Gold occurrence in Central Italy—the Ponte San Pietro mineralization

Gold mineralization related to a sulphide-bearing quartz vein within Triassic phyllites has been identified in a former study of an abandoned Cu–Zn–Pb mine in southern Tuscany–northern Latium. The vein-hosted mineral assemblage includes pyrite, sphalerite, chalcopyrite, galena, arsenopyrite, and tetrahedrite; the gold content reaches up to 20 ppm. The mineralization was related to fluids characterised by moderate temperatures and moderate salinities (5–15% NaCl equivalent) and represents the highest grade of Au in the ore deposits of southern Tuscany. The difference in the estimated values of Te of primary, L+V, pseudo-secondary L+V, secondary L+V fluids inclusions reflects different components present in the solutions.Based on these results one can conclude that euhedral quartz and pyrite deposition was related to fluids having variable salinity and chemical components.The origin of gold in Ponte San Pietro (PSP) deposit may be related to leaching of metapelites/phyllites derived from pelitic rocks containing some amount of sulphur-bearing organic matter; it is worthy noting that quartz–marcasite bearing lenses, interstratified in Triassic phyllites, contain significant amount of visible gold. The Co, Ni, Mn, as well as the δ³⁴S data, suggest a different origin for the phyllite-hosted marcasite, the PSP quartz-vein hosted pyrite, and for gold occurrences.     

土堆矿区金矿体赋存规律及深部预测

通过对山东省海阳市土堆矿区金矿的大地构造背景、矿体的空间赋存规律及成矿构造特征的分析研究,结合本区矿体的产出规律,对比牟平—乳山成矿集中区的总体矿床埋藏深度,提出本区深部找矿预测。     

湘西地区脉状钨锑金矿床的矿体侧伏与板柱状赋存规律

湘西地区脉状钨锑金矿床矿体严格受构造控制,并普遍具有沿倾向发育较深、侧伏和板柱状赋存的规律。文章阐述了矿体侧伏的控制因素,并以沃溪金矿和泥潭冲金矿为例,分析了褶皱和断裂控制的板柱状矿床(体)的构造特点,总结了矿体板柱状赋存的成因以及矿体侧伏和板柱状赋存的规律,认为应该利用矿体的侧伏和板柱状赋存的规律指导勘查工作。     

闽中太华山金矿区金坂矿段矿化类型及找矿方向探讨

太华山金矿区位于福建中部尤溪-德化-永泰三县的结合部位之"闽中金矿集中区",是该区具有找矿前景的靶区之一。随着太华山金矿区金坂矿段深部找矿勘查较系统的工程投入,发现了该区段深部的含矿斑岩体及其矿化蚀变系统。通过对金坂矿段620 m中段以上的含矿斑岩、矿化类型、蚀变分带特征及斑岩与各类型矿化的关系等进行系统分析,初步认为太华山金坂矿段矿化类型具有浅成低温热液型金银矿的特征,其金银矿(化)体在空间上与流纹斑岩紧密相伴,主要产于流纹斑岩体的内外接触带中,自上而下的矿化类型分为:顶部(微)细粒浸染型、中部石英细脉/网脉型及深部热液角砾/黄铁矿浸染石英脉型等,成矿具有"一体多型"的特点。结合太华山矿区太华山矿段、尤岭隔矿段地质特征的对比分析,提出了该区深部金银矿找矿地质模型,对完善太华山热泉-次火山斑岩成矿系统模型及其指导深部探矿工作具有重要的意义。     

The first discovery of uytenbogaardtite in Taimyr (Konechnoe ore occurrence)

Uytenbogaardtite has been observed when examining the ores of the Konechnoe gold ore occurrence, West Taimyr, which is the first find for the entire Taimyr-Severnaya Zemlya region. It is associated with native gold (fineness 520–560‰), pyrite, and sphalerite. Sphalerite is characterized by Fe, Cd, Ag, and Cu impurities. Zinc is present in siderite. In the ores of the Konechnoe ore occurrence, there is also native gold of the early generation with sphalerite, the latter containing chalcopyrite lamellae and being in association with arsenopyrite, pyrite, and galena. The peculiar compositions of microinclusions and impurities in sphalerite and other minerals and the presence of accessory minerals, such as monazite and apatite, reflect the specific metallogenic and geochemical characteristics of the Minina-Bol’shevik structural-metallogenic zone and serve as indicators of the potential of the North Taimyr area in terms of gold, silver, zinc, copper, lead, cadmium, strontium, thorium, and lanthanides.     

New type of gold mineralization of the Tyrnyauz ore cluster (Kabardino-Balkar Republic)

Native Au on the northern flank of the Tyrnyauz ore cluster is related to the pyroxene–garnet association of skarns and is represented by separate idiomorphic ingrowths in rock-forming minerals of skarns and relatively isometric xenomorphic grains in the interstices. Gold mineralization can be attributed to the Au-skarn geological–industrial type with ores of a low-sulfide formation and Au–Bi–Te geochemical specialization.     

Relationship between mercury and arsenic mineralization in the Sarasa ore zone (Gornyy Altay)

Granite gneiss, gneiss, and granite domes of Central Karelia are developed near the junction zone between two tectonic structures, the Western anticlinorium of the Belomorides and the East Karelian zone of the Karelides, The established regular restriction of both shows and deposits of a number of mineral resources to the surroundings of the domes is of importance in forecasting and the future direction of exploration work in this region. —Authors.     

甘肃省阳山金矿田金的赋存状态和金矿物特征

甘肃阳山金矿田属于类卡林型金矿床,金矿化类型主要有蚀变千枚岩、蚀变斜长花岗斑岩、蚀变砂岩、蚀变灰岩四种。金多呈独立金矿物形式出现,少许呈分散状,矿石中金矿物以自然金为主,其次是银金矿。金矿物以包体金、裂隙金、粒间金等形式嵌布于毒砂、黄铁矿、辉锑矿、粘土矿物等主要载金矿物中,且毒砂、黄铁矿、辉锑矿较其它金属硫化物中占优势。金矿物形态各样,粒度以微细粒为主。金矿物特征反映出本区金矿床的成矿物质主要来源于变质岩、岩浆岩和地幔,成矿作用与印支晚期中酸性侵入岩有关。这与地质地球化学研究所获得的矿床成因认识相一致。