Analysis of the fractal clustering of ore deposits in the Spanish Iberian Pyrite Belt   总被引：3，自引：0，他引：3  

P. Gumiel  D.J. Sanderson  M. Arias  S. Roberts  A. Martín-Izard 《Ore Geology Reviews》2010,38(4):307-318

  相似文献   

Interaction of acid mine drainage with waters and sediments at the Corona stream, Lousal mine (Iberian Pyrite Belt, Southern Portugal)   总被引：1，自引：0，他引：1  

E. Ferreira da Silva  C. Patinha  P. Reis  E. Cardoso Fonseca  J. X. Matos  J. Barrosinho  J. M. Santos Oliveira 《Environmental Geology》2006,50(7):1001-1013

This study investigates the geochemical characteristics of the acid mine drainage discharged from the abandoned mine adits and tailing piles in the vicinity of the Lousal mine and evaluates the extent of pollution on water and on the stream sediments of the Corona stream. Atmospheric precipitation interacting with sulphide minerals in exposed tailings produces runoff water with pH values as low as 1.9–2.9 and high concentrations of (9,249–20,700 mg l⁻¹), Fe (959–4,830 mg l⁻¹) and Al (136–624 mg l⁻¹). The acidic effluents and mixed stream water carry elevated Cu, Pb, Zn, Cd and As concentrations that exceed the water quality standards. However, the severity of contamination generally decreases 4 km downstream of the source due to mixing with fresh waters, which causes the dilution of dissolved toxic metals and neutralization of acidity. Some natural attenuation of the contaminants also occurs due to the general reduced solubility of most trace metals, which may be removed from solution, by either co-precipitation or adsorption to the iron and aluminium precipitates.  相似文献   

昭通地区无烟煤中硫的赋存状态     

熊振涛  XIONG Zhen-tao 《云南地质》2011,30(2):198-199,192

滇东北无烟煤多数属难选高硫煤,本文对硫的赋存状态与及在洗选中硫与粒度关系进行了研究。  相似文献   

安徽铜山铜矿床硫化物Re-Os定年及其地质意义   总被引：6，自引：2，他引：4  

陈红瑾  张静  贾鹏飞  李大鹏  张智宇  王遹其 《岩石学报》2011,27(6):1779-1784

安徽铜山矽卡岩型铜矿床是长江中下游成矿带的重要矿床之一,其2件辉钼矿样品和2件黄铁矿样品的Re-Os同位素年龄分别为150.70±1.14～151.22±1.11Ma和148.73±3.22～152.50±6.69Ma,4件样品的等时线年龄为150.98±0.78Ma( MSWD =0.68,误差2σ).这一结果表明,...  相似文献   

湖北古城锰矿Fe同位素特征及其地质意义     

张飞飞  彭乾云  朱祥坤  闫斌  李津  程龙 《地质学报》2013,87(9):1411-1418

本文报导了湖北古城锰矿含锰层位中黄铁矿Fe同位素的研究结果,并利用黄铁矿Fe同位素对黄铁矿成因和大塘坡早期阶段沉积环境的氧化还原状态进行了制约。黄铁矿δ56Fe值变化范围为-0.13‰~+0.54‰,平均值为+0.22‰,显示相对于当时海水（0~-0.5‰）明显富集Fe的重同位素。本文认为黄铁矿的Fe来自海水中Fe2+部分氧化形成的Fe3+,这些Fe3+在成岩过程中被全部还原,与细菌硫酸盐还原作用形成的H2S结合最终以黄铁矿形式保存在沉积物中。大塘坡式锰矿含锰层位中黄铁矿Fe同位素特征表明,古城冰期（Sturtian冰期）结束之后,大塘坡早期阶段海洋深部已经开始氧化,但是并没有完全被氧化。  相似文献   

Organic matter–apatite–pyrite relationships in the Botneheia Formation (Middle Triassic) of eastern Svalbard: Relevance to the formation of petroleum source rocks in the NW Barents Sea shelf     

《Marine and Petroleum Geology》2013

The Middle Triassic Botneheia Formation of eastern Svalbard (Edgeøya and Barentsøya) comprises an organic carbon-rich, fine-grained clastic succession (∼100 m thick) that makes the best petroleum source rock horizon in the NW Barents Sea shelf. The succession records a transgressive–regressive interplay between the prodelta depositional system sourced in the southern Barents Sea shelf (black shale facies of the lower and middle parts of the Muen Member) and the open shelf phosphogenic system related to upwelling and nutrient supply from the Panthalassic Ocean (phosphogenic black shale facies of the upper part of the Muen Member and the Blanknuten Member). The relationships between organic matter, authigenic apatite, and pyrite in these facies allow to characterize the relative roles of redox conditions and oceanic productivity in the organic carbon preservation. The accumulation of terrestrial and autochthonous marine organic matter in the black shale facies occurred under dominating oxic conditions and increasing-upward productivity related to early transgressive phase and retrogradation of the prodelta system. The phosphogenic black shale facies deposited in an oxygen-minimum zone (OMZ) of the open shelf environment during the late transgressive to regressive phases under conditions of high biological productivity, suppressed sedimentation rates, and changing bottom redox. The phosphatic black shales occurring in the lower and upper parts of the phosphogenic succession reveal depositional conditions indicative of the shallower part of OMZ, including high input of autochthonous organic matter into sediment, oxic-to-dysoxic (episodically suboxic and/or anoxic) conditions, intense phosphogenesis, and recurrent reworking of the seabed. The massive phosphatic mudstone occurring in the middle of the phosphogenic succession reflects the development of euxinia in the deeper part of OMZ during high-stand of the sea. High input of autochthonous organic matter in this environment was coupled with mineral starvation and intermittent phosphogenesis. In mature sections in eastern Svalbard, the petroleum potential of the Botneheia Formation rises from moderate to good in the black shale facies, and from good to very good in the phosphogenic black shale facies, attaining maximum in the massive phosphatic mudstone.  相似文献   

Deciphering a multistage history affecting U–Cu(–Fe) mineralization in the Singhbhum Shear Zone,eastern India,using pyrite textures and compositions in the Turamdih U–Cu(–Fe) deposit     

Dipak C. Pal  Mark D. Barton  A. K. Sarangi 《Mineralium Deposita》2009,44(1):61-80

The ～200-km-long intensely deformed Singhbhum Shear Zone (SSZ) in eastern India hosts India’s largest U and Cu deposits and related Fe mineralization. The SSZ separates an Archaean cratonic nucleus to the south from a Mesoproterozoic fold belt in the North and has a complex geologic history that obscures the origin of the contained iron-oxide-rich mineral deposits. This study investigates aspects of the history of mineralization in the SSZ by utilizing new petrographic and electron microprobe observations of pyrite textures and zoning in the Turamdih U–Cu(–Fe) deposit. Mineralization at Turamdih is hosted in intensively deformed quartz–chlorite schist. Sulfides and oxides include, in inferred order of development: (a) magmatic Fe(–Ti–Cr) oxide and Fe–Cu(–Ni) sulfide minerals inferred to be magmatic (?) in origin; followed by (b) uranium, Fe-oxide, and Fe–Cu(–Co) sulfide minerals that predate most or all ductile deformation, and are inferred to be of hydrothermal origin; and (c) Fe–Cu sulfides that were generated during and postdating ductile deformation. These features are associated with the formation of three compositionally and texturally distinct pyrites. Pyrite (type-A), typically in globular–semiglobular composite inclusions of pyrite plus chalcopyrite in magnetite, is characterized by very high Ni content (up to 30,700 ppm) and low Co to Ni ratios (0.01–0.61). The textural and compositional characteristics of associated chalcopyrite and rare pyrrhotite suggest that this pyrite could be linked to the magmatic event via selective replacement of magmatic pyrrhotite. Alternatively, this pyrite and associated sulfide inclusions might be cogenetic with hydrothermal Fe-oxide. Type-B pyrite that forms elongate grains and irregular relics and cores of pyrite with high Co contents (up to 23,630 ppm) and high Co to Ni ratios (7.2–140.9) are interpreted to be related to hydrothermal mineralization predating ductile deformation. A third generation of pyrite (type C) with low Co, low Ni, and moderate Co to Ni ratios (0.19–13.93) formed during and postdating the ductile deformation stage overgrowing, replacing, and surrounding type-B pyrite. The textural evolution of pyrite parallels the tectonometamorphic evolution of the shear zone demonstrating grain elongation during progressive ductile deformation and prograde metamorphism, annealing at the peak metamorphic condition, porphyroblastic growth at the retrograde path and cataclasis following porphyroblastic growth. Compositional characteristics of hydrothermal pyrite and available geological information suggest that the U–Cu(–Fe) deposit at Turamdih might be a variant of the Fe oxide (–Cu–U–rare earth elements) family of deposits.  相似文献   

钦-杭带南段坡仔营斑岩型钼矿中黄铁矿微组构及其标型意义     

安燕飞  李兴远  王语  朱启宽  刘丙祥  张文媛  郑刘根  Nenzhelele JDN 《岩石学报》2017,33(3):729-738

坡仔营钼矿是钦-杭成矿带南段最重要斑岩型矿床之一。该矿床发育典型"中心式面型蚀变"和A、B和D三种类型矿化脉。为了加深对其成矿过程的认识,本研究选取不同矿脉中黄铁矿,通过扫描电镜（SEM）、X射线粉晶衍射（XRD）和激光拉曼光谱（Raman）,研究其微组构标型特征,以期反演成矿过程的热力学及动力学信息。SEM结果显示,A脉内黄铁矿较少,呈100~200μm半自形-他形,籽晶呈扁平乳滴状;B脉黄铁矿强烈发育,呈500~1000μm自形-半自形,籽晶呈近椭圆形层状;D脉内黄铁矿呈立方体产出,粒度10~20mm左右,三组相互垂直晶纹发育,籽晶棱角状线形展布。A脉→B脉→D脉中黄铁矿粒度逐渐变大,籽晶更加规则,指示成矿早期至晚期,黄铁矿结晶速度逐渐变缓,成生环境趋于稳定。XRD结果展示,各样品谱线均发育着多组黄铁矿特征峰,但其强峰发育存在差异。A脉最强峰为28.5°,次强峰37.1°;B脉和D脉相应峰位分别为37.1°、33.1°和33.1°、56.3°。衍射峰型特征表明,A脉样品晶形应以（1 1 1）面组成的正八面体单形为主,其次为（2 1 0）晶面组成的五角十二面体,其成生温度应大于300度;B脉样品应以（2 1 0）组成的五角十二面体单形为主,其次为（1 0 0）晶面组成的立方体单形,形成温度应介于200~300℃之间或略大;D脉样品主要以（1 0 0）晶面组成的立方体为主,其形成温度应小于200℃。Raman光谱揭示,A脉样品的ν_Eg=348.0~350.7cm^-1、ν_Ag=385.2~386.5cm^-1、ν_Tg=441.9~422.8cm^-1,与之相比,B脉和D脉的对应值分别向低频偏移2~6cm^-1和5~14cm^-1;A脉样品的散射强度I_Eg=388.8~745.5、I_Ag=1532.8~2071.8、I_Tg=238.9~254.4,而B及D脉样品的散射强度依次明显增强。自A脉→B脉→D脉,拉曼位移向低频偏移,散射强度依次增强,指示三者的成生压力依次降低。本研究认为,坡仔营斑岩型钼矿的成生早期为一个高温、高压岩浆热液活动为主阶段,随着成矿温度、压力的降低,成矿系统氧逸度逐渐降低,硫及金属元素逐步转变为金属硫化物形式而成矿。  相似文献   

LA-ICPMS原位微区面扫描分析技术及其矿床学应用实例     

周伶俐  曾庆栋  孙国涛  段晓侠  BONNETTIChristophe  RIEGLERThomas  LONGDarrelGF  KAMBERBalz 《岩石学报》2019,35(7):1964-1978

LA-ICPMS原位微区面扫描技术的发展对解析具有包裹体、环带结构的矿物或受多期岩浆/热液活动影响形成的溶蚀再结晶的矿物具有重要的地质意义。黄铁矿作为最普遍的硫化物种类之一,可形成于各种类型矿床中,其微量元素组份记录了矿床形成过程的重要信息。通过LA-ICPMS原位微区面扫描技术获得的黄铁矿晶体内部结构组份信息可用来限定成矿流体的性质、厘定成矿流体的演化规律、示踪成矿物质来源、约束变形变质作用过程中元素的活化和迁移行为,以及约束矿床成因等。本次研究选取了内蒙古二连盆地中巴彦乌拉大型铀矿床、辽宁青城子地区榛子沟铅锌矿、加拿大Pardo砂金矿中的黄铁矿作为研究对象,运用原位微区LA-ICPMS元素面扫描技术揭示其内部组份及结构信息,探索该技术在不同类型矿床中的应用价值。巴彦乌拉大型砂岩型铀矿床中的黄铁矿的内部组构信息显示成矿体系的p H和Eh对硫酸盐还原细菌活动均有影响,并控制与之相关的铀矿化;且成矿体系的p H和Eh受到外界不断供给的地下水的影响,呈振荡性变化。辽宁榛子沟铅锌矿中的黄铁矿的内部组构信息显示矿化过程受到了至少两期流体活动的叠加影响,包括早期同沉积时期的流体以及晚期与燕山期岩浆活动有关的热液流体。加拿大Pardo金矿中黄铁矿的内部组构信息显示矿床中半自形-自形的黄铁矿实际包含碎屑成因的磨圆状核部及后期热液活动形成的增生边;金主要呈浸染状分布在碎屑成因的黄铁矿核部,后期热液活动对金矿化影响微弱。  相似文献   

云南富乐铅锌矿床黄铁矿微量(稀散)元素组成及成因信息:LA-ICPMS研究   总被引：2，自引：2，他引：0  

李珍立  叶霖  胡宇思  韦晨  黄智龙  念红良  蔡金君  DANYUSHEVSKY Leonid 《岩石学报》2019,35(11):3370-3384

川滇黔铅锌矿集区是华南大面积低温成矿域的重要组成部分,区内铅锌矿床是否属于MVT型矿床长期存在争议。该区铅锌矿床以富集Ge等稀散元素为特征,闪锌矿是其主要载体矿物,但稀散元素在黄铁矿中是否富集、赋存状态及微量元素组成特征等研究基本属于空白。本文通过LA-ICPMS研究富乐黄铁矿中微量元素(尤其是稀散元素)的富集特征,发现黄铁矿中也相对富集Ge。本研究样品选自富乐矿床的富乐和富盛两个矿段,包括1350、1410和1536三个中段(由深到浅),LAICPMS分析结果表明,该矿床黄铁矿以富集Cu、As、Co、Ni为特征,局部富集Pb(Sb)和Zn(以方铅矿和闪锌矿显微包裹体形式赋存于黄铁矿中),该类黄铁矿富集的稀散元素主要为Se、Ge及少量Tl、Te,而Cd和In以类质同象形式赋存于含Zn的显微包裹体(闪锌矿)中,类质同象是其余稀散元素主要赋存形式,且黄铁矿中Ge与Cu存在较好相关关系,可能存在Cu~(2+)+Ge~(2+)?2Fe~(2+)耦合置换方式。此外,黄铁矿中稀散元素的富集与成矿元素(特别是Cu)的富集密切相关,随着成矿作用的进行,从矿体深部到浅部,成矿温度逐渐降低,Se/Te比值逐渐升高,且稀散元素与成矿元素呈逐渐增加趋势。研究表明,该矿床黄铁矿的Co/Ni比值基本都小于1. 00,暗示其属于沉积改造型黄铁矿,在Co-Ni和稀散元素Se-Tl含量投影图上,富乐矿床黄铁矿的投影点与MVT型矿床投影区基本一致,而明显有别于SEDEX、VMS和矽卡岩型矿床中黄铁矿的投影区,结合富乐矿床类似于MVT型的地质特征,我们认为富乐矿床属于MVT型铅锌矿床。  相似文献