云南墨江金厂金矿床成矿条件及找矿方向

通过金厂金矿找矿实践及采矿观察,对成矿条件及找矿方向进行研究,认为矿床的形成受构造、地层和岩浆岩三者控制。安定-九甲大断裂制约区域性超基性岩带分布,次级北西向断裂带成为晚期超基性岩侵位空间。矿床赋存于上泥盆统金厂组浅变质岩层内,为含基性火山岩组成的绿片岩相矿源层,其中硅质岩是矿床中主要赋矿的岩石类型。区内超基性岩分为早晚2期:早期超基大岩体(Σ1)的同位素年龄值302 Ma,岩体蛇纹石化、滑石化蚀变广泛,经自变质作用萃取岩体中的金,形成变质热液向有利部位转移;晚期超基性小岩体(Σ2)沿早期岩体外接触带侵位,岩浆热液活动强烈,具有成矿专属性的铬水云母化(同位素年龄值114¹88 Ma)、黄铁矿化、硅化等围岩蚀变生成,并环绕小岩体分布,沿围岩构造、裂隙形成石英脉型矿体。金矿成矿经历了海底火山喷流沉积、变质作用萃取及晚期岩浆热液叠加,形成具层控和岩控特征的层-脉二元结构金矿床,其深部及外围有进一步找矿潜力。     

镇沅金矿田围岩蚀变及成矿系列

镇沅金矿田是云南省唯一超大型金矿。多期次成矿，矿床类型、蚀变种类复杂多样。形成时间基本同步，空间整体配置明显分带。伴随每一成矿阶段有相应的围岩蚀变，自然金、载金黄铁矿与近矿蚀变矿物在同一溶液中同时沉积。随着容矿主岩从内向外，从超基性岩、基性岩－云煌岩－中酸性斑岩、长英质岩渐次变化，表征矿床类型的主要围岩蚀变变化系列为：黄铁矿－碳酸盐化→黄铁矿－碳酸盐－绢云母化→硅化和黄铁－绢英岩蚀变，成因上具有密切的内在联系。特别是花岗岩类斑岩岩浆在侵位过程中，通过不断的液态不混溶或液态分离演变，相继形成斑岩矿浆型、岩浆后期热液成因的斑岩型及以浊积岩为主岩的岩浆后期至岩浆期后热液型金矿体（床）和相应的热液蚀变，构成较复杂的热液蚀变及成矿系列。矿田内与花岗岩类斑岩有关的矿床的勘查程度尚浅，有扩大规模的较大远景。     

辽宁排山楼金矿围岩的岩石学特征

排山楼地区变质作用的主要因素为热量(约600℃)、化学活动流体和压力(地压应力和挤压应力).地壳震动是造成本区造山作用的原因.这种现象与板块构造理论相吻合.矿物分异作用序列为:首先,受火成侵入活动的影响,产生片麻岩、糜棱岩、花岗岩;然后,经历地压和挤压的作用;最后,发生各种类型蚀变作用,包括绢云母化、硅化、碳酸岩化、方解石化、绿泥石化、脱氧作用等.排山楼金矿成矿模式可概述如下:a)成矿作用为热液蚀变型,矿床赋存在太古宙变质岩大型韧性剪切带中;b)矿体产于裂隙中;c)矿体形态与岩脉和细脉形态一致;d)围岩经历了强烈的蚀变作用;e)黄铁矿是最重要的富金矿物,热液流体来源于侵入体,在流经破碎带和裂隙带后,在围岩中沉积黄铁矿.主要岩石类型有花岗岩、角闪岩、片岩、片麻岩和糜棱岩.区内广泛发育青盘岩化、泥化和绢云母化蚀变作用.主要蚀变矿物有石英、黄铁矿、白云母、绢云母、绿帘石、黑云母、微斜长石、方解石、角闪石、云母和锆石.矿体主要赋存在花岗岩和片麻岩中.主要蚀变作用为绢云母化、黑云母化、硅化和方解石化.蚀变过程中,铁氧化物(铁帽、云母)覆于贫硫酸盐矿石表面.蚀变类型有青盘岩化(黏土)、泥化和绢云母化.通常,氧化铁与黏土矿物的混合影响卫星影像中光谱的反射.利用遥感技术方法,适于这类矿床的进一步预测研究.     

辽宁排山楼金矿围岩的岩石学特征

排山楼地区变质作用的主要因素为热量(约600℃)、化学活动流体和压力(地压应力和挤压应力).地壳震动是造成本区造山作用的原因.这种现象与板块构造理论相吻合.矿物分异作用序列为:首先,受火成侵入活动的影响,产生片麻岩、糜棱岩、花岗岩;然后,经历地压和挤压的作用;最后,发生各种类型蚀变作用,包括绢云母化、硅化、碳酸岩化、方解石化、绿泥石化、脱氧作用等.排山楼金矿成矿模式可概述如下:a)成矿作用为热液蚀变型,矿床赋存在太古宙变质岩大型韧性剪切带中;b)矿体产于裂隙中;c)矿体形态与岩脉和细脉形态一致;d)围岩经历了强烈的蚀变作用;e)黄铁矿是最重要的富金矿物,热液流体来源于侵入体,在流经破碎带和裂隙带后,在围岩中沉积黄铁矿.主要岩石类型有花岗岩、角闪岩、片岩、片麻岩和糜棱岩.区内广泛发育青盘岩化、泥化和绢云母化蚀变作用.主要蚀变矿物有石英、黄铁矿、白云母、绢云母、绿帘石、黑云母、微斜长石、方解石、角闪石、云母和锆石.矿体主要赋存在花岗岩和片麻岩中.主要蚀变作用为绢云母化、黑云母化、硅化和方解石化.蚀变过程中,铁氧化物(铁帽、云母)覆于贫硫酸盐矿石表面.蚀变类型有青盘岩化(黏土)、泥化和绢云母化.通常,氧化铁与黏土矿物的混合影响卫星影像中光谱的反射.利用遥感技术方法,适于这类矿床的进一步预测研究.     

广东河台整装勘查区百旁金矿成矿规律

百旁金矿是广东地质五队近年来新发现的一处中型蚀变糜棱岩型金矿。百旁金矿地处粤西—桂东成矿带东段NE向罗定—广宁断裂带北东端部位,矿体受糜棱岩带内面理、裂隙带控制;金矿化具明显的以硅化、硫化物为中心的对称性分布特征,金矿体具有平行斜列、侧伏的分布规律,表现为向NE向侧伏;区内金矿化富集主要与热液活动有关,燕山期的重熔花岗岩侵入的同时伴随有富含硫化物的含金热液充填在糜棱岩、断裂带内而成矿。     

中国造山型金矿围岩蚀变特征

<正>1造山型金矿围岩蚀变Groves主要以围岩变质相和矿脉矿物共生组合与围岩蚀变类型反映金矿的形成深度(Groves,1993),造山型矿床围岩蚀变程度一般较低,为绿片岩相变质。绿片岩相区域的蚀变矿物共生组合以石英、碳酸盐、云母(±钠长石)、绿泥石和黄铁矿(±白钨矿和电气石)为主。大多数该类矿床产于经历过绿片岩相变质作用的地体中,矿床以绿片岩相蚀变矿物组合为特征(张德全等,2005)。蚀变类型主要为白云母化,Ca-Fe-Mg碳酸盐化,     

湖南锡田钨锡多金属矿床成矿地质特征及成矿模式

通过对锡田钨锡多金属矿床地质特征的研究,认为锡田矿区钨锡多金属矿体的形态、产状及空间展布严格受岩体接触带及断裂构造控制;矿床类型主要为矽卡岩型,其次为破碎带蚀变岩型、云英岩型等;钨锡多金属成矿作用与岩浆活动密切相关:印支期花岗岩浆侵位形成矽卡岩型钨锡矿(化)体;燕山期花岗岩浆侵位导致早期矿化矽卡岩发生叠加矿化,同时在构造破碎带中形成云英岩型锡矿或破碎带蚀变岩型钨锡多金属矿体,是形成规模巨大的钨锡多金属工业矿床的必要条件.此外,提出了锡田矿区钨锡多金属矿的成矿模式.     

汉南杂岩与金成矿特征

汉南杂岩区位于扬子地台北缘,围岩为元古界绿片岩 勉县—洋县深大断裂系统在成岩、成矿与盆地形成方面占有重要的地位.杂岩体由斜长花岗岩、二长花岗岩、钾长花岗岩、石英闪长岩和辉长辉绿岩组成.金矿化类型主要有石英脉型和蚀变岩型,与接触带、断裂带、蚀变带有关,蚀变后岩石矿物成分变化.使金重新分布,砂金分布与金源、地貌和新构造运动关系密切.     

内蒙红花沟金矿蚀变岩型金矿体控矿构造分析

红花沟金矿矿区内已发现40余条金矿脉和含金石英脉,它们均产于在区域Ⅰ级和Ⅱ级断裂构造(龙头山断裂)控制下侵位的燕山期龙头山花岗岩岩体与太古宙古老变质岩的内、外接触带上.蚀变岩型矿体是2000年发现和圈定出的新类型金矿体,分布在走向NW305 °的龙头山断裂的下盘,受其次级弧形构造所控制.分析认为沿龙头山断裂向上迁移的含金流体在运移到碎裂状糜棱岩化花岗岩后,在其中交代、充填并产生硅化、绢云母化和黄铁绢英岩化,形成蚀变岩型金矿体.晚阶段含金流体则在已蚀变的碎裂状花岗岩中充填成矿,进一步提高了蚀变岩型矿体和矿石的工业品位.     

胶东谢家沟金矿稀土元素特征及其成矿意义

谢家沟金矿是胶东金矿集中区新发现的一个大型金矿床,为韧性剪切带蚀变岩型金矿床,矿体主要赋存在NE向黄铁绢英岩化糜棱岩、超糜棱岩韧脆性剪切带中。本文对矿区的黑云母花岗岩、脉岩、矿石的稀土元素地球化学特征进行了系统研究,黑云母花岗岩、脉岩及矿石稀土元素地球化学特征表现为ΣREE较小,LREE富集,HREE亏损型,Eu异常不明显,脉岩、花岗岩和矿石的稀土元素球粒陨石标准化图谱曲线基本一致。认为矿区的花岗岩、中基性脉岩、成矿流体具有同源性,继承性;成岩、成矿物质主要来源于深部壳幔过渡带;谢家沟金矿成矿作用受中国东部中生代大规模壳慢相互作用控制。     

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.     

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。     

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     

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。     

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.     

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.     

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.     

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。