陕南羊坪湾金矿床黄铁矿标型特征研究     

李斌  杨兴科  杨宏宇  高雅宁  何虎军 《地质论评》2016,62(S1):311-312

羊坪湾金矿位于陕西石泉-汉阴北部金矿带东部,前人曾在该地区开展过大量勘探和综合研究,并取得一定的认识成果（李会民等,1997;李福让等,2009;任小华等,2015）。羊坪湾金矿床中载金矿物主要为黄铁矿,其次为磁黄铁矿,此外还有少量褐铁矿、石英等。本次重点针对矿区内载金黄铁矿进行电子探针测试分析,探讨其同金成之间关系。  相似文献   

粤西庙山铜多金属矿床硫化物微量元素LA-ICP-MS原位测定及S同位素对矿床成因的制约   总被引：7，自引：0，他引：7  

邢波  郑伟  欧阳志侠  吴晓东  林玮鹏  田云 《地质学报》2016,90(5):971-986

庙山铜多金属矿床是在粤西阳春盆地内新近发现的一处铜多金属矿床。矿体主要呈似层状和透镜状产于泥盆系的陆源碎屑岩和含泥质的碳酸盐岩中。本文以矿石矿物黄铁矿和闪锌矿为研究对象,采用LA-ICP-MS原位微区分析新技术对其微量元素特征进行研究。结果表明,庙山铜多金属矿床中黄铁矿以富Se、Te和As,贫Ni元素为特征,其Co/Ni和S/Se比值特征指示其成因与岩浆热液型矿床密切相关;闪锌矿的微量元素组成指示其主要形成于中高温环境,以富Mn、In、Se,贫Ga、Ge、Tl等元素为特征,总体与国外一些典型的矽卡岩型矿床（如Baita Bihor、Majdanpek、Ocna de Fier和Valea Seaca）相似。同时,闪锌矿的部分微量元素比值（如Zn/Cd、Ga/In等）以及相关的微量元素图解（如Ge-In, Ge-Se等）均表明庙山矿床的成因类型与矽卡岩型矿床一致。硫同位素测试结果表明,矿石的δ34S值较为集中（-0.4‰ ~ +2‰）,平均0.69‰,具有较为明显的塔式分布特征,反映成矿物质具有岩浆来源的特征。以地质现象为基础,结合硫化物原位微区分析和硫同位素数据,我们认为庙山铜多金属矿床属于与岩浆热液有关的矽卡岩型矿床。  相似文献   

Data analysis of a revisited exploration geochemical dataset of quartz porphyrites from SW Jordan using GIS techniques     

《Chemie der Erde / Geochemistry》2016,76(4):519-527

The spatial distribution of Cu and its pathfinder elements in quartz porphyrites along Wadi Araba was studied in order to gain an insight about the geologic framework of Cu mineralization in the area. A geochemical exploration data set of 242 samples was revisited. Multivariate statistical and geostatistical analysis were performed on the data set. The objectives of the study were to define Cu relationships with its possible pathfinder elements and to figure out whether geostatistical treatment of exploration data would help telescoping already existing Cu mineralization in Wadi Araba, SW Jordan. Factor analysis and hierarchical cluster analysis were performed on the data set. The results of which indicate that seven elements, namely, Ba, Cr, Mn, Ni, Sc, Sr and V can be considered as pathfinder elements for Cu. Significant correlations do exist between Cu and these elements. The encountered experimental semivariograms of the defined pathfinders were fit to exponential models with varying nugget effects with the exception of Mn which was fit to the spherical model. Ordinary kriging was found to be most appropriate to generate geochemical exploration maps. The applied methods succeeded in deriving valuable information and visualizing the already existing Cu mineralization in Wadi Abu Khusheiba area.  相似文献   

Bacterially-mediated weathering of crystalline and amorphous Cu-slags     

《Applied Geochemistry》2016

Two types of Cu-slags (CS: crystalline massive slag and GS: granulated amorphous slag) exhibiting a different chemical and mineral phase composition were compared with respect to their susceptibility to bacterial weathering using Pseudomonas aeruginosa (n° CIP 105094). Abiotic conditions e.g. sterile growth medium and ultrapure water were used for comparison. The experiments were extended up to 112 days with a systematic liquid phase renewal every 14 days. The results revealed significant release of elements in the bacterially mediated weathering experiments. Concentrations of elements (Si, Fe, Cu, Zn and Pb) in the biotic solutions were increased at least by 20% up to 99% compared to abiotic ones. From 3 to 77% of the leached elements were associated to the fraction >0.22 μm. Scanning electron microscope observations demonstrated greater weathering of mineral phases in biotic experiments than in abiotic ones which is in accordance with the solution chemistry exhibiting higher concentrations of elements leached in biotic set-ups. In the case of CS, glass and sulfides weathering was yet observed in abiotic experiment, whereas partial dissolution of fayalite (Fe₂SiO₄) was solely affected by the presence of bacteria. GS having a higher bulk content of metallic elements was found to be more stable than sulfide-bearing CS, while its (GS) glass matrix was found to weather easier under biotic conditions.  相似文献   

广西北部湾地区表层土壤中Cu地球化学分布特征及影响因素研究     

郑国东  覃建勋  赵辛金  吴天生  陈彪  陆康运 《矿产与地质》2016,(3):455-460

选取广西北部湾地区表层土壤为研究对象,采集7327件土壤样品,400件岩石样品,分析K_2O、Na_2O、CaO、MgO、SiO_2、Al_2O_3、TFe_2O_3和有机碳,探讨了土壤成土母岩、成土作用、土壤组成和土壤性质等对表层土壤Cu元素的影响。结果表明,研究区表层土壤Cu元素含量低于中国土壤背景值;风化作用对于Cu元素的次生富集起到极为重要的作用,强于成土母岩元素含量背景的影响。Pearson相关分析和主成分分析结果表明,土壤组成和土壤性质等因素中,含Al矿物、含Fe矿物和有机碳(SOC)对土壤Cu的富集起到主导作用;pH和含Ca矿物起到次要作用,而含K矿物、含Na矿物和含Mg矿物的作用较弱,可以忽略不计,SiO_2则起反作用。  相似文献   

西秦岭与赛什塘铜矿床有关的花岗质岩石岩浆源区特征及大地构造背景探讨   总被引：2，自引：1，他引：1  

付长垒  闫臻  郭现轻  牛漫兰  陈雷  夏文静 《岩石学报》2016,32(7):1997-2014

西秦岭赛什塘铜矿区内出露的三叠纪花岗质岩石有闪长玢岩、石英闪长岩、石英闪长玢岩、花岗斑岩和石英斑岩,其岩浆源区与形成构造环境可为古特提斯洋演化和区域成矿作用研究提供证据。岩石地球化学特征共同表明,这些花岗质岩石属于准铝质钙碱性-高钾钙碱性系列,为I型花岗岩;Mg#值变化较大(39~68),LREE富集,HREE亏损,(La/Yb)N比值介于8.50~22.9,具有Eu负异常,δEu介于0.28~0.78,同时富集大离子亲石元素Cs、Rb、K、Pb,亏损高场强元素Nb、Ta、Ti,呈现出与典型俯冲作用密切相关岛弧花岗岩相一致地球化学特征。石英闪长玢岩和石英斑岩SHRIMP锆石U-Pb年龄分别为219.0±2.3Ma和220.0±2.0Ma,锆石εHf(t)分别为-4.5~-2.1和-2.5~+1.0,对应二阶段模式年龄分别为1392~1544Ma和1190~1415Ma。结合前人对西秦岭三叠纪花岗岩以及其南侧阿尼玛卿蛇绿混杂带研究成果,本文认为赛什塘铜矿区花岗质岩石与西秦岭同时期花岗岩形成于与古特提斯洋向北俯冲密切相关的大陆边缘弧环境,其岩浆源区为中元古代下地壳变基性岩,且岩浆可能受到地幔物质混染。  相似文献   

四川会理天宝山矿床深部新发现铜矿与铅锌矿的成因关系探讨   总被引：2，自引：1，他引：1  

孙海瑞  周家喜  黄智龙  樊海峰  叶霖  罗开  高建国 《岩石学报》2016,32(11):3407-3417

天宝山矿床是川滇黔接壤铅锌矿集区内的代表性铅锌矿床之一,赋存于上震旦统灯影组白云岩中。近年来,该矿床深部发现了以铜为主的矿化,甚至形成铜矿体。目前,对铜矿成因及其与铅锌矿的关系尚不清晰。本文报道新发现铜矿的矿物学和同位素地球化学资料,以期揭示铜矿的成矿物质来源,结合铅锌矿的相关研究,探讨铜矿形成机制及其与铅锌矿的成因关系。镜下观察和扫描电镜分析显示,铜矿石中主要金属矿物为黄铜矿和银黝铜矿,其次为方铅矿和毒砂,含少量闪锌矿和黄铁矿;铅锌矿石中闪锌矿是主要金属矿物,方铅矿和黄铁矿次之,含少量黄铜矿和深红银矿。铜矿石中闪锌矿主要呈半自形-他形粒状,与黄铜矿共生或被其包裹,方铅矿主要呈细脉状充填在黄铜矿、银黝铜矿和毒砂的裂隙中或呈他形粒状分布在这些矿物中;铅锌矿石中黄铜矿主要呈浸染状分布于闪锌矿之中。两类矿石金属矿物的组构特征,显示铜矿物与铅锌矿物具有密切的共生、穿插和包裹关系,应属同期成矿。同位素地球化学数据显示,铜矿石中黄铜矿的δ34SCDT值为3.9‰~4.2‰(均值为4.1‰,n=3),铅锌矿石闪锌矿的δ34SCDT值为3.3‰~3.9‰(均值为3.5‰,n=3),十分相近,暗示它们具有相似的S源,应均属赋矿地层海相蒸发岩中硫酸盐热化学还原作用的产物。铜矿石中黄铜矿的~(206)Pb/~(204)Pb=18.441~18.476(均值为18.461,n=3),~(207)Pb/~(204)Pb=15.731~15.751(均值为15.741,n=3),~(208)Pb/~(204)Pb=38.809~38.873(均值为38.849,n=3),μ=9.72~9.76;铅锌矿石中方铅矿的~(206)Pb/~(204)Pb=18.442~18.480(均值为18.455,n=3),~(207)Pb/~(204)Pb=15.746~15.763(均值为15.752,n=3),~(208)Pb/~(204)Pb=38.793~38.892(均值为38.840,n=3),μ=9.75~9.78。两者具有相近的Pb同位素组成且其壳源特征明显,表明它们的成矿金属来源相似,均来自上地壳,与赋矿沉积岩有关。综上,矿物学和同位素地球化学证据表明,天宝山矿床深部新发现铜矿与铅锌矿具有明显的同期共生关系和相似的成矿物质来源,是同一成矿热液体系不同阶段演化的产物。天宝山铜铅锌矿床与MVT矿床的成矿特征不同,暗示其成矿作用(环境)特殊,可能与矿床所处的地质背景有关,其成因认识对川滇黔接壤区同类型矿床深部找铜矿具有重要的指导意义。  相似文献   

流体包裹体和C-H-O同位素对湘中古台山金矿床成因制约   总被引：6，自引：2，他引：4  

李伟  谢桂青  张志远  张兴康 《岩石学报》2016,32(11):3489-3506

古台山金矿是湘中盆地最典型的高品位石英脉型金矿床,主要赋存于新元古界和震旦系板岩-千枚岩中。为了探明古台山金矿的成矿物质和成矿流体来源,本次工作对其开展了详细的野外地质考察,对不同阶段石英进行了系统的包裹体岩相学观察、显微测温、激光拉曼探针及H-O同位素分析,对与金矿化密切相关的铁白云石进行了C-O同位素分析。包裹体岩相学及测温结果显示,不同阶段石英主要发育CO_2三相和水溶液两相包裹体,金沉淀阶段CO_2三相包裹体丰度最高,包裹体均一温度集中在180~320℃之间,盐度集中在0~13%NaCleqv之间。激光拉曼显示不同阶段石英包裹体成分主要为H_2O、CO12及少量的CH_4和N_2。不同阶段石英的δ~(18)O_(V-SMOW)变化范围为15.6‰~17.9‰,对应的δ8OH_2O变化范围为4.5‰~8.3‰,δD_(V-SMOW)变化范围-78‰~-49‰,显示成矿过程中有岩浆水参与。铁白云石的δ~(13)C_(PDB)集中在-10.3‰~-8.6‰,δ~(18)O_(V-SMOW)分布在13.9‰~15.7‰之间,暗示成矿流体中的碳主要来自深部岩浆。流体不混溶、CH_4气体存在、围岩及脉体发生硫化-碳酸盐化等因素是导致古台山矿床Au沉淀富集的重要机制。综合上述分析,推测古台山金矿可能是一个非典型的造山型金矿床。  相似文献   

Copper Speciation in a Collection of Geochemical Reference Materials Using Sequential Extraction and Evaluation of the Validity Using XANES Spectroscopy          下载免费PDF全文

Atsuyuki Ohta  Ran Kubota 《Geostandards and Geoanalytical Research》2016,40(1):117-134

Copper speciation in a collection of Japanese geochemical reference materials (JSO‐1, JLk‐1, JSd‐1, ‐2, ‐3 and ‐4, JMs‐1 and JMs‐2) was achieved by sequential extraction and characterised using X‐ray absorption near‐edge structure spectroscopy. In the first step of the extraction, referred to as the acid fraction, between 1% and 20% total Cu within the reference materials was extracted. Such a result is typically accounted for by absorption of Cu onto clay minerals. However, the presence of Cu sulfate (an oxidation product of chalcopyrite) was observed in some of the stream sediments affected by mining activity (JSd‐2 and JSd‐3) instead. Copper was extracted in the reducible fraction (targeting Fe hydroxide and Mn oxide) (2–49% total Cu). Between 2% and 51% Cu was extracted in the oxidised fraction (targeting sulfides and organic matter). X‐ray absorption near‐edge structure spectroscopy clarified that the reducible fraction consisted of Cu bound to Fe hydroxide, whereas the oxidised fraction was a mixture of Cu bound to humic acid (HA) and Cu sulfide. In the oxidisable fraction, chalcopyrite was the predominant species identified in JSd‐2, and Cu bound to HA was the major species identified in JSO‐1 (a soil sample).  相似文献   

内蒙古北山额勒根乌兰乌拉一带土壤测量地球化学特征及找矿方向     

张善明  兰生科  贺中银  韩志敏  陈强  王永晖 《现代地质》2018,32(4):655

研究区位于内蒙古北山北带,成矿地质条件优越,1∶20万水系沉积物测量异常明显,且分布有额勒根乌兰乌拉斑岩型钼(铜)矿。以1∶5万土壤地球化学测量成果为依据,以地质认识为基础,研究了区内元素地球化学数据特征、地球化学场特征及综合异常特征。认为区内主成矿元素为Mo、Cu、Au,主要的控矿层位为咸水湖组火山岩段,成矿有利侵入体为石炭纪花岗闪长岩。划分出5种综合异常类型,其中与斑岩钼(铜)矿系统有关的综合异常和与奥陶系建造有关的综合异常是今后解剖找矿的重点。  相似文献