High Concentrations Of Trace Elements Research Articles

Geochemistry and geochronology of OIB-type, Early Jurassic magmatism in the Zhangguangcai range, NE China, as a result of continental back-arc extension

AbstractThe Zhangguangcai Range in the Xing’an Mongolian Orogenic Belt, NE China, contains Early Jurassic (c. 188 Ma) Dabaizigou (DBZG) porphyritic dolerite. Compared with other island-arc mafic rocks, the DBZG dolerite is characterized by high trace-element contents, relatively weak Nb and Ta enrichments, and no Zr, Hf or Ti depletions, similar to OIB-type rocks. Analysed rocks have (87Sr/86Sr)i ratios of 0.7033–0.7044, relatively uniform positive ɛNd(t) values of 2.3–3.2 and positive ɛHf(t) values of 8.5–17.1. Trace-element and isotopic modelling indicates that the DBZG mafic rocks were generated by partial melting of asthenospheric mantle under garnet- to spinel-facies conditions. The occurrence of OIB-like mafic intrusion suggests significant upwelling of the asthenosphere in response to lithospheric attenuation caused by continental rifting. These processes occurred in an incipient continental back-arc environment in the upper plate of a palaeo-Pacific slab subducting W–NW beneath East Asia.

Do carnitine and extra trace elements change stability of paediatric parenteral nutrition admixtures?

High concentrations of trace elements (TE), in particular zinc and selenium, along with carnitine, are often added to parenteral admixtures in paediatric patients on long-term Parenteral Nutrition (PN). We aim to evaluate whether lipid droplet diameters of these admixtures maintain the recommended range of 0.4-1.0μm. Stability studies were carried out on six parenteral admixtures with carnitine, trace elements and electrolytes added in different amounts. Each admixture was formulated with five different lipid emulsions with or without fish oil. Analyses were performed at time 0 (t=0) and 24, 48, 72, 96 (t=96) hours after compounding. Droplet diameters were determined by Light Scattering-Reverse Fourier Optics Technique. Samples, stored at 4°C, were triple tested for a total of 450 analyses. Regression analyses were performed using panel-data techniques. During the 4 days, lipid droplet diameters were in the expected range of 0.4-1.0μm regardless of trace element and carnitine amounts in all admixtures apart from those containing fish-oil based emulsions and calcium concentrations equal to 4.5mmol/L. In these latter admixtures, 12% of droplet diameters were larger than 1.0μm and 2% exceeded 5.0μm immediately after compounding. Carnitine and high concentrations of trace elements do not affect PN admixtures stability and can be safely infused in long-term home-PN paediatric patients and prematures. Only high calcium concentrations in compresence with fish oil based lipid emulsions seem to change PN stability.

Evaluating soil extraction methods for chemical characterization of ultramafic soils in Kinabalu Park (Malaysia)

Soils derived from ultramafic bedrock are known for hosting distinct vegetation types as a consequence of atypical soil chemistries consisting of high trace elements concentrations (Ni, Cr, Co) and exchangeable cation imbalances (high Mg:Ca quotients); the high Mg:Ca ratio causes Ca infertility in plant species not adapted to ultramafic soils. Ecological studies use a range of single-stage extraction methods for chemical characterization of such soils in order to be able to interpret plant response, and ultimately to explain plant community composition. Few studies to date have compared different soil extraction methods in relation to tropical ultramafic soils. This study compares eight commonly used extraction methods on a large number of ultramafic soil samples collected from Kinabalu Park (Malaysia). The tested methods were: for trace elements: NH4Ac, DTPA, CaCl2, Sr(NO3)2 and Mehlich-3, for exchangeable cations: NH4Ac and silverthiorea, and for plant-available phosphorus: Mehlich-3 and Olsen-P. These single-stage extraction methods were compared and evaluated for predictive power for chemically characterizing soils, interrelatedness and ecological application. The methods were also contrasted with a sequential extraction scheme. Finally, several operational parameters including molar ratio (0.01 and 0.1 M CaCl2, Sr(NO3)2) and pH buffering (DTPA-TEA) were also evaluated. The majority of single-stage extraction methods are highly inter-correlated and predictive power could be improved by including independent soil parameters (pH, CEC, pseudo-total element concentration) in the multivariate regression equation. Ecological interpretation remains difficult because of lack of experimental studies in relation to plant uptake response and potential phytotoxicity effects on tropical native plants from ultramafic soils.

Assessing the quality of potentially reclaimed mine soils: Environmental implications for the construction of a nearby water reservoir

The cementation complex of Las Viñas (SW Spain) is a partially reclaimed abandoned mine site located in the drainage basin of a water reservoir currently under construction. The aim of this investigation was to analyze these mine soils to evaluate their potential environmental impact, especially on the final reservoir water quality. Results evidence the extremely high acidity of soils (pH of 3.4 and maximum potential acidity of 47 kg CaCO3/ton), with high concentrations of trace elements, especially As, Pb and Cu. Sequential extraction data reveal the potential release of significant quantities of Mn, Cd, Cu and other easily-soluble trace elements by rainfalls. The weathering and transport of soils to the bottom sediments of the planned reservoir could lead to the release of significant quantities of toxic trace elements to the water column if anoxic (mainly As, Sb, Cr, Ni, Cu and Pb) or oxic (mainly Hg, Pb, V, Cu and As) conditions are found in the sediments. The acidity and metals released from these soils could jeopardize the quality of the reservoir waters. Remediation measures must be therefore adopted, focused on the cleanup and liming of soils in order to promote colonization and vegetation succession, thus avoiding soil erosion and limiting metal release to the hydrosphere. This study proposes the use of different low-cost materials to improve the soil quality, limiting the metal transfer to the planned reservoir water. The information contained in this study could be of great importance in other watersheds affected by abandoned mine sites.

Residual pollution and vegetation distribution in amended soils 20 years after a pyrite mine tailings spill (Aznalcóllar, Spain)

The present work assesses the residual pollution in the Guadiamar Green Corridor (SW, Spain) after a long-term aging process (18 years) since the accident of the Aznalcóllar pyrite mine. We have focused on the study of trace elements (Cu, Zn, Cd, As and Pb) in soils, their fractionation and the transference to the surrounding vegetation. The residual polluted areas are characterized by scattered plots with absence of vegetation, presenting high concentrations of trace elements, acidic pH and low organic carbon content. Surrounding these polluted plots, two vegetation gradient belts are clearly identified by changes in plant cover and richness. The inhibition of plant growth in the bare soils is related to the highest mobility of soluble and exchangeable Cu, Zn and Cd forms, which significantly decrease with the distance to the polluted plots.Plant richness and cover show differences between belts; bioaccumulation of trace elements in plants also differs, with a preferential accumulation in roots. Despite the low bioavailability of As and Pb in soils, bioaccumulation factors in plants for these elements are significantly higher in belt 1 in relation to belt 2. High Cu and Cd potential toxic concentrations in aerial parts of vegetation are found, posing a risk for livestock and a potential entrance to the food-chain. On the other hand, Lamarckia aurea (L.) Moench (in belt1) and Trifolium campestre Schreb. (in belt2) were the most dominant species in severely polluted soils. Elevated concentrations of trace elements in the vegetation growing in the area indicate plant adaptation mechanisms to live in these severely polluted soils, which can be used as a good bioindicator of pollution in similar polluted areas.

Genesis of the Xianghualing Sn–Pb–Zn deposit, South China: A multi-method zircon study

The Xianghualing Sn–Pb–Zn deposit is situated near the center of the world-class Nanling W–Sn ore belt, associated with the highly evolved Laiziling granite of Jurassic age. Previous studies focused mainly on geochemical and geochronological features of the mineralization-related granite, whereas research on the source, evolution and geochronology of the ore-forming fluids has been limited. We carried out precise U–Pb dating, trace element, and Hf isotopic analyses on magmatic and hydrothermally-altered zircons from the skarn-stage and sulfide-stage ores in the Xianghualing deposit. Zircon U–Pb dating results from the two ore-forming stages show distinct geochronological populations: the skarn stage ores contain mainly magmatic and hydrothermally-altered zircons in three age clusters (∼150 Ma, ∼220 Ma, and ∼ 420 Ma), whereas the sulfide-stage ores are characterized by abundant old detrital zircons ranging from 497 to 3409 Ma, with a peak at 800–1000 Ma. This pattern may indicate that magmatic–hydrothermal events in the Silurian and Triassic were precursors to the main Sn mineralization event in the Jurassic, when circulation of evolved fluids through older sedimentary rocks led to Pb–Zn mineralization. The Jurassic zircons exhibit high trace-element contents (e.g., Hf, P, Y, Nb, Ta, Th, U) and low Ti contents, Eu anomalies, Nb/Ta and Th/U ratios, which imply that the Laiziling magma experienced significant plagioclase, biotite and muscovite fractional crystallization, and that it interacted extensively with post-emplacement F-rich hydrothermal fluids. The positive Ce anomalies of these zircons (Ce/Ce∗ = 1.0–226) indicate that the magmatic–hydrothermal fluids that led to the Jurassic Sn mineralization event were reducing. The less negative εHf(t) values of Triassic zircons (−18.7 to −2.6) compared to the Silurian zircons (−14.6 to 2.3) suggest more limited interaction between the mantle and the magma source region. The Jurassic magmatic zircons in the skarns exhibit even more negative εHf(t) values (−30.7 to −6.7), along with TDMC model ages ranging from 1627 to 3134 Ma, indicating that the Jurassic magma was derived from partial melting of old continental crustal basement. Based on the combined study of zircons in the skarns and sulfide ores, we propose a three-stage ore genetic model for the Xianghualing Sn–Pb–Zn deposit.

On the making, mixing and trading of glass from the Roman military fort at Oudenburg (Belgium)

This paper presents the analysis of decoloured and naturally coloured glass from well-dated contexts in the southwest corner of the Roman fort at Oudenburg (Belgium) ranging from the late second to the early fifth century AD. The aim is three-fold. First, provide comparative material in the study of glass consumption from the northwestern provinces of the Roman Empire. Secondly, evaluate possible diachronic shifts in the applied decolourizing agent to produce colourless glass as to assess potential correlations between glass production recipes, provenance and chrono-typology. Finally, provide an added value to the research of glass recycling and mixing in the Roman imperial period. Nine subgroups are distinguished based on their chemical composition determined by LA-ICP-MS: Sb-only, two groups of Mn-only, four groups of mixed Mn-Sb, HIMT and one glass without any decolouring agent. The Sb-decoloured glass is used in the earliest phases and can be attributed to an Egyptian provenance. The two subgroups of Mn-glass likely come from different provenances: one from Egypt and the other later one from the Levant. Most of the glass shows high marks of mixing based on high trace elements concentrations and the simultaneous presence of antimony and manganese. Inhomogeneous mixing of manganese and antimony was also detected through μXRF. One Mn-Sb subgroup likely comes from mixing antimony glass with HIMT. The obtained results help better recognise the shifts in applied glass recipes throughout the Roman imperial period and improve our understanding about the mixing and recycling of glass to supply a Roman military camp.

Removal of hazardous trace elements from green liquor dregs by mechanical separation methods

Abstract Green liquor dregs represent the most important inorganic residue of chemical pulp mills. The dregs are usually settled in thickeners, washed and deliquored with lime mud precoat filters, and transported to the landfill. The utilization of dregs is challenging, due to the high concentration of hazardous trace elements (HTE) in their solid phase. There are basically two potential strategies for the reduction of the HTE content of dregs: mechanical classification according to differences in the size and density of particles, and removal of HTE by various chemical treatments. The objective of this study was to evaluate the applicability of straightforward mechanical separation methods for the purification of dregs from HTE. The evaluated separation methods included particle size–based classification by sieving, and classification on the basis of differences in the settling properties of particles in gravitational and centrifugal separation. It can be concluded that all the evaluated separation methods could be used to reduce the HTE content of dregs, although the separation efficiency was not very high in most cases. Centrifugation had clearly the best performance of the investigated techniques. The fractions consisting of large particles contained consistently lower concentrations of HTE, compared to fractions containing a lot of fines.

Chemical and ecotoxicological effects of the use of drinking-water treatment residuals for the remediation of soils degraded by mining activities

The aim of this study was to evaluate the use of drinking-water treatment residuals (DWTR) in the amendment of a soil affected by mining activities (Aljustrel mine, Portuguese sector of the Iberian Pyrite Belt), considering the effects on its chemical, biochemical and ecotoxicological characteristics. The DWTR had neutral characteristics (pH 6.7) and an organic matter (OM) content of 575 g kg−1 dry matter (DM), which makes them a potential amendment for the remediation of mine degraded soils, as they may correct soil acidity and reduce the extractable metal fraction. An incubation assay, with soil and DWTR, with or without lime, was carried out to test the doses to be used in the assisted-phytostabilization experiment. Based on the results obtained, the doses of DWTR used were the equivalent to 48, 96, and 144 t DM ha−1, with and without lime application (CaCO3 11 t DM ha−1). Agrostis tenuis Sibth was used as the test plant. Some amendments doses were able to improve soil characteristics (pH and OM content), to decrease metal extractability by 0.01 M CaCl2 (especially for Cu and Zn), and to allow plant growth, that did not occur in the non-amended soil. Copper, Pb and Zn concentrations in the plant material were lower than the maximum tolerable level for cattle feed, used as an indicator of risk of entry of those metals into the human food chain. The simultaneous application of DWTR (96 and 144 t ha−1), with lime, allowed a reduction in the mine soil ecotoxicity, as evaluated by some lethal and sub-lethal bioassays, including luminescence inhibition of Vibrio fischeri, Daphnia magna acute immobilization test, mortality of Thamnocephalus platyurus, and 72-h growth inhibition of the green microalgae Pseudokirchneriella subcapitata. However, DWTR were unable to increase soil microbial activity, evaluated by dehydrogenase activity, an important soil-health indicator. Also, OM content and NKjeldahl, concentrations increased slightly but remained low or very low (P and K extractable concentrations were not affected). In general, the bioassays highlighted a decrease in soil ecotoxicity with the presence of lime and DWTR (144 t DM ha−1). In conclusion, DWTR are recommended to amend acidic soils, with high concentrations of trace elements, but an additional application of organic or mineral fertilizers should be considered.

Trace element contaminants in mineral fertilizers used in Iran.

The application of mineral fertilizers which have contaminants of trace elements may impose concern regarding the entry and toxic accumulation of these elements in agro-ecosystems. In this study, 57 mineral fertilizers (nitrogen, potassium, phosphate, and compound fertilizers) distributed in Iran were analyzed for their contents of Cd, Co, Cr, Cu, Mn, Ni, Pb, Zn, and Fe. The results revealed that the contents of these trace elements varied considerably depending on the type of the element and the fertilizer. Among these elements, Fe displayed the highest average content, whereas Cd showed the lowest. Generally, the trace element contents in P-containing fertilizers were higher than those in nitrogen and potassium fertilizers. The mean values of trace elements (mgkg-1) in P-containing fertilizers were 4.0 (Cd), 5.5 (Co), 35.7 (Cr), 24.4 (Cu), 272 (Mn), 14.3 (Ni), 6.0 (Pb), 226 (Zn), and 2532 (Fe). Comparing trace element contents to limit values set by the German Fertilizer Ordinance showed that the mean contents of potentially toxic trace elements, such as Cd and Pb, were lower than their limit values in all groups of fertilizers. On the other hand, while a number of fertilizers contained a high content of some essential trace elements, particularly Fe, they were not labeled as such.

Sulfur isotope and metal variations in sulfides in the BIF-hosted orogenic Cuiabá gold deposit, Brazil: Implications for the hydrothermal fluid evolution

Textural, chemical and multiple sulfur isotope analyses of sulfides from the Archean world-class Cuiabá orogenic Au deposit, Quadrilátero Ferrífero district, Brazil, were conducted to track distinct trace element signatures from syngenetic to epigenetic-hydrothermal pyrite types in different host units, and to deduce the nature and source of the mineralizing fluids. Gold mineralization in Cuiabá is hosted in greenschist facies volcanic and sedimentary host rocks belonging to the Archean Rio das Velhas Supergroup, especially in association with quartz veins and sulfide minerals. The BIF-hosted Fonte Grande Sul orebody is controlled by quartz veins and disseminated gold-bearing pyrite, pyrrhotite and arsenopyrite in the wall rocks. Five pyrite types are classified based on textural relations as spongy, syngenetic (Py1), porous early-(Py2), smooth main-(Py3) and smooth isolated and overgrown late-stage (Py4 and Py5) types variably present in metamorphosed carbonaceous pelites, BIF and andesite. Besides pyrite, pyrrhotite and arsenopyrite are also defined according to textural and paragenetic differences, and they display significant trace element contents. Trace element abundance maps and LA-ICP-MS analyses display trace element incorporations in Py1 (present only in carbonaceous pelite), Py2 and Py3 (in all host rocks), and Py4 and Py5 (only in BIF). Py1 yields high As, Co, Ni, Pb and Ag concentrations, whereas Py2 (formed by agglomeration of Py1) maintains high trace element concentrations with slightly less of those elements. Trace element incorporation in Py3 is similar to Py1 in carbonaceous pelite. Early-stage Py2 and main-stage Py3 in BIF and andesite have increased Co and Ni, but have less Au and As. Late-stage Py4 is characterized by lower trace element concentrations, whereas Py5 is further enriched in As, Bi, Co, Ni and Pb. The hydrothermal alteration is divided into early-, main- and late-stage, which correlate to the sulfide hydrothermal evolution. The study shows that carbonaceous pelite is pre-enriched in Co, Ni and Pb, whereas certain elements like Ag, Au, Bi and As are only hydrothermally concentrated either during the early, main or late stage in BIF and andesite. This geochemical pattern supports a syngenetic versus hydrothermal origin of distinct elements, including some trace elements now in the ore zones. Multiple sulfur isotope data suggest that mineralizing fluids at the Cuiabá gold deposit reflect a complex mixing of sulfur evolved from three possible sources: seawater, mantle, and reduced elemental sulfur. Spongy, syngenetic Py1 yields Δ33S values ranging from −2.28 to −0.25‰, separated into two ranges, the first from −2.28 to −1.97‰, and the second from −0.96 to −0.25‰. The first range suggests Py1 in the carbonaceous pelite was deposited in a seawater environment. These pyrites probably mixed with later mantle sulfur carrying a near-zero Δ33S signature, which is indicated by the second Δ33S range, or could have mixed with fluids sourced from sedimentary rocks at depth carrying a positive Δ33S signature. The second scenario is more common in sedimentary and diagenetic pyrites. An unequivocal contrast is shown by early-, main- and late-stage pyrite types (Py2, Py3, Py4 and Py5) in carbonaceous pelite, BIF and andesite, which present a continuous process of crustal assimilation values towards increasingly positive δ34S and Δ33S values. This confirms evidence for a sedimentary-derived sulfur source as also indicated by fluid inclusion data of the andesite-hosted orebody at the Cuiabá deposit.

Comparison of exposure to trace elements through vegetable consumption between a mining area and an agricultural area in central Chile.

Human exposure to trace elements has been a large concern due to the potential health issues. Accordingly, this study aimed to compare the concentrations of arsenic, copper, and zinc in the edible parts of vegetables grown in a mining-agricultural area and in an exclusively agricultural area and to compare the potential human health risks of consuming vegetables from both areas. The consumption habits of the studied population were extracted from the 2010 National Alimentary Survey of Chile. In most cases, the concentrations of trace elements in the edible tissues of vegetables (lettuce, spinach, garlic, onion, carrot, potato, sweet corn, and tomato) were higher in the mining-agricultural area than those in the control area. This difference was most pronounced for leafy vegetables, with arsenic being the trace element of concern. Specifically, the arsenic concentrations in the edible tissues of lettuce and spinach were 8.2- and 5.4-fold higher, respectively, in the mining-agricultural area than in the control area. Lettuce was the vegetable of concern due to its relatively high consumption and relatively high concentration of trace elements. Nevertheless, there was no health risk associated with vegetable consumption in either the mining area or the control area because none of the HQ values surpassed 1.0.

Behavior of trace elements and mineral transformations in the super-high organic sulfur Ganhe coal during gasification

A coal containing high concentrations of hazardous trace elements F, V, Cr, Se, Mo, Cd, and U was selected for the gasification experiment based on the Lurgi fixed-bed pressurized gasifier. The feed coal was a super-high organic sulfur coal sampled from the Ganhe Mine, Yanshan Coalfield, Yunnan Province, China. Fluorine, Ga, Se, Cd, In, Tl, Pb, and Bi were volatilized during gasification, whereas V, Mo, and U were significantly enriched in the residue. The erosion of the gasifier internals resulted in the abnormal enrichment of Cr and Ni in the residue, with the maximum concentrations of Cr and Ni of 26,073 μg/g and 23,982 μg/g, respectively. Except for quartz, other minerals in the feed coals were transformed. The newly formed phases such as mullite, hercynite, magnetite, Fe aluminosilicate, and Al-Si-O-glass containing Fe-Ca-Mg-V-K-Ti were identified in the gasification residue. Pyrite was transformed to elemental iron in some cases. Pyrrhotite with a magnetite rim, representing the high temperature transformation product of pyrite, was observed in the gasification residue by scanning electron microscopy.

RESEARCH OF CHEMICAL COMPONENTS OF SOME SEAWEED SPECIES IN CON CO ISLAND – QUANG TRI PROVINCE

11 samples of 8 seaweed families were collected at Con Co – Quang Tri and determined ofthe chemical compositions. The analysis results showed that these seaweed samples in Con Cocontain high content of trace elements and low content of heavy metals. Many samples havegood lipid quality to meet the requirements of safe food, as well as being good for the humanhealth (such as CC1, N9, N4, and N6 samples). Especially, some seaweed samples were foundto contain long-chain fatty acids with many double bonds presenting high bioactivity in theirlipid composition, such as C20: 4n-6 (AA) up to 22.35% (Hypnea flagelliformis Grev., sampleN6), C20: 5n-3 (EPA) 16.36 % (Grateloupia lithophila, sample N9), C22: 6n-3 (DHA) 1.07 %(Hypnea esperi, sample N2), C22: 5n-3 (DPA) 1.82% (Liagora spl., samples N4).

The Boring Billion, a slingshot for Complex Life on Earth

The period 1800 to 800 Ma (“Boring Billion”) is believed to mark a delay in the evolution of complex life, primarily due to low levels of oxygen in the atmosphere. Earlier studies highlight the remarkably flat C, Cr isotopes and low trace element trends during the so-called stasis, caused by prolonged nutrient, climatic, atmospheric and tectonic stability. In contrast, we suggest a first-order variability of bio-essential trace element availability in the oceans by combining systematic sampling of the Proterozoic rock record with sensitive geochemical analyses of marine pyrite by LA-ICP-MS technique. We also recall that several critical biological evolutionary events, such as the appearance of eukaryotes, origin of multicellularity & sexual reproduction, and the first major diversification of eukaryotes (crown group) occurred during this period. Therefore, it appears possible that the period of low nutrient trace elements (1800–1400 Ma) caused evolutionary pressures which became an essential trigger for promoting biological innovations in the eukaryotic domain. Later periods of stress-free conditions, with relatively high nutrient trace element concentration, facilitated diversification. We propose that the “Boring Billion” was a period of sequential stepwise evolution and diversification of complex eukaryotes, triggering evolutionary pathways that made possible the later rise of micro-metazoans and their macroscopic counterparts.

Distribution of major and trace elements in the bolete mushroom Suillus luteus and the bioavailability of rare earth elements

Fungi are eukaryotic organisms within the kingdom Fungi. They are classified as macrofungi when they produce, usually above-ground, fruit bodies which are often simply referred to as “mushrooms”. Since many species are edible, numerous studies discuss major elements and the accumulation of toxic and radioactive elements. Rare earth elements are economically important metals which are increasingly used for high-technology applications like renewable energies and state-of-the-art electronic devices. Although the significantly increasing anthropogenic input into the environment may affect living organisms, available data on the concentration, distribution and uptake of rare earth elements and yttrium (REY) by fungi are limited and often ambiguous.Here, we present trace element and REY concentrations for the fungus species Suillus luteus and the distribution of major and trace elements between the different compartments of individual fruit bodies separated into cuticle, flesh of cap, tubes & pores, and stipe. Our results show that P, K, Zn, Rb and Cs are the only elements enriched in fruit bodies relative to soil. All elements are unevenly distributed within the fruit bodies and the parts comprising the cap generally contain higher concentrations of trace elements than the stipes. The total REY concentrations in the individual mushroom parts range from 13.1 μg kg−1 in dry matter (DM) to 72.6 μg kg−1 DM, whereas concentrations in the whole mushrooms are 13.4 to 74.2 μg kg−1 DM. The highest of the generally rather low REY concentrations are shown by the cuticles. All mushroom parts have the same rather flat shale-normalized REY patterns very similar to those of ambient soil, but show positive Y anomalies in all and positive La anomalies in most samples. The cuticles and the whole fruit bodies show a slight depletion of light relative to heavy REY (LREY and HREY, resp.), while flesh, tubes & pores and the stipe exhibit no or a small enrichment of LREY relative to HREY. The fractionation between LREY and MREY is only small, whereas the fractionation between MREY and HREY is more pronounced. Soil leaching experiments with the siderophore desferrioxamine B suggest that although Suillus luteus produces siderophores which are important ligands for REY complexation, such hydroxamate siderophores do not significantly affect REY mobilization and transport to the mushrooms. The close similarity of the REY distribution in the fruit bodies of Suillus luteus and ambient soil and the lack of significant fractionation suggest that fungi may have the potential to be developed into bioarchives for tracers used in geochemical exploration.

Origin of dioritic magma and its contribution to porphyry Cu–Au mineralization at Pulang in the Yidun arc, eastern Tibet

The giant Pulang porphyry Cu–Au deposit in the Yidun arc, eastern Tibet, formed due to westward subduction of the Garze–Litang oceanic plate in the Late Triassic. The deposit is hosted in an intrusive complex comprising primarily coarse-grained quartz diorite and cored quartz monzonite. Here, we investigate a suite of simultaneous (216.6 ± 1.9 Ma) diorite porphyries within the complex. The diorite porphyries are geochemically similar to mafic magmatic enclaves (MME) hosted in coarse-grained quartz diorite, and both are characterized by low SiO2 (59.4–63.0 wt%) and high total alkali (Na2O + K2O = 7.0–9.2 wt%), K2O (3.5–6.4 wt%), MgO (3.2–5.5 wt%), and compatible trace element (e.g., Cr = 72–149 ppm) concentrations. They are enriched in large-ion lithophile and light rare earth elements (LILE and LREE, respectively), but depleted in high field-strength and heavy rare earth elements (HFSE and HREE, respectively), and yield variably high (La/Yb)N ratios (17–126, average 65) with weak to negligible Eu anomalies. Furthermore, they yield low (87Sr/86Sr)i ratios (0.7054–0.7067), weakly negative εNd(t) (−2.8 to −0.8) values, and variable zircon εHf(t) (−5.4 to +0.8) and δ18O (6.0‰–6.7‰) values. These geochemical features indicate that the diorite porphyry and MME formed through crustal assimilation of a magma produced during low-degree partial melting of metasomatized phlogopite-rich subcontinental lithospheric mantle. In contrast, the coarse-grained quartz diorite and quartz monzonite have relatively high concentrations of SiO2 (61.1–65.3 wt%), K2O (4.1–5.4 wt%), and total alkali (Na2O + K2O = 7.1–8.1 wt%), and low concentrations of MgO (generally <3.0 wt%) and compatible trace elements (e.g., Cr = 38–61 ppm). They yield high Sr/Y ratios (50–63) that indicate an adakitic affinity, and are enriched in LILE, depleted in HFSE, and yield lower (La/Yb)N values (13–20, average 17) than the diorite porphyry and MME. They yield low (87Sr/86Sr)i ratios (0.7046–0.7066), negative εNd(t) (−3.3 to −1.7) values, and zircon εHf(t) and δ18O values of −2.9 to −0.1 and 5.7‰–6.5‰, respectively, suggesting that they represent high-K calc-alkaline to shoshonitic adakitic magmas that were sourced from subduction-modified juvenile lower crust. Observations of the newly identified diorite porphyry and previously reported MME suggest that input of such dioritic magma into the upper crustal porphyry magma chamber would have contributed not only the necessary metals (e.g., Cu and Au), sulfur, but also H2O to the system, thus aiding in the generation of the giant Pulang porphyry Cu–Au deposit.

Trace elements in Polytrichum commune and Polytrichastrum formosum from the Karkonosze Mountains (SW Poland)

The Karkonosze National Park, an unique mountainous biosphere reserve, is influenced by long-distance anthropogenic atmospheric transport of among others trace elements and additionally by local tourist centres, which may be supplementary sources of pollution. Discharged trace elements are non-degradable, and their level must be precisely monitored. Therefore, the concentrations of As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Mo, Ni, Pb, Rb and Zn in Polytrichum commune and Polytrichastrum formosum collected from the Karkonosze sites influenced only by long-range pollution and from sites in the vicinity of local tourist centres were established. P. commune and P. formosum revealed the ability to accumulate higher concentrations of trace elements while growing in locally contaminated sites in comparison with sites free from such pollution. Therefore, both species may be utilised for bioindication in the Karkonosze National Park. Elevated levels of trace elements in both species (except for Hg) in comparison with concentrations typical for mosses from unpolluted sites point to the existence of pollution of this area. P. commune was a better bioindicator of Cd, Co, Cr, Cu, Mo, Ni, Pb and Rb than P. formosum, probably because of the larger gametophytes and its morphology, which appears prone to an increased uptake of trace elements from the atmosphere.

Exceptional discovery of a shallow-water hydrothermal site in the SW area of Basiluzzo islet (Aeolian archipelago, South Tyrrhenian Sea): An environment to preserve.

The geological, biological and geochemical features of a particular field of hydrothermal vents, discovered in the Panarea Volcanic Complex during a research survey carried out in 2015, are described for the first time. The site, located at 70–80 m depth off the South-western coast of the islet of Basiluzzo, was named Smoking Land for the presence of a large number of wide and high active chimneys and was characterized in terms of dissolved benthic fluxes, associated macrofauna and megafauna communities and preliminary mineralogy and geochemistry of chimney structures. On the whole field, a total of 39 chimneys, different in size and shape, were closely observed and described; 14 of them showed emission of low temperature hydrothermal fluids of marine origin characterized by acidified chemical conditions. The CTD and benthic chamber measurements highlighted that the Smoking Land is able to form a sea water bottom layer characterized by variable acidity and high DIC and trace elements concentrations; these characteristics weaken moving away from the chimney mouths. The SEM-EDS analysis of the collected solid samples revealed a chimney structure principally composed by amorphous and low crystalline Fe-oxyhydroxides of hydrothermal origins. The ROV explorations revealed a wide coverage of red algae (Peyssonnelia spp.) colonized by the green algae Flabiella petiolata and by suspension feeders, mainly sponges, but also bryozoans, and tubicolous polychaetes. Although novent-exclusive species were identified, the benthic communities found in association to the chimneys included more taxa than those observed in the surrounding no-vent rocky areas. These first findings evidence a submarine dynamic habitat where geological, chemical and biological processes are intimately connected, making the Smoking Land an important site in terms of marine heritage that should be safeguarded and protected.

Metal Speciation in the Rivers Around Potchefstroom Based on Seasonality.

About 44 surface water samples were collected in the wet and dry seasons around mining areas near the city of Potchefstroom in South Africa, and physicochemical parameters were analyzed to assess the speciation of pollutants and impact on dispersion potential. It was found that concentrations of the trace elements measured decreased significantly during the dry season. High concentrations of trace elements during the wet season were correlated to high effluents from anthropogenic sources which were flowing into the surface water. Aqueous metal speciation in both seasons was conducted using the PHREEQC geochemical modelling code. The seasonal variation of species observed was due to changes in the physicochemical quality of water between the two seasons. Collected data indicated that high percentages of Ca and Mg were present as free hydrate species, whereas the Fe, Cd, As, and U were mostly present as carbonate or hydroxide species.