The Sukari Gold Mine,Eastern Desert—Egypt: structural setting,mineralogy and fluid inclusion study

The Sukari gold mine (18.8 Mt @ 2.14 g/t Au) is located 15 km west of the Red Sea coast in the southern central Eastern Desert of Egypt. The vein-type deposit is hosted in Late Neoproterozoic granite that intruded island-arc and ophiolite rock assemblages. The vein-forming process is related to overall late Pan-African shear and extension tectonics. At Sukari, bulk NE–SW strike-slip deformation was accommodated by a local flower structure and extensional faults with veins that formed initially at conditions of about 300 °C and 1.5–2 kbar. Gold is associated with sulfides in quartz veins and in alteration zones. Pyrite and arsenopyrite dominate the sulfide ore beside minor sphalerite, chalcopyrite and galena. Gold occurs in three distinct positions: (1) anhedral grains (GI) at the contact between As-rich zones within the arsenian pyrite; (2) randomly distributed anhedral grains (GII) and along cracks in arsenian pyrite and arsenopyrite, and (3) large gold grains (GIII) interstitial to fine-grained pyrite and arsenopyrite. Fluid inclusion studies yield minimum vein-formation temperatures and pressures between 96 and 188 °C, 210 and 1,890 bar, respectively, which is in the range of epi- to mesothermal hydrothermal ore deposits. The structural evolution of the area suggests a long-term, cyclic process of repeated veining and leaching followed by sealing, initiated by the intrusion of granodiorite. This cyclic process explains the mineralogical features and is responsible for the predicted gold reserves of the Sukari deposits. A characteristic feature of the Sukari gold mineralization is the co-precipitation of gold and arsenic in pyrite and arsenopyrite.Editorial handling: H. Frimmel     

Geology and volcanic stratigraphy of the Canatuan and Malusok volcanogenic massive sulfide deposits,southwestern Mindanao,Philippines

The Canatuan and Malusok massive sulfide deposits are located near Siocon, Zamboanga del Norte, in southwestern Mindanao, Philippines. The Canatuan–Malusok area is underlain by the Jurassic–Cretaceous Tungauan schists, which form much of the Zamboanga Peninsula. The volcanic strata at Canatuan and Malusok can be traced for >7 km along strike and is host to at least three discrete massive sulfide bodies: Canatuan, Malusok and SE Malusok. Basal basaltic andesite volcanic rocks are generally chemically uniform and show only moderate alteration. The massive sulfide deposits occur in overlying rhyolitic to rhyodacitic volcanic rocks that are altered to a schistose assemblage of quartz, sericite, chlorite and pyrite. The alteration is texturally destructive but graded clastic beds are locally observed. Despite tropical saprolitic weathering, four lithogeochemical subunits of the felsic package are identified. Stratigraphic interleaving, however, has made correlation of these units over any significant distance difficult. The sulfide lenses are overlain by a few metres of felsic schists which locally contain manganese-bearing silicates and oxides that serve as a stratigraphic marker. Hangingwall andesitic volcaniclastic rocks are discontinuously preserved, although where present, they consist of regularly bedded mafic volcanic sandstones. The lateral continuity of a manganese-bearing marker and flanking felsic volcaniclastic intervals indicate that locally the volcanic strata form a homoclinal sequence. The Canatuan Au–Ag–Cu–Zn deposit consists of a gossan overlying a massive sulfide lens. The sulfides and gossan are flat lying and hosted within felsic volcanic rocks. The gossan is gold–silver-rich, and was formed by a combination of oxidation and volume collapse of the original sulfide lens. The sulfide minerals present below the current water table, are auriferous massive pyrite with base metal sulfides, with some supergene chalcocite. The transition from gossan to sulfides is very sharp, occurring at the water table. Massive sulfide deposits at Malusok are hosted in the same felsic sequence as Canatuan and they have similar base and precious metal contents. Only limited gossan has been found at Malusok. The bimodal nature of the volcanic rocks at Canatuan, together with their low HFSE contents, near-flat REE patterns and tholeiitic affinities, suggest that they formed in an intra-oceanic arc setting above a depleted mantle source. Mafic and felsic volcanic rocks of similar composition have been recovered from the Tonga-Kermadec and Izu-Bonin-Marianas island-arc systems in the western Pacific. Mafic rocks at Canatuan show no evidence for LILE enrichment that characterizes melts derived from metasomatized mantle under more mature arcs, suggesting that they are the product of a nascent, rather than a mature arc. There is no evidence from the REE, or other incompatible trace elements, that continental crust or evolved arc crust was involved in the generation of the Canatuan-Malusok volcanic rocks. Although it has been proposed that the Zamboanga metamorphic complex comprises microcontinental fragments of Eurasian affinity, our data do not support an evolved crustal setting for the Canatuan-Malusok volcanic rocks, which we suggest were derived from an intra-oceanic arc and subsequently accreted to the eastern Mindanao terrane.Electronic Supplementary Material Supplementary material is available in the online version of this article at http://dx.doi.org/10.1007/s00126-003-0350-7Editorial handling: R.R. Large     

刘屯金矿床Ⅰ,Ⅱ地段深部找矿观测

刘屯金矿床由刘屯（Ⅰ）和金屯（Ⅱ）两个地段组成。作者通过矿床地质特征、深部地物理特征、金矿体地球化学异常模式判别及矿体剥蚀程度预测等研究,对刘屯金矿床深部成矿提出了新看法,认为Ⅰ地段矿体已剥蚀到中下部,４０ｍ以下矿化灭灭;Ⅱ地段矿体剥蚀至头部,向下有较大延深,可进一步开展深部找矿。     

北票二道沟金矿床岩石稀土元素特征及岩石岩源

北票二道沟金矿床岩石稀土元素特征表明,其岩浆岩岩源均属上地幔。金矿母岩是来自上地幔不同部位的岩浆侵入岩石,金矿化与多次岩浆热液有关。     

辽宁省大石桥市吕王乡四道沟金矿选矿试验研究

本文介绍了四道沟金矿选矿试验。对采用的单一浮选流程中的主要工艺条件进行了讨论研究，结果表明该矿矿石可选性较好，指标稳定、可靠，可做矿床工业评价及开发利用的依据。     

韧性剪切带内金矿床类型及找矿标志

本文总结了近年来关于韧性剪切带与金矿关系研究的地质成果。根据金矿床与韧性剪切带的时空关系、含矿热液来源、金矿体的地质产状及矿化特征,作者将产于韧性剪切带内的金矿床划分为三个大的类型和六个亚类型,即Ⅰ型(Ⅰa型和Ⅰb型)、Ⅱ型(Ⅱa型和Ⅱb型)、Ⅲ型(Ⅲa型和Ⅲb型)金矿床。提出了每种类型金矿床的找矿标志及应重视产于前寒武纪变质岩区韧性剪切带内Ⅰ型金矿的找矿工作,尤其应注意寻找与围岩界线不清,不易识别的Ⅰa型金矿床。     

山东平邑卓家庄金矿中的碲硒矿物特征

山东平邑卓家庄金矿富含碲矿物和少量硒矿物,通过一系列测试方法手段对其特征和相互关系进行了研究,认为该高品位金矿的形成与富碲低温热液活动密切相关.     

山东平邑卓家庄金矿中的碲硒矿物特征

山东平邑卓家庄金矿富含碲矿物和少量硒矿物 ,通过一系列测试方法手段对其特征和相互关系进行了研究 ,认为该高品位金矿的形成与富碲低温热液活动密切相关     

变质作用的PTt轨迹,地球动力学过程和金矿化

本文论述了典型的大地构造环境下变质作用的PTt轨迹及其反映的地球动力学过程对金矿化的控制作用,从PT演化的角度阐述了金矿床的成矿机理和成矿规律。     

绍兴──江山对接带石英闪长岩金矿带矿化规律独特性

沿江南、华夏古地体斜接遇合的古缝合线。绍兴—江山对接带分布的同构造期的石英闪长岩，为前寒武纪同熔型或M（I）型中酸性侵入岩，属于深源原生含金建造。岩体南部呈NE－SW向分布的糜棱岩带与金矿化密切伴生，构成浙江中部最主要的金矿带。其中金矿地质、金矿元素地球化学规律，金矿成因矿物、稀土、同位素等特征，具有不同于两侧古地体中含金建造的独特性。金矿带中Au与Cd、Cu、Zn、Hg等元素之间相关关系及金矿成因类型的多元化特征，在中国主要金矿类型中尚属少见。