黑龙江三道湾子金矿Au-Ag-Te系列矿物特征及其成矿流体

本文采用光学显微镜、扫描电镜和电子探针对黑龙江省三道湾子金矿中Au-Ag-Te系列矿物碲银矿、碲金银矿、针碲金银矿、斜方碲金矿和碲金矿进行了详细的矿物学研究,本次研究还发现Au2Te的存在。碲化物矿物多呈粒状或脉状分布于石英或硫化物矿物的裂隙中。Au-Ag-Te系列矿物中,Au含量与Ag含量呈负相关性,与Te含量呈弱的负相关性。结合Au-Ag-Te成分共生图解及镜下特征对金银碲化物矿物共生组合进行分析表明Te优先与Ag结合形成碲银矿或碲金银矿,只有成矿流体中Ag被大量消耗后,Te才与Au结合形成针碲金银矿、斜方碲金矿、碲金矿,最后当成矿流体中Te也被大量消耗后,Au才会形成自然金。氦、氩同位素研究表明石英—黄铁矿阶段流体包裹体中3He/4He值为0.01～0.03Ra,金银碲化物阶段3He/4He值为0.08～1.04Ra,指示金银碲化物阶段有大量地幔物质参与。     

应用电子探针技术研究%山东金青顶金矿床碲化物特征

对含碲金矿中碲化物物相组成和元素赋存特征开展系统的研究,有助于对此类金矿矿床成因的理解和找矿勘查工作。山东金青顶金矿床伴生的碲化物由于碲化物颗粒较小,不易被发现,以往的研究缺乏对碲化物元素分布的精细刻画。本文通过电子探针背散射图像、波谱分析、能谱分析结合面扫描技术对金青顶金矿床碲化物进行了分析,研究碲化物的种类、共生关系、化学成分以及元素分布特征等。结果表明:碲金银矿与碲银矿密切共生,常形成连生体,Au、Ag在连生体中不均匀分布,面扫描图局部可见碲金矿亮斑;Te总是优先和Ag结合,生成碲银矿,随着Ag的消耗碲金银矿开始出现,Ag被耗尽后Te与Au生成碲金矿,成矿后期热液中多余的金与碲金银矿或碲银矿反应生成非常规碲化物(如本文发现的Ag2.95Au1.83Te),当Te消耗完后生成自然金;金银矿物的生长顺序是碲银矿—碲金银矿—碲金矿—自然金。本研究为含碲金矿的综合利用提供了技术支持。     

山东乳山金矿中金-银碲化物的矿物学特征与沉淀机理

通过显微鉴定和应用电子探针微束分析,查明乳山金矿中碲化物主要为碲银矿和碲金银矿,少量碲铅矿和碲铋矿,它们呈密切共生的集合体或联生体产出在黄铁矿等硫化物及石英等脉石矿物粒问或裂缝中。碲银矿和碲金银矿中Au含量变化较大,w（Au）为痕量至26．1％,与银呈负相关,与铋为正相关,可能是以类质同象形式替代Ag进入到碲银矿中;碲铅矿中未检测到金。金在金-银碲化物中的含量随温度降低而升高,相关矿物的形成顺序为碲银矿-碲金银矿-（碲金矿）。将金银碲化物成分投到Au-Ag-Te三元成分,共生图解上发现,它们都不是标准成分的端元矿物,推测这些碲化物（尤其是金银碲化物）是在非平衡状态下快速沉淀形成的,可能与含矿浠体的闻歇忡沸腾作用有关。     

大兴安岭东北部永新金矿床金银系列矿物和碲化物的发现及其意义

永新金矿床是早白垩世晚期形成的浅成低温热液型金矿床。对其主要金银系列矿物和碲化物研究显示:金银系列矿物中Au质量分数为65.092%~90.713%(平均为83.942%),Ag为5.652%~16.632%(平均为11.285%);以自然金和银金矿为主,成色集中在870.2~941.3(平均为881.1),主要以包体金、粒间金和裂隙金的形式存在,粒径集中在10~20 μm;碲化物主要有辉碲铋矿、碲金银矿、碲银矿和碲铅矿等,以碲银矿数量最多,主要包裹于黄铁矿内部或产于裂隙中,常与自然金和方铅矿连生,粒径多为5~20 μm。综合研究碲化物组合特征、不同标高金矿物的成色、Te/Au值等认为,永新金矿床碲化物形成时成矿流体的lgf(Te₂)介于-15.2~-9.4范围,lgf(S₂)介于-16.7~-14.0范围,矿床与火山或次火山热液有关,具备中浅成成矿特征,深部尚有较大成矿潜力。     

河南嵩县松里沟金矿床中碲化物的发现及其地质意义

松里沟金矿位于华北陆块南缘熊耳山地区,已探明金资源储量26 t。矿体产于中新太古界-古元古界太华群片麻岩NWW向的断裂带中。其热液成矿过程包括4个成矿阶段:黄铁矿-石英阶段、石英-黄铁矿阶段、金-碲化物阶段和石英-碳酸盐阶段。显微镜下发现金-碲化物阶段存在大量与金共生的碲化物。利用电子探针和能谱分析查明碲化物的种类、共生关系和形成条件,确认的碲化物有碲铅铋矿、碲铅矿、碲铋矿、碲金矿、碲金银矿、硫碲铋铅金矿、辉碲铋矿,此外还有大量的自然金和少量的辉铋矿。该矿床为一与岩浆作用有关的碲金矿床。Au主要以自然金和金银碲化物的形式存在。Au、Ag以硫氢络合物的形式发生迁移,Te2(g)和H2Te(g)冷凝进入含贵金属的氯化物溶液是碲化物沉淀主要机制。相图及化学反应方程式分析表明,金-碲化物阶段受温度、碲逸度、硫逸度、氧逸度和酸碱度控制,其中,黄铁矿-石英阶段和石英-黄铁矿阶段形成于logf_(Te2)-14.4和logf_(S2)=-11.1~-6.5的环境。金-碲化物阶段形成于温度为110~313℃、logf_(Te2)=-15.2~-9.4和logf_(S2)=-16.5~-14.6、f_(O_2)升高和pH值降低的环境。碲化物的发现为探讨该矿床成因和熊耳山地区寻找同类型的矿床提供了依据。     

甘肃党河南山某金矿碲化物的发现及其成因探讨

利用电子探针显微分析技术首次在甘肃党河南山某金矿中发现了碲金银矿、碲银矿、碲金矿、碲铅矿、碲铋矿等碲化物。通过电子探针显微图像观察,发现研究区碲化物均较为细小,赋存状态多以独立矿物形式存在,无连生、交生现象,但空间上与黄铁矿关系密切,多被黄铁矿包裹或产于黄铁矿、石英粒间和黄铁矿裂隙。根据不同碲化物与黄铁矿之间的共生组合关系,推测其形成顺序为碲金矿→碲金银矿→碲铅矿→碲铋矿→碲银矿。依据碲化物矿物组合特征及成矿温度,对其形成时fTe2与fS2进行了限定,lgfTe2范围为-15.2~-11.2,lgfS2范围为-16.7~-14.4。并认为金矿中Au、Te来源与加里东期埃达克质斜长花岗岩体有较大联系,可能为俯冲板片部分熔融形成的埃达克质岩浆与地幔楔相互作用,将成矿元素富集后带入近地表形成含碲化物的金矿床。     

我国某些金矿床中金银碲化物矿物的共生关系

结合Au-Ag-Te三元系的实验矿物学结果,对我国金驹山 、银坑山、归来庄和驾鹿四 个金矿床中的金银碲化物矿物的共生组合特征进行了研究,并阐明了金银碲化物矿物在时空 关系上的共生组合和禁生关系特征。研究表明,金银碲化物是该类型金矿床中最重要的一类 矿物,其产出的种类和数量取决于成矿体系溶液中Au、Ag、Te元素的浓度及其含量比值;而 成矿体系中碲金银矿、碲银矿等低温同质多像变体的存在,反映了该类型矿床形成于成矿温 度和压力较低的环境条件下。     

鲁西铜石地区碲型金矿床中碲化物特征及其成矿机制研究

为探讨鲁西铜石地区归来庄金矿和卓家庄金矿的成矿物质来源及成矿机制,利用显微镜和电子探针对矿石中典型碲化物矿物进行了分析研究。结果显示,碲化物矿物主要为自然碲和碲银矿,其次是针碲金银矿、AgAu_2Te_6、含银自然金和碲铅矿,初步认为AgAu_2Te_6为新矿物。针碲金银矿、AgAu_2Te_6、部分碲银矿、含银自然金可能是在非平衡状态下快速沉淀而成,与含矿流体的间歇性沸腾作用有关。碲化物的沉淀顺序反映了其各自熔化温度的差异,说明熔点高的碲化物将优先沉淀。矿床成矿热液具有多来源性,可能存在含Au、Ag流体和Te流体,二者在一定的条件下发生不混溶;流体沸腾作用可能是导致碲化物和金等成矿物质快速沉淀的主要机制。     

胶东邓格庄金矿床矿物化学研究

本文研究了胶东邓格庄金矿床金银系列矿物、黄铁矿、石英和方解石的化学成分,金银系列矿物主要为银金矿和金银矿,含Pt等微量元素,与金矿化关系密切的黄铁矿以Fe亏损占优势,富Au、Te、As和Ag为特点;石英具高的Al、K、Cu、Pb和Zn,低的Li含量;黄铁矿、石英和方解石的稀土元素组成指示成矿热液可能有二种来源,方解石的稀土元素组成指示成矿热液为岩浆或深部来源。     

鄂东南地区鸡冠嘴铜金矿床Au-Ag-Bi-Te-Se矿物学研究与金银富集机理

鸡冠嘴铜金矿床是鄂东南地区典型的矽卡岩型铜金矿床。矿体主要赋存于下三叠统大冶组大理岩中,矿石矿物以黄铜矿和黄铁矿及少量金银矿物为主,与矿化有关的蚀变包括矽卡岩化、硅化、绿泥石化、碳酸盐化、钾长石化等。根据野外观察和镜下鉴定将成矿过程划分为干矽卡岩阶段、湿矽卡岩阶段、硫化物阶段和碳酸盐阶段,其中硫化物阶段为金矿化的主要阶段。矿相学研究、扫描电子显微镜-能谱分析和电子显微探针分析结果表明,主要载金矿物为黄铜矿和黄铁矿,金的赋存状态包括可见金和不可见金,可见金以银金矿为主,其次为自然金和含银自然金,不可见金为纳米级自然金。主要载银矿物是黄铜矿和斑铜矿,银矿物多以可见银(硒银矿、碲银矿和辉银矿等)产出,包括独立银矿物和显微包体银;不可见银主要以次显微包体的形式分布于硫化物中。鸡冠嘴铜金矿床是高温岩浆热液与碳酸盐岩地层发生接触交代作用形成的,Au在高温热液中可能主要以氯络合物、碲络合物或碲化物熔体的形式搬运。随着矽卡岩化等蚀变作用的进行和热液温度的降低,热液中氯被消耗的同时硫逸度快速上升,Au主要以金硫络合物的形式在热液中运移,硫化物阶段早期大量Bi-Te-S矿物及少量纳米级自然金以显微包裹体的形式包裹于近于同时沉淀的黄铁矿中,随后碲银矿、辉银矿及硫铋铜矿与硫化物及石英和碳酸盐矿物共生产出。成矿流体演化过程中由于温度和硫逸度的进一步降低导致金络合物不稳定,当Logf Te2-20且-14Logf Se2-10时,金矿物与硒化物与黄铜矿近于同时沉淀,或充填于先期沉淀的黄铁矿微裂隙和其他矿物之间的空隙中。综合分析表明,鸡冠嘴铜金矿床成矿过程中Te和Bi对Au的富集具有重要重用。     

Wavelength-dispersive X-ray fluorescence spectrometric determination of Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th in komatiites

Komatiites are mantle-derived ultramafic volcanic rocks. Komatiites have been discovered in several States of India, notably in Karnataka. Studies on the distribution of trace-elements in the komatiites of India are very few. This paper proposes a simple, accurate, precise, rapid, and non-destructive wavelength-dispersive x-ray fluorescence (WDXRF) spectrometric technique for determining Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th in komatiites, and discusses the accuracy, precision, limits of detection, x-ray spectral-line interferences, inter-element effects, speed, advantages, and limitations of the technique. The accuracy of the technique is excellent (within 3%) for Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Zr, Nb, Ba, Pb, and Th and very good (within 4%) for Y. The precision is also excellent (within 3%) for Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th. The limits of detection are: 1 ppm for Sc and V; 2 ppm for Cr, Co, and Ni; 3 ppm for Cu, Zn, Rb, and Sr; 4 ppm for Y and Zr; 6 ppm for Nb; 10 ppm for Ba; 13 ppm for Pb; and 14 ppm for Th. The time taken for determining Sc, V, Cr, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, Pb, and Th in a batch of 24 samples of komatiites, for a replication of four analyses per sample, by one operator, using a manual WDXRF spectrometer, is only 60 hours.     

高压微波消解法测定醋酸纤维过滤器采集的微尘粒子中的砷镉钴铬铜铁锰镍铅钒锌

最新的流行病学研究表明,空气中较高浓度的悬浮细颗粒可能对人类的健康有不利的影响。根据该项研究显示,由于心脏病、慢性呼吸问题和肺功能指标恶化而导致死亡率的升高与细尘粒子有关。这些研究结果已经促使欧盟于1999年4月出台了限制空气中二氧化硫、二氧化氮、氧化氮、铅和颗粒物含量的法案(1999/30/EC),对各项指标包括对可吸入PM10颗粒的浓度提出了新的限制性指标。PM10颗粒是指可以通过预分级器分离采集的气体动力学直径小于10μm的细颗粒。目前研究的兴趣重点逐步偏向PM2.5这些更细微颗粒物,PM2.5这种颗粒物对健康有明显的不利影响。在欧盟指令2008/50/EC中,对PM10和PM2.5都提     

硅酸盐类样品中硅、铁、铝、钛、锰、钙、镁、钾、钠和磷的x射线荧光光谱测定

本文拟定了一种以熔融法制备样片,用X射线荧光光谱测定硅酸盐类样品中Si、Fe、Al、Tj、Mn、Ca、Mg、K、Na、P等元素的分析方法。在对不同靶材X光管和分光晶体实验对比的基础上,选择了最佳的测量条件。该法具有快速、准确,测量范围广,检测限低,价格便宜等优点。经过近百个各种类型标样或管理样品的分析对比表明,本法不仅适用于硅酸盐类岩石样品的分析,还适用于铁矿、铝土矿、碳酸盐类岩矿样品以及水泥、耐火材料等样品的分析。     

Isotopic systematics of He,Ar, S,Cu, Ni,Re, Os,Pb, U,Sm, Nd,Rb, Sr,Lu, and Hf in the rocks and ores of the Norilsk deposits

This paper reports the first results of a study of 11 isotope systems (³He/⁴He, ⁴⁰Ar/³⁶Ar, ³⁴S/³²S, ⁶⁵Cu/⁶³Cu, ⁶²Ni/⁶⁰Ni, ⁸⁷Sr/⁸⁶Sr, ¹⁴³Nd/¹⁴⁴Nd, ^206–208Pb/²⁰⁴Pb, Hf–Nd, U–Pb, and Re–Os) in the rocks and ores of the Cu–Ni–PGE deposits of the Norilsk ore district. Almost all the results were obtained at the Center of Isotopic Research of the Karpinskii All-Russia Research Institute of Geology. The use of a number of independent genetic isotopic signatures and comprehensive isotopic knowledge provided a methodic basis for the interpretation of approximately 5000 isotopic analyses of various elements. The presence of materials from two sources, crust and mantle, was detected in the composition of the rocks and ores. The contribution of the crustal source is especially significant in the paleofluids (gas–liquid microinclusions) of the ore-forming medium. Crustal solutions were probably a transport medium during ore formation. Air argon is dominant in the ores, which indicates a connection between the paleofluids and the atmosphere. This suggests intense groundwater circulation during the crystallization of ore minerals. The age of the rocks and ores of the Norilsk deposits was determined. The stage of orebody formation is restricted to a narrow age interval of 250 ± 10 Ma. An isotopic criterion was proposed for the ore-bearing potential of mafic intrusions in the Norilsk–Taimyr region. It includes several interrelated isotopic ratios of various elements: He, Ar, S, and others.     

Viscous, cohesive, non-Newtonian, depositing, radial slurry flow

Mining induced subsidence can significantly affect mining costs where major surface facilities and natural environment need to be protected. Overburden grout injection is a technology used to control coal mine subsidence by injecting the mine waste material extracted from the coal back into the inter-burden rock during longwall mining. The flowing slurry is here categorised as a nonlinear viscous cohesive (Bingham plastic) fluid. During longwall mining the grout slurry is pumped into the separated beds of the rock mass through a central vertical borehole, which is drilled deep into the inter-burden rock strata above the coal seam. However, a blockage can occur in the injection system when the slurry velocity falls below a certain critical threshold velocity, indicating a material phase change from cohesive-viscous to cohesive-frictional. In situ field injection tests through boreholes have been simulated at a smaller scale at the CSIRO laboratory in Brisbane by pumping the slurry through a radial disk (gap = 4 mm) from its centre. Laboratory experiments indicate a general, nonlinear, cohesive, viscous, frictional model for shear behaviour of the slurry, in which the material shear parameters are functions of the disk radial distance. Complete dimensional and dimensionless analytical solutions have been developed based on an approach related to Bingham–Herschel–Bulkley fluid mechanics. The derived formulae include relations for minimum pump pressure, local pressure and pressure gradient, wall shear stress, volume rate, velocity and velocity gradient. The theoretical results match the experimental measurements. The experiments covered slurries with maximum particle sizes of 0.5 to 2 mm with about 50% being larger than 100 µm. The viscosities at the various solids concentrations were measured with a standard torsion viscometer. This study differs from the previous research in several distinct aspects, namely, consideration of the variable shear parameters rather than fixed values, inclusion of total nonlinear behaviour, and implementation of a friction function to mimic behaviour of the deposited and consolidating stiff slurry, which can cause a significant pressure rise as a result of the increased shear resistance.     

硅酸盐中铁、锰、钛、钙、钾、磷、硅、铝、镁、钠、锶、铷、钡的X-射线荧光光谱定量测定

本文介绍样品经四硼酸锂熔融制成玻璃小饼。采用Lachance模式和理论a系数来校正元素间的效应,由3080E型X-射线荧光谱仪和DF-350B数据处理系统完成硅酸盐中十三个项目的测定。     

岩石密度和超高压岩石折返速率

在常温常压条件下对中国大陆科学钻CCSD主孔100-3000米岩心样品进行了密度测量,建立了密度连续剖面,并界定了不同超高压岩石的密度值。通过对比高温高压物性实验资料,岩石密度随着退变程度增强而降低,榴辉岩密度变化序列为3.52g/cm3→3.49g/cm3→3.07g/cm3→2.93g/cm3。超高压长英质岩石密度变化序列为3.00g/cm→2.80g/cm3→2.65g/cm3。上述实验资料是讨论不同折返阶段岩石所受浮力的基础,为研究折返速率大小提供了基本参数。本文通过折返板块运动平衡时,上浮力与粘滞力平衡这一关系式,定量研究了大陆俯冲板块的折返速率,认为密度差产生上浮力从而引起折返,温度对板块折返速率的影响最为显著;密度差大小、折返角度、折返板块大小对折返速率也有直接的影响。定量模拟分析表明,在温度高于850℃时,板块的折返速率可以超过100mm/a;当温度降至700℃时,折返速率则低于1.5mm/a。作者认为在折返早期,温度较高,板块快速折返至60-70km榴辉岩相深度;随着传导散热,温度降低,板块以较慢的速率折返至中下地壳。折返速率的估算表明,浮力是板块折返第一阶段(从>100km深部折返至<40km的中下地壳)的主要驱动力。     

Bellechester,Minnesota, USA,lagoon collapses

Bellechester, Minnesota, is a small community of approximately 155 residents located on the county line between Goodhue and Wabasha counties in southeast Minnesota's karst region. Bellechester is served by a 21-year-old wastewater treatment facility (WWTF) consisting of three waste-stabilization ponds. On 28 April 1992 six sinkholes were discovered to have drained cell 2 of the WWTF resulting in the loss of approximately 8.7×10⁶ 1 of partially treated effluent and about 600 m³ of soil into previously undetected subsurface voids of unknown dimensions. In the week following the collapse, approximately 200 water wells located within a 5-km radius of the WWTF were sampled in an after-the-fact, emergency sampling program. Twelve samples with elevated fecal coliform levels, 18 samples with nitrate-nitrogen greater than the 10 mg/1 standard, and no samples with elevated chlorides were found. However, the elevated levels could not be unambiguously attributed to the WWTF collapse. This is the third WWTF to fail by sinkhole collapse in southeast Minnesota since 1974. All three collapsed lagoons have been located in similar geomorphic and stratigraphic settings. However, at least two lagoons have collapsed in the adjacent area in northeast Iowa, and these lagoons are located at different stratigraphic positions. Twenty-two WWTFs constructed in southeast Minnesota's karst region in the last 25 years have been identified as subject to potential sinkhole collapse. An unknown but significant number of manure storage lagoons, flood control structures, etc., have also been constructed in the karst region and are at risk. Public agencies are beginning to develop plans to deal with the risk associated with existing and future waste lagoons in this environment. The critical hydrogeologic parameters that can be used to prioritize the risk of collapse at existing facilities include: (1) the lithology of the first bedrock beneath each lagoon, (2) the thickness of surficial materials between the lagoon and the bedrock surface, (3) the presence and construction of liners (seepage rate), and (4) the proximity to existing sinkholes.     

Mercury,arsenic, antimony,and selenium contents of sediment from the Kuskokwim River,Bethel, Alaska,USA

The Kuskokwim River at Bethel, Alaska, drains a major mercury-antimony metallogenic province in its upper reaches and tributaries. Bethel (population 4000) is situated on the Kuskokwim floodplain and also draws its water supply from wells located in river-deposited sediment. A boring through overbank and floodplain sediment has provided material to establish a baseline datum for sediment-hosted heavy metals. Mercury (total), arsenic, antimony, and selenium contents were determined; aluminum was also determined and used as normalizing factor. The contents of the heavy metals were relatively constant with depth and do not reflect any potential enrichment from upstream contaminant sources.     

滇东南花岗岩与锡、银、铜、铅、锌多金属矿床的成因关系

滇东南锡、银、铅、锌多金属矿床主要分布在个旧、白牛厂、都龙3个矿区,而滇东南较大的3个花岗岩体又分别出露在3个矿区或附近.花岗岩体均形成于燕山晚期,岩石化学、矿物成分相似,富含锡、银、铅、锌、钨、铜等成矿元素.矿床主金属元素组合与岩体之间的距离由远而近出现由锡、钨、(铍、铌、钽)→锡、钨、(铁)、铜、铟→锡、铅、锌、银、铟、(锑)有规律的变化.花岗岩浆是成矿物质来源和成矿热源.岩浆侵入初期使上覆地层隆起产生背斜(凹陷部位成向斜);同时使地层产生一系列裂隙、压性断层或层间断裂;岩浆侵入晚期,这些断层再次活动,表现为张性,岩浆产生的含矿热液沿由其活动所造成的断裂迁移、充填、交代、沉淀而形成矿床.