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In present study, a novel organic depressant N-thiourea-maleamic acid (TMA) was synthesized and applied as a galena depressant in the flotation separation of Mo-Pb ores. The depression behaviors of TMA were tested through flotation experiments. A wider separation window for single minerals over 90.0% was obtained at 30.0 mg/L TMA, confirming that TMA could depress galena significantly, while effected molybdenite floatability slightly. An effective separation was obtained for artificially mixed minerals and actual Mo-Pb ores. The adsorption mechanism on galena was revealed by UV–Vis spectra, zeta potential tests, Fourier transform infrared spectroscopy (FT-IR) analysis, contact angle tests and X-ray photoelectron spectroscopy (XPS) analysis. The zeta potentials of galena became more negative and the contact angle of galena dropped from initial 74.36° to 57.8° with 30.0 mg/L TMA depressant, inferring that TMA had adsorbed on galena surface. The analysis results of UV–Vis spectra, FT-IR and XPS gave further evidence that TMA might chemisorb on galena surface via Pb sites on galena surface and the thiourea group in TMA molecular structure, while the carboxyl group played a role of hydrophilicity.

The Laowan super-large (208 t Au) gold deposit is located in the Tongbai orogenic belt, along with a newly-discovered molybdenite deposit at its depth in the northern periphery. The gold deposit is a fault-controlled lode gold deposit featuring sulfide quartz vein-type and altered rock-type mineralization hosted within the metamorphic rocks, whereas the molybdenum deposit is a typical porphyry-type deposit. These two deposits have their respective paragenetic sequences and mineralization types without spatial overlapping in the ore field. Here, we present U–Pb dating of zircon, hydrothermal rutile, and REE phosphates, and Re–Os dating of molybdenite to constrain the relationship between the Au and Mo mineralization, and their relation to Mesozoic granitic magmatism. Textural features indicate that rutiles and associated phosphate minerals are of hydrothermal origin, generated by re-precipitation and dissolution of titanite crystals hosted in the metamorphic host rocks due to hydrothermal alteration during Au and Mo mineralization. LA-ICP-MS U–Pb dating of rutile from the auriferous altered rocks yields a 206Pb/238U age of 120.0 ± 6.7 Ma (MSWD = 1.4), consistent with the ages of the associated monazite (125.0 ± 2.4 Ma) and xenotime (126.3 ± 2.0 Ma), representing the timing of the gold mineralization, coeval with Laowan monzogranite (zircon U–Pb: 128.8 ± 0.7 Ma). Rutile from the molybdenum deposit show an older 206Pb/238U age of 141.0 ± 11 Ma (MSWD = 1.1), consistent with the molybdenite Re–Os age (141.5 ± 1.7 Ma; MSWD = 0.27) and the zircon U-Pb age (141.6 ± 0.8 Ma; MSWD = 1.5) of the Songpa porphyry. Hence, the Au and Mo mineralization in the Laowan district represent two episodic mineralization events related to the late Mesozoic granitic magmatism. Our study also suggested that multiple isotopic dating is helpful to precisely constraint the ages for complex hydrothermal deposits.

The origin of sediment-hosted copper-cobalt deposits (SCDs) within metamorphic terranes remains contentious, particularly in regard to the timing of mineralization relative to basin evolution. Here, we link the timing of Cu-Co mineralization in the Zhongtiao Mountains district, central China, to basin closure during development of the Trans-North China Orogen. Metamorphic apatite from meta-evaporite has a U-Pb age (1844 ± 25 Ma) within error of a Re-Os age for molybdenite from Cu- and Co-bearing veins (1819 ± 10 Ma), implying that mineralization and metamorphism were coincident. In situ trace element and Fe-S isotope analyses of deformed sedimentary pyrite (Py I) and younger euhedral metamorphic pyrite (Py II) in pyritic graphite schist indicate that Co was mobilized from Py I via fluid-mediated dissolution and reprecipitation. In the graphite schist, representing a sulfidic shale metamorphosed at upper greenschist facies conditions, relic Py I has high δ34S values (22.9 ± 0.4‰, n = 10) and δ56Fe values (0.90 ± 0.16‰, n = 8). These values are consistent with bacterial sulfate reduction and pyrite formation in a Paleoproterozoic sulfidic sea (i.e., after the first great oxygenation event). In addition, Py I has unusually high Co contents (0.8–3.0 wt.%), suggesting that transition metals, including Co and Ni, were originally concentrated in sedimentary pyrite in an evaporative setting. The evaporitic setting is supported by the presence of sylvite in sulfidic schists and adjacent scapolitic calc-silicates. Younger Co-poor Py II has slightly lower δ34S values (21.4 ± 0.2‰, n = 19) and higher δ56Fe values (1.61 ± 0.15‰, n = 9), supporting the hypothesis that Co was released from sedimentary sulfide during dissolution and reprecipitation. The great variability of δ34S (14.8 to 22.9‰) and δ56Fe (0.13 to 2.30‰) in hydrothermal pyrite (Py III) associated with Cu-Co mineralization suggests that an external Cu-rich oxidizing fluid was involved in the ore-forming process. Copper and Co in this type of deposit are typically both considered to be derived from fertile basement rocks. This study, however, highlights another potential source for the Co, with its enrichment in a sulfidic sea along an evaporative margin and its upgrading through mobilization during orogenesis that leads to formation of a relatively high-temperature group of SCDs. Tectonometamorphic processes causing such Co enrichments took place during the Paleoproterozoic and Neoproterozoic oxygenation events, implying that the most prospective targets for Co resources are concentrated in ca. 2.2–2.0 Ga and 0.9–0.7 Ga deformed passive margin marine sequences.

Sodium sulfide has been widely used as a bismuth depressant in the flotation separation of molybdenum–bismuth sulfide ores. However, the selective depression mechanism of sodium sulfide on bismuthi...

At El Chucho creek, located to the west of the Valle del Cauca department in Colombia, some hydrothermal alterations affecting the Buga Batholith rocks and dykes of porphyritic quartz-dioritic and tonalitic composition were identified. These lithological units host mineral occurrences of pyrite, chalcopyrite, and molybdenite that occur disseminated in the rocks or associated with quartz veinlets. The hydrothermal alterations identified were phyllic, propylitic, and, in minor quantity, potassic. The two firsts alterations’ distribution is related to structures and pervasive, whereas the last one seems restricted to contact zones of porphyritic dykes on tonalite. Microthermometric data were acquired i) on quartz veinlets of 1 cm thick over a phyllic alteration zone, and ii) on quartz veinlet of 1 cm thick with chalcopyrite ± molybdenite and copper silicates, both veinlets cutting the phaneritic tonalite. Those data suggest that the mineralizing fluids have an aqueous-saline chemical system and were trapped under low volatile content. The microthermal data allowed authors to identify two mineralizing events. One of them of higher temperature, with homogenization temperatures between 275°C-480°C; as the second event is characterized by lower homogenization temperatures that range from 100°C to 139°C.

А new Vovchansk Uranium Ore district is allocated within the Orikhiv-Pavlohrad structural-metallogenic zone (SMZ) of the Azov metallogenic region. It is represented by Dibrova REE-U-Th deposit and a number of less studied ore occurrences. This deposit, according to ore mineralogy and age, geological and structural features, can be related to potassium-uranium metasomatite type. Dibrova deposit is considered to be possible analogue of mineralization of the Central Ukrainian Uranium Ore district. Among the main diagnostic characteristics of Dibrova deposit are: 1) location within the Mesoarchean trough-like structure superimposed on the Paleoarchean basement. 2) Spacial and genetic association with Paleoproterozoic two-feldspar granitoids of Dibrova type, which are considered to be related to Saltychia intrusive complex. 3) Regional and local faults, favorable for emplacement of numerous bodies of aplite-pegmatitic granitoids and associated intensive metasomatic alterations of rocks. The flexural fold was formed at the intersection of multidirectional faults, which is also favorable for ore mineralization. 4) Mineralization is confined to metasomatically altered aplite-pegmatites, less often to microcline quartzites of Dibrova suite. 5) K2O/Na2O ratio of ore-bearing granitoids reaches 3.5 and thorium-uranium ratio varies from 1.0 to 4.0. 6) Ores are composed by quartz (70–90 %) as predominant mineral and microcline. Minor minerals (up to 10–15 %) are represented by sillimanite, muscovite, biotite. 7) Accessory minerals include monazite, zircon, rutile, nasturan, brannerite, uraninite, molybdenite. 8) Among trace elements are niobium, lead, molybdenum, bismuth, copper, zinc and tin. Economic REE-U-Th mineralization was da­ted at 1.9–2.2 billion years. It is formed through circulation of hydrothermal-metasomatic fluids associated with the emplacement of Paleoproterozoic aplite-pegmatitic granites of the Dibrova type. Study of monazite and uraninite inclusions by the CHIME techniques confirms the Paleoproterozoic age of mineralization, 2085–2115 Ma. At the same time, the influence of Mesoarchean Yanvarske granitoids for the formation of REE mineralization during early pre-ore stage is not excluded.

Huangshaping is a world-class skarn deposit hosting abundant W–Sn polymetallic mineralization in the Nanling Range, South China. Although the geochemistry of skarn-hosted mineral deposits has been extensively studied, the role of the prograde-to-retrograde stage transition in the enrichment and precipitation of metallic elements in high-temperature systems has received little study to date. Here, we analyzed garnet, scheelite, and cassiterite in high-temperature granite porphyry-related W–Sn polymetallic system of the Huangshaping deposit to investigate these processes. Three generations of garnet (Grt I, Grt II, and Grt III), two generations of scheelite (Sch I and Sch II), and two types of cassiterite (Cst I and Cst II) were distinguished with regard to their mineral associations, microscopic characteristics, and geochemical features. The results show that grossular–andradite garnet formed from Al-rich andradite (Grt I, Al2O3: 8.18 wt%) in the early prograde stage and pure Fe-andradite (Grt III, Al2O3: 0.15 wt%) in the late prograde stage. Mo-rich scheelite (Sch Ia, MoO3: 19.41 wt%) formed in the prograde stage and coexisted with Grt III, sharing the same REE patterns. A shift from HREE enrichment in Grt I to HREE depletion in Grt III reflects progressive uptake of REEs by secondary mineral phases. Grt III has the highest average contents of W (905 ppm), Mo (19 ppm), and Sn (5610 ppm), suggesting an enrichment of metallic elements at the end of the prograde stage. In contrast, Mo-poor scheelite (Sch II, MoO3: 0.63 wt%) co-crystallized with molybdenite and fluorite in the retrograde stage and shares similar REE patterns with the granite porphyry. Skarn mineralization at Huangshaping was a two-step process controlled by metamorphic stage. The prograde stage was characterized by high temperatures and fO2 and a Cl-rich fluid, and it resulted in enrichment of ore-forming elements with minor scheelite precipitation. The retrograde stage was characterized by lower temperatures and fO2 and a F-rich fluid, and it resulted in major precipitation of ore minerals (scheelite, molybdenite, and cassiterite). Dissolution–reprecipitation reactions played an important role in extraction of metallic elements from decomposing anhydrous skarn minerals and formation of ore minerals. A decrease in the high-field-strength element (HFSE) content of cassiterite from proximal skarn (Cst I) to distal skarn (Cst II) indicates declining temperature accompanied by precipitation of fluorite. This study examines the transition from the prograde stage to the retrograde stage in the Huangshaping deposit, and it provides insights into the genesis of other skarn W–Sn polymetallic deposits in the Nanling magmatic–tectonic–metallogenic belt.

The Qiyugou Au deposit, located in the Xiong'ershan ore cluster of central China, consists of breccia pipe hosted Au ore bodies (>60 t Au) and newly discovered porphyry ore body (8 t Au). The porphyry Au mineralization occurs in the silicified core of the apical part of porphyritic granite stock which shows close spatial relationship with the auriferous breccia pipes. Here we present an integrated study involving detailed field investigation, textural studies, in situ pyrite trace element and sulfur isotope analysis, and U-Pb and Re-Os geochronology to elucidate the genetic relationship and hydrothermal evolution of the porphyry and breccia pipe mineralization. The SIMS sulfur isotopic analyses for the five pyrite generations show consistent δ34S values between −3.6‰ and 0.6‰, indicating that the two styles of Au mineralization had a mixed source including crustal and mantle-derived components. Zircon LA-ICP-MS U-Pb geochronology of two porphyritic granites yield weighted mean ages of 133.0 ± 0.6 Ma and 130.3 ± 0.9 Ma, and six molybdenite samples display an isochron age of 131.3 ± 1.1 Ma, representing the timing of granitic magmatism and Au mineralization in the 189 porphyry ore body. Available geochronological data allow us to constrain the timing of granitic magmatism and gold mineralization to be 135.6–134.1 Ma in the breccia pipes and 133.0–128.6 Ma in the porphyry ore. Among the five pyrite generations, Py1b and Py2b from the J4 breccia pipe are characterized by higher Co, Ni, and comparable contents of other elements (e.g. Au, Ag, Te, Pb, Zn, Cu and Bi) than those in Py1p, Py2p and Py3p from the porphyry ore. The widely consistent metal concentrations and linear relationship of metals in pyrite between the breccia pipe and porphyry ore are most probably the result of fluid exsolution from the same magmatic-hydrothermal system, whereas the enriched Co and Ni values from the J4 breccia pipe can reflect the composition of pyrite precipitating fluid at the early stage of the prolonged magmatic-hydrothermal system. The Qiyugou porphyry and breccia pipe mineralization show close spatial-temporal association and consistent source materials, and thus we propose that they resulted from multiple pulses of fluid exsolution from a large, deep-seated magma chamber.

Pyrite ores on the flanks of the Saum copper–zinc massive sulfide deposit are clastic sediments intensely transformed under conditions of acid diagenesis. Colusite in ores is confined to fine-grained pyrite clasts, which are rimmed by later small-crystalline pyrite aggregates. Colusite forms fine dissemination (1–3 µm) and large isometric grains (up to 50–100 µm), contains inclusions of sulvanite, and belongs to arsenocolusite in chemical compositions (wt %): 12.62–14.87 As, 0.19–0.64 Sb, 0.29–1.46 Sn, 3.05–3.23 V, and 1.51–3.20 Fe. The LA ICP MS analysis of fine-grained pyrite revealed minor Ga, Ge, In, and Se contents in composition of arsenocolusite, which are correlated with chemical elements of colusite according to isomorphous substitutions in its formula. Galena, tellurobismuthite, native gold, molybdenite, rutile, monazite, uraninite, and Ba-bearing muscovite are found in fine-grained pyrite in assemblage with colusite. Interaction of sulfide sediments with seawater led to their enrichment in seawater elements (V, Mo, and U) and the deposition of colusite in assemblage with molybdenite and uraninite from trace element-rich diagenetic fluids under their dehydration.

The Qulong porphyry Cu–Mo deposit, generated in the Miocene post-collisional extension environment of the Gangdese Copper (Molybdenum) Metallogenic Belt, is one of the largest porphyry Cu deposits in China. This study reports the noble gas isotopic compositions of volatiles released from fluid inclusion reserved in pyrite from the Qulong deposit. 3He/4He and 40Ar/36Ar ratios range from 0.54 to 1.015 Ra and 300–359, respectively. Concentrations of 4He and 40Ar range from 1.77 to 2.62 × 10−8 cm3 STP and 1.7–34 × 10−8 cm3 STP, respectively. The isotopic composition of noble gases indicates that the ore-forming fluids of the Qulong Cu–Mo deposit were a mixture of fluid containing mantle component, which is exsolved from the porphyry magma, and crustal fluid characterized by atmospheric Ar and crustal radiogenic He. The δ34S values of pyrite and molybdenite range from − 0.52‰ to 0.31‰, with an average of − 0.12‰, indicating a magmatic origin. More mantle components were involved in the Cu–Mo deposit than in the Mo–Cu deposit in the Qulong-Jiama ore-district.

Understanding the magmatic-hydrothermal cooling and exhumation history is fundamental for investigating porphyry deposit formation and preservation. In the Zhunuo porphyry copper deposit of southern Tibet, hydrothermal biotite related to early potassic alteration likely formed from 14.7 ± 0.3 Ma (zircon U-Pb age) to 14.23 ± 0.13 Ma (molybdenite Re-Os age) and cooled below the closure temperature for 40Ar/39Ar system at 13.91 ± 0.05 Ma (hydrothermal biotite 40Ar/39Ar plateau age). The 40Ar/39Ar spectra of another hydrothermal biotite sample that was selectively replaced by chlorite record the timing of late phyllic alteration at 13.53 ± 0.08 Ma. Zhunuo hydrothermal alteration and mineralization likely ceased at 13.09 ± 0.07 Ma based on the 40Ar/39Ar plateau age of the fresh magmatic biotite crystals. The biotite 40Ar/39Ar systematics have not been reset by ~ 12.0 Ma post-mineralization granite porphyry within ore district, which is likely due to rapid cooling and/or absence of fluid exsolution for the granite porphyry. In combination with previous zircon U-Pb and molybdenite Re-Os data, two-pulses of magmatic-hydrothermal activity from 14.78 ± 0.11 to 14.44 ± 0.05 Ma and from 14.23 ± 0.13 to 13.53 ± 0.08 Ma can be recognized at Zhunuo. (U-Th)/He thermochronological data on zircon and apatite from the inter-mineralization monzogranite porphyry suggest three cooling events characterized by first-stage magmatic cooling at a rate of ~ 1850 °C/m.y., and two later phases of uplift and exhumation at ~ 70 °C/m.y. and ~ 10 °C/m.y. Approximately 1.4-km thickness of materials have been removed from the Zhunuo Miocene monzogranite porphyry during uplift and erosion, including a large volume of ore.

The Yangla Cu deposit is the largest ore deposit in the Jinshajiang polymetallic metallogenic belt, northwest Yunnan, China. There is no consensus on the genesis of the ore deposit owing to the limited studies on the chemical compositions of sulfides. This study used an electron probe micro-analyzer to constrain the chemical compositions of pyrite, chalcopyrite, molybdenite, and sphalerite in the porphyry Cu ore of the Yangla Cu deposit and compared them with the chemical compositions of sulfides in the skarn Cu ore. The trace element contents and their occurrences were used to estimate the metallogenic temperature and infer the genesis of the Yangla deposit. The results show that the sulfides in the porphyry Cu ores have variations of ore element concentrations relative to their theoretical values. Pyrite is depleted in S but elevated in Fe; chalcopyrite is depleted in Cu, Fe, and S; and molybdenite and sphalerite are enriched in S whilst depleted in Mo and Zn. The concentrations of the main metallogenic elements Cu, Fe, Mo, Zn, and S in the porphyry are generally lower than those in skarn, suggesting that the porphyry ore was formed in a moderate to moderate-high temperature metallogenic environment. The formation time may also be slightly later than that of the skarn Cu ore. Elements such as As, Co, Cu, Pb, Zn, Mo, Cd, and Ni mainly exist as isomorphic replacements and mineral inclusions in the sulfides of both porphyry and skarn Cu ores. The trace element features of sulfides in the two ore bodies show that the Yangla Cu deposit may be a composite super imposed ore deposit, and its formation has undergone the process of exhalative-sedimentary to skarn-porphyry mineralization.

The newly-discovered supergiant Huayangchuan uranium (U)-polymetallic (Sr, Se, REEs, Ba, Nb and Pb) deposit is located in the Qinling Orogen, central China. The deposit underwent multistage mineralization, with the main carbonatite ore stage being the most important for the U, Nb, REE, Sr and Ba endowments. According to the mineral assemblages, the main carbonatite ore stage can be divided into three substages, i.e., sulfate (Ba–Sr), alkali-rich U and REE-U mineralization. Main-stage titanite from the Huayangchuan igneous carbonatite are rich in high field strength elements (HFSEs, e.g., Zr, Nb and REEs), and show clear elemental substitutions (e.g., Ti vs. Nb ​+ ​Fe ​+ ​Al and Ca ​+ ​Ti vs. Fe ​+ ​Al ​+ ​REE). High-precision LA-ICP-MS titanite dating yielded a U–Pb age of 209.0 ​± ​2.9 ​Ma, which represents the main-stage mineralization age at Huayangchuan, and is coeval with the local carbonatite dyke intrusion. This mineralization age is further constrained by the Re–Os dating of molybdenite from the Huayangchuan carbonatite, which yielded a weighted mean age of 196.8 ​± ​2.4 ​Ma. Molybdenite Re contents (337.55–392.75 ​ppm) and C-O-Sr-Nd-Pb isotopic evidence of the Huayangchuan carbonatite both suggest a mantle origin for the carbonatite. Our study supports that the Late Triassic carbonatite magmatism was responsible for the world-class U-Mo-REE mineralization in the Qinling Orogen, and that the regional magmatism and ore formation was likely caused by the closure of the Mianlue ocean and the subsequent North China-South China continent-continent collision.

The evolution of the magmatic-hydrothermal system that formed the Eocene Yulong Cu-Mo porphyry deposit of the eastern Tibetan Plateau, China, is reconstructed based on the study of the sequence of stockwork vein sets showing systematic crosscutting relationships in hand specimen. Early A veins associated with potassic alteration of the porphyritic host are composed of vitreous quartz that is extensively recrystallized and has a dark blue cathodoluminescence. Fluid inclusions contained in the quartz have been affected by post-entrapment modification. Some of the A veins were reopened and contain ribbons of microscopic molybdenite flakes. Formation of the molybdenite was associated with recrystallization of the earlier formed quartz and concomitant with the development of a dark purple to brownish cathodoluminescence signature. Reopening of the early veins also resulted in the formation of AB veins containing euhedral quartz crystals that contain encapsulated molybdenite flakes and are intergrown with coarse laths of molybdenite. These euhedral quartz crystals showing a dark purple to brownish cathodoluminescence host vapor-rich, intermediate-density fluid inclusions as well as hypersaline liquid and vapor-rich fluid inclusions, indicating that fluid immiscibility at hydrostatic pressure conditions occurred during crystal growth. Later, C veins that crosscut and commonly reopen the earlier A and AB veins lack quartz as a gangue mineral and consist entirely of chalcopyrite and pyrite with minor molybdenite. Sulfide formation was accompanied by chlorite or sericite alteration of the wall rocks. Late D veins containing quartz and pyrite with associated sericitic alteration of the porphyritic wall rocks crosscut all earlier vein types. Only minor amounts of molybdenite and chalcopyrite are present. Euhedral quartz crystals in the D veins contain liquid-rich fluid inclusions that have not been affected by post-entrapment modification. The results of this study indicate that Mo and Cu mineralization at Yulong was introduced by single-phase, intermediate-density magmatic-hydrothermal fluids as the porphyry system was transitioning from ductile to brittle conditions. The bulk of the Mo endowment predated Cu mineralization and formed during the change from lithostatic to hydrostatic conditions and associated immiscibility of the magmatic-hydrothermal fluids. Chalcopyrite precipitation followed as the single-phase, intermediate-density magmatic-hydrothermal fluids was escaping into the hydrostatic-pressured regime. Cooling of the magmatic-hydrothermal fluids appears to have been the principal control on metal precipitation.

The Yinyan porphyry tin deposit in western Guangdong is spatially associated with quartz porphyry and granite porphyry. LA–ICP–MS zircon U–Pb dating defined an emplacement age of 78.5 ± 0.4 Ma for the quartz porphyry and 79.2 ± 0.9 Ma for the granite porphyry. LA–ICP–MS cassiterite U–Pb dating yielded Tera–Wasserburg lower intercept ages of 78.5 ± 0.6, 78.6 ± 1.2, and 78.2 ± 0.7 Ma, for cassiterite from a cassiterite–sulfide vein, cassiterite–sulfide ore, and a cassiterite–topaz–quartz stringer, respectively. Re–Os dating of molybdenite from seven different veins yielded an isochron age of 77.0 ± 0.5 Ma. All these new age data are indistinguishable within analytical uncertainty and, therefore, indicate a genetic relationship between the Sn mineralization and the porphyry magmatism in the Yinyan deposit. The REE tetrad effect and very low Nb/Ta and Zr/Hf ratios indicate that the quartz porphyry and the granite porphyry are highly evolved. The U–Pb dated cassiterite is enriched in Fe, W, and U and in high field strength elements (HFSEs) such as Zr, Hf, Nb, and Ta. The high Fe, Nb, and Ta contents may be responsible for the dark luminescence of cassiterite in CL images. The Zr/Hf ratio of cassiterite may potentially be used to distinguish the mineralization type. Cassiterite from pegmatites has lower Zr/Hf ratios (~ 5–6) in comparison with granite/greisen-related (~ 9–30) cassiterite. Cassiterite from the early hydrothermal stage typically contains higher amounts of Ti, Nb, Ta, Zr, and Hf than that from the late hydrothermal stage. In combination with published geochronological data of other Sn–W deposits in the western Guangdong Province, two Sn–W metallogenic events at ca. 85 and 77–80 Ma have been identified. These two metallogenic events are part of a larger-scale 75–100 Ma Sn–W mineralization event in South China, which we suggest was probably related to the subduction of the Neo-Tethyan oceanic plate.

The paper reports geochemical and mineralogical data on ores of the Briketno-Zheltuhinskoe U–Mo–Re deposit, which is confined to the Visean paleochannel coal-bearing sandy sediments of the Moscow lignite basin. In addition to main ore elements (Re, Mo, U, and Se), the ores have elevated contents of the following metals (in order of decreasing abundance): Zr, Zn, Mn, Ni, As, Co, V, Pb, Y, Cu, and highly dispersed Tl and Ag. It was found that Re correlates positively with Mo, Ag, Zn, U, Se, and Co. The ores are incoherent and analytical scanning electron microscopy is the main method applied for their study. In order to clarify the speciation of U, Mo, and Re, sequential extraction experiments were performed. The main part of Re is associated with the organic and ion-exchange forms. Molybdenum is approximately equally distributed between the strongly bound (sulfide) and organic-related forms. Uranium mainly occurs in a weakly bound form and easily migrates with water. Authigenic minerals are mainly represented by pyrite, less common marcasite, and accessory sulfides (sphalerite, chalcopyrite, galena, etc.) and selenides (dzharkenite, clausthalite). Mo-minerals (containing up to 1.5 wt % Re) are represented by the tiny grains of molybdenite and jordisite. Uranium occurs as micron-size inclusions of uraninite (pitchblende) in colloform pyrite and is present as a macro-impurity in rhabdophane and zircon. The predominant part of U, Mo, and Re was found in adsorbed forms in carbonaceous, clayey, and strongly altered sulfide particles. Arkose and subordinate ash material together with heavy metals (Fe, Ni, Cu, Zn, Pb, U, Mo, Re), and also S and Se, were transported by river streams and accumulated in terrigenous sediments of shallow marine basin. These elements were adsorbed by plant detritus and, partly, by clay particles and iron oxyhydroxides/sulfides during diagenesis. The main economic U–Mo–Re ores were formed at the second, epigenetic stage, in the course of the lateral filtration of oxygenated groundwater through highly permeable sand horizons. This process was accompanied by the redeposition of U, Mo, Re, Se, Cu, Ni, and Zn from dispersed mineralization of the first stage at the reducing (plant detritus) and sorption (clay sediments) geochemical barriers. In this case, U, Mo, and Re were fixed in the mineral and, mainly, adsorbed forms. Significant contribution to the ore formation was likely provided by endogenous factors associated with activation of faults in the East European Platform (EEP) basement, epiplatform alkaline-basaltic magmatism, and the influx of deep fluids into the ore deposition zone.

Direct dating of W and W Sn deposits by wolframite is more reliable relatively to gangue mineral and important for understanding their timing and genesis. However, such analysis still lacks of homogeneous wolframite standard recently. Due to containing considerable and variable common lead, and inhomogeneous in different grains, the wolframite sample of MTM, which is a promising candidate reference material proposed by previous studies, is not suitable as a primary standard for wolframite U Pb dating by LA-ICP-MS using the normal normalization method as zircons. In this contribution, a modified normalization method is established for wolframite U Pb dating, in which NIST612 or 614 and MTM are used for correction of Pb Pb and U Pb ratios, respectively. Wolframite U Pb dating are performed on the Langcun, Xihuashan, Piaotang, Shamai W or W Sn deposits and the Baiganhu ore district, the obtained lower intercept 206Pb/238U ages are comparable with the ages from syngenetic molybdenite, cassiterite, muscovite and the genetically related granites, as well as wolframite by water vapor-assisted ns-LA-ICP-MS U Pb dating method. The results of this analysis demonstrate that the robust age for W mineralization can be determined by LA-ICP-MS U Pb dating of wolframite using this modified calibration method. Mineralization ages of 125–130 Ma by directly dating of metal minerals for the Langcun W, Jianfengpo Sn and large-size Xianglushan W deposits confirm that there exists an important W Sn mineralization event in this period. The close temporal and spatial correlation indicates the granites and W-Cu-Mo-Pb-Zn-Sn mineralization have a genetic relationship with each other and are resulted from the same tectonic-magmatic-hydrothermal events during 140 to 120 Ma in South China.

Tancaite-(Ce), ideally FeCe(MoO4)3 ⚫ 3H2O , is a new mineral occurring within cavities in the quartz veins which cut the granite at Su Seinargiu, Sarroch (CA), Sardinia, Italy. It is a secondary mineral formed in the oxidation zone of a sulfide ore vein. Associated minerals are quartz, muscovite, molybdenite, pyrite, and a mendozavilite-like phase. Tancaite-(Ce) is red or pale brown in colour, with a vitreous to adamantine lustre. Electron microprobe analyses give (wt %) SiO2 0.34, CaO 0.09, Fe2O3 11.29, SrO 0.02, La2O3 5.04, Ce2O3 10.35, Pr2O3 1.07, Nd2O3 3.66, Sm2O3 0.19, ThO2 2.58, UO2 0.17, MoO3 58.62, and H2O (calculated) 7.43, with a sum of 100.85, from which the empirical formula is calculated. The empirical formula Fe 1.03 3 + ( Ce0.46La0.23Nd0.16Pr0.05Sm0.01U0.01Th0.07 ) Σ=0.99 ( Mo2.96Si0.04 ) Σ=3.00 O12 ⚫ 3H2O can be simplified as Fe3+ (REE) (MoO4)3 ⚫ 3H2O and idealized as FeCe(MoO4)3 ⚫ 3H2O . The presence of H2O was confirmed by micro-Raman spectrometry (stretching and bending vibrations of O–H). The calculated density is 3.834 g cm −3 . The X-ray diffraction pattern of tancaite-(Ce) is characterized by a set of strong reflections, which point to a cubic subcell with a=6.870(1) A and space group P m 3 ¯ m , plus a set of superstructure reflections. Tancaite-(Ce) displays a new structure type not previously reported in natural and synthetic molybdates. By considering only the strong reflections, it was possible to solve and refine its average structure ( R1=0.038 for 192 unique reflections with I>2σ(I) ). The crystal structure consists of FeO6 octahedra centred at the origin of the cubic subcell and linked together through MoO4 tetrahedra by corner sharing. The Mo-centred tetrahedra are statistically distributed in four symmetry-related positions, with one-fourth occupancy. In the centre of the cubic unit cell the REE cations exhibit a 6+3 coordination, bonding six oxygen atoms and three H2O molecules, each of them being disorderly distributed in four symmetry-related positions. One of the possible supercells, with a 48-fold volume with respect to the primitive cubic small subcell, corresponded to a rhombohedral lattice, with a≈19.43 and c≈47.60 A in the hexagonal setting. Several unsuccessful trials were performed to solve the real crystal structure of tancaite, by indexing the additional superstructure reflections and using their intensities to refine an ordered structural model. The new mineral has been approved by the IMA CNMNC (no. 2009-097). The name comes from Giuseppe Tanca, an Italian amateur mineralogist, who discovered the mineral and gave it to us for studying.

The Lower to Middle Proterozoic Sakoli fold belt in Central India forms a triangular belt with significant mineralization of strategic minerals. The Sakoli fold belt comprises metasediments, felsic and mafic volcanics with metabasalts bounded by the gneissic-migmatitic terrain. The last pulses of granitic activity in the form of quartz lenses intrude the metasediments and are associated with tungsten mineralization. The metasediments are intruded by the quartz veins and tourmaline breccias trending 60°N to 65°E and 60°S to 65°W and are parallel to the regional structural foliations. The tungsten mineralization in this area is restricted to tourmaline-quartz mica greisens and quartz veins. The NE-SW trending foliated contact zones of chlorite mica schist and porphyritic granite/gneisses have served as easy channels for the mineralizing vapours and solutions to percolate, which formed ore bearing greisens and quartz veins. This mineralization is erratic and manifested by sparse and sporadic disseminations of wolframite and scheelite associated with minor amount of molybdenite and chalcopyrite. The fluid inclusion microthermometry on mineralized quartz veins and quartz-tourmaline veins reveals the existence of a metamorphogenic aqueous- gaseous (H2O-CO2+NaCl) fluid that underwent phase separation and gave rise to gaseous (CO2) inclusion. The salinity of tungsten mineralizations varies from low to high (1.32 wt.% to 40.44 wt.% NaCl eq.). The estimated P-T range of tungsten mineralization varies from 1.2 to 2.2 kbar at 280 to 390 °C. Raman spectroscopy reveals that the fluid inclusions mainly contain H2O and CO2 with rarely H2S and CH4. Stable isotopic data reveal that the sulfur isotope fractions from the deposits δ34S ranging from +3.1‰ to +3.35‰, suggesting the deep crustal source for the sulfur, which can be further interpreted as a single (magmatic) supply of sulfur during magmatic-hydrothermal mineralization. The studies reveal the presence of chlorides such as FeCl2/MgCl2 and CaCl2, indicating the involvement of chloride complexes in transportation of tungsten to the fluid system and the evolution of the ore-forming fluids by mixing or immiscibility of high-temperature, high-salinity magmatic fluids and low-temperature, low-salinity fluids in hydrothermal system, and also representing magmatic-hydrothermal interactions contributed wolframite and scheelite with minor amount of molybdenite and chalcopyrite.

The article is devoted to molybdenum mineralization of the Eastern flank of Au-Mo Serhiivka deposit, located in the Middle Dnipro megablock of the Ukrainian Shield (USh). The generalized description of mineralization is performed on such important questions: discovery and exploration history, structure and composition of the host rocks, metamorphic and metasomatic alteration of rocks, structural position and localization conditions of molybdenum mineralization, ore composition, description of major ore minerals, morphology of mineralization and the most widespread views about its genesis. Molybdenum ores were discovered and named East-Serhiivka occurrence for the first time in 1974, before the discovery of gold mineralization, which occurred in 1985. Serhiivka deposit consists of two Mesoarchaean volcanic-plutonic associations (VPA) of different composition: the early mafic and the late felsic. The Eastern flank of the deposit, where the molybdenum mineralization is concentrated, is a structural knot similar to the lying letter “T”. It is formed by complex joint of the sub-latitudinal Serhiivka and sub-meridional Solone subvolcanic bodies and the East-Serhiivka massif of plagiogranitoids of the late VPA, which intrude basic rocks of early VPA. Molybdenum mineralization is localized in linearly elongated zones with a chaotic network of thin quartz, carbonate-quartz veinlets and poor (2–5 %) sulfide impregnation, including molybdenite. About 20 vein-impregnated ore zones have been recovered with up to 100–150 m thickness and 0,01 to 0,3 %, sometimes more than 1 % average molybdenum grade. The ores are subdivided into two major mineral types: 1) quartz-molybdenite; 2) quartz-sulfide-gold-molybdenite. The main components of ores molybdenite and native gold are associated with pyrite, chalcopyrite, magnetite, occasionally – pyrrhotite, arsenopyrite, scheelite, bismuth telluride, silver and others. Typical non-metallic minerals are quartz, carbonate, feldspar, chlorite, amphibole, biotite, sericite. It is supposed hydrothermal-metamorphogenic genesis of molybdenum (and gold) ores. Molybdenite and gold are rarely detected in the same intersections, which indicates separate genesis of these minerals. According to the accepted classification molybdenum mineralization is systemized as linear stockwork. Molybdenum ores of Serhiivka deposit are mostly considered as independent, separate from gold mineralization, potentially workable mine. It is the most prospective one in the Middle Dnipro region, USh and Ukraine in general. We suggest a comprehensive approach to studying, resource and reserves evaluation of Serhiivka deposit, taking into account the potential of both molybdenum and gold mineralization, as well as concentrations of rhenium and osmium in molybdenite. Geological exploration on the base of this approach will increase investment prospects of Serhiivka gold-molybdenum deposit.

In order to determine whether sulfides are major reservoirs for Mo in the upper continental crust (UCC), we determined the composition and mode of occurrence of sulfides and evaluated their contribution to the molybdenum budget in twelve glacial diamictites with ages ranging from 2900 to 300 Ma. The diamictites provide a snapshot of UCC mineralogy and composition at the time of their deposition and show systematic depletion in bulk rock Mo concentrations after the Great Oxidation Event (GOE), reflecting the effects of oxidative weathering in their provenance (Gaschnig et al., 2014; Li et al., 2016). Sulfides are generally confined to Archean and Paleoproterozoic diamictites, although they also have been found in one Phanerozoic sample with an ancient provenance. We classify the sulfides based on their compositions and morphologies. Detrital sulfides are generally rounded, may be a single mineral, or an assemblage of minerals, and show a very wide range in mineralogy, including a single molybdenite grain. Sedimentary sulfides are pyrites, generally with framboidal-like textures. Pyrites also include non-framboidal textured authigenic pyrites. Epigenetic sulfides consist of irregular pyrrhotite aggregates (sometimes pyrrhotite intergrown with chalcopyrite and cobaltite), late-stage euhedral pyrites and pyrite aggregates in veins. High Mo concentrations (up to ∼230 ppm) are found in some sedimentary framboidal-like pyrites from the Mesoarchean Coronation and Paleoproterozoic Makganyene Formations, epigenetic pyrrhotite aggregates and chalcopyrite in the Ramsay Lake diamictite, and in detrital sulfides in Timeball Hill diamictites that may have originated from hydrothermal fluids in the sedimentary basins. Other detrital sulfides have widely variable Mo concentrations (0.5–36 ppm). Mass balance calculations show that sulfides can account for only

As the world’s major source of Cu, Mo, and Au, porphyry copper deposits are magmatic-hydrothermal systems in which base and precious metals are deposited from aqueous solutions at temperatures generally >300°C. During formation of the deposits, metal-transporting fluids typically affected large volumes (up to ~100 km3) of upper crustal rocks, which has led to enormous mass redistribution and local concentration of many elements. Several critical elements, including Re, Se, and Te that are typically not found as primary ores, are locally concentrated in some porphyry copper deposits. Presently, mining and milling of porphyry copper deposits supply ~80% of the world’s Re and nearly all of the Se and Te. China has about 70 economic porphyry copper deposits, including 11 giant and 16 large deposits, with total pre-mining resources of ~78 million tonnes (Mt) Cu averaging 0.2% to 1% Cu, ~4.7 Mt Mo averaging 0.01% to 0.08% Mo, and 1400 tonnes (t) Au averaging 0.5 g/t Au. Rhenium, Se, Te, and PGE (platinum group elements) have been reported to be enriched in some porphyry copper deposits in China, but their tonnage, grade, occurrence, and resource potential remain unclear. In this study, based on a simple synthesis of critical elements in the porphyry copper deposits worldwide and geological characteristics of Chinese porphyry copper deposits, we systematically summarize these attributes of critical elements, particularly Re, in the porphyry copper deposits of China. The porphyry copper deposits in China are mainly concentrated in the following belts or districts: The Gangdese belt in southern Tibet, the Yulong belt in eastern Tibet, the Duolong district in central Tibet, the Zhongdian belt in northwestern Yunnan Province, the Central Asian orogenic belt across northern China, the Zhongtiaoshan belt in Shanxi Province, the Middle-Lower Yangtze River Valley belt, and the Dexing district in Jiangxi Province. Chinese porphyry copper deposits were formed during Paleoproterozoic, Ordovician, Carboniferous, Late Triassic to Early Cretaceous, and Eocene to Miocene, with the majority forming during the latter two time periods. Approximately 45% of the giant and ~30% of the large porphyry copper deposits in China formed in arc settings, whereas at least 35% of the giant and ~45% of the large porphyry copper deposits in China occured in post-collisional settings. The porphyry copper deposits in China typically contain ~3−313 t of Re at average grades ranging from 0.03 to 0.5 g/t Re, with ten deposits containing >50 t Re. The Re-rich porphyry copper deposits in China were mainly formed during Jurassic and Eocene to Miocene. The three largest deposits (Yulong, Jiama, and Qulong), in terms of contained Re, were formed during Eocene to Miocene and in a postcollisional setting. Rhenium in these porphyry copper deposits mainly occurs in molybdenite, and is associated with potassic and/or phyllic alteration. Average Re content in molybdenite from these deposits ranges from 30 to 1000 ppm, but shows a negative correlation with the Mo grade of the corresponding deposit. In contrast, there are only limited data on the endowment of Se, Te, and PGE for Chinese porphyry copper deposits. Similar to porphyry copper deposits worldwide, Se, Te, and PGE in Chinese porphyry copper deposits are concentrated in the sulfide minerals. The contents of Se and Te in sulfide minerals from several deposits (e.g., Bolong, Shaxi) range from ~3 to 700 ppm and are typically highest (generally >300 ppm) in Cu-bearing sulfides (e.g., bornite, chalcopyrite). Concentrations of PGE in ores of Chinese porphyry copper deposits are highly variable, with Pd+Pt contents ranging from 0.2 to 450 ppb. In summary, Chinese porphyry copper deposits, particularly those in postcollisional settings, show similar grades of Re, Se, Te, and PGE to porphyry copper deposits worldwide, indicating a large potential of these critical elements in Chinese porphyry copper deposits to meet the nation’s economic needs. To better understand the occurrence, resource potential, and enrichment processes of critical elements in the porphyry copper deposits of China, detailed case studies and regional comparisons, as well as improvements in analytical techniques, are a pressing need.

The Kuntabin Sn-W deposit, located in southern Myanmar, is characterized by abundant greisen-type and quartz vein-type cassiterite and wolframite mineralization. We have conducted multiple geochronological methods and isotope and trace element analyses to reveal the age and evolution of the Kuntabin magmatichydrothermal system.Zircon U-Pb dating of the two-mica granite yielded a weighted mean 206Pb/238U age of 90.1 ± 0.7 Ma. Cassiterite U-Pb dating provided a lower intercept age of 88.1 ± 1.9 Ma in the Tera-Wasserburg U-Pb concordia diagram. Molybdenite Re-Os dating returned a weighted mean model age of 87.7 ± 0.5 Ma and an isochron age of 88.7 ± 2.7 Ma. These ages indicate a genetic relationship between granite and Sn-W mineralization in the Kuntabin deposit and record the earliest magmatism and Sn-W mineralization in the Sibumasu and Tengchong terranes related to subduction of the Neo-Tethys oceanic slab. Three generations of cassiterite have been identified with distinctive cathodoluminescence textures and trace element patterns, indicating the episodic input of ore-forming fluids and distinctive changes in the physical-chemical conditions of the Kuntabin magmatichydrothermal system. Sudden changes of fluid pressure, temperature, pH, etc., may have facilitated the deposition of Sn and W. Rhenium contents of molybdenite from the Kuntabin deposit and many other Sn-W deposits in Myanmar are characteristically low compared to porphyry Cu-Mo-(Au) deposits worldwide. In combination with zircon Hf isotope signatures, we infer that granites associated with Sn-W deposits in Myanmar were predominantly derived by melting of ancient continental crust and contain minimal mantle contribution.Subduction of the Neo-Tethys oceanic slab from west of the West Burma terrane reached beneath the Sibumasu terrane and led to magmatism and Sn-W mineralization at ~90 Ma when the Kuntabin deposit was formed. The Paleoproterozoic Sibumasu crust was activated during the subduction-related magmatism to form predominantly crust derived melts. After a high degree of fractional crystallization and fluid exsolution, physical-chemical changes of the hydrothermal fluid resulted in Sn and W precipitation to form the Kuntabin Sn-W deposit.

The Productora Cu-Au-Mo deposit is hosted by a Cretaceous hydrothermal breccia complex in the Coastal Cordillera of northern Chile. The current resource, which includes the neighboring Alice Cu-Mo porphyry deposit, is estimated at 236.6 Mt grading 0.48% Cu, 0.10 g/t Au, and 135 ppm Mo. Local wall rocks consist of a thick sequence of broadly coeval rhyolite to rhyodacite lapilli tuffs (128.7 ± 1.3 Ma; U-Pbzircon) and two major intrusions: the Cachiyuyito tonalite and Ruta Cinco granodiorite batholith (92.0 ± 1.0 Ma; U-Pbzircon). Previous studies at Productora concluded the deposit had strong affinities with the iron oxide copper-gold (IOCG) clan and likened the deposit to Candelaria. Based on new information, we document the deposit geology in detail and propose a new genetic model and alternative classification as a magmatic-hydrothermal breccia complex with closer affinities to porphyry systems. Hydrothermal and tectonic breccias, veins, and alteration assemblages at Productora define five paragenetic stages: stage 1 quartz-pyrite–cemented breccias associated with muscovite alteration, stage 2 chaotic matrix-supported tectonic-hydrothermal breccia with kaolinite-muscovite-pyrite alteration, stage 3 tourmaline-pyrite-chalcopyrite ± magnetite ± biotite-cemented breccias and associated K-feldspar ± albite alteration, stage 4 chalcopyrite ± pyrite ± muscovite, illite, epidote, and chlorite veins, and stage 5 calcite veins. The Productora hydrothermal system crosscuts earlier-formed sodic-calcic alteration and magnetite-apatite mineralization associated with the Cachiyuyito stock. Main-stage mineralization at Productora was associated with formation of the stage 3 hydrothermal breccia. Chalcopyrite is the dominant hypogene Cu mineral and occurs predominantly as breccia cement and synbreccia veins with pyrite. The Alice Cu-Mo porphyry deposit is characterized by disseminated chalcopyrite and quartz-pyrite-chalcopyrite ± molybdenite vein stockworks hosted by a granodiorite porphyry stock. Alice is spatially associated with the Silica Ridge lithocap, which is characterized by massive, fine-grained, quartz-altered rock above domains of alunite, pyrophyllite, and dickite. Rhenium-Os dating of molybdenite indicates that main-stage mineralization at Productora occurred at 130.1 ± 0.6 Ma, and at 124.1 ± 0.6 Ma in the Alice porphyry. Chalcopyrite and pyrite from Productora have δ34Ssulfide values from –8.5 to +2.2‰, consistent with a magmatic sulfur source and fluids evolving under oxidizing conditions. No significant input from evaporite- or seawater-sourced fluids was detected. Stage 3 tourmalines have average initial Sr of 0.70397, consistent with an igneous-derived Sr source. The Productora magmatic-hydrothermal breccia complex formed as a result of explosive volatile fluid release from a hydrous intrusive complex. Metal-bearing fluids were of magmatic affinity and evolved under oxidizing conditions. Despite sharing many similarities with the Andean IOCG clan (strong structural control, regional sodic-calcic alteration, locally anomalous U), fluid evolution at the Productora Cu-Au-Mo deposit is more consistent with that of a porphyry-related magmatic hydrothermal breccia (sulfur-rich, acid alteration assemblages and relatively low magnetite contents

The small Kedengjian volcanic rock-hosted hydrothermal vein-type Cu deposit (100,000 t Cu metal content at about 3% Cu) is located in the Lanping Basin, one of several Mesozoic–Cenozoic continental sedimentary basins in the northern part of the Indochina block and in the eastern part of the North Qiangtang block. Many sediment-hosted base metal ore deposits with ages of

The Wangjiazhuang porphyry copper (-molybdenum) deposit is located at Zouping volcanic basin in Shandong Province, East China and hosted in the Wangjiazhuang intrusive complex emplaced along a late volcanic conduit. There are two types of ores in this deposit: early disseminated and stockwork ores in the ore-bearing intrusion, and late massive sulfide-quartz veins above brecciated quartz monzonite. The ore minerals are mainly pyrite, chalcopyrite, and subordinately magnetite, tennantite, molybdenite with minor bornite, enargite, galena and sphalerite, etc., and gangue minerals including K-feldspar, biotite, quartz, muscovite-sericite, chlorite and calcite. Combined with fluid inclusion study, the scanning electron microscope-cathodoluminescence (SEM-CL) study of quartz in the deposit and wall rocks shows significant differences between the two types of quartz in the ores. In addition, four types of primary-pseudosecondary fluid inclusions in the quartz have been recognized. They are one- or two-phase aqueous inclusions with vapor/liquid ratios less than 30% to 40% (type I); gas-rich inclusions with vapor/ liquid ratios more than 50% (type II), some of which contain some small opaque minerals, probably chalcopyrite; multiphase fluid inclusions with daughter minerals of halite±anhydrite±opaque (chalcopyrite)± sylvite±hematite±unknown crystal (type III); and mica-bearing fluid inclusions (type IV). Quartz containing abundant muscovite-bearing and halite-bearing fluid inclusions in the mineralized quartz monzonite with potassic-silicic alteration, have better oscillatory growth zoning with CL-colors from bright in the core to darker in the rim, indicating variations of element concentrations in the fluid media from which quartz grew during the later period of magmatic-hydrothermal process. In contrast, the quartz in the sulfide-quartz veins contains mainly fluid inclusions of low-to-medium salinities and does not show oscillatory zoning, indicating that there was less fluctuation in composition and element concentrations of the hydrothermal fluids. However, the quartz containing halite-bearing fluid inclusions and being associated with copper-molybdenum mineralization in the sulfide-quartz veins shows zoning in its rims, indicating variations in composition and element concentrations of the hydrothermal fluids.

The Zhilingtou polymetallic deposit, South China, provides an excellent opportunity to investigate the magmatic-hydrothermal evolution of the porphyry Mo to epithermal Au–Ag–Pb–Zn ore spectrum. New zircon U–Pb, sphalerite 40Ar/39Ar, and pyrite Rb–Sr ages, together with previous molybdenite Re–Os ages, indicate that the granitic magmatism and Mo–Au–Ag–Pb–Zn mineralization were coeval and cogenetic in the Early Cretaceous (~ 113 Ma). Fluid inclusions and H–O isotope results have established the evolution from an early high-temperature H2O–NaCl magmatic fluid system (Mo mineralization), to a medium-temperature mixed fluid system of magmatic and meteoric water (Au–Ag mineralization), to a peripheral late-stage low-temperature H2O–NaCl meteoric water fluid system (epithermal Au–Ag–Pb–Zn mineralization). Moreover, the sulfur isotopic compositions (δ34S = 2.1–7.8‰) of the sulfide minerals confirm a genetic link to the granitic magma. Lead isotope data from pyrite and the granite–rhyolite porphyries are similar, indicating that they share a common Pb source. The geochronological, geochemical, and isotopic lines of evidences consistently suggest that the porphyry Mo and epithermal Au–Ag–Pb–Zn mineralization formed in one magmatic–hydrothermal system. The porphyry-epithermal mineralization model for Zhilingtou has significant importance for prospecting work in South China, where Mo and associated Pb–Zn–Ag resources are abundant.

The newly discovered Shuangjianzishan Ag-Pb-Zn deposit, with 145 Mt of ore grading 128.5 g/t Ag (locally up to 32,000 g/t) and 2.2 wt % Pb + Zn, is located in the Great Hinggan Range metallogenic belt, northeastern China, and is currently the largest Ag deposit in Asia. The Ag-Pb-Zn orebodies occur as veins and are hosted primarily by a Permian slate. Recent drilling and core logging have identified a partially Mo mineralized granite porphyry intrusion adjacent to the Ag-Pb-Zn mineralized veins. This well-preserved magmatic-hydrothermal system therefore offers an excellent opportunity to evaluate the possible temporal and genetic relationship between Mo-mineralized porphyry intrusions and Ag-Pb-Zn veins. Three primary paragenetic stages of veining have been recognized: (I) early pyrite + quartz ± K-feldspar, (II) main ore sulfide + sulfosalt + quartz + calcite + sericite + chlorite ± epidote, and (III) post-ore quartz. The silver mineralization occurs mainly in the late paragenetic part of Stage II, in which canfieldite (Ag8SnS6), argentite (Ag2S) and freibergite [(Ag, Cu)12Sb4S13] are the dominant Ag-bearing ore minerals. A combination of ore mineral chemical and sulfur isotope geothermometers and physicochemical calculations suggest that the Ag-Pb-Zn mineralization took place at a temperature of 250° to 200°C, a pH of 6.7 to 5.6, and a Δlogfo2 (HM) of –2.4 to –8.7. A conspicuous enrichment of Sn and Se in the ore, which is represented by minerals containing the metal suite Ag-Pb-Zn-(Cu-Sn-Se-Sb), likely reflects a close genetic association between the base metal mineralization and a magma. In situ analyses show that the δ34S values of the sulfides and Ag-bearing sulfosalts from the Ag-Pb-Zn mineralized veins vary from –4.67 to +2.44‰; the mean value is –2.11 ± 1.49‰ (n = 77). The calculated mean δ34SH2S value of the ore-forming fluid is –1.65 ± 0.83‰, which is indicative of a magmatic sulfur source. In situ Pb isotope analyses of the ore minerals yielded a narrow range of values (206Pb/204Pb of 18.243–18.310, 207Pb/204Pb of 15.503–15.563 and 208Pb/204Pb of 38.053–38.203, n = 59). Comparisons to corresponding isotopic data for the various rock units in the area and sulfides from nearby ore deposits indicate that there were substantial contributions of Pb and other metals (e.g., Ag and Zn) to the Shuangjianzishan deposit from a Mesozoic granitic source. Diorite-granodiorite dikes and dacite are crosscut by the Ag-Pb-Zn veins, and therefore, predate ore formation. These rock units have zircon U-Pb ages of 250.2 ± 2.0 and 133.9 ± 1.4 Ma, respectively. A concealed, weakly Mo mineralized granite porphyry intrusion proximal to the Ag-Pb-Zn mineralized vein system yielded zircon U-Pb ages of 134.4 ± 1.0 (MSWD = 0.1) and 134.4 ± 1.0 Ma (MSWD = 0.2), for coarse- and fine-grained facies, respectively. These ages are indistinguishable within the uncertainty from the zircon ages for the dacite and a granite intrusion ~2 km north of the mineralized veins, which has a weighted mean zircon U-Pb age of 135.2 ± 1.4 Ma (MSWD = 0.78). Molybdenite from three quartz vein/veinlet samples hosted by slate immediately above the porphyry intrusion yielded Re-Os model ages from 136.3 ± 0.9 to 133.7 ± 1.2 Ma and a weighted mean Re-Os age of 134.9 ± 3.4 Ma. Finally, three pyrite samples separated from the Ag-Pb-Zn mineralized veins have a weighted mean Re-Os model age of 135.0 ± 0.6 Ma. The very similar zircon U-Pb ages for the Mo-mineralized granite porphyry and dacite, and Re-Os ages for molybdenite and pyrite in the Shuangjianzishan ore district indicate that the Mesozoic magmatic-hydrothermal activity was restricted to a relatively short time interval (~136–133 Ma). They also suggest that the weakly Mo mineralized granite porphyry was likely the source of the fluids and metals that produced the Ag-Pb-Zn mineralization. Based on our geological observations and an extensive analytical database, a model is proposed for the genesis of the giant Shuangjianzishan Ag-Pb-Zn deposit in which the ore-forming fluid and its metals (i.e., Ag, Pb, and Zn) were exsolved during crystallization of the final phase of a composite granite porphyry intrusion. This fluid transported metals to the distal parts of the system, where they were deposited in preexisting faults or fractures created by the withdrawal of magma during the waning stages of the magmatic-hydrothermal event. The present study of the Shuangjianzishan Ag-Pb-Zn deposit and those of other magmatic-hydrothermal ore deposits in the region provide compelling evidence that the widespread Mesozoic felsic magmatism and Ag-Pb-Zn mineralization in the southern Great Hinggan Range took place in an intracontinental extensional tectonic setting, which was synchronous with, and spatially associated to, Paleo-Pacific slab rollback and lithospheric delamination and thinning.

The gold mineralization located in Vetas, Santander, consists of auriferous quartz veins hosted in Bucaramanga gneiss rocks, intrusive Jurassic rocks, and intrusive to porphyritic Miocene rocks. This study identified four mineralizing events: (1). Sericite, carbonate (ankerite and calcite?), massive and microcrystalline quartz, sphalerite, adularia, albite, galena, thin pyrite, pyrrhotite, chalcopyrite. The age for this stage is 10.78 ±0.23Ma (Ar/Ar on sericite). (2). Molybdenite, magnetite with exsolution of ilmenite, As-pyrite, sphalerite, fine-grained pyrite and little chalcopyrite quartz with huge, feathery, fine mosaic, flamboyant and microcrystalline textures and, tourmaline and sericite. (3). Gold and tennantite associated with sphalerite, fine- and coarse-grained pyrite, As-pyrite, chalcopyrite like inclusions, and quartz with flamboyant, mosaic, massive and "comb" textures, and tourmaline. Stage 2 and 3 happened from 7.58 ±0.15 Ma to 6,89±0,41Ma (Ar/Ar on sericite). (4). Thick, thin, and pyrite with arsenic, hematite and microcrystalline quartz (forming breccia texture), and sericite. The age for this stage is 5.24 ±0.10 (Ar/Ar on sericite). Post-mineral: quartz comb, alunite, halloysite, kaolinite, and ferrum hydroxides. The stable isotopes, ∂18O, ∂D, and ∂34S and fluid inclusions analysis infer that fluids were producing a mixture of meteoric and magmatic fluids with low salinity and minimum trapping temperatures between 200°C to 390°C. The mineralogy association, and fluid inclusions, in the first event show characteristic of low sulfidation epithermal. The second stage was hottest and with more magmatic signature over printed an intermediate sulfidation system; show a little more salinity on the fluids and more mineralogical diversity, the third and four events, could show an evolution of this fluid, where it was cooling and impoverishing on metals. Two initials stages are contemporaneous with two magmatic Miocene pulses on the area: the first one of granodiorite composition 10, 9± 0.2 Ma (U/Pb zircon), and the other one rhyodacite with 8.4 ±0.2 y 9.0 ± 0.2 Ma. RESUMEN La mineralización de oro ubicada en Vetas, Santander, consiste en vetas auríferas de cuarzo alojadas en rocas del gneis de Bucaramanga, rocas jurásicas intrusivas y rocas intrusivas porfiríticas miocenicas. Este estudio identificó cuatro eventos de mineralización: (1). Sericita, carbonato (ankerita y calcita?), cuarzo masivo y microcristalino, esfalerita, adularia, albita, galena, pirita delgada, pirrotita, calcopirita. La edad para esta etapa es 10.78 ± 0.23Ma (Ar / Ar en sericita). (2). Molibdenita, magnetita con exsolución de ilmenita, arsenopirita, esfalerita, pirita de grano fino un poco de calcopirita y cuarzo con textura plumosa, mosaico fino, flamboyante y microcristalino, turmalina y sericita. (3). Oro y tenantita asociados con esfalerita, pirita de grano fino y grueso, pirita de arsenopirita, calcopirita como inclusiones, y cuarzo con texturas flamboyante, mosaico, masiva y en "peine", y turmalina. Los eventos 2 y 3 ocurrieron entre los 7,58 ± 0,15 Ma a 6,89 ± 0,41Ma (Ar / Ar en sericita). (4). Pirita en cristales finos y gruesos con arsénico, hematita y cuarzo microcristalino (formando una textura brechosa), y sericita. La edad para este evento es de 5.24 ± 0.10 (Ar / Ar en sericita). El evento Post-mineral: peine de cuarzo, alunita, haloysita, caolinita e hidróxidos de hierro. Los isótopos estables, ∂18 O, ∂D y ∂34 S y el análisis de inclusiones de fluidos infieren que los fluidos fueron producto de una mezcla de fluidos meteóricos y magmáticos con baja salinidad y temperaturas de atrapamiento mínimas entre 200° C y 390° C. La asociación mineralogica y las inclusiones fluidas, en el primer evento, muestran características de un ambiente epitermal de baja sulfuración; el segundo evento más caliente presenta una firma magmática más prominente sobreimponiendo un sistema epitermal de intermedia sulfuración sobre el de baja sulfuración, con un poco más de salinidad en los fluidos y más diversidad mineralógica. Para el tercer y cuarto eventos muestran una evolución de este fluido, donde se enfría y se empobrece en metales. De acuerdo a las edades reportadas, los dos eventos iniciales son contemporáneos con dos pulsos magmáticos del Mioceno que fueron identificados en sectores circundantes del área, el primero de composición de granodiorita 10, 9 ± 0.2 Ma (circón U / Pb, Mantilla, et al. 2011), y el otro de riodoritas con 8.4 ± 0.2 y 9.0 ± 0.2 Ma.

Mineralogy is a fundamental characteristic of a given rock mass throughout the mining value chain. Understanding bulk mineralogy is critical when making predictions on processing performance. However, current methods for estimating complex bulk mineralogy are typically slow and expensive. Whole-rock geochemical data can be utilized to estimate bulk mineralogy using a combination of ternary diagrams and bivariate plots to classify alteration assemblages (alteration mapping), a qualitative approach, or through calculated mineralogy, a predictive quantitative approach. Both these techniques were tested using a data set of multielement geochemistry and mineralogy measured by semiquantitative X-ray diffraction data from the Productora Cu-Au-Mo deposit, Chile. Using geochemistry, samples from Productora were classified into populations based on their dominant alteration assemblage, including quartz-rich, Fe oxide, sodic, potassic, muscovite (sericite)- and clay-alteration, and least altered populations. Samples were also classified by their dominant sulfide mineralogy. Results indicate that alteration mapping through a range of graphical plots provides a rapid and simple appraisal of dominant mineral assemblage, which closely matches the measured mineralogy. In this study, calculated mineralogy using linear programming was also used to generate robust quantitative estimates for major mineral phases, including quartz and total feldspars as well as pyrite, iron oxides, chalcopyrite, and molybdenite, which matched the measured mineralogy data extremely well (R2 values greater than 0.78, low to moderate root mean square error). The results demonstrate that calculated mineralogy can be applied in the mining environment to significantly increase bulk mineralogy data and quantitatively map mineralogical variability. This was useful even though several minerals were challenging to model due to compositional similarities and clays and carbonates could not be predicted accurately.

Mine acid water is acidic water and contains iron and sulfate, which is formed under natural conditions when geological strata containing pyrites are exposed to an oxidizing atmosphere or environment. One of the impacts of the mineralization zone where there is a mining process is the potential for the formation of acid mine drainage, especially in the Cibaliung gold mineralization area and its surroundings, Pandeglang Regency, Banten Province. Acid-forming sulfide minerals include pyrite (FeS2), headquarters (FeS2), picoliters (FexSx), calcocytes (CuS), covellite (CuS), chalcopyrite (CuFeS2), molybdenite (MoS), mulenite (NiS), chalocytes (CuS), covellite (CuS), chalcopyrite (CuFeS2), molybdenite (MoS), mulenite (NiS), chalocytes (CuS), covellite (CuS), chalcopyrite (CuFeS2), molybdenite (MoS), mulenite (NiS), galena (PbS) ) and sphalerite (ZnS). Of all these minerals, pyrite is the most dominant sulfide in acid formation. Alkaline mine water (alkaline mine drainage) is mine water that has an acidity level (pH) of 6 or more, containing alkalinity but still containing dissolved metals that can produce acids. The quality of mine water, acid or alkali, depends on the presence or absence of acid mineral content (sulfides) and alkaline materials in the geological strata. Acid water formation tends to be more intensive in mining areas. This can be prevented by avoiding exposure to sulfide-containing materials in the free air. Acid-forming sulfide minerals include pyrite (FeS2), headquarters (FeS2), picoliters (FexSx), calcocytes (CuS), covellite (CuS), chalcopyrite (CuFeS2), molybdenite (MoS), mulenite (NiS), chalocytes (CuS), covellite (CuS), chalcopyrite (CuFeS2), molybdenite (MoS), mulenite (NiS), chalocytes (CuS), covellite (CuS), chalcopyrite (CuFeS2), molybdenite (MoS), mulenite (NiS), galena (PbS) ) and sphalerite (ZnS). Of all these minerals, pyrite is the most dominant sulfide in acid formation. Formation of potential acidic water also occurs in tailings which are residues/processing residues containing sulfide minerals. The formation of acid mine drainage does not always develop in every sulfide-ore mining. In certain types of ore deposits, there are neutralizing agents which prevent the formation of acid mine drainage.

Epidosites occur in association with pelagic and quartzofeldspathic metasediments overlying the Pounamu suprasubduction zone ophiolite. They are dominated by epidote with minor diopside, tremolite,...

This paper proposes selective leaching of molybdenum from Mo/Cu complex bulk concentrates in a 5 M NaCl solution using the electro-oxidation method. Here, the effects of several factors such as pH, pulp density, current density, and temperatures were investigated. A higher leaching yield of Mo increased with increasing pH from 5 to 9 and decreased with increasing pulp density from 1 to 10%. A rise in current density did not help enhance Mo, and the elevating temperature did not always result in a higher leaching yield. Application of ultrasonic led to higher leaching yield of Mo. Ninety-two percent of leaching yield was obtained upon leaching of Mo in 5 M NaCl at 25 °C, pulp density of 5%, and the current density of 0.292 A/g under ultrasonic irradiation with a power of 27 kW. The resultant residue mainly consisted of chalcopyrite.

The newly discovered large-scale skarn deposit of Youmapo tungsten-molybdenum deposit is located in the Bobai-Cenxi metallogenic belt of the southeastern Guangxi, south China. The stratiform, lentoid, and vein ore-bodies occur along the contact zone between the Devonian calcareous-argillaceous siltstone and Youmapo granitic complex pluton. The Youmapo granitic complex pluton consists of main granodiorite (109.7 ± 1.1 Ma) and complementary muscovite granite (100.7 ± 0.5 Ma). Up to now, WO3 reserves were estimated at more than 80 thousand tons, with grades 0.191~1.284% WO3 and 0.001~0.019% Mo. Among them, No. I ore-body accounts for 84% of the total reserve. Four types of fluid inclusions are recorded in the Youmapo deposit (NaCl-H2O, NaCl-CO2-H2O, pure CO2, and monophase H2O) and characterized by medium-high temperature (190~340 °C) and low salinity (3~10 wt%NaCleq). According to the S, H, and O isotopic characteristics, the ore-forming fluid is mainly post-magmatic fluid. The complementary muscovite granite geochemically represents high evolution granite that derived the ore-forming fluid. Six molybdenite samples from No. I ore-body yield an 187Re-187Os isochron age of 100.1 ± 3.3 Ma and a consistent weighted average model age of 100.37 ± 0.62 Ma, suggesting the Cretaceous period for the tungsten-molybdenum mineralization and their spatio-temporal relation to the muscovite granite.

Thirty-seven years of mining and processing of Cu-porphyry ore has been resulting in the production more than 540 million tons of waste tailings in Sarcheshmeh industrial complex, Iran's largest Cu producer. The main objective of this study is to evaluate the changes that occurred in the trace elements content of Sarcheshmeh mine tailings during the flotation desulfurization process. Desulfurization of fresh tailings was carried out using the conventional flotation method. Four samples were analyzed geochemically and mineralogically for each flotation test: rougher feed tailings (RFT), desulfurized tailings (DT), cleaner stage tailings (CT), and cleaned concentrate (CC). Geochemical results showed a remarkable decrease in the concentration of eighteen potentially toxic elements (S, Se, Ag, Mo, Te, Co, Bi, Fe, As, Cu, Cd, Sb, Pb, Ni, Cr, Zn, Zr and Yb) that showed high enrichments in the sulfide (pyrite) concentrate of the desulfurization process. The economical aspect concentrations of S (46.59 ± 1.84%), Fe (40.09 ± 1.87%), Cu (10,620 ± 3980 mg/kg) and Mo (1002 ± 457) were observed in the cleaned concentrate derived from Sarcheshmeh mine tailings. Other sulfide minerals, such as chalcopyrite, chalcocite, molybdenite, and covellite, as well as pyrite, were also identified in the cleaned concentrate of Sarcheshmeh mine tailings. Desulfurized tailings, which consisted on average 84.74 weight percent of the rougher feed tailings, were composed of silicate minerals (quartz, sericite, albite, chlorite, and orthoclase) that is technologically easier to reprocess and use for certain recycling applications. Desulfurized tailings showed slightly enrichment of Ce, Ba, Na, Sr, Al, Mn, P, Si, Nb, Ti, K, Nd, Be, Th, Eu, Sm, Ta, Pr, Tl, Rb, La, Mg, Cs, V, Sc, W and Gd in compared with the primary rougher feed tailings. In addition to the economical aspect, the desulfurization of Sarcheshmeh mine tailings could improve the quality of the tailings dam recycled water on a long-term basis and in the ʻʻintegrated tailings management” approach provided new opportunities for more environmentally friendly tailings management strategies.

Mineralization of Te and Se was found in gold deposits and uranium occurrences, located in the Paleoproterozoic greenstone belts in Northern Fennoscandia. These deposits are of different genesis, but all of them formed at the late stages of the Svecofennian orogeny, and they have common geochemical association of metals Au, Cu, Co, U, Bi, Te, and Se. The prevalentTe minerals are Ni and Fe tellurides melonite and frohbergite, and Pb telluride altaite. Bismuth tellurides were detected in many deposits in the region, but usually not more than in two–three grains. The main selenide in the studied deposits is clausthalite. The most diversified selenium mineralization (clausthalite, klockmannite, kawazulite, skippenite, poubaite) was discovered in the deposits, located in the Russian part of the Salla-Kuolajarvi belt. Consecutive change of sulfides by tellurides, then by selenotellurides and later by selenides, indicates increase of selenium fugacity, fSe2, in relation to fTe2 and to fS2in the mineralizing fluids. Gold-, selenium-, and tellutium-rich fluids are potentially linked with the post-Svecofennian thermal event and intrusion of post-orogenic granites (1.79–1.75 Ga) in the Salla-Kuolajarvi and Perapohja belts. Study of fluid inclusions in quartz from the deposits in the Salla-Kuolajarvi belt showed that the fluids were high-temperature (240–&gt, 300 °C) with high salinity (up to 26% NaCl-eq.). Composition of all studied selenotellurides, kawazulite-skippenite, and poubaite varies significantly in Se/Te ratio and in Pb content. Skippenite and kawazulite show the full range of Se-Te isomorphism. Ni-Co and Co-Fe substitution plays an important role in melonite and mattagamite: high cobalt was detected in nickel telluride in the Juomasuo and Konttiaho, and mattagamites from Ozernoe and Juomasuo contain significant Fe.In the Ozernoe uranium occurrence, the main mineral-concentrator of selenium is molybdenite, which contains up to 16 wt.% of Se in the marginal parts of the grains. The molybdenite is rich in Re (up to 1.2 wt.%), and the impurity of Re is irregularly distributed in molybdenite flakes and spherulites.

The Southern Great Xing'an Range (SGXR) which forms part of the eastern segment of the Central Asian Orogenic Belt (CAOB) is known as one of the most important Cu-Mo-Pb-Zn-Ag-Au metallogenic belts in China, hosting a number of porphyry Mo (Cu), skarn Fe (Sn), epithermal Au-Ag, and hydrothermal vein-type Ag-Pb-Zn ore deposits. Here we investigate the Bianjiadayuan hydrothermal vein-type Ag-Pb-Zn ore deposit in the southern part of the SGXR. Porphyry Sn ± Cu ± Mo mineralization is also developed to the west of the Ag-Pb-Zn veins in the ore field. We identify a five-stage mineralization process based on field and petrologic studies including (i) the early porphyry mineralization stage, (ii) main porphyry mineralization stage, (iii) transition mineralization stage, (iv) vein-type mineralization stage and (v) late mineralization stage. Pyrite is the predominant sulfide mineral in all stages except in the late mineralization stage, and we identify corresponding four types of pyrites: Py1 is medium-grained subhedral to euhedral occurring in the early barren quartz vein; Py2 is medium- to fine-grained euhedral pyrite mainly coexisting with molybdenite, chalcopyrite, minor sphalerite and galena; Py3 is fine-grained, subhedral to irregular pyrite and displays cataclastic textures with micro-fractures; Py4 occurs as euhedral microcrystals and forms irregularly shaped aggregate with sphalerite and galena. LA-ICP-MS trace element analyses of pyrite show that Cu, Pb, Zn, Ag, Sn, Cd and Sb are partitioned into pyrite as structurally bound metals or mineral micro/nano-inclusions, whereas Co, Ni, As and Se enter the lattice via isomorphism in all types of pyrite. The Cu, Zn, Ag, Cd concentrations gradually increase from Py1 to Py4, which we correlate with cooling and mixing of ore-forming fluid with meteoric water. Py2 contains the highest contents of Co, Ni, Se, Te and Bi, suggesting high temperature conditions for the porphyry mineralization stage. Ratios of Co/Ni (0.03–10.79, average 2.13) and sulphur isotope composition of sulfide indicate typical hydrothermal origin for pyrites. The δ34SCDT values of Py1 (0.42‰–1.61‰, average 1.16‰), Py2 (–1.23‰ to 0.82‰, average 0.35‰), Py3 (–0.36‰ to 2.47‰, average 0.97‰), Py4 (2.51‰–3.72‰, average 3.06‰), and other sulfides are consistent with those of typical porphyry deposit (–5‰ to 5‰), indicating that the Pb-Zn polymetallic mineralization in the Bianjiadayuan deposit is genetically linked to the Yanshanian (Jurassic–Cretaceous) magmatic-hydrothermal events. Variations of δ34S values are ascribed to the changes in physical and chemical conditions during the evolution and migration of the ore-forming fluid. We propose that the high Sn content of pyrite in the Bianjiadayuan hydrothermal vein-type Pb–Zn polymetallic deposit can be used as a possible pathfinder to prospect for Sn mineralization in the surrounding area or deeper level of the ore field in this region. Keywords: Trace elements, In-situ sulfur isotope, Pyrite, Bianjiadayuan deposit, Southern Great Xing'an range

The Pinarbasi porphyry Cu Mo mineralization is located at northwest of Gediz (Kutahya-Turkey) and east of Simav (Kutahya-Turkey) in western Anatolia. The Pinarbasi Cu Mo mineralization is hosted by Pinarbasi granitoidic intrusion consisting of granite, granodiorite and quartz monzonite. Geochemical and geochronological evidences for Pinarbasi granitoidic rocks show that they are high-K calc-alkaline, and I-type granitoid magma likely developed post-collisional extensional regime. The U Pb zircon age of granite (18.88 ± 0.17 Ma) and quartz monzonite porphyry (18.27 ± 0.14) obtained from the Pinarbasi granitoid show Early Miocene (Burdigalian). The Pinarbasi Cu Mo mineralization predominantly comprises molybdenite, chalcopyrite, galena, sphalerite, pyrite, fahlore, magnetite, bornite, hematite, jarosite, malachite and orpiment occurred in disseminated form in veins/veinlets associated with potassic, phyllic (sericitic) and advanced argillic alteration zones. According to the paragenetic and crosscutting relationships of veins/veinlets, the ore-forming process were divided into three stages; early-stage: quartz – molybdenite ± K-feldspar ± pyrite veins associated with potassic alteration, middle-stage: quartz ± calcite ± chalcopyrite ± galena ± sphalerite ± molybdenite + pyrite veins in phyllic alteration and late-stage: quartz ± calcite ± pyrite veins associated with advanced argillic alteration. Three types of fluid inclusions in quartz distinguished were designated as L-rich L + V phases (Type-I), salt-bearing L + V + S (Type-II), and V-rich L + V phases (Type-III). FIs of the early and middle stages are predominantly Type-II and Type-III inclusions, whereas the late-stage minerals commonly contain Type-I inclusions. Homogenization temperatures and salinities of FIs trapped in the early-stage quartz range from 481 to 590 °C and 13.19 to 61.1 wt% NaCl equivalent, respectively. FIs in quartz of the middle-stage yield homogenization temperatures (Th) of 310 to 460 °C, while halite dissolution temperatures are ranged from 264 to 430 °C, and salinities of 7.9 to 50.3 wt% NaCl eq. Homogenization temperatures and salinities of FIs in calcite of the middle-stage are range from 270 to 420 °C, 3.4 to 49.1 wt% NaCl eq. The late-stage homogenize at temperatures of 138 to 240 °C, and salinities of 0.9 to 6.5 wt% NaCl eq. The δ34SH2S values (0.6 to 4.5‰) of sulfides (molybdenite, chalcopyrite, pyrite and galena) and the δ18OSMOW (6.9 to 9.6‰) - δD (−71 to −86‰) values of molybdenite-bearing quartz from Pinarbasi Cu Mo mineralization suggest a magmatic origin for the ore-forming fluids. The δ13CPDB (from −4.65‰ to 0.55‰) and δ18OSMOW (from 9.05‰ to 18.76‰) values of calcite which is one of the most common gangue minerals in Pinarbasi mineralization show a high temperature influence and/or sedimentary contamination process to magmatic carbonate as well as continental carbonate. The S–O–H–C and U Pb isotopic compositions indicate that the metallic elements and fluids came primarily from a magmatic source linked to Miocene intrusion. The geological, geochronological, and geochemical data support a magmatic-hydrothermal origin for the Pinarbasi Cu Mo mineralization and confirm that mineralization is formed from an Early Miocene porphyry-related magmatic-hydrothermal system that is genetically linked with Egrigoz and Pinarbasi granitoids.

Slepaya Zalezh’, the largest orebody of the Tyrnyauz Mo–W deposit, is considered a first-priority object should mining operations at the deposit be resumed. Molybdoscheelite, scheelite, and molybdenite impregnation in mineable concentrations is genetically related to metasomatites of the productive stage overprinted on skarns, periskarn rocks, hornfelses, and marble. Ore types have been recognized based on the relative amounts of different ore-bearing metasomatite facies and protoliths acting as a diluting mass. Seven ore types have been recognized and mapped in cross section. Types I and II are characterized by predominant (70–90%) aposkarn ores after endo- and exoskarns, accordingly. Type III is characterized by approximately equal proportions of ores after endoskarns and periskarn rocks; type IV differs from type III by a decrease in periskarn rocks replenished by an increase in hornfels. Type V is dominated by ores after exoskarns and, to a lower extent (up to 25%), after marble. Type VI is intermediate between types III and IV. Type VII represents all protoliths in approximately equal proportions. Each type exhibits a stable mineral and chemical composition inherited from the protolith. The ores of each particular type have simple distinguishing features, convenient for logging and mapping, which can be used for manual picking of grab and bulk samples and preliminary ore separation. The ores exhibit narrow ranges of variation in sizes and shapes of ore mineral grains and intergrowths and concentrations of minerals harmful to flotation. The subtle differences in ore mineral concentrations between ore types enable their selective mining and blending. Maps and cross sections contain data on the spatial distribution of the associated components such as garnet and wollastonite in skarns and productive metasomatites, pyroxene–plagioclase periskarn rocks, and hydrothermally altered rocks with Cu, Au, and other mineralization.

International audience; The Mo-Cu-W Azegour skarn, located in the High-Atlas in Morocco, is associated with a Late Hercynian alkaline granitic intrusion. Here the origin of the mineralisation via Re-Os geochronology and using Mo, S and Pb isotopes is discussed. The age of mineralisation defined by Re-Os molybdenite geochronology is 276 ± 1.2 Ma for the Azegour mine, and 267 ± 1.2 for the Tizgui deposit suggesting for multiple mineralisation events associated with the Hercynian alkaline granitic intrusion. The δ98MoNIST of molybdenite range from −0.60‰ to 0.42‰ (n = 26) for the Azegour mine and from 0.08‰ to 0.40‰ (n = 2) for the Tizgui mine. Variations of the δ98MoNIST occur either at the deposit scale with a difference of about 0.72‰, and at the sample scale (few cm), which exhibits a difference of up to 0.40‰. A multi-phased mineralisation is proposed as the main processes explaining the variation in the δ98MoNIST values although the influence of a Rayleigh fractionation process cannot be precluded. The high δ34S values determined from molybdenite, pyrrhotite, and chalcopyrite (8–14.7‰) suggest a sedimentary origin for sulphur from the Cambrian sedimentary country rocks. Whereas, the initial 206Pb/204Pb compositions of common lead (18.08–18.30) for chalcopyrite and pyrrhotite imply a strong contribution of lead from the host volcano-sedimentary units.

The Xiaoqinling district, the second largest gold producer in China, is situated on the southern margin of the North China Craton and immediately to the north of the Qinling Orogen. The timing and genesis of the gold deposits have been hotly debated because the area has undergone multiple tectono-magmatic events since the stabilization of the North China Craton in the early Paleoproterozoic. Whether they are genetically related to the Triassic orogeny that formed the Qinling Orogen or associated with the early Cretaceous tectonic reactivation of the craton remains controversial. Here we present monazite U-Pb and molybdenite Re-Os dating results from the Hongtuling vein deposit in the eastern part of the Xiaoqinling district to provide new insights into the age and tectonic setting of gold mineralization . The Hongtuling deposit consists of gold veins at the top and minor molybdenum veins at the bottom, with molybdenum veins being locally crosscut by gold veins. Molybdenum veins mainly consist of calcite, quartz, K-feldspar, molybdenite, and pyrite with minor amounts of galena, and a variety of accessory minerals. Gold veins are dominated by quartz and pyrite, with minor to trace amounts of chalcopyrite, galena, sphalerite, and sericite. Monazite grains are well developed both in molybdenum and gold veins, and are intergrown with molybdenite and pyrite, respectively. Monazites from gold vein contain lower REEs contents, more prominent negative Eu anomalies, and higher Th/U ratios than those from molybdenum vein. The textural and geochemical evidence indicates that monazites from both veins precipitated from contrasting ore-forming fluids. Laser ablation ICP-MS U-Pb dating of monazite from the molybdenum vein yields a 206Pb/238U age of 203.5 ± 8.1 Ma (MSWD = 0.23, 2σ), which is statistically indistinguishable from the molybdenite Re-Os age of 204 Ma. In contrast, monazite from the gold vein has a significantly younger 206Pb/238U age of 130.4 ± 5.3 Ma (MSWD = 0.99, 2σ). Results presented here, combined with independent studies, suggest that the molybdenum and gold veins of the Hongtuling deposit, and by inference the other deposits in the district, formed in two discrete mineralization events in the late Triassic and early Cretaceous. The molybdenum mineralization is most likely related to the post-collisional magmatism associated with the Qinling orogeny, whereas gold mineralization occurred in an extensional setting associated with the decratonization of the North China Craton.

China’s W–Sn resources are dominant on a global scale. A series of Sn–polymetallic deposits has been found in recent years at depth on the flanks of known volcanic–subvolcanic Cu–Pb–Zn–Ag deposits in the Southern Great Xing’an Range, NE China. The large-scale Weilasituo tin–polymetallic deposit, formed at the depth of the Weilasituo Cu–Zn deposit, is most typical of these types of deposit. Tin–polymetallic orebodies are hosted in the early Paleozoic Xilingol Complex, and their mineralization is closely related to Early Cretaceous quartz porphyry. In this contribution, bulk-rock and mica chemical compositions, Re–Os geochronology, and He–Ar isotopic analyses are described in addressing the ore-formation mechanism of the deposit. Geochemical characteristics indicate that the ore-bearing quartz porphyry corresponds to the I-type granite serie. Five types of mica have been identified in the study area based on detailed petrography and EPMA and LA–ICP–MS analyses: (i) early magmatic Fe–Li mica in albitized quartz porphyry; (ii) late magmatic Fe–Li mica in mineralized quartz porphyry; (iii) hydrothermal Fe–Li mica in a cryptoexplosive breccia pipe (distributed around breccia fragments); (iv) Fe–Li mica in quartz veins; and (v) Fe–Li mica in plagioclase gneiss (wall rock). Magmatic zinnwaldite from the upper mineralized part of the quartz porphyry is enriched in Nb (100–160 ppm) and Ta (100–150 ppm). Hydrothermal zinnwaldite from the explosive breccia, quartz veins, and surrounding gneiss is unusually rich in Mg (up to 3.4 wt% MgO) and Sn (up to 200 ppm). 3He/4He ratios of the Weilasituo tin–polymetallic and Cu–Zn deposits are in the ranges 3.38–4.91 Ra and 4.8–4.9 Ra, respectively, indicating ore-forming fluids sourced from mixed crustal and mantle materials. Molybdenite Re–Os dating of W mineralization yielded an isochron age of 129.0 ± 4.6 Ma, similar to the porphyry crystallization and mineralization ages of the Weilasituo tin–polymetallic deposit, and also consistent with the mineralization age of the Cu–Zn deposit. We propose a new metallogenic model, with all subtypes of W–Sn–Cu–Pb–Zn–Ag mineralization in the Weilasituo area belonging to a single complex metallogenic system. Compared with other ore districts, ore-related granitoids in the Southern Great Xing’an Range display relatively uniform emplacement ages and were derived from partial melting of juvenile lower crust rather than old basement. Their ore-forming fluid source was greater influenced by mantle fluids than which found in South China.

The Zhuxi W deposit in Jiangxi, South China, with a resource of 2.86 Mt W and an average grade of 0.54% WO3, is the largest W deposit in the world. The deposit occurs at the contact between a late Mesozoic granitic intrusion and Carboniferous – Permian carbonate rocks and Neoproterozoic metamorphic rocks. The ores are divided into three types: skarn ore (dominant), sulfide ore and greisen ore. Based on occurrences and petrographic relationships, scheelite (the dominant ore mineral) is classified into three types, i.e. type I (greisen), type II (skarn, specifically in the retrograde stage), and type III (hydrothermal sulfides). Type I and type II are time equivalent but spatially separated, whereas type III is later. The different types of scheelite have distinctly different REE and trace element compositions. Type I scheelite is characterized by an average ΣREE of 67.9 ppm, LREE/HREE ratio of 24.4, δEu of 8.5, Mo of 0.1 ppm and Sr of 1058 ppm, whereas type II scheelite features an average ΣREE of 48.1 ppm, LREE/HREE ratio of 10.6, δEu of 0.67, Mo of 1892 ppm and Sr of 90.1 ppm. Type III scheelite has an average ΣREE of 53.9 ppm, LREE/HREE ratio of 4.8, δEu of 17.5, Mo of 92.9 ppm and Sr of 37.1 ppm. The extremely high concentrations of Sr and highly positive Eu anomalies in type I scheelite are likely related to release of these elements from plagioclase in the granite during greisenization, whereas the extremely low concentrations of Mo may be related to the reducing and high-temperature nature of the magmatic fluid – Mo probably was mainly in the Mo4+ state and could not replace W6+ in the scheelite lattice. In contrast, the negative Eu anomalies and high Mo concentrations in type II scheelite suggest that the mineralizing environment in the retrograde alteration stage was relatively oxidizing, causing Eu to exist mainly as Eu3+, which is difficult to replace Ca2+ in scheelite, and Mo mainly as Mo6+, which is easy to replace W6+ in scheelite. In the sulfide mineralization stage, the fluid became relatively reducing again, and Eu2+ could easily replace Ca2+ in scheelite causing positive Eu anomalies, whereas Mo mainly exists as Mo4+ and precipitated as molybdenite, and so has limited substitution for W6+ in scheelite. The REE and trace element compositions of the dominant W mineral (type II scheelite), characterized by high concentrations of Mo, high LREE/HREE ratios and negative Eu anomalies, indicate that the ore-forming materials were mainly derived from the granitic intrusions. The variation of REE and trace elements in scheelite in time and space reflects a complex magmatic-hydrothermal mineralization process involving various fluid-rock reactions within the intrusion and in the country rocks. The formation of the Zhuxi W deposit is linked with a large fertile granitic intrusion, which delivered a large amount of W to the site of mineralization through convection within the magma chamber, and W precipitation in the skarn was largely caused by an abrupt drop in temperature and increase in pH of the ore-forming fluid.

There has been a long-term debate about the timing of the incursion of meteoric water into porphyry systems and whether it plays an important role in ore precipitation. To evaluate the role of meteoric water in the mineralization in porphyry Mo deposits, typical hydrothermal veins of different stages from the Chalukou giant porphyry Mo deposit are selected for combined scanning electron microscope cathodoluminescence (SEM-CL), fluid inclusion microthermometry and high-resolution secondary ion mass spectroscopy (SIMS) oxygen isotope analyses. Multiple generations of quartz are identified in almost all of the veins. The barren quartz veins and quartz-magnetite veins of the early Mo mineralization stage are dominated by granular CL-bright quartz (EMQ1), which usually shows dissolution and re-deposition textures and are overprinted by CL-dark quartz (EMQ2)-filled healed fractures. The molybdenite precipitation in the quartz-molybdenite veins of the main Mo mineralization stage is synchronous with small volumes ( 85%) of CL-bright quartz (MMQ1). Similar to the quartz-molybdenite veins, the precipitation of pyrite in the quartz-pyrite veins during the transitional stage and sphalerite in the quartz-sphalerite-pyrite veins during the Zn-Pb mineralization stage are also directly associated with CL-dark quartz (TSQ2, ZPQ2). The SIMS oxygen isotopic values of EMQ1 and MMQ1 fall into the range of 5.42–9.79‰ with calculated equilibrium fluid compositions of 2.07–6.45‰, indicating a magma-dominated fluid composition, whereas MMQ2, TSQ2 and ZPQ2 have very low oxygen isotopic values from −4.68 to 4.29‰ with corresponding fluid compositions of −13.64 to −5.94‰, implying that the fluid formed by the mixing of magmatic water and a large proportion of meteoric water. The contrasting SEM-CL features and oxygen isotopic compositions of the two generations of quartz in the quartz-molybdenite veins demonstrate that the incursion of meteoric water into the hydrothermal system occurred earlier than the molybdenite precipitation. Based on these results and the crosscutting relationships and spatial distribution of the veins, we reconstructed the quartz evolutionary sequence during the vein development process. After the early precipitation of barren quartz, the reduction in fluid pressure from lithostatic to hydrostatic conditions allowed the incursion of convecting cool meteoric water into the relatively hot hydrothermal system, and the temperature of the evolved Mo-rich fluid decreased rapidly from >500 °C to

Sulfur isotopic composition is useful for tracing sources of ore-forming materials. In situ sulfur isotope analysis by laser ablation coupled with multi-collector inductively coupled plasma mass spectrometry (LA-MC-ICPMS) has an advantage over traditional bulk analysis in tracing sources of sulfur in an ore deposit that has complex mineral types and multiple ore-forming processes. However, in using this method, matrix effects exist widely for sulfides from ore deposits. In this work, matrix effects of different sulfides were examined by matrix-unmatched tests, in which the δ34S values of different types of sulfides were calibrated against a laboratory pyrite standard. The results show that the δ34S values of pyrrhotite, chalcopyrite, molybdenite, sphalerite, and arsenopyrite are in agreement with the reference values, suggesting that the matrix effect was negligible. However, a significant matrix effect occurred in the analyses of Ag2S and galena, leading to significant deviations in δ34S values of up to 1.2‰ and 3.2‰, respectively. The matrix effect occurred not only during the laser ablation stage but also during the transition of ions into the mass spectrometer, resulting in significant space charge effects caused by heavy-mass elements. Thus, pyrite can be used as an external bracketing standard for sulfides that do not have a heavy-mass matrix. Based on our matrix-effect study, the following available external standards were selected for the in situ sulfur isotope analysis of complex-type minerals from the Erlihe Zn-Pb deposit. The coarse-grained sphalerite grains (Sph1) and euhedral to subhedral pyrite grains (Py1) from massive ores have δ34S values ranging from 9.2‰ to 18.1‰. Such heavy sulfur isotopic compositions indicate the derivation of sulfur from the deposits of seawater sulfate, related to a thermochemical reducing process. Fine-grained sphalerite (Sph2) and pyrite (Py2) from vein and disseminated ores coexist with pyrrhotite and chalcopyrite, and have relatively light sulfur isotopic compositions, with δ34S values of about 7‰. The slightly positive δ34S values are similar to those of sulfides from sulfide-rich quartz veins, which contain δ34S values of about 4‰, and granodiorite rocks, with δ34S values of about 6‰. Based on previous studies, the light sulfur of the late-stage sulfides may have resulted from a metamorphic or magmatic hydrothermal event during the Indosinian orogeny. In situ sulfur analysis by LA-MC-ICPMS provides new evidence for sources of sulfur from each stage of mineralization in the Erlihe deposit, suggesting that this is a promising method for studying complex ore deposits.

The Gongpengzi Cu-Zn-W polymetallic deposit is a typical skarn deposit located in the Lesser Xing'an-Zhangguangcai Range, NE China. Although the deposit was first discovered in the 1950s, the timing of mineralization, source of the ore-forming materials, and geodynamic setting of the deposit, remain unclear. We present whole-rock geochemical and zircon U-Pb geochronological data for granitoids, molybdenite Re-Os geochronological data, and S-Pb isotopic analyses of sulfide minerals and feldspars from granitoids within the deposit. The results of molybdenite Re-Os and zircon U-Pb dating of biotite granites and granodiorite from the Gongpengzi polymetallic deposit suggest that ore formation occurred at 176.7 ± 5.9 Ma, and that the granodiorite hosting the mineralized zone were emplaced at 173.6 ± 1.0 and 173.9 ± 1.0 Ma, respectively. The granites and granodiorites have high SiO2 and Na2O + K2O contents, are enriched in Rb, Th, U, Ta, and Pb, and depleted in U, P and Ti, and therefore classify as I-type granitoids. One granodiorite sample yielded a (87Sr/86Sr)i value of 0.70444, eNd(t) value of 2.30, and two-stage model age (TDM2) of 785 Ma. The biotite granite samples yielded (87Sr/86Sr)i values of 0.70433–0.70445, eNd(t) values of 2.34–2.54, and TDM2 of 785–765 Ma. These observations suggest that the granites were probably derived by partial melting of both mantle and juvenile crustal material, and that these partial melts underwent fractional crystallization. The ore-forming elements were magmatic source, and may have been derived by mixing between crustal and mantle sources. We interpret granitoid relating to skarn mineralization in the Lesser Xing'an-Zhangguangcai Range to have resulted from subduction of Paleo-Pacific oceanic crust toward the Eurasian continent.