吉林省梅河口市张家沟区金矿床成矿地质特征及找矿方向

吉林省梅河口市张家沟区金矿床矿体位于槽台过渡带靠近台区一侧,且基底岩系金丰度值高。区域构造结点有隐爆角砾岩筒存在,岩筒内有硫化物-石英细脉、网脉出现。找矿重点区域应为靠近烟筒桥子一侧的火山角砾岩筒之中。     

山东金亭岭金矿矿床地球化学异常分带模型

通过对山东金亭岭金矿各类微量元素和烃类组分在该矿床不同中段的含量变化以及在纵向上的异常展布和富集规律进行分析和总结,建立了该矿床的地球化学叠加异常分带理想模型,得出矿床地球化学异常轴向分带序列确定为:甲烷、乙烷、丙烷、正丁烷、异丁烷、乙烯、丙烯、Sb(前缘晕)→As、Hg(矿头晕)→Au、Ag、Pb、Zn、Cu、Mn(矿中晕)→Co、Ni、Mo、Bi(矿尾晕),并总结了找矿预测标志,为其深部找矿预测提供了一定的科学借鉴依据。     

贵州晴隆-安龙露采金矿矿山地质环境质量评价体系探讨与应用

据贵州省晴隆―安龙金矿矿山地质环境背景、现状、矿山环境地质问题、人类工程活动强度与地质环境质量的相关性,并结合金矿露采的特点,探索性地提出了一套金矿露采矿山地质环境质量评价的方法体系并用之于调查区的地质环境质量分区评价,通过专家进行野外验收和成果报告审查,一致认为评价结果比较真实地反映了调查区的实际地质环境质量状况,提出的评价方法是合理可行的,对类似金矿矿山的地质环境质量评价具有一定的借鉴意义。     

遂昌麻车─后山垵糜棱岩的发现及其意义

作者在野外工作中，于遂昌─大柘变质岩断块（下称遂昌变质岩断块）北西侧，麻车─后山垵等地的地表或探矿巷道内，相继发现了多处糜棱岩化岩石露头，认为这一带存在一条较大的韧性剪切带。经对该带的地质，地球化学及金银矿分布的特征的综合分析研究，指出该韧性剪切带有关的金银矿化活动可分为两个期次，即早期金在韧性剪切活动中初始富集，晚期的脆性变形在局部地段形成金矿体。提出在该韧性剪切带找矿工作中，应重视继承韧性剪切带的脆性断裂和断裂带内的浅色蚀变组合及矿化特征。     

浙江中生代陆缘火山岩金矿成矿系统

浙江地处中国东南沿海大陆边缘火山岩成矿带，已发现众多金（银）矿床（点），它们在空间上往往不是孤立地出现，而是在数十至数百平方公里内围绕岩浆热中心相对集中，并与有色金属在矿田范围内伴生。研究证明，金（银）及有色金属矿床是同一火山—侵入旋回过程中形成的有成因联系的矿床。笔者将这种在同一火山—侵入旋回间，围绕同一个岩浆热中心，在不同深度和水平距离内形成的一系列具有成因联系的金（银）和有色金属矿床的总和称为火山岩金矿成矿系统。本文在此概念基础上，详细论述了浙江中生代陆线火山岩金矿成矿系统的类型。时空结构和物质来源。     

山东栖霞马家疃金矿区地质特征及找矿前景分析

马家疃金矿区位于胶东著名的台前-陡崖金成矿带上盘,笏山、西陡崖金矿床东邻。笏山、西陡崖矿区已累计提交金资源储量30余吨,其主矿体倾向深部,向马家疃矿区延伸稳定。区内地层出露单一,岩浆岩发育,矿体产出于玲珑花岗岩体中,严格受NNE向压扭性断裂控制,矿石类型主要为黄铁绢英岩化碎裂岩。通过对矿床地质特征及矿床成因的分析,其深部有较大的找矿前景,在总结成矿规律的基础上,围绕有利构造部位进一步勘查,有望实现栖霞地区找矿的再次突破。     

Surpac软件在归来庄金矿深部矿床资源量估算中的研究和应用

归来庄金矿是目前鲁西南地区唯一的大型新类型碲金型金矿床,近几年深部找矿有了进展。在充分研究归来庄金矿成矿地质特征及金矿化类型的基础上,根据归来庄金矿深部的地质勘查工程资料,以Surpac系统软件为主要工具,首次建立了归来庄深部金矿床的地质数据库, 构建了矿体的三维可视化地质模型。基于归来庄金矿深部矿体三维模型,应用距离幂次反比法对归来庄金矿深部矿体估算了资源量。将估算结果和传统地质块断法进行对比研究,结果表明用此软件进行资源量估算简便且准确,可以为矿产开发提供依据。     

东峰顶金矿床地质地球化学特征及成因

东峰顶金矿区呈脉状赋存于断裂破碎带中，矿石类型为硫化物石英-重晶石脉型，矿体围岩蚀变强烈，根据矿床地质、地球化学特征．结合矿体矿物共生组合、铅和硫同位素组成及成矿年龄、包裹体成分及特征以及原生金的成色等研究，认为金矿床矿源为重熔岩浆岩。成矿溶液主要来自岩浆水和大气降水的混合溶液，成矿温度140℃～400℃．成矿深度约1．5km。矿床成因类型属中温、中深条件下形成的岩浆热液充填型金矿床。     

胶北地区内生金矿成矿规律

胶北内生金矿是壳幔混源岩浆期后热液成矿 ,受复合基底EW向构造的早新华夏系和郭家岭超单元控制 ,蚀变、矿化分阶段连续进行 ,分为焦家式、灵山式、玲珑式及上庄式四个亚类型。金矿床区域上东西成行、南北成列、汇集成片呈棋盘格局 ;矿带内矿床沿走向等距分布、沿横向对应出现 ,矿床类型横向具分带、走向有变化、倾向相对稳定。矿体在控矿构造引张扩容段和构造叠加段赋存 ,并具斜立、侧伏、尖灭再现、斜列、瓦叠等产出规律。     

Compositional zoning of fluid inclusions in the Archaean Junction gold deposit,Western Australia: A process of fluid ‐ wall‐rock interaction?

The Junction gold deposit, in Western Australia, is an orogenic gold deposit hosted by a differentiated, iron‐rich, tholeiitic dolerite sill. Petrographic, microthermometric and laser Raman microprobe analyses of fluid inclusions from the Junction deposit indicate that three different vein systems formed at three distinct periods of geological time, and host four fluid‐inclusion populations with a wide range of compositions in the H₂O–CO₂–CH₄–NaCl ± CaCl₂ system. Pre‐shearing, pre‐gold, molybdenite‐bearing quartz veins host fluid inclusions that are characterised by relatively consistent phase ratios comprising H₂O–CO₂–CH₄ ± halite. Microthermometry suggests that these veins precipitated when a highly saline, >340°C fluid mixed with a less saline ≥150°C fluid. The syn‐gold mineralisation event is hosted within the Junction shear zone and is associated with extensive quartz‐calcite ± albite ± chlorite ± pyrrhotite veining. Fluid‐inclusion analyses indicate that gold deposition occurred during the unmixing of a 400°C, moderately saline, H₂O–CO₂ ± CH₄ fluid at pressures between 70 MPa and 440 MPa. Post‐gold quartz‐calcite‐biotite‐pyrrhotite veins occupy normal fault sets that slightly offset the Junction shear zone. Fluid inclusions in these veins are predominantly vapour rich, with CO₂?CH₄. Homogenisation temperatures indicate that the post‐gold quartz veins precipitated from a 310 ± 30°C fluid. Finally, late secondary fluid inclusions show that a <200°C, highly saline, H₂O–CaCl₂–NaCl–bearing fluid percolated along microfractures late in the deposit's history, but did not form any notable vein type. Raman spectroscopy supports the microthermometric data and reveals that CH₄–bearing fluid inclusions occur in syn‐gold quartz grains found almost exclusively at the vein margin, whereas CO₂–bearing fluid inclusions occur in quartz grains that are found toward the centre of the veins. The zonation of CO₂:CH₄ ratios, with respect to the location of fluid inclusions within the syn‐gold quartz veins, suggest that the CH₄ did not travel as part of the auriferous fluid. Fluid unmixing and post‐entrapment alteration of the syn‐gold fluid inclusions are known to have occurred, but cannot adequately account for the relatively ordered zonation of CO₂:CH₄ ratios. Instead, the late introduction of a CH₄–rich fluid into the Junction shear zone appears more likely. Alternatively, the process of CO₂ reduction to CH₄ is a viable and plausible explanation that fits the available data. The CH₄–bearing fluid inclusions occur almost exclusively at the margin of the syn‐gold quartz veins within the zone of high‐grade gold mineralisation because this is where all the criteria needed to reduce CO₂ to CH₄ were satisfied in the Junction deposit.