http://www.sciencedirect.com/science/article/pii/S1674987111000430

Mineral assemblages formed during hydrothermal alteration reflect the geochemical composition of ore-forming fluids. Gold is mainly transported in solution as AueCl and AueS complexes. The change of physicochemical conditions such as temperature, pressure, oxygen fugacity, and sulfur fugacity are effective mechanisms for gold precipitation. Gold tends to be concentrated in the vapor phase of fluids at high temperatures and pressures. AueAs and AueSb associations are common in gold deposit. Native antimony and/or arsenic e native gold assemblages may precipitate from hydrothermal fluids with low sulfur fugacity. Hydrothermal fluids forming epithermal gold deposits are Au-saturated in most cases, whereas fluids of Carlin-type are Au-undersaturated. Quasi-steady As-bearing pyrite extracts solid solution Au from hydrothermal fluids through absorption. The capability of As-bearing pyrite to absorb Au from under-saturated fluid is the key to the formation of large-scale Carlin-type deposits. With increasing new data, studies on the geochemistry of gold deposits can be used to trace the origin of ore-forming fluids, the source of gold, and the transporting form of Au and other ore-forming elements, such as Si, S, F, Cl, As and Ag.     

The Daduhe gold field at the eastern margin of the Tibetan Plateau: He, Ar, S, O, and H isotopic data and their metallogenic implications

The Daduhe gold field comprises several shear-zone-controlled Tertiary lode gold deposits distributed at the eastern margin of the Tibetan Plateau. The deposits are hosted in a Precambrian granite–greenstone terrane within the Yangtze Craton. The gold mineralization occurs mainly as auriferous quartz veins with minor sulphide minerals. Fluid inclusions in pyrite have ³He/⁴He ratios of 0.16 to 0.86 R_a, whereas their ⁴⁰Ar/³⁶Ar ratios range from 298 to 3288, indicating a mixing of fluids of mantle and crust origins. The δ³⁴S values of pyrite are of 0.7–4.2‰ (n = 12), suggesting a mantle source or leaching from the mafic country rocks. δ¹⁸O values calculated from hydrothermal quartz are between − 1.5‰ and + 6.0‰ and δD values of the fluids in the fluid inclusions in quartz are − 39‰ and − 108‰. These ranges demonstrate a mixing of magmatic/metamorphic and meteoric fluids. The noble gas isotopic data, along with the stable isotopic data suggest that the ore-forming fluids have a dominantly crustal source with a significant mantle component.     

Anomalous gold contents in brown coals and peat in the south-eastern region of the Western-Siberian platform

One hundred twenty-two samples of Jurassic and Paleogene brown coals and 1254 peat samples from the south-eastern region of the Western-Siberian platform were analyzed for gold by the neutron-activation method. Mean content of Au in Jurassic coals is 30 ± 8 ppb, in Paleogene coals is 10.6 ± 4.8 ppb, and in peat is 6 ± 1.4 ppb. Concentrations of gold as high as 4.4 ppm were found in coal ash and 0.48 ppm in the peat ash. Coal beds with anomalous gold contents were found at Western-Siberian platform for the first time.Negative correlation between gold and ash yield in coals and peat and highest gold concentrations were found in low-ash and ultra-low-ash coals and peat. Primarily this is due to gold's association with organic matter.For the investigation of mode of occurrence of Au in peat the bitumen, water-soluble and high-hydrolyzed substances, humic acids, cellulose and lignin were extracted from it. It was determined that in peat about 95% of gold is combined with organic matter. Forty to sixty percent of Au is contained in humic acids and the same content is in lignin. Bitumens, water-soluble and high-hydrolyzed substances contain no more than 1% of general gold quantity in peat.The conditions of accumulation of high gold concentrations were considered. The authors suggest that Au accumulation in peat and brown coals and the connection between anomalous gold concentrations and organic matter in low-ash coals and peat can explain a biogenic–sorption mechanism of Au accumulation. The sources of formation of Au high concentration were various Au–Sb, Au–Ag Au–As–Sb deposits that are abundant in the Southern and South-Eastern peripheries of the coal basin.     

新疆木垒县喀拉沙特金矿地质特征及成因

喀拉沙特金矿产于构造破碎蚀变带中。通过普查工作共圈定2个金矿体和1个金矿化体,I号金矿体产状25。＜84。,长80m,水平厚度0．12～2．40m,倾向延深111．40m。品位1．63×10“～2．98×10－^6,平均品位1．62×10一^6。Ⅱ号金矿体产状168。么82。,长80m,水平厚度0．80～1．02m,平均厚度0．91m,倾向延深115．27m,品位1．72X10一^6～4．44×10一^6,平均品位2．83X10一^6。通过对矿床地质特征的研究,认为该矿床属沉积一变质型金矿床。     

广西金属尾矿排放现状与处置途径研究

广西大多数金属矿山尾矿采用地表堆存方式存放,不仅对环境存在危害,而且占用土地,尾矿库也存在安全隐患.对尾矿有价金属元素进行再回收,大宗尾矿做充填建筑材料,既能够解决矿山充填骨料的来源问题,也能实现矿山固体废弃物的资源化和减量化.     

Gold paragenesis and chemistry at Batu Hijau, Indoneisa: implications for gold-rich porphyry copper deposits

Gold is an important by-product in many porphyry-type deposits but the distribution and chemistry of gold in such systems remains poorly understood. Here we report the results of petrographic, electron microprobe, laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), and flotation test studies of gold and associated copper sulfides within a paragenetic framework from the world-class Batu Hijau (914 mt @ 0.53% Cu, 0.40 g/t Au) porphyry copper–gold deposit, Indonesia. Unlike many other porphyry copper–gold deposits, early copper minerals (bornite–digenite–chalcocite) are well preserved at Batu Hijau and the chalcopyrite–pyrite overprint is less developed. Hence, it provides an excellent opportunity to study the entire gold paragenesis of the porphyry system. In 105 polished thin sections, 699 native gold grains were identified. Almost all of the native gold grains occurred either within quartz veins, attached to sulfide, or as free gold along quartz or silicate grain boundaries. The native gold grains are dominantly round in shape and mostly 1–12 m in size. The majority of gold was deposited during the formation of early A veins and is dominantly associated with bornite rather than chalcopyrite. The petrographic and LA-ICP-MS study results indicate that in bornite-rich ores gold mostly occurs within copper sulfide grains as invisible gold (i.e., within the sulfide structure) or as native gold grains. In chalcopyrite-rich ores gold mostly occurs as native gold grains with lesser invisible gold. Petrographic observations also indicate a higher proportion of free gold (native gold not attached to any sulfide) in chalcopyrite-rich ores compared to bornite rich ores. The pattern of free gold distribution appears to correlate with the flotation test data, where the average gold recovery value from chalcopyrite-rich ores is consistently lower than bornite-rich ores. Our data suggest that porphyry copper-gold deposits with chalcopyrite-rich ores are more likely to have a higher proportion of free gold and may require different ore processing strategies.Editorial handling: R. P. Richards     

新疆伊什基里克成矿带金矿类型及其地质特征

伊什基里克成矿带系西天山成矿区带内重要的金铜成矿带.带内金矿类型主要划分有二种类型岩浆-热液型和火山-热液型,其中岩浆-热液型金矿床与浅成-超浅成侵入体(脉)有成因关系,火山-热液型金矿床与下石炭统火山热液活动有关,矿体赋存于大哈拉军山组火山地层中.两类型金矿均严格受构造、火山岩地层以及花岗岩(脉)体的控制.     

安徽铜陵狮子山铜矿床中伴生金的赋存状态及提高回收率途径

狮子山铜矿床中伴生金以矿物态为主，金矿物主要为银金矿和金银矿。根据金矿物的粒度、嵌布状态及载金矿物特征，结合金在选矿流程中的趋向分析，提出了应考虑采取在浮选前增加重选，并注意破碎同分级设备凹槽中滞留的单体金的回收来提高金回收率的建议。     

陕西凤县马蹄沟金矿床控矿构造特征及其地质意义

马蹄沟金矿床位于陕甘交界陕西境内的凤县一带,西邻甘肃的两当县,东临陕西太白县。地处西秦岭礼县—太白矿集区的东段,凤县—太白矿集区北侧,是西秦岭金矿聚集区的一部分。由于处在商丹断裂带西段,经历过多期强烈的构造岩浆活动,该段有众多的金矿床产出,如太阳寺金矿、庞家河金矿、八卦庙金矿和双王金矿等大中型金矿床,同时褶皱和断裂构造比较发育,金矿床受构造的控制作用明显,并且已经得到多位学者的报道（刘方杰等,1999;胡晓隆等,2008;王义天等,2009;宫勇军,2014;马健等,2015）。马蹄沟金矿床内对该金矿的控矿构造及构造控矿作用的研究尚属于空白区,而其与邻区的金矿床构造环境相似。因此,本文结合该区地质背景,通过详细观测矿化蚀变带内控矿构造的特点,初步探究了马蹄沟金矿床的控矿构造特征,提供了进一步的找矿方向,对于总结商丹断裂带西段的构造控矿理论和完善该区域的矿田构造格局具有重要的科学意义。     

青海都兰沟里金矿整装勘查区1:100 000地质矿产数据集

青海都兰沟里金矿整装勘查区1：100 000地质矿产数据集由系统库、建造构造图、地质矿产图、地磁ΔT平面等值线图、地磁ΔT化极平面等值线图、化探综合异常图、矿产预测成果图及附表组成;每张图文件夹内有对应的编图说明。沟里整装勘查区总体被新元古代-早古生代东昆中缝合带（Pt₃-P₂末）、中-晚古生代兴海-苦海缝合带（D-P₃）、晚古生代-早中生代（C-T₂末）阿尼玛卿缝合带分割为4个二级构造单元。区内岩浆活动以奥陶纪-泥盆纪和二叠纪-三叠纪为主,分别代表了两期不同的造山旋回,成矿期可能在晚三叠世-早侏罗世。此次工作在整装勘查区内共圈定了1：50 000磁异常21处、化探综合异常80处;划分4个三级成矿带（区）、7个四级成矿亚带、8个五级矿带（矿田）、17个六级有利找矿区块;在有利找矿区块中筛选并提交找矿靶区14处;通过后续投入,区内相继发现了那更康切尔大型银矿、德龙金矿、迈龙金矿点、浪木日铜镍矿点、龙什更铜钴矿点等一批有找矿潜力的矿床（点）;估算区内金资源总量588.04吨、银资源总量3 197.85吨、铅-锌资源总量235.83万吨,铜-钴资源总量121.49万吨。