安徽庐江泥河铁矿矿床地球化学特征及其对成因的制约   总被引：6，自引：2，他引：4  

张舒  吴明安  赵文广  张宜勇  李小东  汪晶 《岩石学报》2014,30(5):1382-1396

泥河铁矿位于长江中下游成矿带庐枞中生代火山岩盆地中,矿床具有典型玢岩型铁矿的地质特征,是研究玢岩型铁矿成因的良好对象。本次工作在详细的野外观察及室内研究的基础上,对泥河铁矿主成矿期矿石矿物的稀土元素、硫同位素及铅同位素进行了分析测试工作。主成矿期磁铁矿、黄铁矿稀土元素配分模式呈现LREE富集、HREE曲线平直、Eu轻微负异常的特征,与赋矿砖桥组熔岩、闪长玢岩的稀土元素配分模式较为一致,结合矿石矿物与围岩的铅同位素特征,推测成矿金属元素主要来源于赋矿的火山-次火山岩,可能有少量壳源物质的加入。黄铁矿与硬石膏的硫同位素表现出双峰式分布的特征,说明岩浆活动与三叠纪膏盐层均对硫有所贡献。三叠纪膏盐层在泥河铁矿的成矿过程中,不仅仅是重要的矿化剂,同样是铁质沉淀的氧化剂。综合矿床地质与地球化学特征,认为泥河铁矿是由次火山岩体演化产生的含矿高温热液在闪长玢岩穹窿顶部,通过交代充填作用形成的玢岩型铁硫矿床。  相似文献   

贵州省贞丰县雄黄岩金矿床地质特征及找矿方向          下载免费PDF全文

张贞翔  陈发恩  刘艳  游彬  胡基明  匡宗姣 《贵州地质》2014,31(3):182-189

雄黄岩金矿床位于黔西南灰家堡矿田东段,矿床受灰家堡背斜控制,矿床位于灰家堡背斜东段枢纽产状由缓变陡地段,主要矿体赋存于中上二叠统茅口组与龙潭组岩溶不整合面构造蚀变体中,矿体分布于背斜核部800 m,矿体规模大;其次赋存于龙潭组中上部不纯碳酸盐岩中,矿体分布于背斜核部300～500 m.构造蚀变体普遍具金矿化,能否形成工业矿体受卷入地层厚度、岩性组合、蚀变强弱及古岩溶地貌等因素控制.通过对该矿床地质特征的研究,特别是构造蚀变体矿化研究和深部地球探测,认为在该区沿灰家堡背斜轴线向东延伸段、两翼构造蚀变体及北翼F101断层带中仍有矿体存在,具有较好的找矿远景.  相似文献   

贵州海马谷地区金矿矿床特征及成矿模式          下载免费PDF全文

曾昭光  杨恩林  季国松  向通 《贵州地质》2014,31(4):261-266

本文对海马谷地区金矿进行调查,在贵州安龙海马谷发现北东向陡倾角断层控制金矿体,其围岩为二叠系茅口组生物灰岩,矿石为硅化灰岩角砾岩。根据本次调查及收集已有勘查研究成果,建立了该区的成矿模式,认为该区北东向陡倾角断层是下一步该区重要的找矿目标。  相似文献   

金属矿床的成矿流体成分和流体包裹体   总被引：7，自引：1，他引：6  

卢焕章  单强 《岩石学报》2015,31(4):1108-1116

自然界中的成矿流体按其主要成分,可分为:(1)岩浆,即形成岩浆矿床的岩浆;(2)以H2O为主的流体(含Na Cl);(3)以CO2为主的流体。地壳中的流体类型很多,只有含一定金属元素含量的,并且达到一定浓度时才称为金属矿床的成矿流体。基于对矿床中流体包裹体和天然成矿流体中金属种类和含量的测定,这些金属矿床的成矿流体按金属元素含量可以分为五组,成矿流体可以来自岩浆、岩浆热液、大气降水、盆地卤水和变质流体等地质环境。  相似文献   

Prediction of Seafloors Polymetallic Sulphides Resources in the North Atlantic Ridge Area   总被引：1，自引：0，他引：1  

Fang Jie  Sun Jingwen  Xu Hongqing  Ye Jinhua  Chen Jianping  Ren Mengyi  Tangchao 《地球科学进展》2015,30(1):60-68

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香格里拉县红牛矽卡岩型铜矿     

常开永 《云南地质》2006,25(1):12-18

“三江成矿带”内的红牛铜矿,赋存于大理岩边部矽卡岩化蚀变带及角岩体中。赋矿地层为曲嘎寺组第二段。对矿石结构、构造及矿石矿物成分、共生伴生关系等进行研究,明确找矿标志。  相似文献   

Manganese ore deposits in Koira-Noamundi province of Iron Ore Group, north Orissa, India: In the light of geochemical signature   总被引：1，自引：0，他引：1  

B.K. Mohapatra  P.P. Mishra  P.P. Singh  Rajeev 《Chemie der Erde / Geochemistry》2009,69(4):377-394

Several small Mn–Fe oxide and Mn-oxide ore bodies associated with Precambrian Iron Ore Group of rocks are located within Koira-Noamundi province of north Orissa, India. These deposits are classified into in situ (stratiform), remobilized (stratabound) and reworked categories based on their field disposition. Volcaniclastic/terrigenous shale in large geographic extension is associated with these ore bodies.The in situ ore bodies are characterised by cryptomelane-, romanechite- and hematite-dominating minerals, low Mn/Fe ratio (1.1) and relatively lower abundance of trace (1500–2500 ppm) constituents. In such type of deposits the stratigraphic conformity of oxides with the tuffaceous shale suggests precipitation of Mn and Fe at a time of decreased volcaniclastic/terrigenous contribution. The minor and trace elements were removed from solution by adsorption rather than by precipitation. Both Mn and Fe oxides when precipitated adsorb trace elements strongly but the partitioning of elements takes place during diagenesis. The inter-elemental relationship reveals that Cu, Co, Ni, Pb and Zn were adsorbed on precipitating hydrous Mn oxides and form manganates. Some of these elements probably get desorbed from Fe oxide because of their inability to substitute for Fe³⁺ in the lattice of its oxide. However, P, V, As and Mo were less partitioned and retained in Fe-oxide phase. Positive correlation between Al₂O₃ and SiO₂, MgO, Na₂O, TiO₂ and some traces like Li, Nb, Sc, Y, Zr, Th and U points to their contribution through volcaniclastic/terrigenous detritus of both mafic and acidic composition.The remobilized ore bodies are developed in a later stage through dissolution, remobilization and reprecipitation of Mn oxides in favorable structural weak planes under supergene environment. Increase in average Mn/Fe ratio (8) and trace content (5000–8500 ppm) by 5–2.5 orders of magnitude, respectively, or more above its abundance in adjoining/underlying protore is characteristic of these deposits. The newly formed Mn ores constituting lithiophorite, cryptomelane/romanechite and goethite get quantitatively enriched in traces like Cu, Co, Ni, Pb and Zn. Positive correlation between Mn, Li, Co and Zn is due to the formation of mineral of lithiophorite–chalcophanite group during redistribution and reconcentration of Mn oxide. P and V, which were present in Fe oxide, also get dissolved and reprecipitate with Fe oxyhydroxide in these ores. Some other elements like Y, Th and U show positive relation with Fe. This is probably due to leaching of these elements during chemical weathering of associated shale and getting re-adsorbed in Fe-oxyhydroxide phase.However, under oxidizing environment selective cations like Ba, K, etc. resorb from Mn-structure, resulting in the development of pyrolusite (Mn/Fe>20). In such transformation, trace metals from pyrolusitic structure expels out, resulting thereby in a considerable reduction in total trace value (<3000 ppm).The reworked ore bodies are allochthonous in nature and developed through a number of stages during terrain evolution and lateritisation. Secondary processes such as reworking of pre-existing crust; solution and remobilization; precipitation and cementation and transport, etc. are responsible for their development. Such deposits are usually very low in Mn/Fe ratio (3) and trace content (<2000 ppm).  相似文献   

Upgrading of calcareous phosphate ores by flotation: Effect of ore characteristics   总被引：1，自引：0，他引：1  

A.-Z.M. Abouzeid  A.T. Negm  D.A. Elgillani 《International Journal of Mineral Processing》2009,90(1-4):81-89

Sedimentary phosphates contain-besides the phosphate minerals-, various associated gangue minerals such as: clays, silica, calcareous minerals (mainly calcite and dolomite), carbonaceous matter, iron oxides and/or pyrite. The common practiced flow-sheets for concentrating these types of phosphate ores consist of a combination of various mineral processing units such as: crushing and screening, attrition, washing, magnetic separation, and/or flotation. However, none of these combinations was successfully efficient to upgrade the calcareous ores because of the close similarity of the physical properties (density, particle size, particle shape, etc.) as well as the surface physico-chemical properties of the carbonate and phosphate minerals. For the last five decades extensive efforts have been spent to adopt flotation for separating carbonates from phosphate ores. These efforts include thermodynamic analysis, modification of the technique, controlling the pulp environment, and finding new reagents that can specifically differentiate between carbonates and phosphates.This paper reviews some of the published work on the separation of carbonates from phosphate ores by flotation and presents the flotation results of phosphate ore samples different in their physical properties and mineralogical composition. The results obtained reflect the effect of ore nature on the flotation performance and the reagents consumption.  相似文献   

滇东北富乐铅锌矿床微量元素和S-Pb同位素地球化学研究   总被引：6，自引：3，他引：3  

任涛  周家喜  王蝶  杨光树  吕昶良 《岩石学报》2019,35(11):3493-3505

富乐铅锌矿床位于我国西南川滇黔铅锌多金属矿集区的东南部,矿体呈层状、透镜状赋存于中二叠统阳新组白云岩中,受层间破碎带控制。该矿床铅锌金属资源量超过50万吨,铅锌平均品位大于15. 6%。碳酸盐岩围岩溶蚀、重结晶和热液角砾岩化是该矿床普遍发育的热液蚀变类型,是酸性热液流体与碳酸盐岩围岩化学反应的结果。热液白云岩在成矿期前、成矿期和成矿期后都可形成,晚期形成的热液白云岩往往会部分替换早期形成的白云石,热液沿裂隙充填过程中,会引起围岩重结晶作用,形成明显的蚀变晕。矿石中主要硫化物包括闪锌矿、方铅矿和黄铁矿,伴有少量的黄铜矿和黝铜矿,白云石和方解石是主要脉石矿物。矿石的主要构造有致密块状、浸染状、脉状和角砾状。本次工作在富乐矿床厘定出三种颜色闪锌矿,即黑色、红色和棕色。LA-ICPMS研究表明,三种颜色闪锌矿中Cd、Cu、Ga和Ge等元素不同程度富集,而Fe、Mn和In等元素有不同程度亏损。在LA-ICPMS时间分辨率剖面图中,上述元素均呈水平直线出现,与Zn和S等主要元素的含量曲线平行,表明它们可能以类质同象形式赋存于闪锌矿中。而Sb、Pb和Ag等元素在LA-ICPMS时间分辨率剖面图中,呈较大波动趋势,暗示这些元素可能以微细粒包体存在,这与显微观测发现闪锌矿中有方铅矿微小矿物颗粒相吻合。本研究初步认为富乐闪锌矿颜色可能是Ni、Cu、Tl、Ga、Hg、Fe和Cr等多种元素共同引起的,其中Ni、Cu和Ga使闪锌矿呈紫色,Cu使闪锌矿呈红色,Ga使闪锌矿呈黄色。三种颜色闪锌矿样品的硫同位素组成变化较小,其δ~(34)S值变化范围为12. 2‰～14. 6‰,具有富集34S特征,与二叠系海相硫酸盐的δ~(34)S值相似,暗示热化学硫酸盐还原作用(TSR)可能是该矿床HS~-或S~(2-)离子形成的主要机制。不同颜色闪锌矿的~(207)Pb/~(204)Pb、~(206)Pb/~(204)Pb和~(208)Pb/~(204)Pb值分别为15. 604～15. 737、18. 570～18. 732和38. 532～38. 667。大部分闪锌矿的Pb同位素组成与基底昆阳群浅变质岩石的Pb同位素组成相似,少量闪锌矿具有与峨眉山玄武岩和赋矿沉积岩相似的Pb同位素组成,表明富乐铅锌矿床的成矿金属主要来源于基底岩石,并可能受到沉积岩和玄武岩的影响。综上所述,本文认为富乐铅锌矿床是一个形成于挤压背景下、受层间构造控制的高品位、富分散元素后生碳酸盐岩容矿型铅锌矿床。  相似文献   

贵州省兴义市箐脚金矿床地质特征及找矿前景分析          下载免费PDF全文

王友谊  张维乾 《贵州地质》2019,36(2):137-140

箐脚金矿床位于雄武背斜近轴部南东翼南西段,金矿赋存于中、上二叠统之间的构造蚀变岩石中。矿体为层状、似层状、透镜状,矿石多为莓状、球状、胶状、环边状结构,星散浸染状、角砾状、晶洞状、薄膜状构造。本文对矿床的成矿地质特征、矿石结构构造、物质组成、蚀变特征等进行分析总结并对矿床成因进行探讨,分析了找矿前景。认为沿已知矿体走向和倾向上加强研究和深部钻探揭露可进一步扩大矿床规模,矿区仍有较大的找矿远景。  相似文献