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Modern trends in technological improvement for producing high-quality rhenium-containing molybdenum concentrates are aimed at developing environmentally friendly solutions com-pared to traditional ones, involving a reduction in consumption or complete replacement of toxic substances and the use of plant reagents and microorganisms and make it possible to eliminate energy-intensive processes of steaming and roasting. It is known that up to 25%–30% of Mo, Cu and Re goes to rough flotation tailings and is lost in wastes. Those losses are a consequence of the ore composition variability, chalcopyrite–molybdenite ratio, an increase in the proportion between primary copper sulfide and finely disseminated molybdenite and the recovery of floating pyrite. High rates of valuable metal recovery into bulk concentrate can be achieved by using new compositions of flotation reagents that selectively change the hydrophobic properties of the target minerals. The application of new reagent compositions, including novel chemicals—dithiopyrylmethane (DTM), composite reagent (CR) and conventional butyl xanthate (ButX)—was theoretically and experimentally substantiated for the effective rhenium extraction in the processing of hard-to-beneficiate complex molybdenum ores. It is identified that DTM forms a complex DTM–Re compound and chemically adsorbed on rhenium-containing molybdenite providing an increase in Re recovery into the bulk Cu–Mo–Re concentrate by 17%, reducing by two times the loss of rhenium with flotation tailings, and the subsequent 97.6% Re extraction of the molybdenum concentrate by autoclave leaching. [ABSTRACT FROM AUTHOR]

The Balka Zolota gold-molybdenum deposit is located in the central part of the Solone ore field in the southern part of the Sura greenstone structure of the Middle Dnipro megablock of the Ukrainian Shield. Molybdenum mineralization is confined to the eastern flank of the deposit and is termed as the Solone occurrence. Main questions are address in this study of thе occurrence: i) the discovery and study of the deposit, ii) the composition of wall rock complex, iii) the structural position and localization of molybdenum mineralization, iv) the morphology of orebearing zones and ore bodies, (v) the composition of the ores, (vi) the ore mineral associations and the sequence of their formation, (vii) morphological features of molybdenite and (viii) a general analysis on the genesis of molybdenum mineralization. Mining of molybdenum ore of Balka Zolota deposit is possible in the case of output, first of all, gold ores. It can be realized more realistically after the start of mining operations within the Serhiivka gold-molybdenum deposit. Further geological exploration focusing on the Balka Zolota deposit is needed to assess the resources and reserves potential of the gold and molybdenum mineralization, especially on the eastern flank of the deposit. [ABSTRACT FROM AUTHOR]

Modern trends in technological improvement for producing high-quality rhenium-containing molybdenum concentrates are aimed at developing environmentally friendly solutions com-pared to traditional ones, involving a reduction in consumption or complete replacement of toxic substances and the use of plant reagents and microorganisms and make it possible to eliminate energy-intensive processes of steaming and roasting. It is known that up to 25%–30% of Mo, Cu and Re goes to rough flotation tailings and is lost in wastes. Those losses are a consequence of the ore composition variability, chalcopyrite–molybdenite ratio, an increase in the proportion between primary copper sulfide and finely disseminated molybdenite and the recovery of floating pyrite. High rates of valuable metal recovery into bulk concentrate can be achieved by using new compositions of flotation reagents that selectively change the hydrophobic properties of the target minerals. The application of new reagent compositions, including novel chemicals—dithiopyrylmethane (DTM), composite reagent (CR) and conventional butyl xanthate (ButX)—was theoretically and experimentally substantiated for the effective rhenium extraction in the processing of hard-to-beneficiate complex molybdenum ores. It is identified that DTM forms a complex DTM–Re compound and chemically adsorbed on rhenium-containing molybdenite providing an increase in Re recovery into the bulk Cu–Mo–Re concentrate by 17%, reducing by two times the loss of rhenium with flotation tailings, and the subsequent 97.6% Re extraction of the molybdenum concentrate by autoclave leaching.

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.

Graphical abstract Highlights • Mineralization and alteration at Siruyidie'er prospect are related to a Miocene intrusion of granite porphyry. • The magma source of the granite porphyry is from an ancient lower crust. • The Siruyidie'er prospect has a potential to form porphyry Mo ± (Cu) deposit. • There is a possibility for the presence of porphyry Mo ± (Cu) deposit in the Pamir plateau. Abstract The Pamir and Tibetan plateaus, which have a similar terrane structure and evolutionary history since the Phanerozoic, are both host abundant Eocene to Miocene intrusions, however, unlike the Tibetan plateau, coeval porphyry deposits appear to be devoid in the Pamir plateau. In this study, we first report a potentially economic Cu-bearing sulfide mineralization at Siruyidie'er prospect in the Central Pamir. The Siruyidie'er prospect is characterized by the development of 14 breccia pipes in the north block and of Cu-bearing sulfide veins in the south block. Field evidence indicates that the brecciation and mineralization are intimately related to the intrusion of granite porphyry. Zircon U-Pb dating of the granite porphyry yields an age of 13.74 ± 0.21 Ma. This age overlaps with the hydrothermal muscovite 40Ar/39Ar data of 13.68 ± 0.17 Ma, which confirms the hydrothermal activity and mineralization at Siruyidie'er prospect are induced by the granite porphyry. The granite porphyries are shoshonitic in composition and have high K 2 O (6.03–6.46 wt%; K 2 O/Na 2 O = 1.70–1.92), Ba (2983–3316 ppm), LREE (317–363 ppm) and Sr (331–378 ppm), and low MgO (0.54–0.63 wt%), Cr (6.73–8.28 ppm) and Y (7.88–9.91 ppm) contents. The rocks are LREE-enriched ((La/Yb) N = 53–66) and display weakly negative Eu (Eu/Eu* = 0.79–0.87), positive LILES (Ba, Rb, and K) and negative HFSEs (Th, U, Nb, Ta, Ti, and Y) anomalies. They have enriched Hf isotopic compositions with ɛ Hf (t) values ranging from –8.78 to −5.01. The combined major and trace elements and Hf isotopic characteristics of the granite porphyries suggest that the primitive magmas were produced by high extent partial melting of an ancient crust source, possibly a thickened lower crust in the garnet stability field. A comparison of the granite porphyries at Siruyidie'er prospect with Eocene to Miocene ore-forming granitic porphyries of the Tibetan plateau reveals that the granite porphyries have lower water contents and originated from a continental crust rather than a depleted mantle source. Based on geological, compositional, and age data, we propose that the Siruyidie'er prospect has a potential to form porphyry Mo ± Cu deposit. This study provides the first direct evidence for the possible presence of porphyry Mo ± Cu deposit in the Pamir plateau. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • LA-ICP-MS and SIMS were applied to pyrites from Shapoling vein-type Mo deposit. • Textural and chemical evolution of hydrothermal pyrite was proposed. • The Mo-bearing pyrite identified in our study could be used as a possible pathfinder for the exploration of high-grade Mo mineralization. Abstract The Early Cretaceous (ca. 128 Ma) Shapoling vein-type molybdenum (Mo) mineralization, associated with the Huashan intrusion is a newly discovered deposit in the Xiong'ershan district, East Qinling, China where pyrite is a ubiquitous mineral phase. Here we present results from an integrated study on the texture, in situ trace element chemistry from laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and sulfur isotopic composition using secondary-ion mass spectrometry (SIMS), with a view to understand the geochemical variation, genesis of Mo mineralization and ore-forming process. The distinct textural patterns as revealed by petrographic observations suggest three types of pyrites: Py1 is composed of coarse-grained euhedral pyrite in the wall rock and early barren quartz vein at Stage I, Py2 is represented by subhedral-anhedral grains coexisting with molybdenite in quartz veins at Stage II, and Py3 forms irregular interstitial grains in the quartz + K-feldspar + molybdenite dominated veins at Stage III. The Mo enrichment mainly occurred in Py3 (with Co/Ni ratios >1 and δ34S values mainly <0‰). Our study shows that Mo, Au, Pb, Zn, Ag and Cu are selectively partitioned into pyrite as mineral micro/nano-inclusions, and that the siderophile and chalcophile elements (such as Co, Ni, As, Se and Te) occur substituted within different textural types of pyrite. The δ34S values of the pyrites in Py1 and Py2 range between −2.33‰ and −0.37‰, indicating a dominantly magmatic origin. The δ34S values of Py3 increase from −2.55‰ to +1.48‰. In situ δ34S analysis of pyrite from Py1, Py2 to Py3 shows a progressive and gradual change in redox conditions. The negative values indicate oxidized sulfur in the early generation of pyrite (Py1 that coexists with magnetite). Conversely, positive values represent reduced sulfur found in the later generations of pyrite (Py3), which contain higher concentrations of Cu, Pb, Zn and Ag. The Mo-bearing pyrite identified in our study could be used as a possible pathfinder for the exploration of high-grade Mo mineralization. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Xiaoshuijing Syenogranite hosting Mo mineralisation in the Tengchong Terrane. • Zircons from the syenogranite yield a U-Pb age of 65 ± 1 Ma. • The Re-Os Mo age of 64 Ma for the mineralisation is the same as the syenogranite's. • The syenogranite is related to a thickened crust resulting from the Neo-Tethys Ocean subduction. Abstract The Xiaoshuijing Syenogranite is the host of Mo mineralisation recently discovered in the Tengchong Terrane of southwestern China. Here, we present new zircon U-Pb ages and molybdenite Re-Os ages, whole-rock geochemical data, and zircon Hf isotopic data for the Xiaoshuijing Syenogranite hosting disseminated Mo mineralisation. The syenogranite's mineralogical and geochemical characteristics indicate it is a high-K, alkaline, and peraluminous granite. LA-ICP-MS analysis of zircon yields an age of 65 ± 1 Ma (n = 14, MSWD = 2.1), and yields negative zircon ε Hf (t) values ranging from −18.23 to −12.92, interpreted to have a crustal source. The Re-Os Mo age of 64 ± 2 Ma (n = 4, MSWD = 2.2) for the mineralisation is the same as the syenogranite's age, within error. The geochemistry also indicates that the syenogranite is related to a thickened crust resulting from the eastward subduction of the Neo-Tethyan oceanic lithosphere shortly before the collision of the Indian and Eurasian continental crusts. [ABSTRACT FROM AUTHOR]

Highlights • Pyrogallic acid exhibit selective depression effect on bismuthinite flotation. • Pyrogallic acid expanded the difference in flotation rate of both minerals. • Pyrogallic acid has a destabilizing effect on the froth phase. Abstract Molybdenum ore flotation techniques are constantly challenged by the emergence of complex sulfide minerals, such as bismuthinite, in the mineral processing industry. Conventional flotation depressants, such as sodium sulfide, used in Mo–Bi-containing ore flotation require high dosages, which leads to high cost and low selectivity. Therefore, in this study, pyrogallic acid (PA), a widely distributed organic source, is tested as an alternative depressant to selectively depress bismuthinite in Mo–Bi sulfide ores from Shizhuyuan. Results show that PA has a minimal effect on molybdenite recovery; by contrast, PA has a high depressing effect on bismuthinite amelioration. At 500 g/t PA, molybdenum recovery slightly decreases by 2 percentage points, and bismuth content in molybdenum concentrate sharply declines by 34 percentage points, with respect to samples floated without PA. Batch flotation tests demonstrate that PA addition affects froth stability, as indicated by the variations of solid and water recoveries. The superior selectivity of molybdenite over bismuthinite is promoted by increasing the PA dosage. On the basis of these findings, PA is a feasible option and thus can be used as a depressant for bismuthinite in the flotation of sulfide minerals. [ABSTRACT FROM AUTHOR]

Abstract The Dasuji porphyry Mo deposit is located at the northern margin of North China Craton. Mo mineralization occurs mainly within the intrusions of alkali feldspar granite, granite porphyry, and quartz porphyry, which yield weighted mean 206Pb/238U ages (2σ) of 227.6 ± 1.5, 225.7 ± 1.5, and 224.3 ± 1.8 Ma, respectively. These ages are indistinguishable to the molybdenite Re Os isochron age of 223.9 ± 1.5 Ma (2σ). The Dasuji granites show the petrological, mineralogical, geochemical, and geotectonic characteristics of A-type granites. They exhibit low negative εNd(t) values (−16.7 to −12.6) with corresponding T DM2 (Nd) ages of 1705–2000 Ma, variable but mainly negative εHf(t) values (mostly −21.0 to −7.9) with corresponding T DM2 (Hf) ages of 1715–2728 Ma, and Pb isotopic compositions indicating that the primary magmas were dominantly derived from partial melting of ancient lower crust. In chondrite- and mantle-normalized trace element diagrams, all the granitic rocks show negative anomalies in Ba, Sr, and Eu, and a positive anomaly in Pb. The ratios of LREE/HREE, and (La/Yb) N and δEu values decrease from the alkali feldspar granite to the granite porphyry and quartz porphyry. These data are attributed to fractional crystallization processes. Fractionation of feldspar, biotite, and possibly K-feldspar produced the variations in major elements and Rb, Sr and Ba, and the distribution of REE are controlled mainly by fractionation of zircon, allanite, minor apatite, and possibly a small quantity of monazite. Together with the regional geology, the data infer that the Dasuji porphyry Mo deposit formed in a post-collision extensional setting during the Late Triassic. Graphical abstract Unlabelled Image Highlights • Ore-related Dasuji granites are formed between 227.6 and 224.3 Ma. • The primary magmas were derived from partial melting of ancient lower crust, with a minor mantle contribution. • The magma experienced at least two stages of fractional crystallization. • The Dasuji granites are A-type granites. [ABSTRACT FROM AUTHOR]

This study describes the preparation and characterisation of certified reference materials of three molybdenum ores (GBW07141 to GBW07143, abbreviated to GMo‐1 to GMo‐3) and one molybdenum concentrate (GBW07144, abbreviated to GMo‐4). The source of these materials was molybdenum deposits in Luanchuan in Henan Province, China. Sample homogeneity was tested by WD‐XRF. All the relative standard deviations were < 3.0%, and F‐tests showed that all four materials were homogeneous. Thirteen laboratories participated in this interlaboratory programme, and to set the values, various reliable analytical methods based on different principles were adopted. Up to twenty‐six elements and compounds in the three molybdenum ores and eighteen components in the molybdenum concentrate were characterised as certified values. Owing to the wide spread of the data, only indicative values could be obtained for Ag and Re in GMo‐1 and for nine components in GMo‐4. The certified values and uncertainties for Mo of the three molybdenum ores and the molybdenum concentrate were, respectively, 0.066 ± 0.003, 0.15 ± 0.01, 0.54 ± 0.02 and 50.08 ± 0.14% m/m. Key Points: Three Mo ores and one Mo concentrate were prepared and characterised as CRMs in a thirteen‐laboratory programme.Twenty‐six and eighteen analytes in the ores and concentrate respectively were assigned certified values.Certified values and uncertainties for Mo in the ores and concentrate were 0.066 ± 0.003, 0.15 ± 0.01, 0.54 ± 0.02 and 50.08 ± 0.14% m/m. respectively. [ABSTRACT FROM AUTHOR]

Determining arsenic in tungsten and molybdenum ores using Hydride Generation-Atomic Fluorescence Spectrometry (HG-AFS) without separation and a screening agent commonly suffer from the interferences of associated elements such as W, Mo, Cu, Pb, Zn, Bi and Cd. In this study, the samples were digested by hydrochloric acid-nitric acid (volume ratio of 5 : 1) in a water bath. Citric acid and potassium iodide solution were used to screen interferences of associated elements by reducing these elements to low valences or forming the precipitates. Lastly thiourea-ascorbic acid solution was added and As content was determined directly by HG-AFS. The method yields an As detection limit of 0.014 μg/g, precision of 0.7%-7.5%, and recovery of 92.3%-102.9%. Compared to the national standard method, this method has the advantages of low detection limit, wide detection ranges, and direct determination without separating interference elements.

Mining of mineral resources exerts strong impact on the environment and leads to irreversible changes in vegetation, soils, atmosphere, surface and ground waters. The aim of this study is to assess the modern geochemical state of soil cover in Zakamensk, a city located in Buryat Republic (Russia) and known as one of the biggest ore mining center in the former Soviet Union. The center was operating for 68 years and closed 17 years ago. Soil-geochemical survey was conducted in 2012 and included collection of 103 soil samples in Zakamensk and 27 samples in the background areas. The bulk contents of 16 potentially toxic elements (PTEs) in the soil samples were determined by mass spectrometry and by atomic emission spectrometry with inductively coupled plasma. Background sites are characterized by increased concentrations of ore elements W and Mo. The mineral deposit development and physical and chemical weathering of tailings' material have led to a sharp increase in Bi, Cd, Cu, Mo, Pb, Sb, W and Zn levels in the soils of different land-use areas. Near the tailings, the concentration of Sb in soils was 356 times higher than in the background area; Cd – 70 times; Mo, Bi, Cu, and W – 42–55 times; Pb and As – 34–37 times; and Zn and Sn – 6–12 higher. In the north of the city a prominent anomaly of PTEs occurs in sandy sediments of the Modonkul floodplain. It was formed due to the washout and subsequent sedimentation of suspended matter carried by the Modonkul River from the Barun–Naryn, the Dzhida, and emergency tailings. So, the anthropogenic activities are the most important source of ore and accompanying elements in the urban soils. High levels of accessory elements also depends on natural factors such as physicochemical properties of soils, position in the landscape, and genesis of parent materials. The environmental assessment of topsoils in Zakamensk showed that Pb, Sb, Cd, and As concentrations exceeds the Russian MPCs by 1.7–7.8 times, which creates a significant hazard for the environment and adversely affects human health. [ABSTRACT FROM AUTHOR]

Graphical abstract Kendenggao’er deposit, the only Late Carboniferous deposit in Boluokenu metallogenic belt, is a typical skarn Cu-Mo deposit. The hydrothermal system of Kendenggao’er deposit is complicated, and various types of fluid inclusions and several fluid evolution episodes have been inferred in our study. These give a clear constraint for the origin and evolution of Kendenggao’er skarn deposit, furthermore, will provide a better insight into understanding the ore-forming mechanisms for other skarn type in the Boluokenu. Highlights • Kendenggao’er deposit is a typical skarn Cu-Mo deposit. • The ore-forming fluids of pre-ore and main-ore stages are of magmatic origin. • The ore-forming materials were derived from the host magmatic rocks. • Two types of immiscibility occurred in the skarn and hydrothermal system. Abstract The Boluokenu Range is one of the most important metallogenic belts in northwest China, and it contains numerous Fe, Cu, Mo, Au etc deposits. The Kendenggao’er Cu-Mo deposit is located in the eastern segment of the Boluokenu metallogenic belt within the Western Tianshan orogeny. Skarn and Cu-Mo orebodies occur as lamellae or lenses along the contacts between different units of the Upper Carboniferous Dongtujinhe Formation and the Aimujin granitic intrusions. Based on field investigations and petrographic observations, three main metallogenic stages of skarn formation and ore deposition have been distinguished: (1) The pre-ore stage is characterized by the formation of garnet, wollastonite and diopside and high-temperature, hypersaline hydrothermal fluids with oxygen isotopic compositions that are similar to those of magmatic fluids. These fluids were most likely generated by the separation of brine from the silicate melt due to the immiscibility of primary magmatic fluids that occurred at a depth of approximately 1 km with inferred lithostatic pressure conditions of 300 bars. (2) The main-ore stage coincides with the replacement of garnet and diopside by vesuvianite, epidote, sulfides and quartz. The hydrothermal fluids of this stage are represented by V-type (vapor-rich) fluid inclusions that coexist with L-type (liquid-rich) inclusions. The oxygen isotope (δ18O H2O) values of the main-ore stages are in a narrow range of 7.5–9.9‰, which indicates that the mineralization-related fluid is also of magmatic origin. Based on the fluid inclusion and stable isotopic data, it can be concluded that the ore-forming fluid evolved by the boiling of the magmatic fluids that likely occurred at a depth of ∼1 km and hydrostatic pressure of ∼100 bars, and that this was the predominant mechanism for the large-scale precipitation in the Kendenggao’er Cu-Mo deposit. (3) The post-ore stage is characterized by the development of calcite, quartz and chlorite. The fluids during this stage are represented by the L-type inclusions, which mainly show low-salinity and low-homogenization temperatures. These fluids yield the lowest δ18O H2O values (−2.8 to 3.7‰). The above data indicate that the post-ore stage fluids originated from the mixing of residual main-ore stage fluids with various proportions of external water (low salinity, low temperature). No boiling occurred at this stage at the low temperatures. The δ34S values of the sulfides range from −4.3 to 1.9‰, and the 206Pb/204Pb, 207Pb/204Pb and 208Pb/204Pb values of the sulfides range from 18.220 to 18.554, 15.608 to 15.812 and 38.080 to 39.055, respectively. The S and Pb isotopic compositions indicate that the ore materials were mainly derived from magmas. Taken together, these geologic, geochemical, and isotopic data confirm that Kendenggao’er is a typical skarn deposit. [ABSTRACT FROM AUTHOR]

Major, minor, and trace element abundances in titanite crystals from four granitic plutons in southern Yidun arc, SW China, have been determined using electron microprobe and laser ablation-inductively coupled plasma-mass spectrometry. The selected plutons are the Cretaceous Xiuwacu (CXWC) pluton, with quartz vein-type Mo mineralization (economic-Mo), the Tongchanggou (TCG) pluton, with porphyry-type Mo mineralization (economic-Mo), the Triassic Pulang (PL) pluton, with porphyry-type Cu mineralization (subeconomic-Mo), and the Triassic Xiuwacu (TXWC) pluton, without any Mo mineralization (Mo-barren). Our study reveals that the chemical compositions of titanite crystals from these plutons such as REE, Sr, Ga, δEu, δCe, Fe2O3/Al2O3, halogens, and Mo can be used to track magma compositions, oxidation states, metal fertility, and crystallization history. The data from this study also show that titanite crystals from these plutons with different potential of Mo mineralization have similar Mo contents and exhibit an irregular variation between Mo and Sr abundances (indicating non-Mo enrichment in the residual melt during the progressive crystallization) for some Mo-mineralized plutons. Our new observations support the recent hypothesis that high initial Mo contents in magma and the enrichment of Mo in residual melts formed by fractional crystallization are not the only requirements to form a granite-related Mo ore deposit. Efficient extraction of the residual melts, possibly facilitated by high concentrations of magmatic F is also critical to the ore formation. Evidence for high-F concentration in felsic magma, which facilitates melt and fluid separation and economic Mo mineralization during magma evolution, may be traced by the presence of F-rich titanite crystals in the two Mo-mineralized granite plutons (CXWC and TCG). These new findings from this study confirm that titanite is indeed a good petrogenetic and metallogenic indicator. However, in light of the limited contribution of metal fertility to Mo mineralization, we suggest that titanite Mo concentrations should be used along with other crucial proxies, such as titanite F contents and Fe2O3/Al2O3 ratios to better evaluate the Mo-mineralized potential of granites. [ABSTRACT FROM AUTHOR]

The Wenquan Mo deposit in Gansu Province, China, is one of the large porphyry Mo deposits in the Western Qinling Orogen that associated with the Triassic continental collision between the North China Block and South China Block. In this study, detailed fluid inclusions (FIs) analyses were performed on early stage quartz–biotite–K-feldspar veins, middle stage quartz–polymetallic sulfide veins and late stage sulfide–calcite veins. Four compositional types of FIs are observed, including pure CO 2 (PC-type), CO 2 -H 2 O (C-type), H 2 O-NaCl (W-type), and daughter mineral-bearing polyphase (S-type, with no halite daughter mineral). The early stage quartz contains all the four types, which are mainly homogenized between 285 °C and 495 °C, with salinities ranging from 4.2 to 17.6 wt% NaCl eqv. However, in the middle stage, PC-type FIs are not observed, and S-, W- and C-types FIs yield homogeneous temperatures (T h ) of 200–397 °C and salinities of 2.4–13.1 wt% NaCl eqv. Late stage quartz contains only W-type FIs with T h of 102–246 °C and salinities of 1.2–10.1 wt% NaCl eqv. Results indicate that the fluid-system evolved from an initial CO 2 -rich magmatic-hydrothermal fluid to a late CO 2 -poor meteoric fluid. In the early and middle stages, it is possible that heterogeneous FIs associations may have been trapped from a fluid immiscibility system. The dramatically decreasing percentage of PC- and C-types FIs in the ore stage indicates that CO 2 escaped, which is possibly the result of earlier fluid immiscibility and phase separation. In addition, there are double peaks of T h in this stage that are obviously lower than in the early stage, showing that meteoric water flowed into and mixed with magmatic fluids, thereby cooling the hydrothermal system. These results suggest that metal precipitation resulted from fluid immiscibility, CO 2 escape, and inflow of meteoric water occurred in the middle stage. The initial fluids of the Wenquan deposit are characterized by relatively high temperature, high salinity, high f O 2 , and are CO 2 -rich and NaCl-poor, indicating that the Wenquan deposit is a collisional-type porphyry Mo deposit. The oxygen fugacity ( f O 2 ) constrained by trace element compositions of zircons from the Wenquan Mo-bearing porphyry is uneven with ΔFMQ −10.3–+4.68 (average of −4.32), which could result from the input of mafic magma and its inhomogeneous mixing with felsic magma. Such values are still much higher than those of the adjacent contemporaneous Mo-barren Lujing, Baijiazhuang, Jiaochangba, Luchuba, and Zhongchuan granitic plutons, which confirms the affinity between Mo mineralization and the oxidized melt system and implies that the Wenquan porphyry has relatively high f O 2 characteristics for its tectonic location and epoch. Fluid inclusion, initial mineralization depth (∼8.6 km), magma f O 2 , and the zircon high U/Yb ratio of the Wenquan Mo deposit strongly suggest that Mo mineralization was related to continental collision, rather than oceanic crust subduction. This study therefore proposes that the Wenquan Mo deposit was formed in a rapid crust uplifting setting caused by syn -orogenic crustal thickening followed by post-orogenic delamination of the lithospheric root during the Late Triassic. [ABSTRACT FROM AUTHOR]

The newly discovered giant Dahutang W–Cu–Mo deposit in the central part of the Jiangnan Orogen hosts an estimated resource of 1.1 million tons (Mt) of WO 3 , plus a proven resource of 0.65 Mt Cu and 0.08 Mt Mo. The Dahutang deposit is temporally and spatially associated with the Late Mesozoic S-type granites emplaced into the Neoproterozoic Jiuling granodiorite batholith and the Shuangqiaoshan Group. Based on petrographic observations, eight hydrothermal alteration/mineralization stages have been recognized, comprising pegmatitic (Stage I), potassic alteration (Stage II), albite alteration (Stage III), greisenization and main mineralization (Stage IV), polymetallic sulfide mineralization (Stage V), late scheelite mineralization (Stage VI), carbonate alteration (Stage VII) and supergene alteration (Stage VIII). Stage IV can be further divided into the early greisenization (Stage IV-A), the main wolframite mineralization (Stage IV-B) and the main scheelite mineralization (Stage IV-C). Fluid inclusion and H–O isotope analyses on nine Stage IV to VII ore/gangue minerals (wolframite, cassiterite, scheelite, sphalerite, fluorapatite, fluorite, quartz, calcite and chlorite) suggest the presence of an early W and a late Cu–Mo ore-forming fluid system. The early ore-forming fluids belong to a medium to high temperature (200°–420 °C), low salinity H 2 O–NaCl–CaCl 2 system. This primary magmatic-hydrothermal fluid (δ 18 O fluid  = 5.4 to 8.8‰ and δD = −102 to −75‰) was likely exsolved from the Late Jurassic granites at Dahutang. Wolframite and scheelite coexist closely with fluorapatite and fluorite, respectively, indicating that the volatile-rich fluids at Dahutang were also rich in tungsten, fluorine and phosphorous. Tungsten was likely transported as tungstate species (e.g., WO 4 2− and HWO 4 − ), oxygen fluorine complexes (e.g., [WO 2 F 4 ] 2− , [WO 3 F 2 ] 2− ) and phosphorous heteropolytungstate (e.g., [P(W 12 O 40 )] 3− ) in the fluids. Fluorapatite and wolframite may have precipitated first when the temperature dropped from 400° to 320 °C (along with pH increase) at an estimated depth of 7.8 km. This was likely followed by the extensive scheelite mineralization (with fluorite precipitation) that formed huge disseminated/veinlet-type W orebodies when the temperature further dropped to 200 °C (along with pH increase). After the W mineralization, extensive Cu–Mo polymetallic mineralization and the associated sericite-chlorite alterations may have formed by the granite porphyry and/or muscovite granite emplacement. The late ore-forming fluids belong to a medium to high temperature (200°–360 °C), low salinity H 2 O–NaCl–CaCl 2 system. Molybdenum was likely transported mainly as Mo complexes (e.g., H 2 MoO 4 /MoO 4 2− ), and copper as Cu–Cl complexes. Molybdenite and chalcopyrite may have begun to precipitate when the fluids ascended and the temperature dropped to 330 °C. Meteoric water incursion may have then occurred (δ 18 O fluid  = 1.9–6.9‰ and δD = −99 to −68‰) and further cooled the fluid system to 250 °C, forming large Cu–Mo orebodies. [ABSTRACT FROM AUTHOR]

The Qianfanling quartz–vein type molybdenum deposit is located in the East Qinling–Dabie Mo belt. The Mo mineralization in the deposit is mainly present as structurally controlled Mo-bearing quartz veins. Based on chromatography analysis of the Qianfanling Mo deposit, the gas compositions of fluid inclusions in quartz dominantly contain H 2 O and relatively high concentrations of CO 2 (11.019 to 18.554 mol%). Cations and anions of liquid compositions of fluid inclusions are mainly Na + and Ca 2 + , and SO 4 2 − and Cl − , respectively. The characteristics of gas and liquid compositions of fluid inclusions in quartz indicate that the Qianfanling Mo deposit formed under conditions of high oxygen fugacity. Analytical results of He-Ar isotopes of fluid inclusions in pyrite from the Qianfanling Mo deposit show that 3 He/ 4 He ratios vary from 0.02438 to 0.0796 Ra (Ra is the 3 He/ 4 He ratio of air = 1.40 × 10 − 6 ), with F 4 He values of 252,509–885,224. The calculated He mantle values range from 0.18 to 0.87%, with an average of 0.39%. 40 Ar/ 36 Ar ratios are 694.4–1473.4, with the estimated 40 Ar* (radiogenic 40 Ar) proportion of 79.9%. These He-Ar isotopic data indicate that most of the He in the fluid inclusions was derived from the crust, with negligible atmospheric He and only a very small input from the mantle probably. Furthermore, the Ar in the ore-forming fluid was mainly derived from the crustal source, with minor atmospheric Ar involved. 17 Re–Os model ages of 15 molybdenite samples from the 4 quartz-vein type Mo deposits (Qianfanling, Daxigou, Maogou, and Zhifang) range from 215.0 to 248.2 Ma, with a mean value of 235.6 Ma, which is close to the age of peak collision between the North China and Yangtze Cratons. The Re contents in molybdenite from the 4 deposits range from 0.19 to 39.16 ppm, with an average of 17.41 ppm, indicating a crust-dominated source. Re contents in molybdenite from Mesozoic Mo deposits in different ages and types in the East Qinling–Dabie Mo belt show different characteristics of ore sources. Combined with gas and liquid compositions and He-Ar isotopic characteristics of fluid inclusions, as well as Re contents in molybdenite of this paper and previous studies, we suggest that the ore-forming fluid and material of the Qianfanling Mo deposit were mainly derived from crustal magmatic source. This magmatic source could have formed by partial melting of deep crustal rocks under a certain condition during the collision between the North China and Yangtze Cratons. [ABSTRACT FROM AUTHOR]

The newly discovered Xingwen porphyry Mo deposit is located in the most southern segment of the Xiaoxing'an Range–Zhangguangcai Range metallogenic belt (XZMB), NE China. The Mo deposit occurs with a granitic complex consisting of monzogranite, porphyritic granite and felsite porphyry. The Zircon U–Pb ages of monzogranite, porphyritic granite and felsite porphyry are 170.3 ± 2.1, 168.5 ± 2.5, and 166.7 ± 1.6 Ma, respectively. The inherited zircons from the monzogranite and porphyritic granite yield U–Pb ages of 239.8 ± 5.8 and 249.4 ± 6.2 Ma, respectively. These ages reveal that the Mo mineralization in the most southern segment of the XZMB took place in the Middle Jurassic, and is consistent with the epoch of the largest Daheishan Mo district in the XZMB. In contrast, Triassic ages of the inherited zircons are consistent with the ages of the Triassic magmatic activities along the E–W trending tectono‐magmatic belt in the northern margin of the North China Craton. The εHf(t) of the monzogranite, porphyritic granite and felsite porphyry change from −17.1 to +6.7 , −16.9 to +2.9, −5.94 to −0.90, respectively. The Hf isotopic compositions indicate that old crustal source, juvenile crustal source or depleted mantle contributed to their origin. When compared with the granite in Daheishan Mo district in XZMB, the εHf(t) probably indicates that the granitic complex in the margin of the Central Asia Orogenic Belt may have more old crustal materials than the granitic complex in the inner region of the Central Asia Orogenic Belt. Copyright © 2017 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Over five hundred W-Mo skarns have been reported in the Neoproterozoic Seridó belt in the northeastern Brazil. The origin of these mineralizations has been attributed to metasomatic reactions occuring after the infiltration of hydrothermal fluids that are mostly derived from the plutonic magmatic activity that ranged between approximately 600 and 525 Ma. Here we date molybdenite using N-TIMS on Re-Os analysis of three major scheelite deposits (Brejuí, Bonfim and Bodó) hosted in the skarn horizons of the metasedimentary sequence. Molybdenite is an integral part of the mineralizations that include scheelite in skarns and, in the Bonfim deposit, gold concentrate in late brittle faults. The Re-Os ages are 554 ± 2 Ma (Brejuí), 524 ± 2 Ma (Bonfim) and 510 ± 2 Ma (Bodó). The age of the Brejuí molybdenite, however, appears to be anomalous based on the local geology of the deposit, which is located next to the contact of a batholith dated ca. 575 Ma. In turn, the Bonfim molybdenite yields similar ages in replicated samples with variable high Re contents. New U-Pb SHRIMP ages of four biotite (leuco)granite plutons vary from 577 ± 5 Ma to 526 ± 8 Ma, which overlap with molybdenite crystallization. These results indicate a close connection between the W-Mo mineralizations and the plutonic activity that intruded the belt after the peak HT/LP metamorphism. The latest pulses of felsic magmatism, which were contemporaneous with the emplacement of Be-Ta-Nb-Li pegmatites, therefore constitute a potential guide in the Seridó belt for prospective W-Mo deposits. [ABSTRACT FROM AUTHOR]

The Qinling-Dabie orogenic belt is the largest Mo mineralization belt in the world. The Yaochong porphyry Mo deposit is located in the northwest Dabie Mountains, with a proven reserve of 51 kt Mo metal at an average grade of 0.058%. Here we report geochronology and geochemistry results of the Yaochong porphyry Mo deposit. Zircon U-Pb LA-ICP-MS dating shows that the Yaochong porphyry dykes and a hidden intrusion formed at 135 Ma and 140 Ma, respectively, which are consistent with Early Cretaceous Mo mineralization events in the Qinling-Dabie orogenic belt. Zircon grains from the Yaochong porphyry dikes (2–1788) and the hidden intrusion from drill holes (41–1940) have highly variable Ce 4+ /Ce 3+ values. It is very likely that both the intrusion and the dikes have experienced high oxygen fugacity, but was partially reduced through assimilation. Apatite grains from the Yaochong porphyry and the intrusion are characterized by high but variable F concentrations and low Cl concentrations, suggesting that they formed in an F-enriched environment with high F/Cl components in the magma source. The Ti-in zircon temperatures of the porphyry dikes range from 700 to 710 °C, whereas the average temperature of the buried intrusion nearby is 675 °C. Yaochong porphyry shows geochemical and petrologic characteristics similar to those of low F stockwork type porphyry Mo deposit in North America, which may be inherited from the Dabie suture zone. [ABSTRACT FROM AUTHOR]

The Suyunhe large porphyry Mo deposit (∼0.57 Mt molybdenum), located in the West Junggar, NW China, is the largest known porphyry Mo deposit in Xinjiang. Granitoids in this deposit are mainly characterized by three closely spaced intrusive centers (known as stocks I, II and III respectively). The stocks I and III mainly consist of barren granodiorite porphyry and tonalite porphyry, whereas the stock II is mainly composed of fertile monzonitic granite porphyry and granite porphyry. Based on detailed major and trace element, and Sr–Nd isotopic analyses, two distinct compositional groups can be identified. The first group of high-silica end-members (HSE) is characterized by high SiO 2 (mostly >75 wt%), low MgO (0.07–0.69 wt%) and Mg# (0.19–0.36), significant Eu depletion in the chondrite-normalized diagram, and low Sr/Y and La/Yb, as well as noticeably negative anomalies of Ba, Sr, P and Ti in the primitive mantle-normalized diagram. The second group of low-silica end-members (LSE), however, displays adakite-like features with lower SiO 2 (<75 wt%), higher MgO (0.52–1.32 wt%) and Mg# (0.32–0.52; mostly >0.4), and higher Sr/Y (mostly >20) and La/Yb (>8). The depleted Sr–Nd isotopic characteristics (ε Nd (T) = 3.5–6.4 and I sr = 0.7026–0.7055) and young two-stage model ages of HSE and LSE indicate that they were both derived from partial melting of juvenile lower crust that might be triggered by asthenosphere upwelling subsequent to a slab rollback event. However, the depths of initial melting might be different. The current evidence demonstrates that HSE in the Suyunhe deposit formed by partial melting of juvenile crust at depths of less than ∼33 km with a plagioclase residue, whereas that for LSE occurred at depths of >40 km where a garnet residue existed and the crust was thickened. The lower source depth, as well as subsequently strong plagioclase fractionation, results in the absence of adakite-like characteristics in HSE. The Ce 4+ /Ce 3+ and Eu N /Eu N ∗ ratios in zircons of HSE are much lower than ore-forming intrusions from porphyry Cu deposits in the Central Asian Orogenic Belt, but noticeably higher than barren intrusions from the Lachlan fold belt and ore-bearing intrusions from small-intermediate porphyry Mo deposits from the East Qinling–Dabie and the Nanling metallogenic belts, China, indicating that neither too high nor too low oxygen fugacities are favorable for large porphyry Mo deposits. Based on previous studies of adakitic rocks in the world, adakite-like LSE in the Suyunhe deposit are believed to have higher oxygen fugacities, and thus be less fertile than HSE. We finally suggest that adakites and adakite-like rocks are unproductive for porphyry Mo deposits. [ABSTRACT FROM AUTHOR]

The Suyunhe porphyry Mo deposit, located in the West Junggar terrane, is the largest molybdenum deposit found in Xinjiang to date, with a proven reserve of 0.57 Mt. The Suyunhe deposit is associated with Early Permian granitic rocks, which emplaced into the volcano-sedimentary sequences of the Middle Devonian Barluk Formation. Four metallogenic stages are identified in this study. Stage I is marked by the quartz-magnetite-K-feldspar±biotite±pyrite±molybdenite veins, which mainly occurred in the intensively potassic alternation zone and were formed at high temperature (>481°C), high salinity (58.6−65.18 wt.%), and relatively high oxygen fugacity conditions with a fluid system of NaCl-H2O-CO2. Stage II is the main metallogenic stage and develops numerous quartz-molybdenite±pyrite veins associated with muscovite–chlorite alteration, which were formed by immiscible fluids at medium-high temperature (210−427°C), medium-high salinity (43.36−49.90 wt.%), and relatively low oxygen fugacity conditions with the fluid system of NaCl-H2O-CO2-CH4-C2H6. After the main Mo-mineralization, quartz-polymetallic sulphides veins associated with quartz–sericite alteration were formed by fluids at medium-low temperature, low-salinity conditions with the fluid system of NaCl-H2O-CO2in stage III. The following quartz-polymetallic sulphide veins are quartz-calcite±pyrite veins associated with calcite alteration, which were formed by fluids at low temperature and low-salinity conditions with a fluid system of NaCl-H2O in stage IV. The δ18O‰ values indicate that the ore fluids of stages I and II are dominated by magmatic water, whereas stages III and IV are dominated by meteoric water. A wide range of δ34S‰ values (−7.1 to 3.4‰) of sulphides between stages I and II indicates that increasing the reducibility plays an important role in molybdenum mineralization. The δ13CCH4values suggest that CH4of the ore fluids mainly results from the assimilation–contamination of carbonaceous country rocks, and partly derives from magma. However, the δ13CCO2values suggest that CO2of the ore fluids mainly originates from magma, and minor derives from wall-rocks as well as meteoric water. [ABSTRACT FROM PUBLISHER]

The Donggebi Mo deposit located in NW China is a newly discovered, large, stockwork-type Mo deposit with ore reserves of 441 Mt @ 0.115% Mo. Ore bodies occur along faults and fractures at the external contact zone of a concealed porphyritic granite and volcaniclastic rocks of Gandun Formation, spatially associated with a fine-grained granite. Mo-bearing veins are mainly assemblages of volatile-rich K-feldspar-quartz-oxide, K-feldspar-quartz, polymetallic sulfides and calcite-quartz. Zircon LA-ICP-MS U–Pb dating yielded concordant ages of 234.6 ± 2.7 Ma and 231.8 ± 2.4 Ma for the porphyritic granite and the fine-grained granite, respectively; molybdenite Re–Os dating gave an isochron age of 234.0 ± 2.0 Ma. These ages further confirm an important and extensive magmatic-metallogenic event in Eastern Tianshan during the Triassic Indosinian orogeny. Whole-rock major and trace element analyses indicate that the granitic rocks associated with Mo mineralization are high in Si, K, Rb, Th, Nb, Ta, Ga and LREE, but low in P, Ti, Sr and Ba, belonging to high-K calc-alkaline granites with A-type features. Magma was likely derived from the re-melting of thickened lower crust in a post-collision compression environment in the Late Permian, experienced strong crystal fractionation and formed the large Donggebi Mo deposit under an intra-plate extension setting in the Early to Middle Triassic. [ABSTRACT FROM AUTHOR]

Copper, gold and molybdenum mineralization of the Kalmakyr porphyry deposit in Uzbek Tien Shan occurs as stockworks, veinlets and disseminations in the phyllic and K-silicate alteration zones developed predominantly in a middle to late Carboniferous intrusive complex composed of monzonite and granodiorite porphyry. Zircon U–Pb dating yielded an age of 327.2 ± 5.6 Ma for the ore-hosting monzonite and an age of 313.6 ± 2.8 Ma for the ore-bearing granodiorite porphyry. Re–Os dating of seven molybdenite samples from stockwork and veinlet ores yielded model ages from 313.2 to 306.3 Ma, with two well-constrained isochron ages of 307.6 ± 2.5 Ma (five stockwork ores) and 309.1 ± 2.2 Ma (five stockwork ores and two veinlet ores), respectively. These results indicate that Cu–Au mineralization post-dated the emplacement of the monzonite, started right after the emplacement of the granodiorite porphyry, and lasted for ca. 7 Ma afterward. The geochronological and geochemical data suggest that the Kalmakyr deposit was formed in a late Carboniferous mature magmatic arc setting, probably related to the latest subduction process of the Turkestan Ocean beneath the Middle Tien Shan. The ε Hf (t) values of zircon grains from the monzonite vary from +11 to +1.7, with an average of +5.1, and those of zircon grains from the granodiorite porphyry range from +5.7 to −1.8, with an average of +2.4. These data indicate that the magma of both monzonite and granodiorite porphyry was derived from partial melting of a thickened lower crust with input of mantle components and variable crustal contamination, and that there was more mantle contribution to the formation of the monzonite than the granodiorite porphyry. The high rhenium concentrations of molybdenite (98–899 ppm) also indicate major mantle contribution of rhenium and by inference ore metals. The relatively high Eu N /Eu N ∗ values (average 0.68), Ce 4+ /Ce 3 values (average 890) and Ce/Nd values (average 36.8) for zircon grains from the granodiorite porphyry than those from the monzonite (average Eu N /Eu N ∗ = 0.33, average Ce 4+ /Ce 3 = 624, average Ce/Nd = 3.9) suggest that the magma for the syn-mineralization granodiorite porphyry has higher oxygen fugacity than that for the pre-mineralization monzonite. Based on these data, it is proposed that while the monzonite was emplaced, the oxygen fugacity and volatile contents in the magma were relatively low, and ore metals might disperse in the intrusive rock, whereas when the granodiorite porphyry was emplaced, the oxygen fugacity and volatile contents in the magma were increased, favoring copper and gold enrichment in the magmatic fluids. The Kalmakyr deposit formed from a long-lived magmatic-hydrothermal system connected with fertile magmatic sources in relation to the subduction of the Turkestan Ocean beneath the Middle Tien Shan. [ABSTRACT FROM AUTHOR]

The Ga'erqiong Cu-Au deposit, which sits on the north side of the Coqên-Xainzamagmatite belt, is a large-scale skarntype deposit, whose ore body has formed in the skarn zone in the contact part of quartz diorite and marble of Duoai formation or the cracks of quartz diorite. Its mineralization is closely related to quartz diorite. And granite porphyryrelated molybdenum ore still exists in its deep part. Currently, there are disputes about the metallogenic dynamics background of this deposit. From previous studies, this paper carried out zircon LA-LCPMS U-Pb dating and petrogeochemistry study for quartz diorite of Ga'erqiong Cu-Au deposit. The testing result indicates: quartz diorite and granite porphyry were formed respectively in 88±2Ma and 83±1Ma, belonging to the magmatic activity of the early stage of Upper Cretaceous; quartz diorite and granite porphyry have geochemical characteristics similar to those of island arc rock of subduction zone and geochemical indexes similar to "adakite." Combining with the regional tectonic evolution, we think that quartz diorite and granite porphyry were all formed in the extension environment after the collision of Lhasa block and Qiangtang block. Quartz diorite is the result of the migmatization of basic melt and acid melt evoked by asthenosphere material raise caused by lower crustal delamination; the formation of granite porphyry may be crust-mantle material's partial melting results due to delaminated lower crustal. Therefore, Ga'erqiongskarn-type Cu-Au deposit belongs to the metallogenic response to the collisional orogeny in the closing process of Meso-Tethys. [ABSTRACT FROM AUTHOR]

Porphyry Cu and Mo deposits are two economically important types of metal deposits worldwide, but factors controlling their difference remain enigmatic. Compared with the well-studied large porphyry Mo province in the south margin of the North China Block (S-NCB), the origin of newly discovered porphyry Cu deposits in the South Qinling (SQB) is poorly constrained. Integrated zircon LA-ICPMS U-Pb and molybdenite Re-Os ages and geological evidence indicate three stages of magmatism at Lengshuigou: (1) late Neoproterozoic (718 to 704 Ma) quartz diorite + albitite + granite association during the pre-ore stage, (2) 146 to 145 Ma granodiorite porphyry during the syn-ore stage, and (3) 145 Ma granite porphyry during the post-ore stage. Elemental and Sr-Nd isotopic evidence provide important constraints on their magma source. Pre-ore Neoproterozoic quartz diorite + albitite + granite was derived by re-melting of a mixture of crustal and juvenile mantle materials, and stronger fractional crystallization was involved in these ore-hosting intrusions than in contemporary granitoids hosted in the Douling Group. Syn-ore granodiorite porphyry was derived from mantle-derived magma with contributions from different proportions of crustal components. Post-ore granite porphyry was derived mainly from a crustal source. Nearly contemporaneous porphyry Cu and Mo systems were identified in Qinling Province, including the 147-139 Ma porphyry Mo systems in the S-NCB and 150-146 Ma porphyry Cu systems in the SQB. Granitic stocks related to porphyry Cu systems in the SQB are characterized by moderate SiO contents (58.01-69.07 %) and less radiogenic Nd-Hf isotopes (εNd = −3.8 to −6.3, εHf = −4.5 to +1.6), whereas the granitic stocks related to porphyry Mo deposits in the S-NCB have high SiO concentrations (64.00-76.00 %) and more radiogenic Nd-Hf isotopes (εNd = −18.0 to −11.6, εHf = −26.3 to −13.5). In addition, molybdenite from the Chigou and Lengshuigou porphyry Cu deposits in the S-NCB show higher Re contents (77.50-394.3 ppm) than those from nearly contemporaneous porphyry Mo deposits (9.34-49.7 ppm) in the S-NCB. These lines of evidence indicate that a higher proportion of mantle component was involved in the formation of porphyry Cu deposits in the SQB than nearly contemporaneous porphyry Mo deposits in the S-NCB. It is most likely that the nature of the magma source plays an essential role in the differences between porphyry Cu and Mo deposits. [ABSTRACT FROM AUTHOR]

The Kaladawan Fe–Mo ore field in Altyn (Xinjiang Province, NW China) contains six Fe (–Mo) deposits, with total proven reserves of 60 Mt Fe and 10,000 t Mo. Tabular, lensoidal and stratiform orebodies occur in the Cambrian foliated marble, phyllite, carbonaceous slate, chlorite–sericite schist and quartz–sericite schist along the exocontact zone of the Kaladawan granite. Skarns are extensively developed and dominated by garnet, pyroxene, epidote, tremolite and actinolite, with minor chlorite, zoisite, quartz and calcite. Ore minerals are mainly magnetite and molybdenite. Five alteration and mineralization stages (I–V) were identified: the prograde (I) and retrograde (II) skarns are characterized by assemblages of garnet–pyroxene and epidote–tremolite–actinolite, respectively, intruded and replaced by mineral assemblages of magnetite–epidote–zoisite (III), quartz–sulfides (IV) and calcite–chlorite (V) in younging order. The Kaladawan garnet contains more andradite (61.2–94.4 mol%) than grossularite (37.5–5.0 mol%). Pyroxene is Mg-rich and Fe-poor, with an endmember range of 55.4–94.7 mol% diopside and 42.5–4.7 mol% hedenbergite. Amphibole comprises mainly tremolite and actinolite. The Kaladawan skarn mineral contents resemble typical skarn Fe and Mo deposits. In-situ LA-ICP-MS magnetite trace element analysis had identified unusually high Mg, Mo and Cr concentrations. The high Mo and the absence of molybdenite inclusions in magnetite suggest that the hydrothermal fluids may have been Mo-rich. The magnetite also contains similar (Ti + V) and (Al + Mn) values with typical skarn Fe deposits. Therefore, the Kaladawan Fe–Mo mineralization is best attributed to be skarn-type, and related to the Kaladawan granite intrusion. [ABSTRACT FROM AUTHOR]

The Altaids is a Paleozoic orogenic collage in central Asia. It occupies ~ 10% of the Eurasian continent, and it is one of the richest concentrations of mineral deposits in the world, comparable to those of the Circum-Pacific and Tethyan orogenic belts. In particular, it contains many types of hydrothermal ore deposits that are sensitive to the nature and origin of their host terranes, including porphyry copper (gold–molybdenum), volcanogenic massive sulfide copper–lead–zinc and orogenic gold deposits, which are all diagnostic of convergent continental margins, extensional arc-related submarine basins, and transpressional terrane boundaries. Within the Altaids, porphyry copper deposits are mostly concentrated within the Kazakhstan and Tuva–Mongolia micro-continents, where they formed almost continuously from the Early Ordovician to Permian; only a few are Cambrian and Triassic, and most are Late Carboniferous. Most volcanogenic massive sulfide ore deposits are distributed along the South Urals and Rudny Altai in the western Altaids, where they formed in a short time-window from the Early to Middle Devonian. Important orogenic gold deposits formed along regional strike-slip faults between craton, island arc or micro-continent boundaries from the Neoproterozoic to Permian, mostly in the Early Permian. In limited key areas volcanogenic massive sulfide deposits formed upon much older (> 100 Ma) basement rocks than those of coeval porphyry deposits indicating that the Altaids could not have developed from a single arc. Furthermore, the porphyry deposits outline the distribution of several continental fragments, the combined area of which is far less than that of the Altaids, which suggests that extensive new juvenile material has been added into island arc systems, which may have been accreted to surrounding continental margins. These metallogenic distributions in localized areas were a result of the mechanisms of crustal growth within the overall tectonic evolution of the Altaids, and they are consistent with the interpretation that the Altaids is a multiple subduction–accretion collage. [ABSTRACT FROM AUTHOR]

The Kozbudaklar scheelite skarn deposit in the Tavşanlı Zone, located approximately 22 km southeast of Bursa, is hosted by the Triassic calcic İnönü Marble and Eocene Topuk Pluton. At least four stages have been recognized through skarn evolution. Scheelite skarn distributed close to the Topuk Pluton occurred during the early (stage 1) and late (stage 2) prograde substages. The early prograde endo and exoskarn are composed of hedenbergite (Hd 96 Joh 4 )–plagioclase (An 55–64 ) and hedenbergite (Hd 61–94 Joh 4–7 ), accompanied by calcic garnet (Grs 38–94 Sps 1–5 Alm 0 ) and scheelite (Pow 1–6 ). The second stage represents a relatively oxidized mineralogy dominated by diopside (Hd 16–48 Joh 0–9 ), subcalcic garnet (Grs 24–92 Sps 0–11 Alm 0–31 ) and scheelite (Pow 7–32 ). The stage 3 and 4 mineral assemblages are characterized by few hydrous minerals in the retrograde stage and intense fracturing. Fluid inclusions from skarn rocks are indicative of multiple fluid events: (1) low-moderate salinity (5–16 wt.%NaCl equiv.) inclusions homogenized dominantly by a high-temperature (308 °C to > 600 °C) liquid phase in stage 1. Fluid inclusions in an early garnet homogenized over a similar temperature range (440 °C and 459 °C) into both liquid and vapor phases. Eutectic temperatures ranging from − 61.7 °C to − 35.0 °C that indicate the presence of H 2 O–NaCl–(± MgCl 2 ± CaCl 2 )–CO 2 solutions; (2) coexisting daughter mineral-bearing high salinity (29.5 ≥ 70 wt.%NaCl equiv.) and vapor-rich moderate salinity (11.5–16.7 wt.%NaCl equiv.) inclusions that homogenized in the liquid phase by the disappearance of the vapor phase at a similar temperature range (308 °C to > 600 °C) in stage 2. Eutectic temperatures range from − 67.9°C to − 51.8°C that shows the presence of H 2 O–NaCl–CO 2 –(± CH 4 /N 2 ) solutions; (3) low-moderate salinity (12.5–7.6 wt.%NaCl equiv.) and temperature (320 °C to 215 °C) inclusions homogenized by the liquid phase in stage 3. Eutectic temperatures range from − 59.5 °C to − 44.2 °C indicating the presence of H 2 O–NaCl–(± MgCl 2 ± CaCl 2 )–CO 2 solutions; (4) inclusions of low salinity (9.9–0.9 wt.%NaCl equiv.) and homogenization temperature (183 °C to 101 °C) in stage 4. These data show that the Kozbudaklar skarn deposit was formed in a magmatic–hydrothermal system. In this model, carbonaceous fluids may have been exsolved from the plutonic rock during its emplacement and crystallization. Fluid inclusion data indicate that fluid boiling and immiscibility occurred at temperatures between 440 °C and 459 °C and pressures ranging from 50 MPa to 60 MPa based on hydrostatic considerations. Early scheelite was precipitated with relatively reduced mineral compositions. As a result of depressurization, Mo-rich scheelite with oxidized minerals formed via high salinity and vapor-rich inclusions. The second scheelite mineralization occurred in a normal hydrothermal system by an infiltration mechanism at pressures between approximately 40 and 1.5 MPa. At shallow depths (< 1.5 MPa) with increasing permeability, sulfide and oxide minerals were deposited in the retrograde stage, greatly assisted by meteoric water. Finally, as a result of the diminishing of ore-forming fluids, post-depositional barren quartz and calcite veins were formed. [ABSTRACT FROM AUTHOR]

The importance of molybdenum deposits has been increased in Turkey as well as the molybdenum industry in the world. In this context, the aim of this study was to evaluate the flotation behavior of low-grade porphyry copper-molybdenum ore obtained from the Kirklareli region of Turkey. The ore sample used in this study contained 0.18% Mo and 0.15% Cu. In this study, the effect of several parameters such as particle size, pH, types and amounts of collector, depressant, and frother on the flotation were investigated. Based on the results obtained from this study, gas oil as collector, pine oil as frother, and sodium sulphide as depressant at pH 12 were found to be optimum parameters for the flotation of molybdenite ore. Meanwhile, the kinetics of batch flotation behavior of the molybdenum ore was obtained by applying the first order and second order kinetics models. The results indicated that the flotation rate constant responds to second-order kinetics model with correlation coefficient of 0.99. At the end of the multi stage flotation test performed under the optimum flotation parameters, Mo recovery and content for final concentrate were found as 72.3% and 52.15%, respectively. [ABSTRACT FROM AUTHOR]

The Taolaituo porphyry-type molybdenum deposit is located in the eastern Inner Mongolia Autonomous Region in China. The mineralization occurs mainly as veins, lenses and layers within the host porphyry. To better understand the link between the mineralization and the host igneous rocks, we studied samples from the underground workings and report new SHRIMP II zircon U-Pb and Re-Os molybdenite ages, and geochemical data from both the molybdenites and the porphyry granites. Five molybdenite samples yield a Re-Os isochron weighted mean age of 133.0 ± 0.82 Ma, whereas the porphyry granitoids samples yield crystallization ages of 133 ± 1 Ma and 130.4 ± 1.3 Ma. The U-Pb and Re-Os ages are similar, suggesting that the mineralization is genetically related to the Early Cretaceous porphyry emplacement. Re contents of the molybdenites range from 21.74 to 42.45 ppm, with an average of 32.69 ppm, whereas δ34S values vary between 3.7‰ and 4.2‰, which is typical of mantle sulphur. The 206Pb/204Pb, 207Pb/ 204Pb and 208Pb/204Pb vary in the ranges of 18.276-18.385, 15.566-15.580 and 38.321-38.382, respectively. The Taolaituo Early Cretaceous granitoids are A-type granites. These observations indicate that the molybdenites and the porphyry granites were derived from a mixed source involving young accretionary materials and enriched subcontinental lithospheric mantle. A synthesis of geochronological and geological data reveals that porphyry emplacement and Mo mineralization in the Taolaituo deposit occurred contemporaneously with the Early Cretaceous tectonothermal events associated with lithospheric thinning, which was caused by delamination and subsequent upwelling of the asthenosphere associated with intra-continental extension in northeast China. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

A two-stage ball milling circuit for the grinding of molybdenum ore was investigated based upon the grinding kinetic model. To this end, batch grinding tests at the laboratory-scale were conducted to obtain the specific rate of breakage and the primary breakage distribution in wet and dry environments. The test results were then scaled-up to the conditions of a full-scale ball milling circuit for grinding molybdenum ores. A two-stage ball milling circuit algebra was employed to predict the capacity, circulation ratio, and size distributions. Comparison of the simulated results and the observed values showed that the model represents accurately the actual milling process in the plant. Simulation results indicated that the classification in the milling process was operated under non-optimal conditions, and that an increase in the mill output of more than 47% was possible simply by modifying the cut size of the classifier. [ABSTRACT FROM AUTHOR]

The Yinyan Sn deposit, one of the three typical porphyry Sn deposits in China, is located in the western Guangdong province of the Cathaysia Block. Rhenium and osmium isotopes of molybdenites from the Yinyan deposit were first used to constrain the age of mineralization. Rhenium concentrations in molybdenite samples range from 0.13 to 1.3 µg g−1, indicating a crustal source for the ore-forming materials. The Re-Os dating yield model ages ranging from 78.1 to 79.52 Ma, with an average of 78.65 ± 0.98 Ma, and give an isochron age of 78.8 ± 2.6 Ma. Evidently, isochron age is consistent with model ages in the error within the allowable range, so we can constrain the precise age of Yinyan Sn deposit at the Late Cretaceous. Based on the geological history and spatial-temporal distribution of the Sn deposits, it is proposed that the formation of Sn deposits in the Cathaysia Block were related to lithospheric extension that are associated with a change in the polarity of the subduction of the Paleo-Pacific Plate from oblique subduction to parallel the eastern margin of the Eurasian Plate after 135 Ma. [ABSTRACT FROM AUTHOR]

The east-central part of Jilin Province, located on the eastern continental margin of northeast China along the eastern Xing–Meng orogenic belt, hosts more than 10 large- and medium-scale Mo deposits. The major types of mineralization include porphyry, skarn, and quartz vein. To better understand the formation and distribution of porphyry Mo deposits in this area, we investigated the geological characteristics of the deposits and applied molybdenite Re–Os isotope dating to constrain the age and source of mineralization. The results, combined with existing data, show that: (a) the Daheishan Mo deposit yields an isochron age of 168.7 ± 3.1 Ma; (b) the Shuangshan Mo deposit yields an isochron age of 171.6 ± 1.6 Ma; (c) the Liushengdian Mo deposit yields a weighted mean model age of 168.7 ± 1.4 Ma; (d) the Jiapigou Mo deposit yields a weighted mean model age of 196 ± 4 Ma; and (e) the Sancha Mo deposit yields a weighted mean model age of 183.1 ± 1.8 Ma. Therefore, the Mo mineralization occurred in the Early–Middle Jurassic (196–167 Ma), during the late stages of magmatism or during the late evolution of magma chambers. The geodynamic setting at this time was dominated by subduction of the paleo-Pacific Plate beneath the Eurasian continent. The rhenium content of molybdenite varies from 0.2 to 99.7 ppm, suggesting that the ore-forming materials may come from a crustal source or a mixed crustal and mantle source. [ABSTRACT FROM AUTHOR]

The Baishan molybdenum deposit is located in the eastern section of the Jueluotage tectonic belt, Eastern Tianshan. There is a granite porphyry intrusion beneath the Baishan Mo ore bodies discovered by recent exploration drilling, and the Cu–Mo minerals are widely distributed in the porphyry. The zircon LA-ICPMS U–Pb age of the granite porphyry intrusion is 228.1 ± 8.0 Ma, which is in coincidence with the age of Mo mineralization (227.7 ± 4.3 Ma). The granite porphyry intrusion is calc-alkaline and peraluminous. The magma was derived from a lower crustal source, it experienced distinct crystal fraction during its evolution, and the magma intruded in a Triassic compressional background, and was probably influenced by far-field effects of the Tethys system to the south. Based on the geological, geochemical and geochronological characteristics of the granite porphyry intrusion, we propose that there is probably a porphyry Cu deposit beneath the Baishan high-Re Mo deposit. [ABSTRACT FROM AUTHOR]

Vacuum decomposition process of molybdenite concentrate was investigated under pressure of 5–35 Pa for 15–120 min at the temperature range 1473 K–1973 K. The theoretical and experimental results showed that Gibbs free energy of vacuum decomposition reactions and evaporation rate of pure sulfur provided the theoretical calculation basis for temperature and heat preservation time selection in vacuum decomposition experiments of molybdenite concentrate. Melting points and saturated vapor pressures of pure substances and compounds predicted the evaporation behavior of impurity elements and its compounds during the experimental process. Both Cu and Fe could partly evaporate into condensate and Cu had better evaporation ability than Fe. MoO 3 could easily and Al 2 O 3 , SiO 2 could partly evaporate into the condensate. Kilo-scale experiment was performed based on the small experiments and its results showed that the Mo content of molybdenum metal product was 92.38% and the S content of sulfur product was 96.28%, and the molybdenum recovery rate reached to 95.94%. Both the theoretical and experimental results proved that it was feasible to produce crude molybdenum and sulfur from molybdenite concentrate through vacuum decomposition. [ABSTRACT FROM AUTHOR]

Shallow magmatic-hydrothermal systems are characterized by steep gradients in temperature and pressure, and because the fluid is of low density and highly compressible, the solubility of ore minerals in these systems varies considerably as a function of both temperature and pressure. We use novel pressure- and temperature-dependent experimentally derived thermodynamic data to geochemically model the transport and deposition of Au, Ag, and Mo by vapor and low- to intermediate-density supercritical fluids in the context of Au and Mo porphyry and Au-Ag epithermal ore formation. The results show that there is a strong compositional control on the Au/Mo ratio of the parental ore fluid, which can explain Au-Mo zoning in porphyry ore deposits and the formation of Au-rich and Mo-rich subtypes. Gold solubility reaches a maximum between 320 °C and 500 °C, depending on the fluid density, whereas Mo and Ag concentrations decrease with decreasing temperature and pressure. These differences in mineral solubility help explain the fractionation of Au from Ag and Mo and the preferential mobilization of Au into sites of epithermal ore deposition. Application of this modeling of metal solubility in vapor-like fluids offers an important opportunity for understanding individual ore-forming hydrothermal systems and determining the limiting factors for metal enrichment. [ABSTRACT FROM AUTHOR]

The recently discovered Baizhangyan skarn-porphyry type W- Mo deposit in southern Anhui Province in SE China occurs near the Middle- Lower Yangtze Valley polymetallic metallogenic belt. The deposit is closely temporally-spatially associated with the Mesozoic Qingyang granitic complex composed of granodiorite, monzonitic granite, and alkaline granite. Orebodies of the deposit occur as horizons, veins, and lenses within the limestones of Sinian Lantian Formation contacting with buried fine-grained granite, and diorite dykes. There are two types of W mineralization: major skarn W- Mo mineralization and minor granite-hosted disseminated Mo mineralization. Among skarn mineralization, mineral assemblages and cross-cutting relationships within both skarn ores and intrusions reveal two distinct periods of mineralization, i.e. the first W- Au period related to the intrusion of diorite dykes, and the subsequent W- Mo period related to the intrusion of the fine-grained granite. In this paper, we report new zircon U- Pb and molybdenite Re- Os ages with the aim of constraining the relationships among the monzonitic granite, fine-grained granite, diorite dykes, and W mineralization. Zircons of the monzonitic granite, the fine-grained granite, and diorite dykes yield weighted mean U- Pb ages of 129.0 ± 1.2 Ma, 135.34 ± 0.92 Ma and 145.3 ± 1.7 Ma, respectively. Ten molybdenite Re- Os age determinations yield an isochron age of 136.9 ± 4.5 Ma and a weighted mean age of 135.0 ± 1.2 Ma. The molybdenites have δ34 S values of 3.6‰-6.6‰ and their Re contents ranging from 7.23 ppm to 15.23 ppm. A second group of two molybdenite samples yield ages of 143.8 ± 2.1 and 146.3 ± 2.0 Ma, containing Re concentrations of 50.5-50.9 ppm, and with δ34S values of 1.6‰-4.8‰. The molybdenites from these two distinct groups of samples contain moderate concentrations of Re (7.23-50.48 ppm), suggesting that metals within the deposit have a mixed crust-mantle provenance. Field observation and new age and isotope data obtained in this study indicate that the first diorite dyke-related skarn W- Au mineralization took place in the Early Cretaceous peaking at 143.0-146.3 Ma, and was associated with a mixed crust-mantle system. The second fine-grained granite-related skarn W- Mo mineralization took place a little later at 135.0-136.9 Ma, and was crust-dominated. The fine-grained granite was not formed by fractionation of the Qingyang monzonitic granite. This finding suggests that the first period of skarn W- Au mineralization in the Baizhangyan deposit resulted from interaction between basaltic magmas derived from the upper lithospheric mantle and crustal material at 143.0-146.3 and the subsequent period of W- Mo mineralization derived from the crust at 135.0-136.9 Ma. [ABSTRACT FROM AUTHOR]

In an effort to contribute to the discussion concerning the age of rocks of the Moldanubian Variegated Group, we have undertaken Re-Os dating of molybdenite of banded carbonatite-like marbles (CLM) from the graphite mine Václav at Bližná (Southern Bohemia), which belong to the metamorphic sequence of this group. The Re-Os model ages for the molybdenites range between 493 and 497 Ma and apparently correspond to the early stages of metamorphism connected with pre-Variscan rift-related tectono-metamorphic events, which affected and recrystallized sedimentary CLM material rich in Mo-Th-Nb-REE. The molybdenite bearing carbonatite like marbles situated in the footwall of Bližná graphite mine have been interpreted as carbonates with a large share of volcano-detritic material derived from contemporaneous primitive alkaline (carbonatite-like) volcanism deposited in a shallow marine lagoonal environment. There is no geological evidence for the participation of fluids mobilized from host rocks in the formation of the CLM. Because the Re-Os chronometer in molybdenite is demonstrably stable through later Variscan facies metamorphism, the molybdenite chronometer has not been affected by subsequent thermal overprints associated with the Variscan orogeny. [ABSTRACT FROM AUTHOR]

Voluminous Late Mesozoic granitoids and the world’s largest Mo deposits occur in the East Qinling. This paper presents the results of Nd–Hf isotopic mapping for the Late Mesozoic granitoids (155–105 Ma) and demonstrates their constraint on the basements and distribution of the Mo deposits in the East Qinling. This isotopic map, made by 98 (21 new and 77 published) whole-rock Nd isotopic and 29 (7 new and 22 published) average zircon Hf isotopic data, shows large variations of whole-rock ε Nd ( t ) values from −22.1 to −1.5, and the correspondingly Nd model ages ( T DM(Nd) ) from 2.83 to 0.79 Ga, and zircon ε Hf ( t ) values from −26.3 to +0.1 and two-stage Hf model ages ( T DM2(Hf) ) from 2.86 to 0.96 Ga. Three regions of variations have been identified from north to south: (a) ε Nd ( t ) values range from −22.1 to −10.9 with T DM(Nd) of 2.82–1.47 Ga, and ε Hf ( t ) values 26.3 to −13.5 with T DM2(Hf) 2.86–2.04 Ga; (b) ε Nd ( t ) values −13.9 to −1.5 with T DM(Nd) 2.02–0.79 Ga, and ε Hf ( t ) values −16.2 to +0.1 with T DM2(Hf) 1.96–0.96 Ga; and (c) ε Nd ( t ) values −6.3 to −4.5 with T DM(Nd) 1.28–1.12 Ga, and ε Hf ( t ) values −1.0 to −0.3 with T DM2(Hf) 1.25–1.22 Ga, respectively. The three regions approximately correspond to the three different terranes, the southern margin of the North China Block (NCB), the North Qinling Belt (NQB) and the South Qinling Belt (SQB), respectively. These demonstrate that the granitoids in the different terranes have distinct sources and their sources change from old to more juvenile from the north (southern margin of the NCB) to the south (SQB). These also reveal the distinct basements for the terranes in Late Mesozoic. The southern margin of the NCB contains widespread Neoarchaean to Paleoproterozoic basement, the NQB comprises Archaean to Neoproterozic basement and the SQB Mesoproterozic to Neoproterozic basement. All these suggest that the three terranes underwent different tectonic evolution and the continental crust of the East Qinling were mainly formed during Archaean to Neoproterozic, different from a typical accretion orogen. The old sources of the granitoids and basements of the terranes constrain the distribution, scale and number of the Mo mineralization and deposits. Mo mineralization is closely related to the small granitic bodies with old continental component sources and Mo deposits are mainly hosted by the terranes with oldest basement. The scale and number of the Mo mineralization and deposits decreased from the southern margin of the NCB to SQB. [ABSTRACT FROM AUTHOR]

The Bangpu porphyry Mo–Cu deposit is a representative Mo-dominated deposit besides the Sharang porphyry Mo deposit in the Gangdese metallogenic belt. The Mo–Cu mineralization has a close relationship with the monzogranite porphyry and diorite porphyrite. We identify three stages during the ore formation: a pre-ore stage, a main-ore stage with Mo–Cu deposited dominantly, and a post-ore stage. In this study, He–Ar, H–O, S and Pb isotopic compositions of the Bangpu deposit were determined. Based on these determinations, integrated isotope geochemistry studies were performed to constrain the possible sources of the ore-forming fluids and metals. The 3 He/ 4 He and 40 Ar/ 36 Ar ratios of fluid inclusions exhibit a range of 0.12209–0.36370 Ra and 275.6–346.1, respectively. The 4 He and 40 Ar concentrations vary from 1.51 to 3.57 (10 −7 cm 3 STP g −1 ) and 0.49 to 9.31 (10 −7 cm 3 STP g −1 ), respectively. He–Ar isotopic compositions suggest dominantly crustal-derived fluid with minor amount of meteoric water in the main ore stage. The δ 18 O fluid and δD fluid values vary from −1.3‰ to 3.9‰ and −140.5‰ to −73.7‰, respectively, indicating that magma fluids mixed with meteoric water. The average δ 34 S value of the sulfides (0.3‰) in the main-ore stage is close to the ore-forming porphyries, indicating a magmatic source. The lead isotopic components of ore sulfides exhibit restricted ranges with 206 Pb/ 204 Pb, 207 Pb/ 204 Pb, and 208 Pb/ 204 Pb ratios of 18.450–18.728, 15.602–5.672, and 38.715–39.211, respectively and μ values in the range of and 9.46–9.58, indicating ore-forming metals of primarily an upper crust source with a small amount of mantle materials. Compared to the Bangpu deposit, the ore metals derived from mantle are even greater in the Jiama and Qulong deposits, which leads to Cu being the dominant mineralization in the Jiama and Qulong deposit. [ABSTRACT FROM AUTHOR]

The Dabie orogen is among the most famous continent–continent collisional orogenic belts in the world, and is characterized by intensive post-collisional extension, magmatism and Mo mineralization. However, the genetic links between the mineralization and the geodynamic evolution of the orogen remain unresolved. In this paper, the Yaochong Mo deposit and its associated granitic stocks were investigated to elucidate this issue. Our new zircon U–Pb ages yielded an Early Cretaceous age (133.3 ± 1.3 Ma) for the Yaochong granite, and our molybdenite Re–Os dating gave a similar age (135 ± 1 Ma) for the Mo deposit. The Yaochong stock is characterized by high silica and alkali but low Mg, Fe and Ca. It is enriched in light rare earth elements (LREEs) and large ion lithophile elements (LILEs: Rb, K, Th and U), but strongly depleted in heavy REEs, and high field strength elements (HFSEs: Nb, Ta, Ti and Y). The Yaochong granite has initial 87 Sr/ 86 Sr ratios of 0.7087–0.7096, and Pb isotopic ratios of ( 206 Pb/ 204 Pb) i = 16.599–16.704, ( 207 Pb/ 204 Pb) i = 15.170–15.618 and ( 208 Pb/ 204 Pb) i = 36.376–38.248. The granite has ε Nd ( t ) of −18.0 to −16.3 and ε Hf ( t ) values of −26.5 to −20.0. All these data indicate that the Yaochong granite is a high-K calc-alkaline fractionated I-type granite, and may have originated from partial melting of the thickened Yangtze continental crust. The Mo ores also show low radiogenic Pb isotopes similar to the Yaochong stock. Medium Re content in molybdenite (21.8–74.8 ppm) also suggests that the ore-forming materials were derived from the thickened lower crust with possibly minor mixing with the mantle. Similar to the Eastern Dabie orogen, the thickened crust beneath the Western Dabie orogen may also have experienced tectonic collapse, which may have exerted fundamental geodynamic controls on the two-stage Mo mineralization in the region. [ABSTRACT FROM AUTHOR]

With the vigorously growing demand of the steel industry, oil and gas industry, corrosion resistance alloys, cast iron, and catalyst industries, high-grade molybdenum ores are being exhausted gradually in the world. Thus, much attention have been drawn to the recovery of molybdenum from low-grade molybdenum ores in recent years. With the increasingly stringent environmental requirements, the shortcomings due to SO2emission in the roasting process of traditional technology becomes obvious. This review outlines metallurgical processes for molybdenum production from various resources, particularly focusing on recent developments in direct hydrometallurgical and recovery processes to identify potential sources of molybdenum products and by-products such as uranium which can be economically produced. Several methods have been extensively reviewed for molybdenum separation and purification from solution which are potentially applicable to leach solutions of molybdenum ores and raw materials. The main methods include solvent extraction, ion exchange, membrane-based separation, and precipitation. Solvent extraction is highly selective for recovery of molybdenum and the most promising method recommended for future research and development. Membrane-based separation is the next preferred method for selective extraction of molybdenum, purification of molybdenum solutions, or co-recovery of other valuable metals. Ion exchange offers useful means for purification and/or co-recovery of other base metal impurities, although the scale of application of ion exchange in the industry is limited. [ABSTRACT FROM PUBLISHER]

Porphyry dikes and hydrothermal veins from the porphyry Cu-Mo deposit at Butte, Montana, contain multiple generations of quartz that are distinct in scanning electron microscope-cathodoluminescence (SEM-CL) images and in Ti concentrations. A comparison of microprobe trace element profiles and maps to SEM-CL images shows that the concentration of Ti in quartz correlates positively with CL brightness but Al, K, and Fe do not. After calibrating CL brightness in relation to Ti concentration, we use the brightness gradient between different quartz generations as a proxy for Ti gradients that we model to determine time scales of quartz formation and cooling. Model results indicate that time scales of porphyry magma residence are -1,000s of years and time scales from poqrhyry quartz phenocryst rim formation to porphyry dike injection and cooling are ~10s of years. Time scales for the formation and cooling of various generations of hydrothermal vein quartz range from 10s to 10,000s of years. These time scales are considerably shorter than the ~0.6 m.y. overall time frame for each porphyry-style mineralization pulse determined from isotopic studies at Butte, Montana. Simple heat conduction models provide a temporal reference point to compare chemical diffusion time scales, and we find that they support short dike and vein formation time scales. We interpret these relatively short time scales to indicate that the Butte porphyry deposit formed by short-lived episodes of hydrofracturing, dike injection, and vein formation, each with discrete thermal pulses, which repeated over the ~3 m.y. generation of the deposit. [ABSTRACT FROM AUTHOR]

The Gaogangshan Mo deposit, located in the northern part of the Lesser Xing'an Range (the eastern part of the Xing'an- Mongolia Orogenic Belt), is one of the newly discovered Mo deposits in northeast China. Ore bodies occur in the granite and are generally in vein and stockwork forms. Major metallic minerals in the ore include pyrite and molybdenite. The styles of mineralization are disseminated, veinlet-disseminated, and veinlet. The major types of wall-rock alteration are silicification-potassic alteration, phyllic alteration and propylitization. Fluid inclusion analyses indicate that the ore-forming fluid during the major mineralization stage is an H2O- NaCl- CO2 system, with wide homogenization temperature and salinity ranges. The abundant CO2-rich and coexisting halite-bearing fluid inclusion assemblages in the main stage of mineralization highlight the significance of intensive fluid boiling for porphyry Mo mineralization. Comprehensive study of the ore-forming conditions, geological features of the deposit, micro-thermometric analysis of fluid inclusions and comparison of the Gaogangshan deposit with other typical porphyry deposits leads to the conclusion that the deposit is a porphyry type. We obtained a weighted mean age of the molybdenite deposit at Gaogangshan of 250.7 ± 1.8 Ma. The isotopic dating results indicate that the Gaogangshan deposit was formed in the Permo-Triassic, which is the earliest Mo-only deposit in northeast China. The formation of the Gaogangshan Mo deposit may be related to the extension and break-up of the Songnen Block and Jiamusi Block in the Permo- Triassic. [ABSTRACT FROM AUTHOR]

The Baiyanghe Be–U–Mo deposit is located in the Late Paleozoic Xuemisitan–Kulankazi island arc of the northwestern margin of the Junggar plate, Northwest China. It is the largest Be deposit (2.2 M tons of ore with grades ranging from 0.2% to 1.4%) in Asia. Orebodies in the deposit occur as fractures along contact zones between the Yangzhuang granite porphyry intrusion and Devonian pyroclastic country rocks and within the porphyry itself. Muscovite–fluorite veins are closely associated with the Be–U–Mo mineralization. A new Ar–Ar dating of the muscovite in this study yields a plateau age of 303.0 ± 1.6 Ma, which constrains the timing of the Be–U–Mo mineralization of the deposit. Three stages of fluorite of different colors have been identified at the deposit, with the earliest dark-purple fluorite more closely associated with the mineralization. Microthermometry of fluid inclusions obtained from the three stages of fluorite suggests that the fluorites were precipitated as veins from low temperature (120–150 °C) hydrothermal fluids with salinity ranging from 4.7 to 19.7 wt.% NaCl eqv. Based on the trace elemental concentrations and REE patterns of the fluorite, the style of veining, and the low salinity and low temperature characters of the fluid inclusions, it is suggested that Be and U were most likely transported as fluoride complexes and Mo as hydroxyl complexes. Pb isotopic compositions of the ores and country rocks, as well as O and H isotopic characters of the ore-related muscovite, indicate mixing between magmatic and meteoric waters; both contributed to formation of the ore-forming fluids. Metallic Be, U, and Mo were most likely leached out from the granite porphyry by the fluids. The fluid mixing led to the reduction of U, Mo, and Be and their precipitation at the deposit. [ABSTRACT FROM AUTHOR]

The Huanglongpu carbonatite-related Mo ore field is located in the Lesser Qinling Orogenic belt in the southern margin of the North China block. The ore field is composed of six deposits, Yuantou, Wengongling, Dashigou, Shijiawan, Taoyuan and Erdaohe, all of which are genetically related to carbonatite dykes except for the Shijiawan deposit which is associated with a granitic porphyry. The Yuantou carbonatite dykes intruded into Archean gneiss and other carbonatites emplaced into Mesoproterozoic volcanic and sediment rocks. The carbonatites are mainly composed of calcite and variable amounts of quartz and K-feldspar and minor molybdenite. Re–Os dating of molybdenite from the Yuantou carbonatite yields a weighted average age of 225.0 ± 7.6 Ma, consistent with the molybdenite age (221 Ma) from the Dashigou deposit. The rocks are characterized by high heavy REE (HREE) contents and consistent flat REE distribution patterns with La/Yb cn ~ 1. Quartz in the carbonatites from Yuantou and Dashigou deposits shows consistent O isotopes (8.1–10.2‰) similar to the associated calcite (7.2–9.5‰). The quartz and associated K-feldspar contain lower Zr, Hf and higher HREE abundances and negligible Eu anomaly relative to those from the granite porphyry in Shijiawan. Both minerals are primary products in the carbonatitic liquid, and not captured from the wall-rocks or crustal-derived silicate magmas, or a hydrothermal origin. Thus, the Huanglongpu carbonatitic liquids were enriched in Si and Mo, which may be produced by intensely fractional crystallization of non-silicate minerals. [ABSTRACT FROM AUTHOR]

The Daheishan giant porphyry Mo deposit is located at the eastern segment of the CAOB, NE China. The ore-bearing intrusion of Daheishan deposit is a Jurassic granitic complex that includes Changgangling biotite granodiorite, Qiancuoluo seriate granodiorite, and Qiancuoluo granodioritic porphyry. Mineralization consists of disseminated, breccia and veined types. The hydrothermal fluids show significant magmatic signatures, as evidenced by the hydrogen and oxygen isotopic compositions of quartz and sulfur isotopic characteristics of ores. Consistence of lead isotopic compositions of the sulfides and the Daheishan intrusive complex further indicate a close relationship between the mineralization and magma. The fluid inclusions in quartz comprise of predominant aqueous two-phase as well as gas-rich fluid inclusions and a small number of daughter mineral-bearing inclusions. The gas species in the fluid inclusions are H 2 O, CO 2 , N 2 , CH 4 , C 2 H 6 , Ar ∗ and minor H 2 S; the liquid compositions are SO 4 2 − , Cl − , Na + , K + , Ca 2+ and Mg 2+ . Raman spectroscopy on individual fluid inclusions reveals a main gaseous composition of H 2 O, minor H 2 S and CO 2 . The fluid system in Daheishan Mo deposit can be described as NaCl–KCl–H 2 O type. Fluid inclusion microthermometry reveals subsolidus homogenization temperatures for fluid inclusions in the magmatic quartz phenocrysts ( T h = 400–450 °C, salinities = ∼21 eq. wt.%), suggesting an obliteration of higher temperature history of the porphyry system by the superimposed processes. Most of the mineralization occurred at temperature range of 220–360 °C, or higher. The temperature and salinity decreased to 100–170 °C and 0–15 eq. wt.%, respectively, when the hydrothermal fluid activities were gradually ending. No distinct evolution pattern based on the homogenization temperature or stable isotopic analyses is observed among the different mineralization stages. Mineralization was supposed to be related to the multi-phased boiling of fluids, instead of the gradual cooling of fluids. Pressure may be more critical than temperature in controlling the precipitation of molybdenite. [ABSTRACT FROM AUTHOR]