Zn Ag Research Articles

Ore-formation mechanism of the Weilasituo tin–polymetallic deposit, NE China: Constraints from bulk-rock and mica chemistry, He–Ar isotopes, and Re–Os dating

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

Experimental evidence of the Mg7(Zn, Ag)3 continuous solid solution in Mg-rich corner of Mg–Zn–Ag ternary system at 335 °C

The phase constituents and compositions of a series of Mg–Zn–Ag ternary alloys held at 335 °C have been determined using X-ray diffraction and scanning electron microscopy assisted X-ray energy dispersive spectroscopy. The results indicate that a continuous solid solution, i.e., Mg7(Zn, Ag)3 phase exists stably in the Mg-rich corner at 335 °C, whose composition range is 65.1–76.9% Mg, 2.3–24.3% Zn, and 2.3–24.6% Ag (mole fraction), instead of the Mg3Ag phase reported in earlier studies. Moreover, the Mg7(Zn, Ag)3 phase is in equilibrium with the α-Mg solid solution in the Mg-rich corner, which is completely different with the presently accepted phase equilibria in the Mg–Zn–Ag ternary system. Additionally, Ag and Zn are simultaneously soluble in the α-Mg solid solution, and the maximum total solubility reaches approximately 3 at.%. Simultaneously, the c/a ratio of α-Mg decreases owing to the common solution of Ag and Zn.

Scaling Printable Zn–Ag2O Batteries for Integrated Electronics

AbstractPrinted batteries are an emerging solution for integrated energy storage using low‐cost, high accuracy fabrication techniques. While several printed batteries have been previously shown, few have designed a battery that can be incorporated into an integrated device. Specifically, a fully printed battery with a small active electrode area (<1 cm2) achieving high areal capacities (>10 mAh cm−2) at high current densities (1–10 mA cm−2) has not been demonstrated, which represents the minimum form‐factor and performance requirements for many low‐power device applications. This work addresses these challenges by investigating the scaling limits of a fully printed Zn–Ag2O battery and determining the electrochemical limitations for a mm2‐scale battery. Processed entirely in air, Zn–Ag2O batteries are well suited for integration in typical semiconductor packaging flows compared to lithium‐based chemistries. Printed cells with electrodes as small as 1 mm2 maintain steady operating voltages above (>1.4 V) at high current densities (1–12 mA cm−2) and achieve the highest reported areal capacity for a fully printed battery at 11 mAh cm−2. The findings represent the first demonstration of a small, packaged, fully printed Zn–Ag2O battery with high areal capacities at high current densities, a crucial step toward realizing chip‐scale energy storage for integrated electronic systems.

Ultrasensitive Electrochemiluminescent Sensor for MicroRNA with Multinary Zn-Ag-In-S/ZnS Nanocrystals as Tags.

For the screening of novel toxic-element-free and biocompatible electrochemiluminophores, electrochemiluminescence (ECL) of multinary nanocrystals (NCs) was investigated for the first time with Zn-Ag-In-S (ZAIS) NCs as model. Aqueous soluble ZAIS NCs could bring out efficient reductive-oxidation ECL with tri- n-propylamine as coreactant, while coating the ZAIS NCs with a ZnS shell could reduce the surface defects of ZAIS NCs, and enable 6.7-fold enhanced ECL of ZAIS/ZnS NCs as compared to ZAIS NCs. ECL of ZAIS/ZnS NCs was about 4.2-fold that of ternary CuInS2/ZnS NCs, spectrally similar to that of Ru(bpy)32+ with maximum emission around 605 nm, and favorable for less electrochemical interference with a lowered triggering potential (∼0.95 V) than that of Ru(bpy)32+. An ultrasensitive ECL microRNA sensor was fabricated with ZAIS/ZnS NCs as tags, which could sensitively and selectively determine microRNA-141 with a wide linearity range from 0.1 fmol/L to 20 pmol/L and a low limit of detection at 50 amol/L ( S/ N = 3). Multinary NCs might provide a promising alternative to the traditional binary NCs for both electrochemiluminophore screening and NC ECL modulating.

The polymetallic magmatic-hydrothermal Xiangdong and Dalong systems in the W–Sn–Cu–Pb–Zn–Ag Dengfuxian orefield, SE China: constraints from geology, fluid inclusions, H–O–S–Pb isotopes, and sphalerite Rb–Sr geochronology

Vein-type deposits, including the Xiangdong W–Sn and Dalong Pb–Zn deposits, occur in or near the Dengfuxian composite granite pluton, comprising predominantly Triassic and minor Jurassic intrusions. Liquid-rich NaCl-aqueous inclusions, vapor-rich NaCl-aqueous inclusions, liquid-rich CaCl2-NaCl-aqueous inclusions, two-phase CH4-rich inclusions, three-phase CO2-H2O inclusions, and three-phase calcite-bearing inclusions occur in the quartz veins at Xiangdong, whereas only liquid-rich NaCl-aqueous inclusions occur at Dalong. The Xiangdong veins formed at temperatures near 241 °C, from NaCl-CaCl2-H2O-CH4-CO2 fluids averaging 11.4 wt% NaCl eq. The Dalong deposit formed at temperatures near 186 °C from NaCl-H2O(-CH4) fluids averaging 6.2 wt% NaCl eq. The ore-forming mechanisms at Xiangdong include fluid immiscibility during stage I, fluid mixing during stage II, and mixing with meteoric water accompanied by cooling during stage III. The ore-forming mechanisms at Dalong include cooling and mixing with meteoric water. Oxygen and hydrogen isotopes suggest that the ore-forming fluids from both deposits originated as mixtures of magmatic water with various amounts of meteoric water. Sulfur and strontium isotopes suggest an igneous origin for both deposits and possibly mixing with S and Sr from sedimentary rock for Dalong. Lead isotopes indicate that ore metals originated mainly from the upper crust with minor mantle contributions. Sphalerite from Dalong gives a Rb-Sr isochron age of 151.6 ± 7.1 Ma, consistent with the mineralization age of Xiangdong. Both the W–Sn and Pb–Zn ore-forming events are closely related to Late Jurassic magmatism, which occurred in an environment of lithospheric extension and thinning.

(Keynote) Architectural Re-Design of Zinc Anodes Physically Thwarts Dendrite Formation—with Zinc Batteries Now Rechargeable, What’s Next?

We recently demonstrated that redesigning dendrite-prone zinc anodes as 3D monolithic Zn architectures solves the limited rechargeability of alkaline batteries. Three structural features of these emulsion–derived “sponges” physically ensure dendrite suppression: (i) long-range electronic conductivity within the electrode volume throughout charge–discharge; (ii) more uniform current distribution; and (iii) confined internal void volume that controls Zn/Zn2+ precipitation/dissolution dynamics and product redistribution. With Li-ion competitive cyclability to deep depths-of-discharge (theoretical DODZn), primary utilization to >90% DODZn (with >90% recovery), and tens of thousands of cycles at low-DODZn creates new performance curves for the entire family of alkaline Zn batteries (Ni–Zn, Ag–Zn, MnO₂–Zn, Zn–air) plus neutral pH zinc-ion batteries. Our second-generation emulsion protocol increases volumetric density of the sponge, which improves the energy density of the cell, and adds mechanical ruggedness to the anode. Development paths for this safer energy-storage breakthrough will be discussed.

Effect of parameter setting and spectral normalization approach on study of matrix effect by laser induced breakdown spectroscopy of Ag–Zn binary composites

The complex nature of laser-material interaction causes non-stoichiometric ablation of alloy samples. This is attributed to matrix effect, which reduces analyzing capability. To address this issue, the analytical performance of three different normalization methods, namely normalization with background, internal normalization and three point smoothing techniques at different parameter settings is studied for quantification of Ag and Zn by Laser induced breakdown spectroscopy (LIBS). The LIBS spectra of five known concentration of silver zinc binary composites have been investigated at various laser irradiances (LIs). Calibration curves for both Ag(I) line (4d105s2S1/2 → 4d105p2P1/2 at 338.28 nm) and Zn(I) line (4s5s3S1 → 4s4p3P2 at 481.053 nm) have been determined at LI of 5.86 × 1010 W cm−2. Slopes of these calibration curves provide the valuation of matrix effect in the Ag–Zn composites. With careful sample preparation and normalization after smoothing at optimum parameter setting (OPS), the minimization of sample matrix effect has been successfully achieved. A good linearity has been obtained in Ag and Zn calibration curve at OPS when normalized the whole area of spectrum after smoothing and the obtained coefficients of determination values were R2 = 0.995 and 0.998 closer to 1. The results of matrix effect have been further verified by analysis of plasma parameters. Both plasma parameters showed no change with varying concentration at OPS. However, at high concentration of Ag, the observed significant changes in both plasma parameters at common parameter setting PS-1 and PS-2 were the gesture of matrix effect. In our case, the better analytical results were obtained at smoothing function with optimized parameter setting that indicates it is more efficient than normalization with background and internal normalization method.

A fluorescent probe for Cd2+ detection based on the aggregation-induced emission enhancement of aqueous Zn–Ag–In–S quantum dots

A sensitive and selective fluorescent probe for the cadmium ion (Cd2+) was developed based on the aggregation-induced emission enhancement (AIEE) of Zn–Ag–In–S quantum dots (ZAIS QDs).

An ultra-high endurance and high-performance quasi-solid-state fiber-shaped Zn–Ag2O battery to harvest wind energy

The synergistic effect of a 3D conductive skeleton and protective layer endows an admirable electrochemical durability to fiber-shaped quasi-solid-state Zn–Ag2O batteries.

Multiple mineralization events in the Zhaxikang Sb–Pb–Zn–Ag deposit and their relationship with the geodynamic evolution in the North Himalayan Metallogenic Belt, South Tibet

The Zhaxikang Sb–Pb–Zn–Ag deposit, the only super-large deposit identified within the North Himalayan Metallogenic Belt (NHMB), is still debated to date with perspectives of mineralization age and genesis. The previous genetic models mainly include hot-spring, magmatic hydrothermal fluid, coarse-grained hydrothermal Pb–Zn vein overprinted by Sb-rich magmatic hydrothermal fluid, and SEDEX overprinted by hydrothermal fluid. Here, we present new and credible isotope geochronological evidence to discuss the genesis and mineralization age of Zhaxikang deposit. The isotopic ages of minerals from different mineralization stages in Zhaxikang deposit coincide with the mineralization ages of three main regional mineralization events. In detail, the older 206Pb/238U (218 ± 10 Ma), Sm–Nd (173.7 ± 7.4 Ma) and Rb–Sr (147 ± 3.2 Ma) isochron ages match three regional extensive seafloor volcanic events during synsedimentary period (220–130 Ma); the younger 206Pb/238U (62 ± 8.2 Ma) and older Re–Os (47.7 ± 7.9 Ma; 43.1 ± 2.5 Ma) ages are in accord with the formation age of regional orogenic Au–Sb deposits associated with metamorphic fluid system during syn-collision period (60–42 Ma); and the Ar–Ar (19.3 ± 1.1 Ma) and younger Re–Os (9.0 ± 1.9 Ma) isochron ages are consistent with the regional magmatic-hydrothermal mineralization event during post-collision period (25 Ma to now). We thus proposed that Zhaxikang deposit is a superimposed deposit that experienced three pulses of mineralization corresponding to three regional mineralization events: the first pulse of mineralization (stages 1 and 2) is related to multiple seafloor volcanic events during synsedimentary period with submarine hydrothermal sedimentation (metasomatism) genesis; the second pulse of mineralization (stages 3 and 4) is associated with metamorphic fluid system during syn-collision period that overprint the Pb–Zn mineralization; and the third pulse of mineralization (stages 5 and 6) relates to magmatic-hydrothermal activity during post-collision period and also overprints early mineralization. Furthermore, the complicated superimposed mineralization results in the discordance of different geochronological methods.

Cation Exchange in Zn–Ag–In–Se Core/Alloyed Shell Quantum Dots and Their Applications in Photovoltaics and Water Photolysis

Quantum dot-sensitized solar cells (QDSSCs), especially those based on ternary AgInX2 (X = S, Se) QDs, suffer from very low power conversion efficiencies (PCEs) owing to presence of high density of trap states and imperfect surface coverage by surfactants. This has a similar adverse effect on water photolysis when the solar cells are integrated with the electrolyzer. Passivation of the QD surface with an inorganic shell is vital and temporally regulated cation exchange can come to the rescue, whereby an alloyed shell can minimize the interfacial trap states which are mostly abundant in core/shell QDs with sharp interfaces. Herein, Zn–Ag–In–Se (ZAISE) core QDs were cation-exchanged with Cd2+ ions to create an alloyed shell of Ag–In–Zn–Cd–Se. When the QDs were used as absorbers, the PCE was enhanced from 3.01% for core ZAISE QDs to 4.71% for core/alloyed shell QDs by optimizing the shell thickness; 4.71% is also one of the superior PCEs in AgIn(S/Se)2-based photovoltaic systems. The density of states invest...

Effects of Ag Doping and Point Defect on the Magnetism of ZnO

The magnetism sources and magnetic mechanism of Ag doping and point defect, which coexist in the presence of ZnO, are frequently controversial. To solve these problems, the effects of Ag doping and Zn or O vacancy on the magnetism of ZnO were investigated using geometry optimization and energy calculation according to the first-principles generalized gradient approximation + U (GGA+U) method of density functional theory. Results revealed that the system which Ag doping and Zn vacancy coexists in ZnO could achieve room-temperature ferromagnetism. This system had an extremely high spin polarization, which was advantageous for the spin electron injection sources applied in dilute magnetic semiconductors. Result also revealed that the magnetism of Zn14AgO16 was caused by the electron hybrid coupling effects among the O-2p, Ag-4d, Ag-5s, and Zn-4s orbits. And these effects were produced by the hole carriers after complexes were formed by the Ag doping and Zn vacancy. With regard to the most stable structure of the ground state, all doping systems which Ag replacing Zn and O vacancy coexisted in ZnO and those which Ag replacing Zn, interstitial Ag, and O vacancy coexisted in ZnO were all non-magnetic. Thus, these doping systems were unsuitable for dilute magnetic semiconductors. By contrast, the doping systems of interstitial Ag and Zn vacancy were magnetic, although the magnetism was relatively weak, thus rendering such systems inapplicable as well.

High-Performance Quasi-Solid-State Flexible Aqueous Rechargeable Ag–Zn Battery Based on Metal–Organic Framework-Derived Ag Nanowires

Silver–zinc (Ag–Zn) batteries are one of the promising aqueous batteries to collect and store solar energy with high energy density, a stable output voltage, and being environmentally benign, but most Ag–Zn batteries have large contact resistance caused by polymer binders and conductive additives, thus leading to their low specific capacity and rate performance. As a proof-of-concept demonstration, we constructed a solar charged planar flexible quasi-solid-state aqueous rechargeable Ag–Zn battery using metal–organic framework (MOF)-derived Ag nanowires on carbon cloth as a binder-free cathode. Our electrochemical results show that the as-fabricated Ag–Zn battery has a remarkable energy density of 1.87 mWh/cm2 because MOF-derived Ag nanowires can provide abundant reaction sites and short electron and ion diffusion paths. Moreover, the as-fabricated Ag–Zn battery integrated with a solar cell can be charged by sunlight. Thus, our findings pave an avenue to develop solar energy-powered portable and wearable e...

Geology, Mineralogy, Fluid Inclusion, and H–O–S–Pb Isotope Constraints on Ore Genesis of the Keyue Sb–Pb–Zn–Ag Deposit in Southern Tibet

The Keyue deposit is a medium-sized deposit similar to the Zhaxikang deposit within the North Himalayan Metallogenic Belt (NHMB). The ore formation can be divided into Pb–Zn mineralization (stages 1 and 2), Sb–Ag mineralization (stages 3 and 4), and Sb–Hg mineralization (stages 5 and 6). The fluid inclusion data show that the first two pulses of mineralization have different characteristics, but both belong to the epithermal category (stage 2: 172.9~277.2°C, 7.4~17.0 wt% NaCl eq.; stages 3 and 4: 142.1~321.0°C, 2.7~17.96 wt% NaCl eq.). The H–O isotopic compositions of stages 3 and 4 quartz (δDV-SMOW: –174‰~−120‰, δ18OH2O: 1.59‰~11.34‰) are similar to those of stages 3 and 4 minerals (δDV-SMOW: –165‰~−150‰, δ18OH2O: 6.14‰~13.03‰), whereas they are different from stage 1 and 2 (δDV-SMOW: –108.3‰~−103.6‰, δ18OH2O: 1.92‰~3.82‰) and stage 5 and 6 (δDV-SMOW: –165‰~−138‰, δ18OH2O: −12.91‰~0.82‰) minerals from the Zhaxikang deposit. Additionally, stage 2 sulfides have δ34S values of 5.4‰~11.2‰ that are similar to stage 2 sulfides in the Zhaxikang deposit (7.8‰~12.2‰), and these δ34S values overlap those of many SEDEX-type deposits. The δ34S values also show a decreasing trend from stage 2 through stages 3 and 4 to stage 5 in Keyue and Zhaxikang deposits, which may relate to the overprint by later mineralization events. The Pb isotopic data (206Pb/204Pb: 18.530~19.780, 207Pb/204Pb: 15.674~15.939, and 208Pb/204Pb: 38.618~40.559) show a significant crustal contribution. However, the minerals from different pulses of mineralization also exhibit slightly different Pb isotopic characteristics. These inferences from fluid inclusions and isotope are also demonstrated by geological and mineralogical evidence. Overall, the Keyue deposit is an epithermal deposit and has mainly experienced three pulses of mineralization.

Integration of Zn-Ag and Zn-Air Batteries: A Hybrid Battery with the Advantages of Both.

We report a hybrid battery that integrates a Zn-Ag battery and a Zn-air battery to utilize the unique advantages of both battery systems. In the positive electrode, Ag nanoparticles couple the discharge behaviors through the two distinct electrochemical systems by working as the active reactant and the effective catalyst in the Zn-Ag and Zn-air reactions, respectively. In the negative electrode, in situ grown Zn particles provide large surface areas and suppress the dendrite, enabling the long-term operating safety. The battery first exhibits two-step voltage plateaus of 1.85 and 1.53 V in the Zn-Ag reaction, after which a voltage plateau of 1.25 V is delivered in the Zn-air reaction, and the specific capacity reaches 800 mAh gZn-1. In addition, excellent reversibility and stability with maintaining high energy efficiency of 68% and a capacity retention of nearly 100% at 10 mA cm-2 are demonstrated through 100 cycles, outperforming both conventional Zn-air and Zn-Ag batteries. This work brings forth a conceptually novel high-performance battery, and more generally opens up new vistas for developing hybrid electrochemical systems by integrating the advantages from two distinct ones.

Interfacial reactions of Sn–Zn–Ag–Cu alloy on soldered Al/Cu and Al/Al joints

ABSTRACTThis work shows the effect on the soldering process of the addition of Ag and Cu to Sn–Zn alloys. Soldering of Al/Cu and Al/Al joints was performed for a time of 3 min, at a temperature of 250°C, with the use of flux. Aging was carried out at 170°C for Al/Cu and Al/Al joints for 1 and 10 days. During the aging process, intermetallic layers grew at the interface of the Al/Cu joint at the Cu substrate. Intermetallic layers were not observed during wetting of Al/Al joints. On the contrary, dissolution of the Al substrate and migration of Al-rich particles into the bulk of the solder were observed. The experiment was designed to demonstrate the effect of Ag and Cu addition on the dissolution of Al substrate during the soldering and aging processes. In the solder alloys, small precipitates of AgZn3 and Cu5Zn8 were observed.

Clausthalite (PbSe) and tiemannite (HgSe) from the type locality: New observations and implications for metallogenesis in the Harz Mountains, Germany

Clausthalite and tiemannite from the type locality, Clausthal, in the Harz Mountains, Germany, have virtually gone undocumented since their discovery in the nineteenth century. The minerals and their selenide assemblages are here documented in historical samples from the Königin Charlotte mine in the former Clausthal Pb–Zn–Ag mining district. Clausthalite and tiemannite are the main selenide components; naumannite is generally subordinate, whereas klockmannite and eskebornite are accessory minerals. The absence of inversion lamellae in naumannite constrains the formation temperature to <130 °C, a temperature that is compatible with salbands of tiemannite and clausthalite that occur in the wall rock of bleached and reddened greywacke along a calcite–quartz veinlet. The veinlet calcite and quartz trapped highly saline, Ca-rich brines (26–33 wt% NaCl equivalent), at temperatures between 96 and 212 °C. Tiemannite and clausthalite also form massive to semi-massive pockets. Tiemannite hosts inclusions of celestine, anhydrite and carrollite. This inclusion assemblage indicates that tiemannite precipitated from sulfate-bearing brines that likely originated from the overlying Zechstein evaporitic sediments. Such an origin is reflected in the less radiogenic 87Sr/86Sr values of 0.70914 and 0.71133 for two samples of tiemannite aggregates containing celestine–anhydrite inclusions. The Clausthal selenide assemblages postdated the main sulfide-bearing, polymetallic vein-style mineralisation of the Harz Mountains.

Genesis of the Jianzhupo Sb–Pb–Zn–Ag deposit and formation of an ore shoot in the Wuxu ore field, Guangxi, South China

The Jianzhupo Sb–Pb–Zn–Ag deposit in the southeastern Dachang Sn–polymetallic ore belt, Guangxi region, South China is the largest deposit in the Wuxu district and is hosted by Devonian limestone and mudstone. The deposit mainly comprises a stage I jamesonite–sphalerite ore shoot and stage II jamesonite–sphalerite–calcite–quartz (JSCQ) veins. We use homogenization temperatures, salinities, and the H–O isotopic compositions of fluid inclusions from the Jianzhupo deposit to constrain the genesis of the deposit and determine factors that controlled the formation of the ore shoot. Fluid inclusions from both stages of mineralization contain large volumes of CO2 and minor bitumen, C6H6, and CH4. Fluid inclusions from the ore shoot yield homogenization temperatures of 120 °C–290 °C (mainly 250 °C–270 °C) and salinities of 3.4–13.6 wt% NaCl equiv. Fluid inclusions from the stage II mineralization yield homogenization temperatures of 150 °C–350 °C (mainly 240 °C–310 °C) and salinities of 1.4–12.0 wt% NaCl equiv. Ore-forming fluids of the Jianzhupo deposit yield δ18OH2O and δDV-SMOW values of 4.9‰–9.9‰ and −78‰ to −111‰, respectively, and plot close to the composition of magmatic water on the δDV-SMOW vs. δ18OH2O diagram. CO2 in the ore-forming fluids was likely generated through deep skarnization beneath the Wuxu ore field rather than from metamorphism, thermal degradation, or the oxidization of organic matter. H–O isotopic compositions of ore-forming fluids that contain large volumes of CO2 (with minor bitumen and C6H6) indicate that they were derived from magmatic water that was mixed with basin brines. Ore-forming fluids of the stage I ore shoot yield lower δ18OH2O values (4.9‰–6.7‰) than those associated with the stage II mineralization (7.5‰–9.9‰). Moreover, ore-forming fluids of the ore shoot and the JSCQ veins yield strongly and weakly positive correlations between homogenization temperature and salinity, respectively. This difference suggests that rapid and large-scale mixing between magmatic water and basin brines was the key factor that controlled the formation of the ore shoot.

Synthesis, structure, photoluminescence and electrochemical properties of mononuclear Ag(I) and polymeric Zn(II) complexes of potassium 4-methyl piperazine-1-carbodithioate

New heteroleptic mononuclear complex [Ag(mpdtc)(PPh3)2] (1) and homoleptic polymeric complex [Zn(mpdtc)2]n (2) have been synthesized from potassium 4-methyl piperazine-1-carbodithioate [K(mpdtc)]. The complexes have been characterized by elemental analyses, IR, NMR, UV–vis, thermal, cyclic voltammetry, and X-ray diffraction technique. Complexes 1 and 2 are fluorescent materials and exhibit emission maxima at around 32000 cm−1 upon excitation at 39000 cm−1. Thermogravimetric analysis of complexes as investigated by TG-DTA, suggests the formation of their respective metal sulfides as final thermally stable chemical entities. Electrochemical studies of silver(I) complex reveals the formation of silver nanoparticle which catalyses the oxidation of the ligand. The Ag(I) ion adopts a distorted tetrahedral geometry in complex 1 and the geometry around Zn(II) ion in complex 2 is in halfway between square planar and trigonal bipyramidal. The crystal structures of complexes are stabilized by intermolecular C-H…S interactions.

The relationship between stratabound Pb–Zn–Ag and porphyry–skarn Mo mineralization in the Laochang deposit, southwestern China: Constraints from pyrite Re-Os isotope, sulfur isotope, and trace element data

The Laochang polymetallic deposit is located in the Sanjiang Tethyan metallogenic province of southwestern China. This deposit contains stratabound (and locally vein-type) Pb–Zn–Ag mineralization and underlying porphyry–skarn Mo mineralization. The stratabound Pb–Zn–Ag mineralization is characterized by massive sulfide ores composed mainly of pyrite, sphalerite, galena, and minor chalcopyrite, whereas the underlying porphyry–skarn Mo mineralization is characterized by quartz–sulfide veins comprising mainly pyrite, chalcopyrite, molybdenite, and minor sphalerite and galena. The age and origin of the stratabound Pb–Zn–Ag mineralization has long been debated, and its relationship to the porphyry–skarn Mo mineralization remains unknown. Integrated pyrite Re-Os isotope, sulfur isotope, and in situ trace element data are used here to constrain the age and origin of both types of mineralization and their genetic relationships.Pyrite related to porphyry–skarn Mo mineralization yields a Re-Os isochron age of 47.3 ± 4.8 Ma, which is consistent with a previous molybdenite Re-Os age of the quartz–sulfide ores and zircon U-Pb ages of the granite porphyry (~44–50 Ma). Pyrite from the stratabound Pb–Zn–Ag mineralization failed to yield a geologically meaningful age, but associated sphalerite and galena have a Re-Os isochron age of 308 ± 25 Ma (Liu et al., 2015), which is consistent with the Carboniferous age of the host basalts. Pyrite, sphalerite, galena, and chalcopyrite from the stratabound Pb–Zn–Ag mineralization have δ34S values (−2.1 to 0.5‰; average 0.48‰) indistinguishable from those of sulfides from the porphyry–skarn Mo mineralization (−4 to 1.9‰; average 0.52‰). Initial Os isotope ratios indicate a mainly crustal origin for both types of mineralization. The calculated (Se/S)fluid and Co/Ni values of pyrite from the stratabound Pb–Zn–Ag mineralization indicate a mixed sedimentary and hydrothermal origin, with a significant magmatic contribution. The identification of a magmatic component, Eocene sulfide mineralization, and phyllic and propylitization alteration in stratabound Pb–Zn–Ag ores indicates that the magmatic–hydrothermal component reflects the overprinting of Carboniferous volcanogenic massive sulfide mineralization by magmatic–hydrothermal fluids derived from an Eocene granite porphyry.