不同类型矿体(砂岩型和灰岩型)的构造类型、矿石显微构造及矿石组构的特点。本文研究表明,极其发育的断裂构造系统是兰坪盆地地质构造发育的基本特点,在盆地边缘、盆地内部普遍发育了具有薄皮式逆冲断层和推覆构造组合特点的成矿前断裂,它们造成矿区内大规模地层倒转与堆叠现象;盆地中发育了由构造角砾岩与透镜体带构成、宽度达近3km的NE-NNE向成矿期中轴断裂,它控制着矿体或矿床的发育与分布;近SN方向的成矿后地堑构造对于矿床具有破坏作用,并使之剥露于地表。金顶铅锌矿床主要有两种重要的矿床类型,即板状或层状砂岩型矿床和角砾状灰岩型矿床,它们分别位于白垩系钙质长石石英砂岩与三叠系沥青质灰岩构成的两个逆冲席体内。以凤凰山矿区为典型,金顶铅锌矿床具有3层结构:上部的三叠系白云质灰岩岩盖,中部的砂岩型矿体和下部的灰岩型矿体,三者之间被两条作为圈闭存在的重要逆冲断层带间隔。砂岩型矿体与灰岩型矿体之间由几个角砾岩筒连接,作为成矿时期的矿液运移通道存在。破裂与微破裂构造、块状构造、对生脉状构造及假晶构造等是最常见的显微构造型式,它们的存在揭示出破裂与碎裂、充填和交代作用过程在铅锌矿化过程中均起着重要的作用。金顶铅锌矿床的形成与就位,直接受构造作用控制。成矿前的逆冲推覆作用为高压成矿流体的形成以及成矿圈闭的发育创造了条件,成矿期中轴断裂的活动性促使成矿流体向上运移,而灰岩与砂岩的物理性质(包括孔隙度/渗透率以及力学属性)则制约了两种不同类型矿体的出现。致密的灰岩渗透率较低,含矿流体加热了灰岩并使之软化,同时高流体压力使得围岩易碎,形成由早期到晚期的细角砾岩、粗角砾岩和破裂,成矿物质同时沉淀结晶,胶结围岩角砾形成角砾型灰岩矿体。高压流体通过流体通道进入低孔隙度的砂岩后,便迅速弥散于其中,沿着颗粒边界或裂隙充填,并交代岩石中的钾长石碎屑及方解石胶结物,形成块状的砂岩型矿体。  相似文献   

内蒙古图古日格金矿床流体包裹体研究：对矿床成因的约束   总被引：1，自引：1，他引：0  

李永  熊伊曲  邵国钰  刘忠仁  孙诺  祁程 《矿床地质》2019,38(2):319-330

图古日格金矿床是内蒙古狼山-渣尔泰山多金属成矿带一大型金矿床,根据野外矿石类型和矿物共生组合关系可将金成矿作用分为钾长石-石英-黄铁矿阶段(早)、黄铁矿-方铅矿-黄铜矿-石英阶段(中)和石英-碳酸盐-黄铁矿阶段(晚)。文章对早、中、晚阶段的流体包裹体进行了系统的岩相学、显微测温和激光拉曼分析。研究结果表明,早阶段流体包裹体主要为富气、富液水溶液包裹体和CO_2三相包裹体,中阶段主要为水溶液包裹体和纯CO_2包裹体,晚阶段主要发育富液相水溶液包裹体。从早阶段到晚阶段,流体包裹体的均一温度逐渐降低,盐度先升高再降低。激光拉曼分析显示,包裹体的组分主要为水和CO_2,以及少量N_2。综合研究可知,早阶段成矿流体在演化过程中发生了以CO_2逸失为特征的流体不混溶作用;中阶段成矿主导因素为流体的混合作用;晚阶段成矿元素沉淀的主要原因为流体体系的自然冷却。综合矿床地质特征及前人研究成果,认为图古日格金矿是一个与岩浆岩有关的造山型金矿床。  相似文献   

Sulfur and lead isotope systematics: Implications for the genesis of the Riópar Zn-(Fe-Pb) carbonate-hosted deposit (Prebetic Zone,SE Spain)     

《Ore Geology Reviews》2017

The Zn-(Fe-Pb) deposits of the Riópar area (Prebetic Zone, SE Spain) are hosted by dolostones that replace Berriasian to Valanginian (Upper Jurassic-Lower Cretaceous) limestones. Mineralization consists of hypogene sphalerite, marcasite and galena, and supergene calamine zones. The hypogene ores are associated with a saddle dolomite gangue. The ore bodies occur as discordant and stratiform lenses, ore-cemented breccias, cm- to mm-wide veins and veinlets, disseminations and stylolite porosity filling within the host dolomites. The main ore controls include stratigraphy and/or lithology, tectonics (faults, fractures and breccias) and availability of metals and sulfur. The morphologies and epigenetic character of the hypogene ore bodies are consistent with the classification of this mineralization as a Mississippi Valley-type (MVT) deposit. The Ga/Ge geothermometer in sphalerite yielded a temperature range of 194–252 °C, which represents the temperature of the source region of the ore solution. This value is comparable to the temperature obtained in the ore deposition site, 159 ± 15 °C from the Δ³⁴S geothermometer in sphalerite galena pairs. This similitude points to a hydrothermal fluid that did not cool down significantly during flow from the fluid reservoir area to the precipitation site. δ³⁴S values of base-metal sulfides (−7.5 to +3.5‰) are consistent with thermochemical reduction of Triassic sulfate (seawater and/or derived from dissolution of evaporites) by interaction with organic compounds (e.g., hydrocarbons, methane), which reduced sulfate to sulfide in the deposition site. The lead isotope ratios (²⁰⁶Pb/²⁰⁴Pb = 18.736–18.762; ²⁰⁷Pb/²⁰⁴Pb = 15.629–15.660; ²⁰⁸Pb/²⁰⁴Pb = 38.496–38.595) of galena suggest that Pb, and probably other metals as Zn, is derived from continental crustal rocks. On the other hand, these relations points to a unique metal source probably derived from the Paleozoic basement rocks. The relationship between bedding-parallel stylolites, dolomitization, sulfide precipitation and Alpine tectonic affecting the MVT ore, suggests a relative timing range for the mineralization in the Riópar area of 95–20 Ma (Upper Cretaceous-Tertiary). The sulfide mineralization and the associated dolomitization are thus explained by the contribution of two fluids that mixed in different proportions during dolomitization and mineralization: i) a fluid probably derived from Cretaceous seawater saturating Mesozoic sediments (Fluid A), characterized by being dilute and initially low temperature, which should have contained organic rich compounds in the ore deposition site (e.g., hydrocarbons and CH₄ dissolved gas); and ii) a high salinity hydrothermal brine (Fluid B) rich in both metals and sulfate, circulated through the Paleozoic basement. During the pre-ore dolomitizing stage the fluid phase was dominated by the diluted fluid (Fluid A > Fluid B), whereas in a later fluid pulse, the proportion of the high salinity fluid increased (Fluid A < Fluid B) which allowed sulfide precipitation. MVT exploration in the Prebetic Zone should focus towards the SW of the Riópar mines, in the vicinity of the Alto Guadalquivir-San Jorge fault.  相似文献   

赣西北大湖塘石门寺钨矿区花岗岩的成因及其对钨矿的指示意义   总被引：1，自引：0，他引：1       下载免费PDF全文

潘大鹏  王迪  王孝磊 《中国地质》2017,44(1):118-135

江西省晚中生代大湖塘钨矿是近年来中国勘查出的世界级钨矿产地之一,位于新元古代江南造山带的东段,地处赣北武宁、修水、靖安三县交界处。该区属于江南地块中生代钨铜钼等多金属成矿带,大规模出露晋宁期闪长岩和燕山期花岗岩。文章对赣西北大湖塘石门寺钨矿区新元古代和燕山期的4种花岗岩进行详细的岩相学,锆石和锡石U-Pb年代学、微量元素的研究。锆石U-Pb研究结果表明,新元古代黑云母花岗闪长岩的成岩年龄为(829.9±4.7)Ma;燕山期云英岩化似斑状黑云母花岗岩、细粒黑云母花岗岩和云英岩化黑云母花岗斑岩的成岩年龄分别是(148.3±2.6)Ma,(145.5±3.6)Ma和(147.7±1.5)Ma,与锡石所获得的U-Pb年龄相互吻合。主要含矿的似斑状黑云母花岗岩中锡石所含的钨含量明显高于其他燕山期花岗岩,暗示了似斑状黑云母花岗岩岩浆中高的钨含量。锆石钛温度计表明,燕山期的花岗岩均形成于较低的温度,加权平均值的变化范围为734~788°C。锆石的微量元素结果表明,似斑状黑云母花岗岩形成于较低的氧逸度环境,更有利于形成钨矿。  相似文献