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[Display omitted] • Cu after magnetization roasting tends to be enriched in iron concentrate. • Magnetization roasting can reduce the environmental risk of Cu in tailings. • Temperature and overreduction can regulate the allocation of Cu. • Primary copper sulfide → secondary copper sulfide → free copper oxide → CuFe 2 O 4. Magnetic iron concentrate (MIC) and nonmagnetic tailings (NT) are obtained from magnetization roasting of iron tailings (IT). MIC containing Pb adversely affects blast furnace ironmaking, while Cu in NT poses leaching risks. This study utilizes fast pyrolysis-suspension magnetization roasting to recover iron from IT. The enrichment of Pb, Cu, and the phase transformation mechanism of Cu in the process of suspension magnetization roasting and magnetic separation were clarified. Results show 96.13 % of Cu in IT is in limonite and 47.23 % of Pb is associated with iron. At 750 °C, with 10 % dosage of biomass pyrolysis and 10 min roasting, Pb, Cu and Fe contents in MIC are 0.96, 2.14 and 3.17 times that of NT. Increasing roasting temperature enhances Cu associated with iron enrichment into the MIC, while oxidation of free copper oxide associated with iron forms magnetic copper ferrite. Increased pyrolyzed biomass leads to over-reduction of magnetite associated with Cu to FeO associated with Cu, promoting magnetic copper ferrite decomposition into FeO and free copper oxide. This research holds significant importance in controlling the quality of MIC and the storage risk of IT, and provides theoretical guidance for the regulation and recovery of valuable metals in subsequent processes. [ABSTRACT FROM AUTHOR]

Copper radioisotopes are gaining increasing significance for medical use in recent years for both diagnostic and therapeutic applications. To answer the growing clinical demand, fast, reliable and efficient purification methods to isolate copper isotopes from the irradiated target materials used for their production were developed. Chromatographic techniques have been extensively studied and used to isolate copper isotopes from other metals such as nickel, zinc, or cobalt. This review comprehensively surveys the ion exchange and extraction chromatographic methods developed for copper radioisotope purification to produce radiopharmaceuticals for medical use. Key factors such as target material, isotopic enrichment, number of steps and clinical application are discussed. It concludes with thoughts on automated purification and its importance in the future of the field. [ABSTRACT FROM AUTHOR]

The elemental analysis of ancient gold items in the context of provenance studies in archaeology and history may characterize metallic stocks and highlight metal circulation in a given space and time; however, they cannot point to a specific geological province and/or ore. In contrast, isotope analysis may offer valuable insight into provenance studies. For instance, lead isotopes may provide relations with the geodynamic provinces of the host mineralizations and some insight into their timing. Iron and copper isotopes may give information on the ore type, i.e., supergene versus hydrothermal or igneous. We thus adapted a single column separative chemistry, initially intended for silicate rocks, for ancient gold matrices to recover purified fractions of Pb, Fe and Cu based on anionic exchange chromatography. Isotopic measurements of these elements on new home-made gold standards, as well as on ancient gold test coins, were carried out using Multi-Collector – Inductively Coupled Plasma – Mass Spectrometry (MC-ICP-MS). Our results show that it is possible to obtain precise and accurate measurements of Pb, Cu and Fe isotope compositions in gold matrices reflecting various elemental compositions. We characterized our gold test coins with the following uncertainties: ±0.036 on 208Pb/204Pb, ±0.016 on 207Pb/204Pb, ±0.019 on 206Pb/204Pb, ±0.00041 on 208Pb/206Pb and ±0.00006 on 207Pb/206Pb (2SD; n = 14); ±0.047‰ for δ57FeIRMM14 (2SE; n = 15) and ±0.043‰ for δ65CuSRM976 (2SE; n = 12). These uncertainties are in good agreement with the long-term (>1.5 years) reproducibilities (2SD) estimated in the course of this study on the basis of repeated measurement of in-house standards. The potential of these new tracers in addressing archaeological and historical questions, such as the provenance of ancient gold coins, is then emphasized. The combination of Pb, Fe and Cu isotopes with gold chemistry appears particularly promising. [ABSTRACT FROM AUTHOR]

Unlike their eruptive counterparts, plutonic rocks often experience post-cumulus evolution prior to their final solidification. These processes have the potential to exert significant control on the distributions of elements and their isotopic compositions of plutonic rocks. However, our understanding in these effects remains limited, particularly for metal stable isotopes. Here, we carried out high-precision δ65Cu measurements for a suite of primitive to evolved cumulates from the Kane area, 23oN of Mid-Atlantic Ridge. Most mid-ocean ridge basalts (MORBs) exhibit uniformly bulk silicate Earth (BSE)-like δ65Cu of + 0.09 ± 0.08 ‰, indicating limited Cu isotopic fractionation in crustal magma reservoirs prior to melt extraction. However, our new Cu isotopic data on these cumulates show that large Cu isotopic variations (δ65Cu = -0.6 ‰ to + 0.9 ‰) occur in variably evolved cumulates (MgO/total FeO < 3.0), while the most primitive cumulates (MgO/total FeO > 3.0) exhibit BSE-like δ65Cu (+0.06 ± 0.06 ‰). Petrological and geochemical observations indicate limited hydrothermal effects on Kane cumulate Cu isotopes. Modeling results indicate that the variable δ65Cu in Kane cumulates are unlikely to result from magmatic processes during the cumulus stage. Instead, the large Cu isotopic variation in Kane cumulates requires post-cumulus melt evolution involving fractionation between sulfide and intercumulus melts at relatively low temperatures. Textures and mineral chemistry indicate pervasive post-cumulus modifications of Kane cumulates by porous melt flow. Thermodynamic calculations indicate that intercumulus melts persist at temperatures even to 200 °C lower than the initial liquidus temperatures. Our data indicate that lower temperatures in the post-cumulus melt evolution and lower sulfide Ni contents result in lower sulfide-silicate melt Cu isotope fractionation factor (α sulfide-melt), then causing greater Cu isotopic variations in cumulates. We suggest that post-cumulus melt evolution reconcile both the Cu depletion and large Cu isotope fractionation in oceanic cumulates that are unexpected by a simple process of crystal accumulation from MORBs. This study highlights the essential role of post-cumulus evolution in controlling metal budget and their stable isotope fractionation during intra-crustal differentiation, which might also be applied to island arc and continental settings. [ABSTRACT FROM AUTHOR]

Copper deposits hosted by volcanic rocks can have different genetic types. Many copper vein deposits at the margin of the Cenozoic Lanping-Simao foreland fold-thrust belt in southwest China are controlled by thrust faults and hosted by Triassic volcanic rocks formed in association with the evolution of the Paleo-Tethys Ocean. The genesis of these copper deposits is poorly understood. Wenyu is a typical Cu deposit hosted in the Middle-Late Triassic basaltic-andesitic rocks and experienced three major hydrothermal stages characterized by mineral assemblages of calcite, anhydrite, and barite (Stage I); early quartz, chlorite, and epidote (Stage II); and Cu sulfides, galena, pyrite, hematite, and late quartz (Stage III). Consistency of the boiling temperature from fluid inclusions in the calcite and the temperature inferred from the C-O isotopes of the calcite, and the oxygen isotopes of the anhydrite and barite indicate that the stage I fluids probably have a δ13C value of ∼-4.5‰ and δ 18O values in the range of ∼-3‰ to +4‰. Oxygen isotopes of the early quartz (δ 18O = 15.1‰ to 17.4‰), D-O isotopes of chlorite and epidote, and the fluid inclusion data indicate that the stage II fluids have δ 18O values of ∼2.4‰ to 5.0‰ and δ 18D values of -68‰ to -53‰. Thus, the stage I and II fluids were inferred to be deep-seated brines with temperatures predominantly between 180 °C and 240 °C and salinities of 16-18 wt% NaCl eq. More significant meteoric water was involved during stage III based on the oxygen isotopes of the late quartz (δ 18O = 6.2‰ to 9.5‰). The large variation in δ 34S values (-21.3‰ to 1.6‰) in the sulfides, the sample- and grain-scale sulfur isotope fractionation, combined with the ore textural evidence that the sulfates and chlorite were replaced by Cu sulfides accompanied by hematite, indicate that the reduced sulfur responsible for sulfide precipitation was generated by inorganic reduction of the previously formed anhydrite and barite (δ 34S = 6.3‰ to 8.6‰) or sulfates in the brines by oxidation of chlorite to hematite. Lead isotopes of galena (206Pb/204Pb = 18.67-18.87; 207Pb/204Pb = 15.68-15.72) and copper isotopes of Cu sulfides (δ 65Cu = -0.34‰ to 0.51‰) indicate that the ore-forming metals (e.g., Cu and Pb) were derived from the orehosting Triassic volcanic rocks. The Wenyu copper deposit cannot be classified as a porphyry, epithermal, or volcanogenic massive sulfide deposit. It is believed that the deepseated brines, such as the saline formation water in the Permian marine strata, migrated upward along the thrust faults into the Triassic basaltic-andesitic volcanic rocks, and leached metals from the volcanic rocks and precipitated Cu sulfides via inorganic sulfate reduction at Wenyu during the Cenozoic. Such mineralization processes may explain the genesis of the volcanic-hosted copper vein deposits in the Lanping-Simao foreland fold-thrust belt and other similar belts in the world. [ABSTRACT FROM AUTHOR]

Dual‐ion batteries, as one of the most promising alternatives to Li‐ion batteries, face severe challenges in terms of side reactions, particularly at the anode. These side reactions result in the consumption of limited cations and the deactivation of anions in graphite during cycling. To date, most reports are focused on reducing these side reactions. Here, a new way is proposed to achieve the stable cycling of dual‐ion batteries using Mg as an example. Mg can be oxidized to Mg2+ during the discharge process, thereby replenishing the cation loss due to the side reactions. Meanwhile, anions are released from graphite to maintain the charge balance in the electrolyte. Another advantage is that the formation of Li3Mg7 during cycles facilitates Li plating/stripping. Therefore, Mg||Graphite exhibits a high Coulombic efficiency (≈96.5%) and a stable cycling performance (≈94.6% after 1700 cycles at 2 C) even without prelithiation, much better than Cu||Graphite and Graphite||Graphite. The mechanism also works for other active metals, such as K, Ca, and Na. The results demonstrate the promising potential of this strategy. [ABSTRACT FROM AUTHOR]

The diffuse presence of small copper ore deposits in the Alpine area, mostly exploited since Late Medieval times, led most scholars to assume that these deposits may actually be active much earlier and that many of the circulating prehistoric metal objects found in the area were produced with local copper sources. This assumption was recently validated for the Recent Bronze Age through the use of lead isotope tracers, and well supported by the archaeometallurgical evidences found in the South-Eastern Alps. However, the scarcity of available lead isotope data for pre-Bronze Age metals precluded to date the reconstruction of the metal flow through the Late Neolithic and Eneolithic (or Copper Age). Based on 49 new analyses of important archaeological objects from the Alpine region, the Po River Valley and Central Italy, mostly axes dated from the Late Neolithic to the Late Eneolithic, here we show that the diffusion of copper in Northern Italy (approximately 4500–2200 BC) includes three major periods of metal use and/or production, each related to specific ore sources. The South Alpine copper was massively used only starting from the middle of the 3rd millennium BC, in connection or slightly earlier than the Beaker event. [ABSTRACT FROM AUTHOR]

The role of metasomatized mantle in the genesis of magmatic Ni–Cu sulfide deposits in orogenic belts remains vigorously debated. The greatest challenge in clarifying uncertainties is how to track the behavior of metals during metasomatic processes in the mantle. Copper isotopes can shed new light on this enigmatic topic as the transfer of Cu during metasomatic processes can significantly fractionate Cu isotopes. In this regard, we have characterized the Cu isotope and trace-element compositions of fertile and barren mafic–ultramafic intrusions, and coeval basalts in the Eastern Tianshan, Central Asian Orogenic Belt (CAOB). Fertile mafic–ultramafic intrusions are characterized by elevated and highly variable Ba/Nb (40–756, average of 172) and Ba/La (16–219, average of 48) ratios, and exhibit δ65Cu values (−0.97 ‰ to +0.57 ‰) that vary over 1.54 ‰. In contrast, barren intrusions and coeval Permian basalts are characterized by relatively low and invariable Ba/Nb (2–95, average of 29) and Ba/La (0.9–26, average of 8) ratios, and have δ65Cu values that are comparatively less variable (−0.06 ‰ to +0.49 ‰ for δ65Cu) and more similar to bulk silicate Earth (BSE, δ65Cu = 0.06 ± 0.20 ‰). The difference in Cu isotope compositions of fertile and barren intrusions, alongside the variability in Ba enrichment, suggests that a high degree of mantle metasomatism promotes the fertilization of primary magmas in metals and, thus, represents one of the first stages in the development of magmatic Ni–Cu sulfide deposits in convergent margins. [ABSTRACT FROM AUTHOR]

A self-cleaning transparent thin-film photovoltaic device composed of a perovskite LaAlO 3 nanoparticle modified Cu 2 O/CeO 2 nanoarray pn junction is prepared via an electrochemical sol–gel surface-plasma method. The fabricated Cu 2 O/LaAlO 3 /CeO 2 thin-film photovoltaic device exhibits a transmittance of ∼80–85 % in the visible-light regime (λ > 520 nm), photovoltaic enhancement of ∼2.6 × 103 (photovoltaic conversion efficiency of ∼1.37 %), stable output over five months of cycling, and decent hydrophobicity (contact angle of 93.54°). These characteristics are mainly attributed to the perovskite LaAlO 3 nanoparticles and surface plasma modification. The appropriate Fermi level and high quantum yield improves the carrier kinetic equilibrium, balancing the transparency and photovoltaic conversion efficiency (supported by the Density Functional Theory). Surface plasma modification further enhances the solar and carrier efficiencies, while producing decent self-cleaning performance. Additionally, the extra hole-related carriers produced by the Cu vacancies optimize the kinetic equilibrium and the orderly CeO 2 array interval releases interfacial stress, providing good structural stability. [ABSTRACT FROM AUTHOR]

The basal unit of the Early Cambrian black shale sequence of South China hosts sulfide-rich polymetallic units, non-sulfidic vanadium-rich black shales, sapropelic alginite (combustible shale), barite, and phosphorite. This rock spectrum occurs in a paleoceanographic similar, and stratigraphically correlated, transgressive upwelling setting on the passive continental margin of the Neoproterozoic Yangtze Platform. Several centimeter-thick polymetallic sulfidic units (3–13 wt% Mo+Ni, 100–600 ppm U) have relatively light Mo (δ98/95Mo = 1.1 ± 0.2‰) and relatively heavy U isotope composition (δ238/235U = 0.2 ± 0.1‰). Several meter-thick V-rich shales with multiple ore-grade layers (0.1–0.8 wt% V, < 100 ppm U, Mo and Ni ~ 100 ppm) have isotopically lighter Mo (δ98/95Mo = 0.3 ± 0.4‰) and heavier U composition (δ238/235U = 0.4 ± 0.2‰ and up to 0.7‰). The inverse Mo versus U isotope correlation suggests that both metals were enriched by removal from anoxic to strongly euxinic bottom water in restricted basins along the rifted continental margin. Metal replenishment probably occurred via the cycling of Fe–Mn-oxyhydroxide particles across the redox boundary, with sorption/desorption of Mo (and likely Ni) in a stratified water column. In contrast, V enrichment with much lower Mo, Ni, and U contents, but more fractionated Mo and U isotope composition, reflects non-sulfidic anoxic depositional conditions in a partly open system with higher bottom water renewal rates. While Mo isotope fractionation likely occurred in the water column, U isotope fractionation may dominantly have occurred at the water-sediment interface, perhaps in a benthic organic flocculent layer. These findings indicate that local hydrodynamic control and stratified water column redox conditions may explain the observed variation of metal enrichment (Mo–Ni versus V) in the black shales. Furthermore, the high δ98/95Mo values up to 2.6‰ of the black shales studied and the correlated U and Mo isotope data suggest that Early Cambrian seawater was at least episodically broadly similar to modern seawater. [ABSTRACT FROM AUTHOR]

Submarine volcanos are the most active areas in the deep sea, but the environmental consequences of frequent volcanic activity on the geophysical fields and biogeochemical processes near hydrothermal chimneys have not been fully understood yet. In particular, how continuous high‐flux thermal energy, the most typical form of energy in active submarine volcanic systems, affects electron transport and geoelectric field remains unknown. This study provides the first evidence that thermal energy can be efficiently converted to electrical energy at an extremely small spatial scale of the submarine black chimneys. The Seebeck coefficient of sulfide chimneys can reach more than 200 μV/K, with high electrical conductivity of 104 S/m and low thermal conductivity of 1.0 W/(m·K) within 300–700 K. A maximal potential gradient of 300 mV/cm under a temperature difference of 300–700 K can be generated by the thermoelectric conversion of sulfide chimneys, with a maximum energy converting efficiency up to 1%. The thermoelectric conversion effect of a global‐scale submarine volcanos could enable electroactive bacteria to fix appromaxiately 105–106 tons of carbon per year. In addition, the thermal‐electrochemical experiments indicated sulfides underwent rapid oxidation under thermoelectric effects, which may help explain the intense oxidative weathering of sulfides in some anoxic deep‐sea hydrothermal zones. Plain Language Summary: Hydrothermal vents are the most active areas for energy and material exchange in the submarine volcanic systems. The conversion of chemical and biomass energy has been considered as the major driving force for biogeochemical processes in hydrothermal vents, while the primary thermal energy has rarely been a concern. This study revealed that hydrothermal black chimneys could achieve stable thermoelectric conversion with a maximum energy conversion efficiency of 1%. The thermoelectric transport performance of sulfides is mainly influenced by crystal structure, chemical composition and substituting ions. Both the generation of natural electric field and the growth and metabolism of electroactive microorganisms in deep sea are clolsely related to the thermoelectric effects of sulfides. The rapid oxidation of sulfides under a thermoelectric potential well explains the intense weathering of minerals in anoxic seafloor regions. Key Points: Proposing a geoelectric mechanism caused by thermoelectric effects of sulfides in submarine volcanic systemsBuilding a quantitative model to estimate the efficiency of thermoelectric conversion and carbon fixationExplaining rapid oxidative weathering of hydrothermal vent sulfides by thermoelectric mechanism [ABSTRACT FROM AUTHOR]

Most large-scale porphyry-style mineralization is genetically associated with oxidized, sulfur-rich, and hydrous magmas, the sources of which were enriched in mantlederived or juvenile crust--derived materials. Geochemical indices for these features can distinguish fertile magmas and barren magmas. However, fertile magmas that generate different-sized porphyry deposits are usually geochemically indistinguishable, and the factors controlling the size of porphyry mineralization are poorly understood. Here, we used zircon H2O contents and the compositions of apatite hosted in zircon, phenocrysts, and groundmass to compare the water contents and volatile evolution of fertile magmas in the Yulong ore belt, Tibet, which generated giant-, large-, and medium-sized porphyry deposits. We found that these porphyries have comparable major- and trace-element and zircon Hf-O isotope compositions, with high oxygen fugacity and sulfur contents. A negative correlation between XClAp/XOHAp versus XFAp/XClAp of apatites suggests that the magmas consistently achieved H2O saturation before zircon crystallization, and zircon hydroxyl contents reveal that the water contents of the melt positively correlate with the size of the deposits, consistent with larger deposits achieving H2O saturation at deeper crustal levels. The deeper H2O saturation also caused larger amounts of Cl extraction, as indicated by the trends of increasing XFAp/XClAp and decreasing XClAp/XOHAp with larger deposit sizes. These data sets can be reconciled by magmas forming larger deposits having higher H2O contents and suggest that the H2O content is a key control on their fertility. Our study highlights the utility of integrated hydrous and nominally anhydrous mineral analyses for constraining enigmatic magmatic volatile processes in magmatic ore-forming systems. [ABSTRACT FROM AUTHOR]

A Schiff base ligand, 3-((6-amino-1,6-dihydropyridin-2-yl)imino)indolin-2-one, was synthesized by condensing isatin with 2,6-diaminopyridine in this study. Elemental analysis, NMR spectroscopy, and infrared spectroscopy enabled confirmation of the structure of the pyridine incorporated ligand. Additional coordination compounds of this ligand with Mn(II), Co(II), Ni(II), Cu(II), Zn(II), and Cd(II) metals were synthesized with metal-to-ligand proportions verified through trace elemental examinations using CHN. Various spectroscopic techniques including UV-visible absorption spectrophotometry, IR spectrophotometry, electrical conductivity quantifications, melting point determinations, and magnetic susceptibility analyses facilitated characterization of the produced complexes. The antimicrobial potential of the organic ligand and inorganic complexes was screened against Bacillus subtilis and Staphylococcus aureus bacterial strains through the agar disc diffusion technique. Both the uncoordinated ligand and metal-ligand coordination compounds displayed appreciable antibacterial effects on the tested microorganisms. Tetrahedral configurations were proposed for all prepared complexes based on combined analytical and spectroscopic evidence. [ABSTRACT FROM AUTHOR]

A time-saving and highly efficient chemical separation procedure to isolate Zn and Mo from various geological samples is developed, which is based on a single pass of a double-stack column. The first column, filled with AG MP-1M resin (100–200 mesh, Bio-Rad), quantitatively removed matrix and interference elements from sample matrices; while the second column, filled with the DGA spec resin (50–100 μm, Eichrom), further isolated Zn and Mo from sample matrices. The proposed protocol was time-saving (50% column running time) and afforded efficient separation and quantitative recovery (more than 96% and 92% for Zn and Mo, respectively) from complex sample matrices of three geological reference materials W-2a, GSR-1 and GSR-2. Both Zn and Mo isotope ratios in the purified Zn and Mo solutions were determined by multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS) with the use of the combined standard-sample bracketing and internal normalization (C-SSBIN) method and double-spike method, respectively, for mass bias correction. In addition, the effects of two cone combinations and three mass bias correction methods on Zn isotopic analysis were investigated. The results show that the jet + X cone and the C-SSBIN method with Cu as the internal standard provided high accuracy and precision Zn isotope ratio measurements. Zn and Mo isotope ratios were measured in thirteen geological reference materials for the validation of the feasibility and effectiveness of the proposed method with satisfactory results in this study. [ABSTRACT FROM AUTHOR]

3-Aminopropyltriethoxysilane and -silatrane readily enter into the Michael aza reaction with various acrylates. Depending on the ratio of the reagents, Michael mono- or diadducts, containing functional groups (triethoxysilyl, carbonyl, nitrile, amino, etc.), are formed. These compounds have been characterized by IR and NMR spectroscopy, mass spectrometry, elemental and X-ray diffraction analyses. The siloxanes obtained from corresponding trialkoxysilanes form carbonyl and nitrile complexes with Ag, Cu, and Ni salts and comprise chemically and thermally stable promising sorbents (enterosorbents) of noble and heavy toxic metal ions. In silico calculations (Protos-II, PASS and Swiss ADMET programs) show that the synthesized silatranes are non-toxic and bioavailable compounds with a pronounced antitumor effect. The effect of silatranes on the growth of pathogenic bacteria (listeria, staphylococci, and plague bacilli) has been studied in vitro. It has been found that these silatranes in microconcentrations exhibit a significant stimulating effect and can be used as growth stimulators of bacterial biomass for rapid diagnosis of diseases caused by these and other pathogens. [ABSTRACT FROM AUTHOR]

Geochemical overprinting on placer gold deposits produces complex deposits with apparently paradoxical geochemical and morphological attributes. The La Cholla placer gold deposits near Quartzsite, Arizona, USA, contain sharp and often undamaged gold crystals within high-energy gravels as a result of postdepositional recrystallization by localized hot springs. Geothermal fluids emanated from a basin-bounding fault and left a distinct signature that includes recrystallized gold with low Pb and δ65Cu > 1.14‰, secondary uraninite and carnotite, travertine deposits, and mounds of highly silicified placer gravels. Surrounding these deposits are placer gravels with angular gold morphology and geochemistry indicative of flash-flood pulse placers with a lode gold source < 5 km and gold particles with low Pb and δ65Cu < 0.77‰. The multitude of small local lode gold source veins is likely related to specialized fluid migration along mid-Tertiary detachment faults. The unroofing of these veins at 5 to 17 Ma by high-angle Basin and Range faulting led to extensive placer development, with subsequent localized modification by geothermal fluid migration along the same faults. This study documents geochemical overprinting and modification of placer deposits and bears upon the study of other placers containing crystalline gold and uranium mineralization. Similar deposits may document past geothermal activity and identify structural fluid conduits and steep paleo-topographic gradients. [ABSTRACT FROM AUTHOR]

Quantifying and identifying the introduction of metal in ore deposits that have experienced multiple overprinting hydrothermal events remains an elusive yet essential goal in metallogenic studies. Here, we constrain the origin of Co in the Idaho Cobalt Belt (ICB) that experienced two distinct metal-rich events that introduced Co and Cu. We performed a detailed petrographic study of sulfide ore at Iron Creek in the ICB, in concert with the quantification of trace metal element concentrations and copper isotope values to identify the introduction of Co in the system. The pyrite displays various degrees of alteration, with the highest Co concentrations (up to 6 wt.%) in less-altered pyrite grains (e.g., sharp edges, absence of altered boundaries and fissures) and highest δ65Cu isotope value. The most-altered pyrite grains (e.g., corroded grains, round and altered boundaries) have lower Co contents and lower δ65Cu isotope values that match the copper isotope values of the chalcopyrite. The least-altered pyrite shows a narrow δ65Cu range between −0.39‰ to −0.58‰. In contrast, the most-altered pyrite grains are isotopically depleted, showing a δ65Cu range from −1.35‰ to −0.90‰. Chalcopyrite shows a δ65Cu range between −1.07‰ and −0.77‰. We interpret, from the Cu isotope compositions and Co concentrations in pyrite, that the Co was originally introduced into the siliciclastic host rock package in a Mesoproterozoic SEDEX environment. The heavier Cu was then preferentially leached in a second event, resulting in isotopically lighter Cu in the altered pyrite. Remobilization of the SEDEX cobalt was likely associated with CO2-rich metamorphic fluids present in the region during the Mesoproterozoic East Kootenay orogeny, the late Mesoproterozoic Grenville orogeny, and the Late Jurassic to Late Cretaceous Cordilleran orogeny. [ABSTRACT FROM AUTHOR]

The transition metals Fe, Cu and Zn are the key elements for life, and their isotope compositions are expected to be a new index to estimate the trophic level of organisms and diagnose human diseases. Therefore, it is important to analyse these isotopes precisely and accurately in biological samples with low Fe, Cu and Zn abundances. In this study, we modify the one-column method to purify Cu–Fe–Zn for isotope analysis. The parameters that could affect the accuracy and precision of isotopic measurement were evaluated. The Fe, Cu and Zn isotope values of nine biological reference materials are reported, including plants, marine and terrestrial animals, human hair and serum. The isotope compositions of plant and marine animal organs are different from terrestrial animals and human organs. The variation ranges of δ56Fe, δ65Cu and δ66Zn from plant and marine animals are −1.23‰ to 0.11‰, 0.39‰ to 0.53‰ and 0.28‰ to 0.87‰, respectively, while those from terrestrial animals and human tissues are −2.40‰ to 0.06‰, −0.33‰ to 2.76‰ and −0.65‰ to 0.24‰, respectively. This one-column method is important to provide comprehensive isotope information for biological individuals and efficient study Fe, Cu and Zn isotope distribution in paleontology and biomedicine fields. [ABSTRACT FROM AUTHOR]

Isotopic analysis by mass spectrometry relies on certified reference materials (CRMs) in order to correct instrumental isotopic fractionation (aka mass bias). Currently, SRM976 copper isotopic standard from the National Institute of Standards and Technology (NIST) remains the sole internationally recognized reference material for copper isotope ratio. However, the SRM976 material is no longer available and new copper isotopic CRMs are needed to serve as reference points for decades to come. In this study, we report an independent and fully calibrated isotope ratio measurement of a high-purity copper certified reference material, HICU-1, at the National Research Council Canada (NRC). MC-ICP-MS was employed for the isotope ratio measurements which were calibrated using the gravimetric isotope mixture approach involving two near-pure enriched copper isotopes. Copper isotope ratio n(63Cu)/n(65Cu) = 2.2413 ± 0.0009 (95% CI, k = 2) was established in the NRC HICU-1 and its isotopic composition has been shown to be nearly identical to that of NIST SRM976. [ABSTRACT FROM AUTHOR]

The new Neoma MC-ICPMS/MS is equipped with a prefiltering system consisting of a double-Wien filter and a collision/reaction cell whose performances are challenged using different combinations of magnetic and electrostatic field values and adjustable slit apertures. The results show an asymmetrical attenuation of transmission relative to the chosen axial mass-to-charge value, with higher efficiency at removing low masses than high masses, even when magnetic induction is minimal. The resulting asymmetry of the bandpass window is fully predictable by theoretical calculations of ion trajectories in a Wien filter, either as a function of the magnetic field value or that of the aperture of the adjustable slit. With an axial mass-to-charge value set at 120Sn, the vertical deviation for a magnetic field value at 100% will be approximately 3 mm and 4 mm for a variation of mass-to-charge of ±20%, respectively. In these conditions, Ar was already barely detectable with the lowest magnetic field value (10%) and a fully open adjustable slit, while Pb is quantitatively transmitted. We then use the prefiltering system to remove on-line the 40Ar23Na+ compound that produces an isobaric interference with 63Cu, hampering high-precision measurement of Cu stable isotope composition (65Cu/63Cu). While Na is not transmitted thanks to the double-Wien filter, 40Ar23Na+ still interferes with 63Cu, demonstrating that this argide is produced in the plasma source but not in the reaction cell. Helium in the collision/reaction cell is necessary to remove the 40Ar23Na+ interference. The MS/MS technology of the Neoma allows for the correction of the 40Ar23Na+ interference up to a Na/Cu ratio of 10, where other classic MC-ICPMS already show an offset of the Cu stable isotope composition for a Na/Cu ratio of 1. The inability to correct the Cu stable isotope composition with a Na/Cu ratio higher than 10 suggests that the Na-based interference is no longer spectral and becomes linked to the matrix. We next measure the Cu stable isotope composition in eight certified reference materials prepared with a simple automated single step ion-chromatography procedure to purify Cu. The results show a very good agreement with previously reported values. The overall results suggest that the MS/MS technology of the Neoma MC-ICPMS allows efficient on-line isolation of analytes, therefore reducing potential spectral and matrix interferences to permit much better resolved and controlled subsequent effects in the collision/reaction cell. [ABSTRACT FROM AUTHOR]

This work presents the generation of a post‐synthetically modified Metal‐Organic Framework (MOF), denoted as Cu‐BDC‐NH2‐DHB, achieved through a Schiff‐base reaction by converting the pendant amino group in pristine Cu‐BDC‐NH2 MOF to an imine group using 3,4‐dihydroxybenzaldehyde (DHB). The resulting material exhibited exceptional luminescence and fluorescence stability in water, prompting investigation into its potential as a metal sensor. Fluorescence tests revealed that Cu‐BDC‐NH2‐DHB could be transformed into a highly selective and sensitive sensor for detecting Fe3+ ions amid co‐interfering metal ions, with a remarkable detection limit of 3.08 μM. Furthermore, the results demonstrated that Fe3+ induced a rapid and strong quenching effect, with a reaction time measured in seconds. This research provides a promising technique for the facile and immediate detection of Fe3+ ions in practical applications. [ABSTRACT FROM AUTHOR]

Redox-driven copper (Cu) isotope fractionation has been widely observed in low-temperature weathering and hydrothermal processes. However, how Cu isotopes may fractionate during magmatic processes remain unknown. To address this issue, we studied MORB samples from the East Pacific Rise (EPR) at 10°30′N to explore the Cu isotope behavior during magma differentiation. These samples are globally ideal because they are generated from a uniformly depleted sub-ridge mantle source but have experienced varying extents of fractional crystallization and sulfide segregation with large variations of MgO (1.76–7.38 wt%) and Cu (16.0–75.2 μg/g). Lavas with MgO ≥ 4.9 wt% involving olivine, clinopyroxene and plagioclase as the major liquidus minerals show homogeneous δ65Cu of 0.05 ± 0.03‰, suggesting little Cu isotope fractionation at this stage of magma differentiation. However, after Fe-Ti oxides appear on the liquidus, melt δ65Cu values first decrease rapidly to –0.41‰ at MgO of 3.9 wt% and then increase with the most evolved sample having δ65Cu of 0.08‰. Such a significant Cu isotope fractionation during magma differentiation has never been reported before. We suggest the large Cu isotope variation at MgO < 4.9 wt% reflect a redox change of MORB melt resulting from fractional crystallization of Fe-Ti oxides. The crystallization of ilmenite (Fe2+TiO 3), which is the first Fe-Ti oxide phase during MORB differentiation, causes a sudden increase of Fe3+/∑Fe in the residual melt and drives the redox reaction Fe3+ + Cu1+ → Fe2+ + Cu2+. As a result, sulfides segregated from the MORB melts have high Cu2+ content and heavy Cu isotope compositions with Δ65Cu Sulfide-Silicate melt > 0 because of the preferential bonding of heavy Cu isotopes (65Cu vs. 63Cu) with Cu2+, whose fractionation rapidly decreases δ65Cu of the residual melts. The increase of Fe3+/∑Fe will quickly drive the melt to be saturated in titanomagnetite (magnetite-Ulvöspinel solid solutions), whose crystallization decreases melt Fe3+/∑Fe and drives the redox reaction Fe2+ + Cu2+ → Fe3+ + Cu1+. As a result, the segregated sulfides after titanomagnetite saturation have decreasing Cu2+ content. These sulfides are also predicted to have low Ni content and exhibit Δ65Cu Sulfide-Silicate melt < 0, whose segregation raises δ65Cu in the residual melts. Therefore, we suggest a significant influence of redox states of Cu and abundance of Ni in the segregated sulfides on the Cu isotope fractionation during MORB differentiation. During mantle melting for MORB at ΔFMQ < 0, Cu isotope fractionation between melt and mantle sulfide is inferred to be limited, and the upper mantle has primitive MORB-like δ65Cu of 0.06 ± 0.05‰. [ABSTRACT FROM AUTHOR]

A non-functional printed circuit board assembly was developed using ULTIboard and a simple computational transport model was created for use with the Monte Carlo software MCNP. EBT3 film radiography was used to compare with Monte Carlo simulation to validate the board representation. The computational transport model was then revised to include connection pins, solder balls, highly attenuating internal structures, and copper trace distribution. Results from the revised model were compared to the EBT3 films to observe improvements to dose profiles. It was found that this method was useful in verifying the placement of components, as the dose profiles were observed to follow the same trends. The experiment was then repeated using XRQA2 films to achieve the same level of contrast with 1% the dose of EBT3 films. It was found that high contrast may be achieved using these films to identify major issues with the model geometry, at a cost of dose profile accuracy. A second validation method was applied to the model using 37 CaF 2 thermoluminescent dosimeters (TLDs). TLD measurements were compared with the simplified and complex transport models to identify the features that have the greatest impact on simulation accuracy. The TLD calibration to CaF 2 was found to be accurate within 5.6%, while calibration to dose in Si was found to be accurate within 4.7%. It was observed that the accurate representation of solder balls and proper modeling of highly attenuating internal structures had the greatest impact on simulation accuracy. [ABSTRACT FROM AUTHOR]

Rationale: Laser ablation multicollector inductively coupled plasma mass spectrometry (LA‐MC‐ICP‐MS) has become a powerful technique for in situ Cu isotopic analysis in natural geological samples. Cu isotopic compositions in natural chalcopyrites have been used to reveal aspects of the mineralization processes directly. However, internationally or commercially available matrix‐matched chalcopyrite reference materials for mass fractionation correction or quality control purposes are still lacking for in situ Cu isotopic analysis using LA‐MC‐ICP‐MS. Methods: Three natural chalcopyrites 14ZJ12‐1, JGZ‐29 and JGZ‐78, and one copper metal GBW02141 with different Cu isotopic compositions were investigated as potential microanalytical reference materials by LA‐MC‐ICP‐MS. Ga element was used as an internal standard to correct the mass fractionation of Cu isotopes during LA‐MC‐ICP‐MS analysis. Results: A large number of Cu isotope ratio measurements using femtosecond LA‐MC‐ICP‐MS were conducted and produced good intermediate precision of δ65CuNIST976 (0.07–0.08‰, 2 standard deviations), demonstrating the homogeneous Cu isotopic distribution in the recommended samples. The mean δ65CuNIST976 values of −0.21 ± 0.04‰, 0.46 ± 0.04‰, −0.06 ± 0.04‰ and 0.11 ± 0.05‰ (2 standard deviations) in 14ZJ12‐1, JGZ‐29, JGZ‐78 and GBW02141, respectively, were obtained using solution‐MC‐ICP‐MS in the four recommended samples. Conclusions: Here, we describe three natural chalcopyrites 14ZJ12‐1, JGZ‐29, JGZ‐78, and one copper metal GBW02141 as the potential Cu isotopic reference materials for LA‐MC‐ICP‐MS analysis. Our analyses demonstrate that these recommended materials have a high degree of elemental and isotopic homogeneity, indicating that they are suitable for microanalysis techniques for data quality assurance or interlaboratory calibration. [ABSTRACT FROM AUTHOR]

As a promising candidate for next‐generation energy storage devices, Zn metal battery excels with their good safety, high specific capacity, and economic attractiveness. However, it still suffers from a narrow electrochemical window, notorious dendrite formation, and sluggish Zn ion transfer. Aqueous electrolyte engineering has been regarded as an effective way to improve these. It is shown that by adding sodium polystyrene sulfonate (PSS) polymers into a dilute 1 m Zn(OTf)2 aqueous electrolyte, compact water shells with stronger hydrogen bonding and more ordered structures are formed around the polymer chains. As a result, a fast transport channel to the zinc ions is provided. The PSS chains also protect the zinc electrode from directly contacting the water molecules and thus suppress water decomposition. With these merits, a Zn//Cu cell demonstrates a high coulombic efficiency of ≈99% after 1500 h cycling. Meanwhile, a record‐high cumulative Zn plating capacity of 10 000 mA h cm−2 is obtained using a Zn||Zn cell. In addition, the Zn//C@V2O5 full cell achieves almost 100% capacity retention after 1000 cycles. This work provides a new strategy for designing advanced electrolyte systems excelling in ion transport kinetics. [ABSTRACT FROM AUTHOR]

Prospects of controlling the absorption of the cost‐effective plasmonic metal nanoparticles (MNPs) Cu and Al using quantum emitters (QEs) are demonstrated semi‐analytically. The resulting spectra are compared with the absorption of commonly used noble plasmonic metal nanoparticles Au and Ag under similar conditions. It is observed that Cu and Au based plasmonic nanoparticles exhibit largely similar exciton–plasmon Fano interaction signatures in addition to their similar spectral regions of operation (lower end of the visible range). Furthermore, the QE‐enhanced maximum absorption (Fano maximum) of Cu based nanohybrids are seen to approach the maximum absorption level of isolated Au MNPs, with decreasing QE‐Cu separation, increasing QE dipole element magnitude, and increasing medium permittivity, in the parameter region considered. This renders Cu based exciton–plasmon nanohybrids as more economical alternatives for Au MNPs and Au‐based nanohybrids in absorption‐based applications (such as thermoplasmonic), when stabilized in protective embedding media such as poly (methyl methacrylate) (PMMA). [ABSTRACT FROM AUTHOR]

The North Eastern Baltic has no copper resources of its own, meaning that Cu alloy was imported either as raw material or as finished objects. The north‐eastern coastline of Estonia during the late pre‐Roman and Roman Iron Age was connected to the south by sea to the long‐distance 'amber' trade route and to the east by Russian river systems. This study quantitatively assesses the direction of the Cu alloy supply in the region before and after brass enters circulation at the beginning of the Roman Iron Age. After an initial portable X‐ray fluorescence (pXRF) survey, 18 objects were chosen for Pb isotope analysis. This isotope analysis resolved a group of nine brass artefacts from the Roman Iron Age amongst a 'melting pot' of other Cu alloys. The similarity between the isotope ratios found in the Roman world suggests the presence of the same 'melting pot' in the North Eastern Baltic, possibly created by a large amount of Roman Cu alloy being traded north. No evidence for Cu alloy from Scandinavia or the Ural Mountains could be found. The hypothesis from this small study is that the Cu alloy entering Estonia was dominated by metal from Southern Europe from the late pre‐Roman Iron Age and the Roman period. [ABSTRACT FROM AUTHOR]

High-precision Cu isotopic analysis has been suggested as a complementary tool to Pb isotopic analysis in archaeometry. Pronounced Cu isotope ratio variations can be found in Cu-dominated minerals, stemming from the complex redox chemistry underlying their formation. In this work, the Cu isotopic composition of Cu ores (azurite/malachite) from three important mining centres exploited during the Copper and Early Bronze Age in the Northwest of Spain was evaluated using multi-collector inductively coupled plasma-mass spectrometry. The δ65Cu data showed high variability for samples from within the same mines, with an important overlap of the ranges for the different mines. This variability was due to the heterogeneity of the copper isotopic composition observed even within a single sample from one mine divided into 13 different subsamples. The δ65Cu values obtained for samples from the 4 mines varied within a large range (of about 4‰). These results were compared to previously published δ65Cu data for both primary and secondary minerals and good agreement between the ranges observed was established. The comparison of δ65Cu data for the minerals investigated in this work with 27 previously measured archaeological artefacts (arsenical copper from the Copper Age or Early Bronze Age) did not provide meaningful results, although most of these archaeological samples were previously assigned to one of the mines studied based on their clearly radiogenic Pb isotopic signature. This case study demonstrates that the potential application of the ore Cu isotopic composition for archaeological studies is strongly jeopardized by intra-mine variability. [ABSTRACT FROM AUTHOR]

Copper sulfide ore is one of the most important sources of Cu in nature. In situ Cu isotope analysis of sulfides is critical for providing useful information on the sources of Cu and tracking the process of sulfide precipitation. The accuracy of in situ Cu isotope analysis relies heavily on matrix-matched reference materials to correct the instrumental mass bias. In this study, a natural chalcopyrite (TQ-Ccp) from the Tianqiao Pb–Zn deposit (Guizhou Province, China) was evaluated as a potential reference material for Cu isotope microanalysis. Major element mapping and determination by electron probe microanalysis (EPMA) demonstrated that there was no internal growth or zonation within the TQ-Ccp chalcopyrite grains. The Cu isotope homogeneity of the chalcopyrite sample was tested by micro-drill sampling and solution multi-collector inductively coupled plasma-mass spectrometry (MC-ICP-MS) as well as by laser ablation MC-ICP-MS (LA-MC-ICP-MS). Thirty-two chalcopyrite powders were micro-drilled randomly from the whole hand specimen and from four fragments of chalcopyrite prepared in an epoxy mount, and measured by solution MC-ICP-MS. The dissolved chalcopyrite solutions processed with and without column chromatography yielded a mean δ65CuNIST976 of 0.05 ± 0.03‰ (2SD, n = 20) and 0.04 ± 0.03‰ (2SD, n = 32), respectively, suggesting Cu isotope homogeneity at the whole specimen scale. The Cu isotope homogeneity at the micro-scale was further verified by LA-MC-ICP-MS analyses of the four chalcopyrite fragments in the epoxy mount. In summary, TQ-Ccp chalcopyrite is potentially a suitable reference material for in situ Cu isotope microanalysis, whose recommended δ65CuNIST976 value is 0.04 ± 0.03‰ (2SD, n = 52), as determined by solution MC-ICP-MS analyses. [ABSTRACT FROM AUTHOR]

This study focuses on the changes in diet and mobility of people buried in the La Sassa cave (Latium, Central Italy) during the Copper and Bronze Ages to contribute to the understanding of the complex contemporary population dynamics in Central Italy. To that purpose, carbon and nitrogen stable isotope analyses, strontium isotope analyses, and FT-IR evaluations were performed on human and faunal remains from this cave. The stable isotope analyses evidence a slight shift in diet between Copper and Bronze Age individuals, which becomes prominent in an individual, dating from a late phase, when the cave was mainly used as a cultic shelter. This diachronic study documents an increased dietary variability due to the introduction of novel resources in these protohistoric societies, possibly related to the southward spread of northern human groups into Central Italy. This contact between different cultures is also testified by the pottery typology found in the cave. The latter shows an increase in cultural intermingling starting during the beginning of the middle Bronze Age. The local mobility during this phase likely involved multiple communities scattered throughout an area of a few kilometers around the cave, which used the latter as a burial site both in the Copper and Bronze ages. [ABSTRACT FROM AUTHOR]

CaCu 3 Ti 4 O 12 and CaCu 2.95 Zn 0.05 Ti 4- x Al x O 12 (x = 0.025, 0.05, and 0.10) ceramics were created using a conventional solid-state reaction method. A single phase of CaCu 3 Ti 4 O 12 was present in all ceramics. Co-doping with Zn2+ and Al3+ resulted in a significantly increased grain size. According to the DFT results, both Zn and Al atoms preferentially occupy Cu sites, resulting in LPS processes caused by excess Cu concentrations at the grain boundary. CaCu 2.95 Zn 0.05 Ti 4- x Al x O 12 ceramics with dielectric permittivities of more than 7.00 × 104 and dielectric loss tangents less than 0.04 have been produced. It was also discovered that the temperature stability of dielectric permittivity could be boosted. Improved electrical properties of grain boundaries, particularly grain boundary resistance, in co-doped ceramics caused by the influence of metastable phases such as Cu-related phases and oxygen enrichment at the grain boundaries, might well be related to improved dielectric properties. The Cu-related phases and the structure without oxygen vacancy at the grain boundary can act as a stable insulative layer, preventing long-range charge migration. From our electron density calculations, the Zn and Al ions become more positive, whereas the O ions are more negative. Moreover, Cu+ and Ti3+ could be generated from the V O ++ in the Zn05Al10 structure. Based on experimental and theoretical data, an internal barrier layer capacitor structure in these ceramics could account for the giant dielectric characteristics of these materials. [ABSTRACT FROM AUTHOR]

Porphyry Mo deposits are important suppliers of molybdenum for industrial applications, but the origin and source of metals in these deposits remain debated. Here, we present Mo isotope data for Miocene mineralized porphyritic monzogranites (MPMs) and Paleocene barren biotite monzogranites and tuffs (BMTs) from the Bangpu porphyry Mo (Cu) deposit in the Gangdese metallogenic belt. The results show that the MPMs display radiogenic Sr and Pb isotopes and elevated δ98/95Mo (relative to NIST SRM 3134; +0.07%c-1.2%c) and Mo contents, which exceed the range of the depleted mantle. These characteristics cannot be attributed to surface weathering, hydrothermal alteration, magmatic differentiation, or partial melting but rather reflect the incorporation of Mo from black shales into their magma sources, as evidenced by the significant correlations between δ98/95Mo and εNd(i) and aluminum saturation index (ASI) values. In contrast, the BMTs display lower Mo and δ98/95Mo values than the mineralized samples, and their δ98/95Mo values display no correlations with radiogenic isotopes or ASI values. The contrasting characteristics of mineralized and barren samples provide strong evidence that the addition of black shales played an important role in the formation of the Bangpu porphyry Mo deposit. Our study thus establishes a possible link between porphyry Mo deposits and organic-rich sediments and highlights the great potential of Mo isotopes in studying porphyry Mo deposits. [ABSTRACT FROM AUTHOR]

Copper-64 (T1/2 = 12.7 h) is a positron and beta-emitting isotope, with decay characteristics suitable for both positron emission tomography (PET) imaging and radiotherapy of cancer. Copper-67 (T1/2 = 61.8 h) is a beta and gamma emitter, appropriate for radiotherapy β-energy and with a half-life suitable for single-photon emission computed tomography (SPECT) imaging. The chemical identities of 64Cu and 67Cu isotopes allow for convenient use of the same chelating molecules for sequential PET imaging and radiotherapy. A recent breakthrough in 67Cu production opened previously unavailable opportunities for a reliable source of 67Cu with high specific activity and purity. These new opportunities have reignited interest in the use of copper-containing radiopharmaceuticals for the therapy, diagnosis, and theranostics of various diseases. Herein, we summarize recent (2018–2023) advances in the use of copper-based radiopharmaceuticals for PET, SPECT imaging, radiotherapy, and radioimmunotherapy. [ABSTRACT FROM AUTHOR]

Northern Xinjiang in Northwest China is an important part of the Central Asian Orogenic Belt (CAOB) and is characterized by Fe, Cu, Ni, Pb, Zn, W, Mo, Au and rare metal deposits. Cobalt is a critical mineral resource and new energy material, but cobalt resources are scarce in China. Many by-product cobalt deposits have been found in the CAOB of Xinjiang. In addition to cobalt-dominant minerals that contain essential Co, cobalt mainly occurs in sulphides, with minor amounts present in arsenic, oxides, and natural metal elements in the form of isomorphic substitutions. Co deposits are mainly distributed in East Tianshan and Beishan, and minor deposits occur in Junggar and West Tianshan. We recognize five types of Co deposits in the Central Asian Orogenic Belt of Xinjiang: magmatic, magmatic-hydrothermal, volcanogenic, skarn, and sedimentary. Of these types, magmatic deposits are the most common. The ore formation in Co deposits can be divided into five mineralization phases: Early Cambrian, Early Silurian, Early Devonian, early Carboniferous, and Early Permian. Among these phases, the Early Permian was the main mineralization phase, in which magmatic-type (Cu–Ni–Co and Ni–Co) and skarn-type (Fe–Co and Ag–Cu–Pb–Zn–Co) deposits formed. The evolution of subduction, collision, and postcollision in the Paleo-Asian oceanic plate resulted in the formation of diverse types of Co deposits. [ABSTRACT FROM AUTHOR]

In order to provide further insights into the origin of Pt–Fe minerals, this study presents the first copper isotope data for Pt–Fe minerals from the Nizhny Tagil massif, an international standard of the zoned Ural-type complexes. The chemical and isotopic composition of Pt–Fe minerals were determined by electron microprobe analysis, chemical sample preparation with selective chromatographic separation of copper from a solution of the studied sample, followed by high-precision determination of the δ65Cu value using multiple-collector inductively coupled plasma mass-spectrometry. The majority of platinum group minerals (PGM) from chromitites of the Alexandrovsk Log and Krutoy Log deposits within the Nizhny Tagil massif are formed by Pt–Fe minerals, among which high-temperature ferroan platinum (Pt2Fe) containing subordinate inclusions of Os–Ir alloys and laurite (RuS2) predominate over other PGM. The concentrations of copper and δ65Cu values in the studied samples of ferroan platinum vary from 0.4 to 1.4 wt % Cu and from –0.37 to 0.26‰, respectively. Secondary low-temperature PGM assemblage is represented by the tetraferroplatinum (PtFe)—tulameenite (PtFe0.5Cu0.5) solid solutions series. The concentrations of copper in these PGM vary in the range of 6.8–11.3 wt %; the values of δ65Cu are characterized by lighter Cu-isotopic compositions ranging from –1.15 to –0.72‰. The lighter Cu-isotopic composition in secondary Cu-bearing PGM compared to that in ferroan platinum (δ65Cu = –1.01 ± 0.17‰, n = 8 and δ65Cu = 0.03 ± 0.23‰, n = 7, respectively) is consistent with a secondary nature of isotopic variations, due to evolved composition of the ore-forming fluid during the low-temperature formation of the tetraferroplatinum—tulameenite solid solution series. [ABSTRACT FROM AUTHOR]

The intercalation of 8-hydroxyquinoline (HQ) organic chelating ligand onto the structure of Na+-montmorillonite (MMT) was prepared and investigated by using Fourier transform infrared spectrometry (FT-IR), X-ray diffraction spectrometry (XRD), elemental analysis, and scanning electron microscope with energy X-ray dispersive (SEM–EDS) techniques; the results indicated that 8-hydroxyquinoline was successfully intercalated in the interlayer space of montmorillonite. This intercalation compound was used to construct a potentiometric electrode. Potentiometric results showed the best response to Cu2+ ion with a slope of 30.45 ± 0.36 mV decade−1 (R2 = 0.9987) and provided a good linearity within a concentration range of 10−5–0.5 M. The limit of detection of the electrode was determined as 1.99×10−6 mol L−1. The selectivity coefficient of electrode was evaluated by a separate solution method (SSM), and the resulting values of the selectivity coefficient were small which indicated the electrode gave the best response to Cu2+ ion. This electrode also showed good precision, repeatability, durability, fast response time, and selective to copper ion. Cyclic voltametry and electrochemical impedance spectroscopy (EIS) analysis exhibited that 8-hydroxyquinoline could help enhance the specificity of the montmorillonite to form with Cu2+ ion in solution. The proposed potentiometric electrode was successfully applied to determine Cu2+ in a real micronutrient fertilizer sample by the standard addition method. [ABSTRACT FROM AUTHOR]

The Palaeozoic mafic-ultramafic complexes hosting Ni-Cu-Co mineralization occurred discontinuously and coexisted with early Palaeozoic eclogites in the East Kunlun orogenic belt (EKOB), western China. The giant Xiarihamu Cu-Ni-Co sulphide deposit in the EKOB is the largest Cu-Ni-Co sulphide deposit in an orogenic setting in the world. Early Palaeozoic eclogites are distributed as a belt for ca. 530 km in length in the Central Kunlun Zone of the EKOB. The geochronological data, geology and geochemistry of mafic-ultramafic complexes and eclogites in the EKOB are summarized for the tectonic settings of magmatic Cu-Ni-Co mineralization under the Proto- and Paleo-Tethys evolution. The mafic-ultramafic complexes show diverse lithofacies with different formation ages, indicating the multiple stages of long-lived Palaeozoic mantle-derived magmatism in the EKOB. The tectonic location, Neoproterozoic Ocean island basalt (OIB)-like mafic volcanic rocks and eclogite protolith of the EOKB imply the presence of the Neoproterozoic mantle plume magmatism as well as its contribution for enrichments of Ni-Cu-Co beneath EKOB. The ultramafic complexes show a close spatio-temporal relationship with eclogites. The basaltic protoliths of EKOB eclogite were derived from same mantle source as the mafic-ultramafic complexes. A positive correlation of geochronological data between ultramafic complexes with the eclogites in the EKOB is determined and indicated that the mafic magmatism with Cu-Ni-Co mineralization and eclogites were related to the tectonic-magmatic events in process of Proto-Tethys. The ultramafic complexes were formed under the subduction compression and post-collisional extensional settings of the Proto-Tethys and Paleao-Tethys Ocean corresponding to the peak (430–450 Ma) and retrograde (~405–410 Ma) metamorphic periods of eclogites. The Cu-Ni-Co metals were enriched extremely in the stage magma chamber by multi-stage magmatism in EKOB. Therefore, the mafic-ultramafic complexes with a large age span co-occurred with eclogites (especially retrograde eclogites) could be a favourable area for Ni-Co mineralization. [ABSTRACT FROM AUTHOR]

Rechargeable anode-free Li metal batteries (AFLMBs) with improved energy density and reduced cost are beneficial for emission peak and carbon neutralization. Herein, multi-walled carbon nanotubes reinforced Cu matrix composite (Cu-CNTs) enabled by deformation-driven metallurgy (DDM) technology is proposed to retrieve the lithiophilicity of current collectors (CCs) in AFLMBs. Fine-grained Cu-CNTs with a large number of grain boundaries and homogenous distribution of broken CNTs are achieved based on the severe plastic deformation principle since the CNTs inhibit slide of dislocations and migration of grain boundaries. Grain boundaries in fine-grained Cu-CNTs with low-size distribution gradients provide desirable nucleation sites due to their higher disorder and active state. Excellent lithiophilicity of the broken CNTs is exhibited where its layered structure for Li ion insertion contributes to uniform Li deposition. Half cells assembled by Cu-CNTs CC with 2 vol% CNTs display advanced cycling stability with an average coulombic efficiency of 97.8% after 500 cycles at 1.0 mA‧cm−2. Full cells with LiFePO 4 cathode possess excellent capacity retention of 69.4% after 100 cycles at 0.5 C. This work provides a novel strategy for fabricating CCs to achieve superior electrochemical performances for future applications of AFLMBs. [Display omitted] • Cu-CNTs CC is proposed by deformation-driven metallurgy technology. • Fine-grained Cu-CNTs with more grain boundaries provide desirable nucleation sites. • Even CNTs distribution enhances lithiophilicity and guides uniform Li deposition. • Excellent average CE remains 97.8% after 500 cycles at 1.0 mA‧cm−2 in AFLMBs. [ABSTRACT FROM AUTHOR]

Graybody materials exhibit systematically low emissivity across their spectrum. This characteristic violates the key assumption of unit emissivity at some wavenumber in the spectrum used to calibrate thermal‐infrared emission data. This assumption makes graybody materials "appear colder" than their actual physical temperature and imparts a slope in emission spectra that is non‐physical in nature, both of which affect interpretations of planetary surfaces. Pyrrhotite derived from the Stillwater Complex's J‐M Reef in Montana, USA exhibits systemic graybody behavior across its mid‐infrared spectrum and thus has a steep negative spectral slope from high to low wavenumbers when calibrated using conventional methods. A new measurement technique is introduced for deriving the absolute emissivity of graybody materials using reference samples with known Christiansen Frequencies during calibration. The reference temperature method significantly reduces the spectral slope of and provides a more accurate estimation of the absolute emissivity of graybody materials. After correcting the temperature of pyrrhotite using results from a series of reference experiments, we conclude that the emission spectrum of pyrrhotite is spectrally featureless and has a maximum emissivity of ∼0.7. If sulfide mineral deposits are exposed on Mars, they will not be identified using spectral features found in the mid‐infrared (5–40 μm). However, they could be located by identifying basaltic terrain that appears colder than their surroundings and with apparent emissivity spectra that exhibit negative spectral slopes from high to low wavenumbers and are spectrally neutral. Plain Language Summary: An integral step to off‐Earth human settlement is identifying the minerals with the critical metals required to support a new form of human life in space that would be heavily dependent on robotics and technology. This work investigates whether remote thermal infrared emission spectroscopy can be used to identify extraterrestrial sulfide mineral deposits. For this purpose, we acquired emissivity measurements of a 100% pure sulfide (pyrrhotite; Fe(1−x)S) derived from the Stillwater Complex's J‐M Reef. We show that when deriving emissivity using the conventional calibration routine, pyrrhotite's spectrum exhibits a steep spectral slope and is nearly featureless. The slope results from an incorrect estimation of pyrrhotite's temperature. The temperature error stems from pyrrhotite exhibiting systematically low emissivity, which violates the key assumption that somewhere in its spectrum that the emissivity is equal to that of a blackbody at the same temperature. A new laboratory procedure was developed to constrain the temperature error and produce a more accurate emissivity spectrum of pyrrhotite, revealing that pyrrhotite exhibits low emissivity in the mid‐infrared. Rather than relying on absorption features for prospecting, temperature errors, the presence of a spectral slope, and a featureless spectrum can be used to prospect for sulfide mineral deposits across the solar system. Key Points: We developed a new calibration and measurement technique for deriving the absolute emissivity of graybody materials in the mid‐infraredPyrrhotite is spectrally neutral and exhibits systematic graybody behavior, with a maximum absolute emissivity of ∼0.7–0.6 from 5 to 40 μmAnomalously cold brightness temperatures and sloped, featureless emissivity spectra may indicate the presence of sulfide deposits on Mars [ABSTRACT FROM AUTHOR]

Felsic volcanic rocks of rhyolite to dacite composition, hosting copper mineralization, are exposed near Mundiyawas-Khera area within the Alwar basin of Proterozoic North Delhi Fold Belt. Distinct variations in grain size, mineralogical composition, texture, sulfide mineral associations, structure, and outcrop patterns of the felsic volcanic rocks are observed in the field. In this study, litho-facies analysis of felsic volcanic rocks around Mundiyawas-Khera copper deposit has been attempted for the first time to understand their spatial distributions and bearing on copper mineralization. Signatures of five distinct facies variations in felsic volcanic rocks are recorded based on the field and laboratory studies. These facies variations recorded in the study area are (a) vitrophyric felsic volcanics; (b) fine grained felsitic fiamme bearing tuff; (c) fiamme-bearing welded ash flow tuff; (d) poorly welded ash flow tuff; and (e) volcanic ash. Presence of glass shards in the study area indicates phreatomagmatic eruptions in an aqueous to sub-aqueous environment. Occurrences of massive sulfide associated with the felsic volcanic unit can also correlate with well-known volcanic hosted massive sulfide (VHMS) deposit and is taken as an additional evidence of felsic volcanic rock occurrences at a submarine environment. [ABSTRACT FROM AUTHOR]

The large to middle-sized magmatic Ni–Cu sulfide deposits are spatially situated in the eastern portion of Eastern Tianshan, whereas those in the western portion have been poorly understood due to their quantity and scale. The Haibaotan Ni–Cu sulfide occurrence is newly discovered in the western portion of Eastern Tianshan, which provides an opportunity for understanding how its magmatic conduit system was generated and evolved. The Haibaotan mafic–ultramafic intrusion is dominated by peridotite, pyroxenite, olivine gabbro, and gabbro, and sulfide orebodies occur mainly within gabbro. Gabbro from the Haibaotan intrusion is dated at 315.5 ± 1.9 Ma, which suggests that the Haibaotan intrusion is generated in a subduction evironment. The age is much earlier than the emplacement of other mineralized mafic–ultramafic intrusions (~ 280 Ma) in Eastern Tianshan. High zircon εHf(t) values (+ 7.09 to + 18.44) indicate that the parental magmas of the Haibaotan intrusion have been derived from a metasomatized mantle source. Additionally, mafic–ultramafic rocks in the Haibaotan intrusion exhibit enrichment of large ion lithophile elements (LILE) and light rare earth elements (LREE), together with a depletion of Zr, Ti, and Nb, which is indicative of a subduction-modified mantle source. Core–rim variations of olivine forsterite (Fo) and Ni contents imply that the Haibaotan intrusion resulted from successive magma pulses, and the variable PGE tenors reflect that the sulfide droplets scavenged metals from multiple magma pulses. The low Se/S ratios of sulfide mineralization suggest that the addition of crustal sulfur triggered sulfide segregation in the shallow magma conduit system. The evolution history of the Haibaotan magma conduit system meets the requirements for generating a magmatic Ni–Cu deposit. This study highlights that the subduction environments are favorable for the formation of magmatic sulfide deposits in Eastern Tianshan. [ABSTRACT FROM AUTHOR]

Scapolite occurrences are widely observed in the metasedimentary rocks exposed around the Khetri Copper Belt and adjoining Nim ka Thana copper mineralized area in western India. Amoeboidal to well-developed and rounded/elliptical-shaped marialitic scapolite (Na-rich end-member) rich zones with variable Cl contents ranging from 1.0 wt % to 2.9 wt % have been identified in proximity to the ore-bearing hydrothermal fluid activity zones. Although scapolite is formed as a product of regional metamorphism in many places, in this study, we propose a strong possibility that scapolite was formed by hydrothermal ore-bearing fluid interaction with metasediments. The evidence of hydrothermal activity and Cl sourcing is attributed to (i) the absence of evaporite beds in the area and no Na-rich plagioclase as inclusions within the scapolite suggesting the formation of marialitic scapolite from sodic plagioclase in the metasediments with the interacting hydrothermal fluid; (ii) an epithermal to mesothermal hydrothermal fluid with moderate salinity responsible for the Cu mineralization that is ascribed to be the source of Cl for the formation of marialitic scapolite; (iii) diffusion of SO2 in the scapolite in close association with the sulfide mineral phase (chalcopyrite) supporting the involvement of ore-bearing fluid in the development of scapolite; (iv) the absence of zoned scapolite, the spatial distribution of scapolite in a particular lithology, the occasional incorporation of sulfur into marialitic scapolite and the texture/geometry in the scapolite suggesting a broad hydrothermal linkage instead of a pure metamorphic origin. [ABSTRACT FROM AUTHOR]

Raman spectroscopy is an important method to analyze and measure mineral composition and structure, which has the advantages of being non-destructive and rapid. This study considered garnet from the Jiama copper polymetallic deposit in Tibet to carry out micro-Raman spectrum and electron microprobe research to analyze the Raman spectrum characteristics of garnet with different components to reveal its indicative significance for garnet composition and skarn mineralization. The results showed that the Raman peaks T, X, A1, A2, and A3 shift toward lower wavenumber with the increase in andradite (And) content. The variations in T, X, and A2 are more obvious than those of A1 and A3. When And > 50%, the three Raman peaks (T, X, and A2) range are 173–174, 234–239, 513–525 cm−1; when And < 50%, they are 177–178, 240–244, 527–543 cm−1. The Raman peaks also shift with the cation radius and relative atomic mass. Different peaks moved in the low-frequency direction with the increase in the X2+ and Y3+ radius, and the X2+ atomic mass. The Raman spectrum can indicate the composition change in garnet. Raman spectrum analysis of garnet is of great significance for skarn zoning and prospecting. [ABSTRACT FROM AUTHOR]

Significant variations of oxygen fugacity (f O 2) in silicate magmas are widely suggested to play an important role in formation of magmatic Ni–Cu deposits in convergent margin settings. Copper isotopes have potential to track redox change of magmatic systems, but the linkage of silicate magma oxygen fugacity with Cu isotope fractionation in magmatic Ni–Cu mineralization systems is still uncertain. A combined study of Cu isotopes and estimated oxygen fugacities can provide novel and direct insights into this issue. In this study, four magmatic Ni–Cu deposits in Eastern Tianshan (NW China) were investigated in order to reveal the f O 2 variations in silicate magmas as a function of redox-induced Cu isotope fractionation. The silicate magma f O 2 of the four deposits widely varies from ∼QFM –2.2 to + 0.6, from ∼QFM –0.7 to 0.0, from ∼QFM –1.4 to –0.2, and from ∼QFM –1.2 to –0.6 for the Tulaergen, Huangshandong, Huangshannan, and Hulu deposits, respectively. Models using olivine compositions, Cu/Pd ratios, and estimated silicate magma f O 2 suggest that the silicate magmas gradually became more oxidized as Ni–Cu mineralization proceeded. The closed-system R factor equation and the Rayleigh equation were used to model mineralization processes and related Cu isotope fractionation. Modelling using δ65Cu values and the estimated f O 2 indicates that the evolved silicate magmas with high f O 2 tend to incorporate heavier Cu isotopes. Our studies indicate that the f O 2 variation of silicate magmas is the key factor governing Cu isotope fractionation in magmatic Ni–Cu mineralization systems in convergent tectonic settings, which is potentially applicable for other magmatic Ni–Cu deposits worldwide. [ABSTRACT FROM AUTHOR]

Here we present an analytical method for Cu isotopic measurement using standard-sample bracketing on a Nu Sapphire multi-collector inductively coupled plasma mass spectrometer. The effects of Cu concentration and HNO3 molarity mismatch between the standard and the sample, as well as the presence of matrix elements have been evaluated. Intermediate precision of better than ±0.030‰ for δ65Cu (2SD) was routinely obtained on NIST SRM 3114 and NWU-Cu-A. Accurate measurements were achieved when CNa/CCu < 0.5, CTi/CCu, CFe/CCu and CCo/CCu < 1, CNi/CCu < 3 and CZn/CCu < 10. High-precision Cu isotopic data were determined for nineteen geological reference materials, including igneous rocks, sedimentary rocks, metamorphic rocks and chalcopyrite, with an overall range of ∼0.44‰ (−0.056‰ to 0.384‰), nearly 15 times the current analytical precision. The Cu isotopic data of these reference materials can be used for future interlaboratory comparisons. [ABSTRACT FROM AUTHOR]

Lipase B from Candida antarctica (CALB) and lipase from Thermomyces lanuginosus (TLL) were immobilized on octyl agarose. Then, the biocatalysts were chemically modified using glutaraldehyde, trinitrobenzenesulfonic acid or ethylenediamine and carbodiimide, or physically coated with ionic polymers, such as polyethylenimine (PEI) and dextran sulfate. These produced alterations of the enzyme activities have, in most cases, negative effects with some substrates and positive with other ones (e.g., amination of immobilized TLL increases the activity versus p-nitro phenyl butyrate (p-NPB), reduces the activity with R-methyl mandate by half and maintains the activity with S-isomer). The modification with PEI increased the biocatalyst activity 8-fold versus R-methyl mandelate. Enzyme stability was also modified, usually showing an improvement (e.g., the modification of immobilized TLL with PEI or glutaraldehyde enabled to maintain more than 70% of the initial activity, while the unmodified enzyme maintained less than 50%). The immobilized enzymes were also mineralized by using phosphate metals (Zn2+, Co2+, Cu2+, Ni2+ or Mg2+), and this affected also the enzyme activity, specificity (e.g., immobilized TLL increased its activity after zinc mineralization versus triacetin, while decreased its activity versus all the other assayed substrates) and stability (e.g., the same modification increase the residual stability from almost 0 to more than 60%). Depending on the enzyme, a metal could be positively, neutrally or negatively affected for a specific feature. Finally, we analyzed if the chemical modification could, somehow, tune the effects of the mineralization. Effectively, the same mineralization could have very different effects on the same immobilized enzyme if it was previously submitted to different physicochemical modifications. The same mineralization could present different effects on the enzyme activity, specificity or stability, depending on the previous modification performed on the enzyme, showing that these previous enzyme modifications alter the effects of the mineralization on enzyme features. For example, TLL modified with glutaraldehyde and treated with zinc salts increased its activity using R-methyl mandelate, while almost maintaining its activity versus the other unaltered substrates, whereas the aminated TLL maintained its activity with both methyl mandelate isomers, while it decreased with p-NPB and triacetin. TLL was found to be easier to tune than CALB by the strategies used in this paper. In this way, the combination of chemical or physical modifications of enzymes before their mineralization increases the range of modification of features that the immobilized enzyme can experienced, enabling to enlarge the biocatalyst library. [ABSTRACT FROM AUTHOR]

We compare the stable isotope compositions of Zn, S, and Cl for Apollo mare basalts to better constrain the sources and timescales of lunar volatile loss. Mare basalts have broadly elevated yet limited ranges in δ66Zn, δ34S, and δ37ClSBC+WSC values of 1.27 ± 0.71, 0.55 ± 0.18, and 4.1 ± 4.0‰, respectively, compared to the silicate Earth at 0.15, –1.28, and 0‰, respectively. We find that the Zn, S, and Cl isotope compositions are similar between the low- and high-Ti mare basalts, providing evidence of a geochemical signature in the mare basalt source region that is inherited from lunar formation and magma ocean crystallization. The uniformity of these compositions implies mixing following mantle overturn, as well as minimal changes associated with subsequent mare magmatism. Degassing of mare magmas and lavas did not contribute to the large variations in Zn, S, and Cl isotope compositions found in some lunar materials (i.e., 15‰ in δ66Zn, 60‰ in δ34S, and 30‰ in δ37Cl). This reflects magma sources that experienced minimal volatile loss due to high confining pressures that generally exceeded their equilibrium saturation pressures. Alternatively, these data indicate effective isotopic fractionation factors were near unity. Our observations of S isotope compositions in mare basalts contrast to those for picritic glasses (Saal and Hauri 2021), which vary widely in S isotope compositions from –14.0 to 1.3‰, explained by extensive degassing of picritic magmas under high-P/PSat values (>0.9) during pyroclastic eruptions. The difference in the isotope compositions of picritic glass beads and mare basalts may result from differences in effusive (mare) and explosive (picritic) eruption styles, wherein the high-gas contents necessary for magma fragmentation would result in large effective isotopic fractionation factors during degassing of picritic magmas. Additionally, in highly vesiculated basalts, the δ34S and δ37Cl values of apatite grains are higher and more variable than the corresponding bulk-rock values. The large isotopic range in the vesiculated samples is explained by late-stage low-pressure "vacuum" degassing (P/PSat ~ 0) of mare lavas wherein vesicle formation and apatite crystallization took place post-eruption. Bulk-rock mare basalts were seemingly unaffected by vacuum degassing. Degassing of mare lavas only became important in the final stages of crystallization recorded in apatite—potentially facilitated by cracks/ fractures in the crystallizing flow. We conclude that samples with wide-ranging volatile element isotope compositions are likely explained by localized processes, which do not represent the bulk Moon. [ABSTRACT FROM AUTHOR]

Curcumin (Cur) is a natural polyphenol with a wide spectrum of biological activities and appealing therapeutic potential. Herein, it has been delivered by electrospray ionization as gaseous protonated species, [Cur + H]+, and as a Cu(ii) complex, [Cu(Cur − H)]+, a promising antioxidant and radical scavenger. The gas phase structures were assayed by infrared multiple photon dissociation (IRMPD) spectroscopy in both the fingerprint (800–2000 cm−1) and hydrogen stretching (3100–3750 cm−1) ranges. Comparison between the experimental features and linear IR spectra of the lowest energy structures computed at the B3LYP/6-311+G(d,p) level reveals that bare [Cu(Cur − H)]+ exists in a fully planar and symmetric arrangement, where the metal interacts with the two oxygens of the syn-enolate functionality of deprotonated Cur and both OCH3 groups are engaged in H-bonding with the ortho OH. The effect of protonation on the energetic and geometric determinants of Cur has been explored as well, revealing that bare [Cur + H]+ may exist as a mixture of two close-lying isomers associated with the most stable binding motifs. The additional proton is bound to either the diketo or the keto-enol configuration of Cur, in a bent or nearly planar arrangement, respectively. [ABSTRACT FROM AUTHOR]

Based on analysis of anomalous magnetic and gravity fields, magnetic (to a depth of 18 km) and density (to a depth of 35 km) depth models were calculated for the Malmyzh and Poni–Mulino gold–copper–porphyry ore clusters located in the northern part of the Middle Amur sedimentary basin. A ring structure of magmatogenic origin has been distinguished, which determines the spatial location of mineralization in the Malmyzh and Poni–Mulino ore clusters. This structure can be considered as a promising area for searching for gold–copper–porphyry ore mineralization. In addition, a number of promising areas associated with granitoid and diorite intrusions developed along the periphery of the ring structure can be identified. Some of these intrusions are under the Amur River and are overlain by the sedimentary cover of the Middle Amur sedimentary basin. The calculated geophysical depth model for the Malmyzh ore cluster is consistent with the petrological models of giant Cu-porphyry deposits. [ABSTRACT FROM AUTHOR]

Early Cambrian black shales on the Yangtze Platform host a regionally distributed highly metalliferous sulfide-rich carbonaceous unit which has been the subject of extensive debate. This marker unit, with a few centimeters or tens of centimeters in thickness, displays extreme enrichment in Mo and Ni (wt% range), and in a broad spectrum of other metals such as As, Au, PGE, Re, Cu, Zn, Cd, Ag, Sb, Se, Tl, and Hg, and occurs discontinuously along the western passive margin of the Yangtze Platform. It grades laterally in stratigraphically equivalent meter-thick vanadium-rich shale and tens-of-meter-thick sapropelite (combustible shale). New Cu and Zn isotope data, combined with existing Cd, Cr, Ni, Mo, Hg, and Se isotope and other chemical data, allow to attempt an integrated view on the formation of this intriguing unit of hyper-enriched metalliferous black shale. The authigenic Cu enrichment in the 1000-ppm range has produced no or little Cu isotope fractionation (0.03 ± 0.26 ‰ δ65Cu) beyond the lithogenic background. Heavy zinc and cadmium isotope enrichment in the sulfidic samples (1.11 ± 0.18 ‰ δ66Zn, 0.31 ± 0.10 ‰ δ114Cd) is controlled by sulfide fractionation and contrasts with V-rich and barren shale (0.60 ± 0.18 ‰ δ66Zn, 0.00 ± 0.14 ‰ δ114Cd). The distinctly negative Ni isotope composition of the metalliferous unit (−0.84 ± 0.05 ‰ δ60Ni) with Ni in the percent range has been interpreted as due to hydrothermal activity related to the leaching of mafic rocks and their sulfides. Sorption processes (Fe-oxyhydroxides) and redox cycling in the water column and the bottom sediment with microbial activity could be an alternative interpretation. The extreme metal enrichment can be understood as due to a process chain, from high biological productivity in the oxic photic zone to sulfate reduction in the deeper sulfidic water column and upper sediment layer. Key to the metal enrichment seems to be extremely low clastic sedimentation and advanced carbon destruction by anaerobic oxidation. Hydrothermal input of basinal brines along the rifted margin of the Yangtze Platform was likely a part of this scenario. [ABSTRACT FROM AUTHOR]