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Zinc (Zn) exerts a significant influence on the global environment, terrestrial ecosystems, and human health. The application of Zn isotopes (δ66Zn) has been suggested as a potent tool for tracing environmental contamination. However, studies focusing on Zn isotope tracing within the cryosphere areas are notably limited. Here we present the first data set on Zn isotopes in glacial cryoconite, based on observations over a large regional scale in High Asian Mountains (including Tibetan Plateau (TP) and its surroundings of western China). The results showed that glacial cryoconite had a general heavy Zn isotopic signature in various TP locations, with δ66Zn values ranging from −0.22‰ to +0.87‰. Employing the MixSIAR model, the overall Zn contribution source to the cryoconite was mineral dust (36%) > coal burning (33%) > non‐exhaust traffic emissions (22%) > industrial smelting (10%). We ascertained that anthropogenic sources account for the primary contribution (about 60%–73%) of Zn inputs in all glacial locations, with coal burning emerging as the foremost anthropogenic contributor (mean 33%). Anthropogenic Zn in various TP locations was primarily derived from Zn emissions resulting from coal combustion, though it is also predominantly influenced by industrial smelting source in cryoconite of the Tianshan Mountains. Our results aligned with coal combustion data from the energy inventory of western China, suggesting that regional coal burning likely represents the foremost source of atmospheric Zn pollutant emission and deposition in the High Asia mountain glaciers. Plain Language Summary: This is the first to investigate Zn isotope deposition in glacial cryoconite on a large scale in the High Asian Mountains. We find that anthropogenic sources dominate glacial Zn input, contributing approximately 60%–73%, with coal combustion being the most significant anthropogenic source, accounting for a mean of 33%. This study underscores the significant potential of Zn isotopes in cryoconite for tracing atmospheric pollution transport routes and identifying pollutant sources. Key Points: The first study of Zn isotopes as geo‐environmental tracers for Zn sources and pathways in large range glacial environmentAnthropogenic emissions constitute the main source of Zn in all glacial areas, with the largest origins associated with coal burningCoal‐related Zn emissions in western China and surrounding areas (including South Asia and East Asia) influence the Tibetan Plateau environment [ABSTRACT FROM AUTHOR]

Zinc (Zn) is an essential trace element that is involved in both biotic and abiotic processes in Earth's surface environments. Over the last 20 years, advances in mass spectrometry instrumentation have enabled unprecedented high-precision Zn isotope abundance ratio determinations in natural and anthropogenic samples. Supported by a solid theoretical background inherited from the traditional non-metal stable isotopes (C, N, H, O, S), the understanding of the controlling factors of Zn isotope fractionation has rapidly evolved. In this article, we review the main applications and findings of Zn isotopes in a variety of scientific domains, including metal contamination, magmatic differentiation, plant uptake, weathering, global climate change, dietary and trophic chains, and biomedicine. The analytical aspects of Zn isotope determination in solid and water samples and the principles and mechanisms of Zn isotope fractionation are also reviewed. This work aims to provide a general yet in-depth panorama of Zn isotope chemistry and to demonstrate the versatility and potential of this isotope system for studying the biological, geological and chemical cycling of Zn. [ABSTRACT FROM AUTHOR]

Trophic ecology and resource use are challenging to discern in migratory marine species, including sharks. However, effective management and conservation strategies depend on understanding these life history details. Here we investigate whether dental enameloid zinc isotope (δ66Znen) values can be used to infer intrapopulation differences in foraging ecology by comparing δ66Znen with same-tooth collagen carbon and nitrogen (δ13Ccoll, δ15Ncoll) values from critically endangered sand tiger sharks (Carcharias taurus) from Delaware Bay (USA). We document ontogeny and sex-related isotopic differences indicating distinct diet and habitat use at the time of tooth formation. Adult females have the most distinct isotopic niche, likely feeding on higher trophic level prey in a distinct habitat. This multi-proxy approach characterises an animal's isotopic niche in greater detail than traditional isotope analysis alone and shows that δ66Znen analysis can highlight intrapopulation dietary variability thereby informing conservation management and, due to good δ66Znen fossil tooth preservation, palaeoecological reconstructions.

Understanding the compositional heterogeneity of the deep mantle requires identifying the nature of recycled crustal materials in the sources of mantle-plume-related magmas. However, it is still unclear whether or not the deep mantle contains recycled carbonates from the Earth's surface. In this study, we present comprehensive data on whole-rock high-precision zinc isotopes, as well as major- and trace-element geochemistry, and Sr–Nd–Pb isotopes of basalts on Hainan Island to examine the influence of recycled materials (particularly carbonates) on the mantle source heterogeneity of the Hainan mantle plume. The basalts have highly variable δ66Zn values ranging from 0.21‰ to 0.42‰. These variable Zn isotopic compositions cannot be accounted for by processes such as post-magmatic alteration and crustal contamination, or by fractional crystallization and partial melting; instead, they reflect mantle heterogeneity. Comparisons of the major- and trace-element compositions (e.g., CaO and TiO2 contents and Zn/Fe and Fe/Mn ratios), FC3MS and FCKANTMS peridotite and pyroxenite melting parameters, as well as pseudo-ternary projections of the primary Hainan basaltic magmas with experimental data suggest that the primary magmas were partial melts of silica-deficient pyroxenitic lithologies with peridotite residue. The heterogeneous geochemical and lithological compositions of the Hainan basalts indicate that recycled sedimentary carbonates and siliceous rocks were important constituents in their mantle source. Quantitative modeling reveals that the addition of 1–10% subducted sediments into the source of the Hainan basalts closely reproduces their Zn–Sr–Nd–Pb isotopic values. The source component with the heaviest Zn isotopic composition measured for the Hainan basalt samples could have contained more than 9% recycled carbonate. Our findings provide insights into the role of subducted materials to mantle heterogeneity and highlight the contribution of subducted sedimentary carbonates in the deep recycling of oceanic slabs, including—in the case of the Hainan mantle plume—recycled deep mantle (i.e., the mantle transition zone and lower mantle). [ABSTRACT FROM AUTHOR]

The isotope ratios of zinc (66Zn/64Zn expressed as δ66Zn), a vital nutrient, increasingly demonstrate trophic discrimination among vertebrates, making δ66Zn a valuable dietary proxy for ecological, archaeological, and palaeontological studies. Given the novelty of the methodology, tissue-diet and tissue-tissue zinc isotope fractionation factors remain poorly understood and have so far only been studied in a few terrestrial mammals. Here, we investigate δ66Zn compositions of enameloid, bone, and white muscle of seven artificially-fed pisciculture gilt-head seabreams (Sparus aurata) from offshore Israel, in comparison to the Zn isotope composition of their diet. In addition, we also analysed δ66Zn values in the same tissues of wild-caught S. aurata, bluespotted seabream (Pagrus caeruleostictus) and grey triggerfish (Balistes capriscus) caught off the coast of Israel. We determine a tissue-diet δ66Zn offset for Sparus aurata of − 0.04 ± 0.09 ‰ (2SD) for bone, − 0.29 ± 0.06 ‰ (2SD) for enameloid, and − 0.45 ± 0.07 ‰ (2SD) for white muscle. Wild-caught fish have much higher among-individual δ66Zn variability with values distinct from the pisciculture S. aurata, documenting a much more isotopically heterogeneous diet consumed by the wild individuals. Still, tissue–tissue δ66Zn differences in wild-caught individuals are close to those observed in the pisciculture ones with progressively lower δ66Zn values in the order bone > enameloid > white muscle. Our results demonstrate predictable tissue-diet and tissue-tissue δ66Zn differences among fish hard and soft tissues and can be applied to identify the δ66Zn values of dietary input, thereby informing trophic (palaeo)ecological reconstructions. [ABSTRACT FROM AUTHOR]

We analyzed the Zn isotopic compositions of nuclear debris samples from atmospheric and underground nuclear tests. Samples from the site of atmospheric tests exhibit a range of Zn isotopic fractionation (δ66ZnJMC-Lyon = 0.23–0.86 ‰) while samples from underground tests exhibit Zn isotopic compositions with minimal variation among samples and from terrestrial igneous rock standards (δ66ZnJMC-Lyon = 0.28–0.39 ‰). The larger range of δ66ZnJMC-Lyon observed in atmospheric test samples relative to underground test samples is likely the result of the open system characteristics of atmospheric nuclear tests and the closed system characteristics of underground nuclear tests. [ABSTRACT FROM AUTHOR]

Here we present an analytical method for Zinc (Zn) isotopic measurements using "standard‐sample bracketing" on a Nu Sapphire multi‐collector inductively coupled plasma‐mass spectrometer. The effects of Zn mass fraction and HNO3 molarity mismatch between the standard and the sample, as well as the presence of matrix elements have been evaluated. Long‐term reproducibility of better than ±0.03‰ for δ66Zn (2s) was routinely obtained. Accurate measurements were achieved when CNi/CZn < 0.001, CTi/CZn < 0.03, CBa/CZn < 0.05, CNa/CZn and CAl/CZn < 0.5, CMg/CZn < 0.1, CFe/CZn < 5 and CCu/CZn as well as CCd/CZn < 10. High‐precision Zn isotopic determination were performed on twenty‐one widely available geological certified reference materials, with an overall range of ~ 0.62‰ (0.15 to 1.07‰), which is nearly twenty times the current analytical precision (0.03), and the results are in agreement with most previously published data within 2s. Among them, δ66ZnJMC 3‐0749L of eleven geological certified reference materials are reported for the first time: 0.22 ± 0.03‰ (dolerite, DR‐N), 0.23 ± 0.02‰ (gabbro, GSR‐10), 0.20 ± 0.04‰ (microgabbro, PM‐S), 0.15 ± 0.02‰ (andesite, GSR‐2), 0.22 ± 0.08‰ (diorite, GSR‐9), 0.19 ± 0.07‰ (syenite, GSR‐7), 0.30 ± 0.06‰ (granite, GSR‐1), 0.25 ± 0.00‰ (rhyolite, GSR‐11), 0.37 ± 0.01‰ (shale, GSR‐5), 0.21 ± 0.03‰ (limestone, GSR‐6) and 0.20 ± 0.03‰ (hornblendite, GSR‐15). The novel Zn isotopic data from these certified reference materials can be used for future interlaboratory comparisons. [ABSTRACT FROM AUTHOR]

Lamprophyres are mantle-derived rocks characterized by enrichment of incompatible elements and volatiles; however, the origin of their enriched sources remains enigmatic. Here we present zinc isotopic data for contemporary Mesoproterozoic (~ 1.1 Ga) lamprophyres from three localities of the Eastern Dharwar Craton. The Mudigubba and Kadiri lamprophyres with island-arc basalt (IAB)-like trace element features, such as positive Pb and negative Nb–Ta, Zr–Hf and Ti anomalies, have mid-ocean ridge basalt (MORB)-like δ66Zn values ranging from + 0.22‰ to + 0.29‰. In contrast, the Udiripikonda lamprophyre shows higher-than-MORB δ66Zn values of + 0.39‰ to + 0.48‰ and elemental features of intra-plate magmas with a lack of pronounced Nb–Ta-negative anomalies. Based on the covariations between Zn isotopes and trace element ratios, we infer that the Mudigubba and Kadiri lamprophyres with MORB-like Zn isotopes and high Ba/La, K/Nb and low Nb/La, Ce/Pb ratios are inherited from sub-continental lithospheric mantle metasomatized by fluids derived from a subducted slab. On the contrary, the higher-than-MORB Zn isotopic compositions, with low Ba/La, K/Nb and high Nb/La, Ce/Pb, K/U and Ba/Th ratios for the Udiripikonda lamprophyre are inferred to derive from lithospheric mantle enriched by carbonatitic melts or subducted carbonate-bearing sediments within the mantle transition zone. Hence, our study suggests that contemporary lamprophyres can be derived from disparate enriched mantle sources. [ABSTRACT FROM AUTHOR]

A sensitive and reliable biomarker of zinc status has yet to be identified, but observational research suggests that the exchangeable zinc pool (EZP) size may be a possible biomarker. This randomized, placebo-controlled trial aimed to compare the change in EZP size from baseline to endline in 174 children who were preventatively supplemented with 10 mg of zinc as part of a multiple micronutrient power (MNP) or as a standalone dispersible tablet for 24 weeks versus a placebo powder. The effects of systemic inflammation on EZP size were also evaluated. Zinc stable isotopes were administered intravenously to children at baseline and endline, and the EZP was measured by the urine extrapolation method. A total of 156 children completed the study with the zinc dispersible tablet group having the greatest increase in EZP (14.1 mg) over 24 weeks when compared with the MNP group (6.8 mg) (p < 0.01) or placebo group (2.0 mg) (p < 0.001). Median EZP size was not different between children with normal or elevated serum inflammatory markers. EZP size was responsive to longitudinal zinc supplementation and reflected the expected difference in bioavailability for two forms of supplementation. The apparent absence of an effect of inflammation on EZP size may offer an advantage for use as a biomarker for group comparisons between different interventions.

To constrain how impacts influence the behavior of moderately volatile elements (MVEs), we report potassium (K) and zinc (Zn) contents and isotopic compositions of shock melt pockets (SMPs) and unmelted parts of three heavily shocked ordinary chondrites and bulk rocks of Chelyabinsk meteorite. All SMPs are enriched in K content and have lower isotopic values (δ41K = −1.99‰, −1.22‰ and −1.40‰) while the adjacent unmelted parts are enriched in heavy K isotopes (δ41K = −0.41‰, −0.01‰ and 0.04‰) compared to the bulk rocks of Chelyabinsk meteorite (δ41K = −0.77‰ and −0.73‰). By contrast, Zn is depleted in SMPs and the isotopic compositions are heavier (δ66Zn = −0.19‰, 2.42‰, 1.74‰) in SMPs than that in unmelted parts (δ66Zn = −0.65‰, 1.76‰, −0.97‰). Our results indicate a decoupling between the two MVEs that Zn is lost from shock melts while K is dramatically enriched in shock melts during impacts. The isotope fractionation of Zn is probably caused by evaporation of shock melts, while K isotope fractionation is most likely caused by solid-melt diffusion which is controlled by its incompatibility. The isotopic decoupling of K from Zn during major impacts further enhances our understanding of high temperature elemental and isotopic behavior of MVEs and may shed new light on the variously heterogeneous distribution of MVEs in solar system. [ABSTRACT FROM AUTHOR]

Modified 241Am-Be neutron beams showed an ability to change the optical properties of zinc oxide (ZnO) photoluminescence (PL) spectra by transmuting zinc (Zn) into gallium (Ga) after irradiation. This study investigates the time required by slow neutron irradiation to register the transmutation of the Zn into Ga. Two series of samples from different suppliers hydrothermally (HT) grown by TEW Tokyo Denpa Co. Ltd., Tokyo, Japan, and MTI corporation, China, are irradiated for 6, 12, 18, and 24 days on the Zn-polar face of each sample to specify the relationship between the irradiation intensity and transmutation. [ABSTRACT FROM AUTHOR]

Zinc (Zn) isotope data for mid-ocean ridge basalts (MORB) are scarce. The possible effects of MORB differentiation and mantle compositional heterogeneity on MORB Zn isotope compositions are poorly understood. In this paper, we report Zn isotope data of MORB lavas from the East Pacific Rise (EPR) at 10°30′N, which are understood to have been derived by a similar extent of melting from a compositionally uniform mantle source but manifest significantly varying extents of magma differentiation (MgO = 7.38–1.76 wt%) to demonstrate unequivocal Zn isotope fractionation during MORB differentiation. These lavas have a small δ66Zn (relative to the JMC-Lyon standard) range of 0.21–0.32‰, with an average of 0.26 ± 0.07‰ (2SD, N = 24), overlapping with literature data. However, δ66Zn values show significant correlations with indices of magma differentiation (e.g., MgO and CaO), with the more differentiated samples having isotopically heavier Zn. We can thus conclude that MORB differentiation can lead to ∼0.1‰ δ66Zn elevation, which is similar to that observed in Hawaiian Kilauea Iki lava lake samples. Fractional crystallization of olivine and clinopyroxene at MgO > ∼3.5 wt% and clinopyroxene and Fe–Ti oxides dominated by ilmenite at MgO < ∼3.5 wt% results in the observed Zn isotope fractionation. The δ66Zn values for primitive N-MORB and MORB source mantle are estimated to be ∼0.22‰ and ∼0.17‰, respectively. Furthermore, we observe a positive correlation between δ66Zn and [La/Sm] N in primitive (MgO = 7.58–9.01 wt%) literature MORB, indicating the existence of possible Zn isotope heterogeneity in the oceanic upper mantle. We thus predict heavy Zn isotope enrichment in mantle sources for E-MORB samples with high [La/Sm] N , which requires future testing. [ABSTRACT FROM AUTHOR]

In the past few years, zinc isotope systematics of basaltic magmas have been widely used as novel proxies for terrestrial mantle heterogeneity induced by recycled crustal materials and for planet formation and evolution. The influence of crystal-melt isotope disequilibrium during magma differentiation on the zinc isotopic composition of basaltic melts, nonetheless, has received little attention. In addition, no quantitative constraint has yet been given for the diffusion-driven Zn isotope fractionation between olivine crystals and melts. Here we present high-precision zinc isotope data (δ66Zn JMC-Lyon) for a series of olivine phenocrysts separated from intra-plate alkali basalts from the Jiaodong Peninsula in Eastern China, together with in-situ chemical analysis. Olivine phenocrysts have Zn isotopic compositions which are too light in comparison with the host basaltic melts (Δ66Zn ol-melt = −0.41‰ to −0.10‰; n = 16) to be explained by equilibrium isotope fractionation at magmatic temperatures. Instead, the decrease of δ66Zn values with decreasing Mg# (i.e., Mg/[Mg + Fe2+] × 100) and increasing Zn + Fe2+ contents in olivine phenocrysts suggests diffusion-driven kinetic fractionation during olivine crystallization. The data is well-fitted with a diffusion model in which Zn together with Fe2+ diffuse from surrounding melt into olivine crystals and approximately equal flux of Mg diffuses into melt due to the large chemical gradient, yielding a kinetic Zn isotope fractionation factor β Zn of 0.07. By utilizing the fractional crystallization model under equilibrium or disequilibrium conditions, it is suggested that diffusion-induced isotope disequilibrium during olivine crystallization may drive Zn isotopic composition of the residual melt toward heavier values. When using zinc isotope systematics of any basaltic magma to probe the source heterogeneity, this impact must be taken into account if the Zn isotope disequilibrium widely exists in olivine phenocrysts. Based on the time-related quantitative diffusion model, our results show that the magma residence time for strongly alkali basaltic lavas (∼20 days) is 10–60 times shorter than that for weakly alkali basaltic lavas (6 months to 4 years). This supports the generation of weakly alkali basalts via interaction between silica-undersaturated melts and the surrounding lithospheric mantle, implying a probable common mechanism in intra-plate basalts that could be comparable globally. Thus, Zn isotope disequilibrium between olivine crystals and melts could provide valuable information on the evolution history of intra-plate basaltic magmas. [ABSTRACT FROM AUTHOR]

The North Pacific has played an important role in ongoing discussions on the origin of the global correlation between oceanic dissolved Zn and Si, while data in the North Pacific have remained sparse. Here, we present dissolved Zn and δ66Zn data from the US GEOTRACES GP15 meridional transect along 152°W from Alaska to the South Pacific. In the south (<20°N) Zn and Si exhibit a tight linear correlation reflecting strong Southern Ocean influence, while in the north (>20°N) an excess of Zn relative to Si in upper and intermediate waters is due to regeneration of Zn together with PO4. Using a mechanistic model, we show that reversible scavenging is required as an additional process transferring Zn from the upper to the deep ocean, explaining the deep Zn maximum below the PO4 maximum. This mechanism applied for reversible scavenging also provides an explanation for the observed isotope distribution: (a) fractionation during ligand binding and subsequent removal of residual heavy Zn in the upper ocean, drives the upper ocean toward lower δ66Zn, while (b) release of heavy Zn then coincides with the PO4 maximum where carrier particles regenerate, causing a mid‐depth δ66Zn maximum. In the upper ocean, seasonal physical stratification is an additional important process influencing shallow δ66Zn signals. At the global scale, this mechanism invoking fractionation during ligand binding coupled with reversible scavenging offers a global explanation for isotopically light Zn at shallow depths and corresponding elevated mid‐depth δ66Zn signals, seen dominantly in ocean regions away from strong Southern Ocean control. Plain Language Summary: Zinc (Zn) is a vital micronutrient for marine phytoplankton and shows a global distribution similar to dissolved silicon, with greatest enrichment deeper than the macronutrients phosphate and nitrate. The correlation between Zn and silicon arises from their similar biogeochemical behavior in the Southern Ocean and the large‐scale circulation. In this study, we investigate the distribution of Zn and its isotopes along a transect from Alaska to the South Pacific. Using a mechanistic model, we show that adsorption of Zn onto sinking organic particles, termed reversible scavenging, transfers Zn from the upper ocean to depths, providing an explanation for the observed deep Zn maximum below the phosphate maximum. Furthermore, the applied mechanism for reversible scavenging is consistent with the observed Zn isotope distribution. In the upper ocean, removal of isotopically heavy Zn via scavenging leads to enrichment of light Zn in surface waters. The heavy Zn is released back to the water column where carrier particles remineralize, causing an enrichment of heavy Zn at mid‐depth (∼1,000 m). At the global scale, our mechanism offers an explanation for isotopically light Zn at shallow depths and corresponding elevated mid‐depth signals, seen dominantly in ocean regions away from strong Southern Ocean control. Key Points: Regeneration of Zn together with PO4 and reversible scavenging play important roles for the Zn‐Si relationship in the North PacificFractionation during ligand binding coupled with reversible scavenging of Zn can explain the large‐scale δ66Zn distributionSeasonal physical stratification is an important process influencing surface and subsurface δ66Zn signals in the North Pacific [ABSTRACT FROM AUTHOR]

Material inherited from different nucleosynthesis sources imparts distinct isotopic signatures to meteorites and terrestrial planets. These nucleosynthetic isotope anomalies have been used to constrain the origins of material that formed Earth. However, anomalies have only been identified for elements with high condensation temperatures, leaving the origin of Earth’s volatile elements unconstrained. We determined the isotope composition of the moderately volatile element zinc in 18 bulk meteorites and identified nucleosynthetic zinc isotope anomalies. Using a mass-balance model, we find that carbonaceous bodies, which likely formed beyond the orbit of Jupiter, delivered about half of Earth’s zinc inventory. Combined with previous constraints obtained from studies of other elements, these results indicate that ~10% of Earth’s mass was provided by carbonaceous material. [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]

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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]

This study presents a high-resolution record of Cu and Zn isotopes in four Fe-Mn crusts from the North and South Pacific oceans. North Pacific crusts were collected on the Apuupuu seamount south of the Hawaiian archipelago and South Pacific crusts were recovered near Rurutu Island in the Tahiti archipelago. Major and trace element compositions suggest that Cu and Zn in these crusts is of hydrogenous origin, i.e., precipitated from seawater, and they may therefore mirror deep seawater metal isotope. We show that Cu and Zn display different isotopic patterns between the North and the South Pacific Oceans but show similar temporal evolution within each geographical area. Copper and Zn isotope composition of both North Pacific crusts vary between 0.57 ‰ to 0.73 ‰ for δ 65/63Cu NIST976 and 0.97 ‰ to 1.25 ‰ for δ 66/64Zn JMC-Lyon. In contrast, South Pacific crusts show resolvable temporal variations, with Cu and Zn isotopic ratios increasing sharply over the last ∼ 6 Ma from 0.16 ‰ to 0.51 ‰ and 0.67 ‰ to 1.09 ‰ respectively. Notably, we observed a positive correlation between δ 65/63Cu NIST976 and δ 66/64Zn JMC-Lyon values in Fe-Mn crusts from the South Pacific. The correlation suggests mixing between two components in Fe-Mn crusts, a hydrothermal component with δ 65/63Cu NIST976 ∼ 0.2 ‰ and δ 66/64Zn JMC-Lyon ∼ 0.7 ‰, and a Pacific deep seawater component with δ 65/63Cu NIST976 ∼ 0.7 ‰ and δ 66/64Zn JMC-Lyon ∼ 1.2 ‰. These values are fractionated from modern dissolved Cu and Zn by a factor of −0.3 ‰ and 0.5 ‰ respectively. We suggest that the deep Southern Pacific Ocean received sustained hydrothermal input during the last 6 Ma, which was recorded in the Cu and Zn isotope composition of Fe-Mn crusts precipitated thousands of kilometers away. Our study highlights that hydrothermal venting may be a significant source of Cu and Zn in the deep oceans despite their extensive precipitation within hydrothermal vent fields. We show that this source could be persistent through time, and thus, it could have a significant impact on the biogeochemical cycling of Cu and Zn in seawater which would ultimately be recorded by Fe-Mn crusts. [ABSTRACT FROM AUTHOR]

This study examined the micro‐homogeneity of zinc isotope composition of the NIST SRM 683 and NBS 123 reference materials using femtosecond laser ablation multi‐collector inductively coupled plasma‐mass spectrometry (fsLA‐MC‐ICP‐MS). NIST SRM 683 and NBS 123 are homogeneous in Zn isotope composition based on numerous measurements performed on twenty chips and four mounts of sphalerite using solution nebulisation (SN)‐MC‐ICP‐MS and fsLA‐MC‐ICP‐MS. The mean δ66ZnJMC‐Lyon values of NIST SRM 683 and NBS 123 determined by SN‐MC‐ICP‐MS were 0.11 ± 0.02‰ (2 standard deviation (2s), n = 100) and 0.16 ± 0.02‰ (2s, n = 62), respectively. The mean δ66ZnJMC‐Lyon values determined by fsLA‐MC‐ICP‐MS analyses for NIST SRM 683 and NBS 123 were 0.12 ± 0.05‰ (2s, n = 200) and 0.16 ± 0.05‰ (2s, n = 212), consistent with the bulk isotope compositions within uncertainty. The in situ measurement precision for NIST SRM 683 and NBS 123 was better than 0.06‰ (2s), suggesting NIST SRM 683 and NBS 123 are suitable to serve as microanalytical reference materials for Zn isotope measurement. Zinc isotopic compositions of Zn‐rich materials were also determined using fsLA‐MC‐ICP‐MS under wet/dry plasma conditions. Their δ66ZnJMC‐Lyon values were in agreement with those obtained by SN‐MC‐ICP‐MS analysis, suggesting that fsLA‐MC‐ICP‐MS is suitable to measure Zn isotopic ratios in Zn‐rich materials. Thus, this method could potentially analyse spatially resolved Zn isotope compositions at the mineral or even sub‐mineral scale, such as to address the process of ore formation or Zn redistribution in near‐surface environments. [ABSTRACT FROM AUTHOR]

Elucidating the migration processes of zinc (Zn) is crucial for comprehending its influence on global biogeochemical cycling. However, significant gaps remain in the knowledge of these processes in glacier-fed rivers of the northeast Tibetan Plateau (NETP). This study determined the isotopic compositions (δ 66 Zn) of dissolved and particulate Zn in three alpine rivers fed by the Laohugou Glacier (LHG), the Lenglongling Glacier (LG), and the Yuzhufeng Glacier (YG) in the NETP. Results show that the δ 66 Zn of particulate Zn varies from -0.01 ± 0.04 to +0.97 ± 0.12‰, generally higher than that of dissolved Zn (-0.82 ± 0.06 to +0.19 ± 0.03‰). This suggests a migration behavior in which isotopically lighter Zn is enriched in the dissolved phase and isotopically heavier Zn preferentially adsorbs onto the particulate matter. Moreover, the δ 66 Zn in the dissolved phase exhibits obvious spatial variation, with an upward trend from the LHG-fed river to the YG-fed river and subsequently to the LG-fed river. In contrast, this trend is less pronounced in the particulate phase due to an anomalously high δ 66 Zn value (0.97 ± 0.12‰). This isotopic anomaly is primarily attributed to anthropogenic impacts. A comparison with global terrestrial aquatic environments emphasizes the unique response of Zn isotope variability in NETP glacier-fed rivers to both migration processes and anthropogenic impacts.

Abstract Background Some subspecies of Dichapetalum gelonioides are the only tropical woody zinc (Zn)-hyperaccumulator plants described so far and the first Zn hyperaccumulators identified to occur exclusively on non-Zn enriched 'normal' soils. The aim of this study was to investigate Zn cycling in the parent rock-soil-plant interface in the native habitats of hyperaccumulating Dichapetalum gelonioides subspecies (subsp. pilosum and subsp. sumatranum). We measured the Zn isotope ratios (δ66Zn) of Dichapetalum plant material, and associated soil and parent rock materials collected from Sabah (Malaysian Borneo). Results We found enrichment in heavy Zn isotopes in the topsoil (δ66Zn 0.13 ‰) relative to deep soil (δ66Zn -0.15 ‰) and bedrock (δ66Zn -0.90 ‰). This finding suggests that both weathering and organic matter influenced the Zn isotope pattern in the soil-plant system, with leaf litter cycling contributing significantly to enriched heavier Zn in topsoil. Within the plant, the roots were enriched in heavy Zn isotopes (δ66Zn ~ 0.60 ‰) compared to mature leaves (δ66Zn ~ 0.30 ‰), which suggests highly expressed membrane transporters in these Dichapetalum subspecies preferentially transporting lighter Zn isotopes during root-to-shoot translocation. The shoots, mature leaves and phloem tissues were enriched in heavy Zn isotopes (δ66Zn 0.34–0.70 ‰) relative to young leaves (δ66Zn 0.25 ‰). Thisindicates that phloem sources are enriched in heavy Zn isotopes relative to phloem sinks, likely because of apoplastic retention and compartmentalization in the Dichapetalum subspecies. Conclusions The findings of this study reveal Zn cycling in the rock-soil-plant continuum within the natural habitat of Zn hyperaccumulating subspecies of Dichapetalum gelonioides from Malaysian Borneo. This study broadens our understanding of the role of a tropical woody Zn hyperaccumulator plant in local Zn cycling, and highlights the important role of leaf litter recycling in the topsoil Zn budget. Within the plant, phloem plays key role in Zn accumulation and redistribution during growth and development. This study provides an improved understanding of the fate and behaviour of Zn in hyperaccumulator soil-plant systems, and these insights may be applied in the biofortification of crops with Zn.

Collagen extraction from bones or dentine, commonly used for radiocarbon (14C) dating and stable carbon and nitrogen isotope (δ13C and δ15N) analyses, involves the dissolution of the bioapatite of skeletal elements. This fraction is typically disposed of during pretreatment. Here, we test the possibility of utilising this dissolved mineral solution for analysis of the bioapatite zinc isotope composition (δ66Zn). Bioapatite δ66Zn is a novel trophic level indicator similar to collagen δ15N but with isotopic fractionation independent from nitrogen, thus providing additional dietary information. We tested ways to minimise Zn contamination of the dissolved mineral phase during collagen extraction. We then used archaeological bone samples from Ain Difla (Jordan) and Ranis (Germany) to compare δ66Zn values of dissolved bioapatite following our collagen extraction protocol with δ66Zn values from the same sample material dissolved in a metal-free cleanroom. Our results demonstrate that with only minor adjustments to minimise Zn contamination, the dissolved mineral solution from collagen extraction protocols commonly employed for 14C dating and (palaeo)dietary analysis can be used for additional δ66Zn analyses even when collagen extraction does not take place in a cleanroom. Our protocol allows us to gain an additional dietary proxy to complement δ15N trophic level interpretations and perform more robust (palaeo)ecological investigations without further destructive sampling. [ABSTRACT FROM AUTHOR]

Subducting oceanic crust is a critical driver of chemical and lithological heterogeneity within the deep mantle. Zinc isotopes (δ66Zn JMC-Lyon) have been widely utilized to trace recycled oceanic crust and surficial materials. However, the lower oceanic crust rocks are not well studied given limited sampling, making it unclear if the δ66Zn estimated from mid-ocean ridge basalts (MORBs) is valid to represent that of the bulk oceanic crust. In this study, we report δ66Zn data for a series of gabbro cumulates (n = 37) from the ultraslow-spreading Southwest Indian Ridge, alongside MORBs (n = 12) from the fast-spreading East Pacific Rise and the slow-spreading South Mid-Atlantic Ridge. MORBs across various spreading rates exhibit homogeneous δ66Zn values (0.27 ± 0.05 ‰, 2sd), in agreement with previous studies. In contrast, the gabbros with several magma episodes exhibit a significant variation of δ66Zn from 0.11 ‰ to 0.34 ‰, with an average of 0.22 ± 0.11 ‰ (2sd). Magma differentiation to form oceanic crust can partly explain such variation (∼ 0.10 ‰), and post-cumulus modification further extends this range. Given the voluminous lower oceanic crust, the weighted δ66Zn estimated for the bulk oceanic crust (0.23 ± 0.03 ‰) is lower than the MORB-based value, which reconciles with the predictions from mantle partial melting. Therefore, recycled oceanic crust with significantly varied Zn isotopic compositions would lead to heterogeneous δ66Zn of the metasomatized mantle. The overall lower δ66Zn value underscores the importance of surficial materials other than oceanic crust, such as carbonates, to explain high δ66Zn of many mantle-derived magmas. • Gabbros show highly variable δ66Zn, contrasting with homogeneous isotopes in MORBs. • Magma differentiation with post-cumulus modification accounts for δ66Zn variation. • The estimated δ66Zn of bulk oceanic crust (0.23 ± 0.03 ‰) is lower than MORBs. • Recycled oceanic crust would lead to heterogeneous δ66Zn of metasomatized mantle. [ABSTRACT FROM AUTHOR]

• Negative anomalies and low δ56Fe in the Gaoyuzhuang Formation Member II indicate a transient oxygenation event at ∼1.57 Ga. • Positive δ66Zn excursion is observed in the same interval, indicating enhanced organic carbon burial and promoted primary productivity. • Enhanced organic carbon burial and promoted primary production triggered the oxygenation event at ∼1.57 Ga. The Mesoproterozoic era has long been thought to have low atmospheric oxygen and predominant oceanic anoxia, but recent studies argue that the oxygen levels in Mesoproterozoic oceans transiently raised at 1.58–1.56 Ga. To constrain the primary driving mechanism for this oxygenation event, here we present the first zinc isotope study of carbonates across the 1.58–1.56 Ga Gaoyuzhuang Formation in the Jixian section, North China, as well as rare earth elements and Fe isotope analyses that are sensitive to the redox changes of seawater. The coupled decline of Fe isotopic ratios (δ56Fe) from –0.02 ‰ to –0.83 ‰ and Ce anomalies ( Ce/Ce n ∗ = Ce n /(Pr n 2 /Nd n) or C e n / (L a n × P r n) 1 / 2 ) from 1.12 to 0.74 starting at Member II suggests an episode of increase in oxygen levels. Meanwhile, a positive excursion of Zn isotopic ratios (δ66Zn) from 0.63 ‰ to 1.38 ‰ is observed at the same interval, indicating enhanced organic carbon burial. The organic matter deposited in the shallow sediments preferentially incorporated isotopically light Zn, accounting for the elevated Zn isotopic values of seawater as recorded in the carbonates. Enhanced sequestration of carbon may have contributed to the rise in oceanic O 2 levels, which in turn provided positive feedback on ocean oxygenation in the context of biological pump. Our results suggest that the pulsed rise in oxygen levels in the Mesoproterozoic ocean was most likely driven by an increase in primary productivity and enhanced organic carbon burial at ∼1.57 Ga. [ABSTRACT FROM AUTHOR]

Many high silica granites (>70 wt% SiO 2) are closely linked to ore deposits. There has been an ongoing debate about whether they are formed through extensive fractional crystallization or partial melting, as traditional major-trace element and radiogenic isotopes make it challenging to distinguish among these mechanisms. Recent studies suggest that zinc isotopes have the potential to trace crustal differentiation and monitor fluid evolution during the late stage of magma evolution. In this study, we investigated the Lenglongling leucogranites in the North Qilian Orogenic belt, characterized by high SiO 2 contents ranging from 72 % to 78 wt%, extremely low Zr/Hf ratios (15.8–21), low Nb/Ta ratios (3.8–9.3), and strongly negative Eu/Eu* anomalies (0.04–0.32). The invariant and basalt-like zinc isotopic compositions of the Lenglongling high silica leucogranites (0.27 ‰ ±0.03 ‰ to 0.38 ‰ ± 0.03 ‰) reveal that they did not undergo extensive fractional crystallization or fluid exsolution. Instead, their homogeneous zinc isotope compositions and distinct geochemical characteristics were inherited from their protoliths during partial melting. [ABSTRACT FROM AUTHOR]

Modified 241Am-Be neutron beams showed an ability to change the optical properties of zinc oxide (ZnO) photoluminescence (PL) spectra by transmuting zinc (Zn) into gallium (Ga) after irradiation. This study investigates the time required by slow neutron irradiation to register the transmutation of the Zn into Ga. Two series of samples from different suppliers hydrothermally (HT) grown by TEW Tokyo Denpa Co. Ltd., Tokyo, Japan, and MTI corporation, China, are irradiated for 6, 12, 18, and 24 days on the Zn-polar face of each sample to specify the relationship between the irradiation intensity and transmutation.

Zinc isotopes ratios provide qualitative and quantitative information about contributions from different Zn sources in the environment. Here we present the results of a preliminary study to identify the main sources controlling Zn isotope signatures of sediments from Lake Paranoá (Brazil), an urban water reservoir. The Zn isotope ratios were measured by MC-ICP-MS and expressed as δ66/64Zn notation relative to the JMC 3-0749-L solution. The studied sediments showed a narrow isotopic range (+0.00 to +0.13 ‰; n = 10) similar to that reported for intensely weathered soils worldwide (from -0.4 to +0.2‰). The geoaccumulation index (Igeo) also suggests low or negligible influence of Zn anthropogenic source. This research provides a baseline assessment of the Zn isotopes signatures in lake sedimentary environments under the influence of these weathered soils.

Carbonate dissolution in subduction zones transfers surface carbon to the mantle and plays an important role in regulating global carbon cycles through geologic time. Petrological observations and thermodynamic models predict substantial dissolution of subducting carbonates induced by slab-derived fluids at arc mantle depths, but this dissolution process has rarely been verified by existing geochemical tracers. In this paper we show that zinc and magnesium isotopes can serve as such tracers through a comparative study on carbonate-bearing and carbonate-free sediments from the South China Sea and the Philippine Sea that are going to be subducted. Leaching experiments are further performed to characterize the isotopic difference between dissolved carbonates and silicate components in sediments. Bulk carbonate-bearing sediments and carbonate-free sediments surprisingly have indistinguishable δ66Zn (0.26 ± 0.04‰ versus 0.25 ± 0.04‰), but the former display systematically lower δ26Mg (−0.85‰ to −0.17‰, n = 10) than the latter (−0.26‰ to +0.13‰, n = 13). Leaching experiments show that dissolved carbonates have much higher δ66Zn (0.82 ± 0.26‰) and lower δ26Mg (−2.70 ± 0.35‰) compared with the silicate residues (δ66Zn = 0.21 ± 0.06‰; δ26Mg = −0.06 ± 0.14‰). These results indicate that the presence of carbonate components has insignificant influence on Zn isotopic compositions of bulk sediments but prominent influence on their Mg isotopic compositions. In this respect, the final fate of carbonates in subducting sediments can be tracked by a combined Mg and Zn isotope analysis on mantle-derived magmas. For instance, bulk carbonate-bearing sediment addition (i.e., no carbonate dissolution) during subduction would produce low δ26Mg but normal δ66Zn values (i.e., Mg-Zn isotopic "decoupling") in mantle-derived magmas. By contrast, if carbonate dissolution occurs during subduction, the high δ66Zn and low δ26Mg (i.e., Mg-Zn isotopic "coupling") signals of dissolved carbonates will be transferred to the sources of mantle-derived magmas. We test this application for a Cenozoic subduction-related, arc-like volcanic exposure from Tengchong, Southwestern China and find significant Mg-Zn isotopic coupling, which demonstrates carbonate dissolution during Indian Oceanic slab subduction. Our results also shed constraints on the amount of dissolved carbonates in the sub-arc mantle. Available data reveal the absence of high δ66Zn and low δ26Mg in global arc lavas, for which we suggest to be the result of a relatively low proportion (<20%) of dissolved calcium carbonates in the sub-arc mantle. [ABSTRACT FROM AUTHOR]

Metal stable isotopes in marine carbonates have been widely used as novel proxies for metal cycling through the geological past. Amongst these metals, copper (Cu) and zinc (Zn) have received great attention owing to their vital roles in metabolic processes. However, whether modern marine biogenic carbonates record the seawater isotope signatures of Cu (δ65Cu) and Zn (δ66Zn) and mechanisms and factors controlling isotope fractionation of these metals remain unclear, hindering applications of both isotope systems in paleoceanography. Here we present annually-resolved records of δ65Cu and δ66Zn in seven coral (Porites) cores sampled from different marine settings in the South China Sea and the Luzon Strait, western Pacific. We find that the aragonitic skeletons of corals are enriched in light Cu but heavy Zn isotopes relative to surface seawaters, with δ65Cu and δ66Zn in the range of −0.16 ± 0.06‰ to 0.40 ± 0.05‰ and 0.06 ± 0.04‰ to 0.46 ± 0.08‰ (2SD), respectively. The coral δ65Cu exhibits significant inter- and intra-colony variations, which are most likely controlled by Rayleigh-type fractionation in the calcifying fluids of corals rather than by changes in environmental factors or seawater δ65Cu. We thus suggest that δ65Cu in ancient carbonates may not be a direct record of Cu isotope compositions in coeval seawaters. In contrast, coral δ66Zn shows insignificant temporal variation, and the Zn isotope fractionation between individual corals and seawaters are relatively small and constant (0.10 ± 0.05‰, n = 33, 2SD). This limited Zn isotope fractionation is much lower than that determined during inorganic precipitation of calcite, which is likely due to pH up-regulation by the coral that changes aqueous Zn speciation, and preferential organic complexation of the heavy Zn isotopes in the calcifying fluids. Therefore, Porites corals are promising archives for tracking historical changes of surface seawater δ66Zn. Our new datasets of reef carbonates, particularly the coral δ65Cu values which are measured for the first time, could provide a better constrain on marine Cu and Zn geochemistry and their modern oceanic mass and isotope budgets. [ABSTRACT FROM AUTHOR]

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Zinc (Zn) is a bioessential element whose cycling in the marine environment is closely linked to the biological pump. As a vital micronutrient, Zn is depleted in marine surface waters and enriched in deep waters. This has given rise to the longstanding hope that Zn could serve as a robust paleoproductivity proxy. There has been a recent focus on how Zn isotope signatures can be used to track the evolution of the biological pump. However, the factors controlling variations in the sedimentary Zn isotope composition of core-top sediments are debated and these values are influenced by changes in the relative contributions of biological uptake and scavenging processes and by mineral fractionations. In order to provide a new perspective on the Zn isotopic signature of marine core-top sediments and their potential for tracing ocean biogeochemical processes, we developed a sample preparation procedure to extract organically bound Zn (excluding inorganic Zn) without a significant isotope fractionation. We tested five potential organic solvents and found that the isopropanol extraction procedure provided a reproducible and robust result that yielded the highest recovery rate of organically bound Zn without a significant associated isotopic fractionation and appeared to exclude common mineral bound forms of Zn. This extraction procedure was used to analyze the Zn concentrations and isotopic compositions (δ66Zn) of core-top sediment samples from Long Island Sound and the Peruvian continental margin. Our results suggest that the δ66Zn value of organic Zn increases with water depth, thus providing additional support for the finding that burial of isotopically light Zn occurs predominantly in shallow high-productivity sediments. However, we also found that the δ66Zn values of the estimated authigenic Zn component are consistently lighter than those of the organic Zn fraction, consistent with diagenetic (sediment pile) scavenging of organic derived Zn in sulfides imparting an isotope fractionation. [ABSTRACT FROM AUTHOR]

Mantle source heterogeneity of arc‐related magmas was traditionally thought to be predominantly affected by slab‐derived components. However, the role of forearc serpentinites in causing subarc mantle heterogeneity remains poorly constrained. Here, we present the first Zn isotope data for lavas from the Mariana and Ryukyu subduction zones. Notably, the δ66Zn values of basaltic lavas from the Mariana arc (0.16–0.18‰) and southern Okinawa Trough (0.15–0.17‰) are generally lower (∼0.10‰) than those of the mid‐ocean ridge basalts (MORB) (0.27 ± 0.05‰). Since mantle melting and magmatic differentiation respectively induce heavy Zn isotope enrichment in primary and evolved magmas, while melt extraction yields the limited Zn isotope fractionation in the mantle, lavas with low δ66Zn values thus potentially indicate the addition of subducted components. The negative correlation between the δ66Zn values and the Ba/La ratios of the basaltic lavas suggests the involvement of isotopically light fluids in their mantle sources. Forearc serpentinites are typically characterized by extremely light Zn isotope compositions. Such forearc materials were likely dragged downward to subarc depths and released isotopically light Zn in fluids to modify the overlying mantle wedge, thereby producing low δ66Zn values in arc‐related magmas. Beyond subarc depths, forearc serpentinites are broken down completely, so light Zn isotope fluids are absent. Accordingly, the basalts from the middle Mariana and Okinawa Trough display MORB‐like δ66Zn values. Collectively, Zn isotope provides new insights into the role of the recycling of forearc serpentinites in generating chemical heterogeneity in the mantle source of subduction‐related magmas. Plain Language Summary: Forearc serpentinites are hydrated by fluids released from the subducting slab, and they typically have negative δ66Zn values and strong enrichment in fluid‐mobile elements. To understand this forearc material recycling in subduction zones, we analyzed the Zn isotope composition of lavas from the Mariana and Ryukyu subduction zones. To our knowledge, this is the first study to find that the arc‐related lavas have lower δ66Zn values than those of the mid‐ocean ridge basalts. Notable negative correlations between δ66Zn and proxies for fluid addition (e.g., Ba/La and Sr isotope ratios) provide critical evidence for the importance of recycled forearc serpentinites in generating mantle Zn isotopic heterogeneity in subduction zones. Most importantly, this study proves the efficiency of using Zn isotopes as a powerful tool to distinguish the contributions of slab and mantle wedge serpentinite‐derived fluids to arc magmas. Key Points: Lavas from the Mariana and Ryukyu subduction zones have δ66Zn values lower (∼0.10‰) than those of mid‐ocean‐ridge basaltsLight Zn isotope enrichment in arc‐related lavas reflects the recycling of forearc serpentinites into subarc mantle sourcesZn isotopes can be used for discriminating the contributions of slab and mantle wedge serpentinite‐derived fluids to arc magmas [ABSTRACT FROM AUTHOR]

Background: Some subspecies of Dichapetalum gelonioides are the only tropical woody zinc (Zn)-hyperaccumulator plants described so far and the first Zn hyperaccumulators identified to occur exclusively on non-Zn enriched 'normal' soils. The aim of this study was to investigate Zn cycling in the parent rock-soil-plant interface in the native habitats of hyperaccumulating Dichapetalum gelonioides subspecies (subsp. pilosum and subsp. sumatranum). We measured the Zn isotope ratios (δ66Zn) of Dichapetalum plant material, and associated soil and parent rock materials collected from Sabah (Malaysian Borneo). Results: We found enrichment in heavy Zn isotopes in the topsoil (δ66Zn 0.13 ‰) relative to deep soil (δ66Zn -0.15 ‰) and bedrock (δ66Zn -0.90 ‰). This finding suggests that both weathering and organic matter influenced the Zn isotope pattern in the soil-plant system, with leaf litter cycling contributing significantly to enriched heavier Zn in topsoil. Within the plant, the roots were enriched in heavy Zn isotopes (δ66Zn ~ 0.60 ‰) compared to mature leaves (δ66Zn ~ 0.30 ‰), which suggests highly expressed membrane transporters in these Dichapetalum subspecies preferentially transporting lighter Zn isotopes during root-to-shoot translocation. The shoots, mature leaves and phloem tissues were enriched in heavy Zn isotopes (δ66Zn 0.34–0.70 ‰) relative to young leaves (δ66Zn 0.25 ‰). Thisindicates that phloem sources are enriched in heavy Zn isotopes relative to phloem sinks, likely because of apoplastic retention and compartmentalization in the Dichapetalum subspecies. Conclusions: The findings of this study reveal Zn cycling in the rock-soil-plant continuum within the natural habitat of Zn hyperaccumulating subspecies of Dichapetalum gelonioides from Malaysian Borneo. This study broadens our understanding of the role of a tropical woody Zn hyperaccumulator plant in local Zn cycling, and highlights the important role of leaf litter recycling in the topsoil Zn budget. Within the plant, phloem plays key role in Zn accumulation and redistribution during growth and development. This study provides an improved understanding of the fate and behaviour of Zn in hyperaccumulator soil-plant systems, and these insights may be applied in the biofortification of crops with Zn. [ABSTRACT FROM AUTHOR]

Although carbonate rocks are important for carbonate-hosted Pb Zn deposits, there is no effective constraint on the role of carbonate rocks during the Pb Zn mineralization process. This paper uses the giant Huize Pb Zn deposit (>7 Mt. metals @ 25–35 % Pb + Zn) as a case study and employs zinc isotopes to gain new insights into such issue. The Huize deposit, located in the Sichuan-Yunnan-Guizhou (SYG) Pb Zn metallogenic province, is the largest carbonate-hosted deposit in the western Yangtze Block, SW China. Zinc isotope compositions of sphalerite, altered carbonate rocks and fresh carbonate rocks from the Huize deposit are of +0.39 ‰ to +0.68 ‰ (mean + 0.52 ‰, n = 20), −0.25 ‰ to +0.34 ‰ (mean + 0.07 ‰, n = 11) and + 0.35 ‰ to +0.71 ‰ (mean + 0.51 ‰, n = 6), respectively. The initial δ66Zn value of hydrothermal fluids calculated by the Rayleigh fractionation simulation is +0.4 ‰. Such zinc isotope signatures are significantly different from those of potential source rocks, such as the basement Proterozoic metamorphic rocks (δ66Zn = +0.10 ‰ to +0.34 ‰, mean + 0.22 ‰), the host Upper Ediacaran to Middle Permian sedimentary rocks (δ66Zn = −0.24 ‰ to +0.35 ‰, mean + 0.1 ‰) and the cover Upper Permian Emeishan basalts (δ66Zn = +0.30 ‰ to +0.44 ‰, mean + 0.35 ‰). Hence, it is likely that the carbonate rocks acted zinc source and provided heavy zinc isotopes for the Pb Zn mineralization. The ore-forming fluids extracted the heavy zinc isotopes of the ore-hosting carbonate rocks, resulting in the zinc isotopes of the altered carbonate rocks being far lighter than those of the marine carbonate rocks (δ66Zn = +0.24 ‰ to +1.32 ‰). The sulfur isotope compositions (+12.9 ‰ to +15.6 ‰, mean + 14.3 ‰, n = 20) of sphalerite from the Huize deposit also suggested that the source of reduced sulfur is the marine sulfate minerals within the ore-hosting carbonate rocks. Therefore, carbonate rocks play key roles in the formation of carbonate-hosted Pb Zn deposits: 1) provide ore-forming elements and ore-hosting space through dissolution; 2) cause isotope variation (e.g., zinc isotopes) by isotope exchange; 3) act as a carbonate buffer to adjust physicochemical conditions (e.g., pH) via cyclical carbonate dissolution, CO 2 degassing and recrystallization. On the other hand, the zinc isotope mapping shows that the western part of the SYG Pb Zn metallogenic province has lighter zinc isotopes than those of the eastern part. This suggests that the migration pathway of hydrothermal fluids is likely west to east, which provides a new clue for regional Pb Zn ore prospecting. The outcomes have important benefits for understanding the genesis of Pb Zn deposits, the role of carbonate rocks and the application of zinc isotopes. [Display omitted] • Zinc isotope fractionation was jointly controlled by fluid mixing and Rayleigh fractionation. • Heavy zinc isotopes were extracted from carbonate rocks through water/rock interaction. • Carbonate rocks played a key role in the formation of carbonate-hosted Pb Zn deposits. • Zinc isotope mapping provides a new clue for regional Pb Zn ore prospecting. [ABSTRACT FROM AUTHOR]

Magnesium (Mg) and zinc (Zn) are essential nutrients for plants. Mg deficiency often occurs in rice plants grown in Zn-polluted soil. However, the mechanism for this correlation is unclear. Here, we performed culture experiments on rice plants (Oryza sativa L.) and used Mg isotopes to investigate mechanisms of Zn stress on plant Mg deficiency. Our results show that excess Zn can significantly reduce the uptake of Mg in rice tissues. The root displays positive Δ 26 Mg plant-nutrient values (δ 26 Mg plant -δ 26 Mg nutrient ; 1.90 ‰ to 2.06 ‰), which suggests that Mg enters the root cells mainly via Mg-specific transporters rather than non-selective diffusion. The decreased Δ 26 Mg plant-nutrient values with increasing Zn supply can be explained by the competition between Zn and Mg, both of which combine with same transporters in roots. In contrast, the shoots (stem and leaf) display much lower δ 26 Mg values than roots, which suggests that the transport of Mg from roots to aerial biomass is mainly via free Mg ions, during which Zn cannot competitively inhibit the movement of Mg. Our study suggests that the Mg deficiency in rice plants can be caused by high Zn-levels in soils and highlights the necessity of soil Zn-remediation in solving Mg deficiency problems in rice plants., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Metallothioneins (MTs) are cysteine-rich proteins involved in metal homeostasis, heavy metal detoxification, and protection against oxidative stress. Whether the four mammalian MT isoforms exhibit different metal binding properties is not clear. In this paper, the Cu(I) binding properties of the apo MT1A, apo MT2, and apo MT3 are compared and the relative Cu(I) binding affinities are reported. In all three isoforms, Cu4, Cu6, and Cu10 species form cooperatively, and MT1A and MT2 also form a Cu13 species. The Cu(I) binding properties of Zn7-MT1A, Zn7-MT2, and Zn7-MT3 are compared systematically using isotopically pure 63Cu(I) and 68Zn(II). The species formed in each MT isoform were detected through electrospray ionization-mass spectrometry and further characterized using room temperature phosphorescence spectroscopy. The mixed metal Cu, Zn species forming in MT1A, MT2, and MT3 have similar stoichiometries and their emission spectral properties indicate that analogous clusters form in the three isoforms. Three parallel metallation pathways have been proposed through analysis of the detailed Cu, Zn speciation in MT1A, MT2, and MT3. Pathway ① results in Cu5Zn5-MT and Cu9Zn3-MT. Pathway ② involves Cu6Zn4-MT and Cu10Zn2-MT. Pathway ③ includes Cu8Zn4-MT. Speciation analysis indicates that Pathway ② is the preferred pathway for MT2. This is also evident in the phosphorescence spectra with the 750 nm emission from Cu6Zn4-MT being most prominent in MT2. We see no evidence for different MT isoforms being optimized or exhibiting preferences for certain metals. We discuss the probable stoichiometry for MTs in vivo based on the in vitro determined binding constants., (© The Author(s) 2024. Published by Oxford University Press.)

The zinc (Zn) stable isotope system has emerged as a powerful tool for investigating natural and anthropogenic processes of interest to disciplines ranging from the Earth and planetary sciences to biomedical research. In nature, Zn isotopes typically fractionate (66Zn/64Zn) within the range of −1 and +1 permil (‰), and however, analytical limitations restrict the application of the Zn isotope system. Specifically, there is a lack of well‐characterised matrix‐matched reference materials covering most Zn isotope applications that are essential for validating laboratory performance, particularly given the contamination prone nature of Zn. Furthermore, the increasing demand for analysis of size‐limited materials and sample types displaying small, sub‐permil level Zn isotope variations requires improvements in measurement procedures. To address these limitations, the δ66Zn values of two pure Zn solutions and eighteen reference materials including the previously uncharacterised RGM‐2, BCR‐279, DOLT‐4, DOLT‐5, NASS‐7, SBC‐1, SGR‐1b, MESS‐3 and HISS‐1, and the understudied QLO‐1, SDC‐1, BCR‐414, NASS‐6 and COQ‐1 materials are reported. Furthermore, a 70Zn‐67Zn double‐spike design has been implemented that routinely achieves intermediate measurement precision better than ± 0.02‰. This represents at least a two‐fold improvement when compared with other double‐spike designs, providing a robust platform of δ66Zn values required for quality control procedures. [ABSTRACT FROM AUTHOR]

This study was done to determine the effect of age on zinc metabolism and status among healthy Korean women. Measures of zinc metabolism and status were measured in eight young women (22-24 years) and seven elderly women (66-75 years) consuming a typical Korean diet. Oral and intravenous tracers highly enriched in (67)Zn and (70)Zn were administered simultaneously. Multiple plasma, 24-h urines, and fecal samples were collected after isotope administration. In the young women, additional plasma were collected to determine zinc kinetics using a seven-compartmental model. Exchangeable Zinc Pool (EZP) was estimated by Miller's method. Plasma zinc concentrations were higher in older women than younger women (p < 0.05). EZP and urinary zinc tended to be higher in older women than younger women. Fractional and total zinc absorption and endogenous fecal zinc losses did not differ between young and older women. A comparison of the zinc kinetics of the Korean and American women showed no differences in plasma or EZP zinc parameters. However, absorbed zinc and zinc flux to slowly turning over tissues (Q7) were lower in Korean women than that of Americans (p < 0.01) suggesting the total body zinc content of Korean women is lower than that of American women.

A sensitive and reliable biomarker of zinc status has yet to be identified, but observational research suggests that the exchangeable zinc pool (EZP) size may be a possible biomarker. This randomized, placebo-controlled trial aimed to compare the change in EZP size from baseline to endline in 174 children who were preventatively supplemented with 10 mg of zinc as part of a multiple micronutrient power (MNP) or as a standalone dispersible tablet for 24 weeks versus a placebo powder. The effects of systemic inflammation on EZP size were also evaluated. Zinc stable isotopes were administered intravenously to children at baseline and endline, and the EZP was measured by the urine extrapolation method. A total of 156 children completed the study with the zinc dispersible tablet group having the greatest increase in EZP (14.1 mg) over 24 weeks when compared with the MNP group (6.8 mg) (p < 0.01) or placebo group (2.0 mg) (p < 0.001). Median EZP size was not different between children with normal or elevated serum inflammatory markers. EZP size was responsive to longitudinal zinc supplementation and reflected the expected difference in bioavailability for two forms of supplementation. The apparent absence of an effect of inflammation on EZP size may offer an advantage for use as a biomarker for group comparisons between different interventions.

Analysis of naturally occurring isotopic variations is a promising tool for investigating Zn transport and cycling in geological and biological settings. Here, we present the recently installed double-spike (DS) technique at the MAGIC laboratories at Imperial College London. The procedure improves on previous published DS methods in terms of ease of measurement and precisions obtained. The analytical method involves addition of a 64Zn–67Zn double-spike to the samples prior to digestion, separation of Zn from the sample matrix by ion exchange chromatography, and isotopic analysis by multiple-collector inductively coupled plasma mass spectrometry. The accuracy and reproducibility of the method were validated by analyses of several in-house and international elemental reference materials. Multiple analyses of pure Zn standard solutions consistently yielded a reproducibility of about ±0.05‰ (2 SD) for δ66Zn, and comparable precisions were obtained for analyses of geological and biological materials. Highly fractionated Zn standards analyzed by DS and standard sample bracketing yield slightly varying results, which probably originate from repetitive fractionation events during manufacture of the standards. However, the δ66Zn values (all reported relative to JMC Lyon Zn) for two less fractionated in-house Zn standard solutions, Imperial Zn (0.10 ± 0.08‰: 2 SD) and London Zn (0.08 ± 0.04‰), are within uncertainties to data reported with different mass spectrometric techniques and instruments. Two standard reference materials, blend ore BCR 027 and ryegrass BCR 281, were also measured, and the δ66Zn were found to be 0.25 ± 0.06‰ (2 SD) and 0.40 ± 0.09‰, respectively. Taken together, these standard measurements ascertain that the double-spike methodology is suitable for accurate and precise Zn isotope analyses of a wide range of natural samples. The newly installed technique was consequently applied to soil samples and soil leachates to investigate the isotopic signature of plant available Zn. We find that the isotopic composition is heavier than the residual, indicating the presence of loosely bound Zn deposited by atmospheric pollution, which is readily available to plants. Figure Zinc isotope ratio pools of bulk soil and the associated acid leach (estimated plant available pool) as measured by double-spike MC-ICPMS. δxZnLyon-JMC=(Rsample/RJMC-Lyon -1)x103, where Rsample and RJMC-Lyon denote the xZn/64Zn isotope ratio of the sample and standard (JMC-Lyon), respectively, and where x denotes either 66 or 68.

To test the ability of Mg and Zn isotopes in discriminating between different types of mantle metasomatism and identifying deep carbon cycling, here we present a comparative study on two types of Cenozoic lavas in SE Tibet, that is, K‐rich (potassic‐ultrapotassic) lavas and Na‐rich alkali basalts. The contrasting bulk rock chemical compositions, Sr‐Nd isotopic ratios, and olivine chemistry between them suggest distinct sources in the lithospheric mantle and asthenosphere, respectively. The K‐rich lavas have mantle‐like δ26Mg, slightly lighter δ66Zn relative to global oceanic basalts, high 87Sr/86Sr, and low 143Nd/144Nd, indicating source metasomatism by recycled siliciclastic sediments. By contrast, the alkali basalts possess remarkably lighter δ26Mg and heavier δ66Zn values relative to the mantle that are typically characterized by carbonates. The coupling of high δ66Zn with high‐Zn contents and Zn/Fe ratios further suggests a pyroxenite source containing recycled Zn‐rich magnesium carbonates. This is strongly corroborated by the similarity in major elements between the alkali basalts and experimental partial melts of pyroxenite + CO2. Thus, mantle silicate and carbonate metasomatism contributed to the origin of K‐rich and Na‐rich lavas in SE Tibet, respectively. Notably, the occurrence of the alkali basalts is spatially consistent with a stagnant slab in the mantle transition zone (410–660 km), the latter of which is interpreted to represent the deeply subducted oceanic slab. These observations provide evidence for recycling of carbonates into the deep mantle, which represents a long‐term circulation of subducted carbon compared with that of arc‐trench systems and has crucial significance for global deep carbon cycling. Key Points: A combined study of Mg and Zn isotopes on two types of Cenozoic mafic lavas in SE TibetCarbonate and silicate metasomatism can be discriminated by Mg and Zn isotopesNew evidence for recycling of magnesium carbonates into the deep mantle [ABSTRACT FROM AUTHOR]

Deformation in crustal‐scale shear zones occurs over a range of pressure‐temperature‐time (P‐T‐t) conditions, both because they may be vertically extensive structures that simultaneously affect material from the lower crust to the surface, and because the conditions at which any specific volume of rock is deformed evolve over time, as that material is advected by fault activity. Extracting such P‐T‐t records is challenging, because structures may be overprinted by progressive deformation. In addition, granitic rocks, in particular, may lack syn‐kinematic mineral assemblages amenable to traditional metamorphic petrology and petrochronology. We overcome these challenges by studying the normal‐sense Simplon Shear Zone (SSZ) in the central Alps, where strain localization in the exhuming footwall caused progressive narrowing of the shear zone, resulting in a zonation from high‐T shearing preserved far into the footwall, to low‐T shearing adjacent to the hanging wall. The Ti‐in‐quartz and Si‐in‐phengite thermobarometers yield deformation P‐T conditions, as both were reset syn‐kinematically, and although the sheared metagranites lack typical petrochronometers, we estimate the timing of deformation by comparing our calculated deformation temperatures to published thermochronological ages. The exposed SSZ footwall preserves evidence for retrograde deformation during exhumation, from just below amphibolite‐facies conditions (∼490°C, 6.7 kbar) at ∼24.5 Ma, to lower greenschist‐facies conditions (∼305°C, 1.5 kbar) at ∼11.5 Ma, with subsequent slip taken up by brittle faulting. Our estimates fall within the P‐T‐t brackets provided by independent constraints on the maximum and minimum conditions of retrograde ductile deformation, and compare reasonably well to alternative approaches for estimating P‐T. Plain Language Summary: Major shear zones deform material over a wide range of conditions, from low pressures and temperatures near the Earth's surface, where rocks are brittle, to high pressures and temperatures in the deep crust, where they are ductile and flow like warm toffee. The age and conditions of deformation can be estimated using mineral chemistry. However, this is difficult where rocks have been deformed over a range of conditions at different times. It is especially challenging in granite, which commonly lacks traditionally used minerals. In studying the Simplon Shear Zone, we overcome these challenges by carefully investigating its structure to untangle the deformation stages; by using the chemistry of quartz and phengite to estimate deformation conditions, both of which occur in granite; and by linking our temperatures to a published cooling history, to determine when our samples were deformed. We show that exposed rocks deformed between ∼490°C at 6.7 kbar (∼25 km depth) approximately 24.5 Myr ago, and ∼305°C at 1.5 kbar (∼6 km) approximately 11 Myr ago. Subsequent deformation was taken up by brittle faulting. Our estimates compare well to independent constraints and alternative approaches. Key Points: The conditions of deformation in crustal‐scale shear zones may vary spatially (with depth) and temporally (due to dip‐slip motion)We use a multidisciplinary approach to quantify the timing and pressure‐temperature conditions of shearing in the Simplon Shear ZoneExposed rocks preserve evidence of deformation conditions from ∼490°C and 6.7 kbar at 24.5 Ma, to ∼305°C and 1.5 kbar at 11.5 Ma [ABSTRACT FROM AUTHOR]

The trace metal element zinc (Zn) participates in coral metabolic processes and therefore accumulates in their skeletons. These metabolic processes are largely controlled by the changes of environment in which they live, so Zn isotopic compositions (δ66Zn) in coral skeletons may possibly serve as potential tracers for climate and environmental changes. In this study, we first reported the δ66Zn in shallow‐water coral skeletons by investigating with monthly resolution δ66Zn values in the skeleton of a modern Porites coral 10AR2 from the Great Barrier Reef of Australia, and the bulk skeletal δ66Zn values of several coral species from the Luhuitou Reef of Hainan Island in the northern South China Sea. Correlations between δ66Zn and other climate and environmental proxies (Sr/Ca, δ18O, and δ13C) and instrumental environmental variables (sea surface temperature, river runoff, and chlorophyll a) are poor, suggesting that the effects of external environmental changes on monthly variations in δ66Zn in coral skeletons are not significant. However, significant interspecific differences in the skeletal δ66Zn of corals growing under identical external environments may suggest the occurrence of biologically controlled δ66Zn fractionation during coral skeletons formation. In addition, the monthly δ66Zn in the 10AR2 coral skeleton roughly decreases with increasing temperature, which is in agreement with the recent finding that δ66Zn in coral tissues and zooxanthellae increases with increasing temperature and can serve as a proxy for thermal stress in corals. We thus suggest that the complicated coral internal biological processes hinder the use of skeletal δ66Zn as a climate and environmental proxy. Plain Language Summary: Zinc (Zn) is an essential micronutrient during the growth process of corals, and its contents in coral skeletons have been investigated for tracing the history of marine environmental pollution. However, the characteristics and potential applications of δ66Zn in coral skeletons have not been reported so far. In order to better understand the significance of δ66Zn in coral skeletons, we first investigated the monthly resolution δ66Zn values in the skeleton of a modern Porites coral from the Great Barrier Reef, and the bulk skeletal δ66Zn values of other shallow water coral species from the Hainan Island in the northern South China Sea. The results indicate that the changes of monthly δ66Zn values in coral skeletons may not be primarily controlled by external climate and environmental factors. The significant differences of skeletal δ66Zn values among different coral species imply that internal biological activities of coral holobiont play an important role in Zn isotopic fractionation in shallow‐water coral skeletons. In this regard, the application of δ66Zn in shallow water coral skeletons as a climate and environmental indicator is limited. Key Points: The seasonal and bulk zinc (Zn) isotope compositions in shallow‐water coral skeletons were first reportedThe correlations between seasonal Zn isotope composition in coral skeletons and environmental variables are poorInterspecific differences in coral skeletal Zn isotope compositions suggest a biologically controlled fractionation process [ABSTRACT FROM AUTHOR]

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Identification of the nature of recycling crustal materials in the sources of large igneous provinces (LIPs) is crucial for understanding compositional heterogeneity of the deep mantle. To provide new constraints on this issue, here we reported high‐precision zinc isotope data on picritic and basaltic lavas from the Emeishan LIP, SW China. Using olivine‐melt Mg‐Fe equilibrium and log (incompatible elements)‐log (MgO) systematics, the parental magma of picritic lavas is estimated to have a MgO content of 21.8 wt.%. All picrites and basalts analyzed have δ66ZnJMC 3‐0749L values of ~0.30‰, which is heavier by ~0.14‰ than that of the terrestrial mantle (0.16 ± 0.05‰, 2s.d.). Olivine and clinopyroxene phenocrysts in picrites are isotopically lighter by ~0.15‰ than the whole rocks, and a negative correlation between Zn and MgO contents for picrites is observed, indicating that olivine accumulation could lower Zn contents and δ66Zn values of the magmas. Taking this into account, the parental magma of picrites has a δ66Zn value of 0.33 ± 0.04‰ (2s.d.). This value is significantly higher than that of other large‐degree partial melts derived from the mantle (e.g. Archean komatiites and the Baffin Island picrites; ~0.20‰), which requires addition of recycled crustal materials into the mantle sources. Modeling suggests that this difference can be best explained by partial melting of a hybridized mantle source containing ~15% recycled basaltic oceanic crust. Our data also show no evidence for recycled marine carbonates into the source of Emeishan LIP and thus possibly into the Earth's deep mantle (>660 km). Key Points: High‐precision zinc isotope data on picrites and basalts from a large igneous province are reportedHigher δ66Zn of parental magmas relative to the mantle reflects recycled oceanic crust in sourcesNo evidence for recycling of marine carbonates into the Earth's deep mantle (>660 km) [ABSTRACT FROM AUTHOR]