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Phosphate competition with arsenic is one of the leading causes of As release from sediments into freshwaters. An important P source to freshwaters is wastewater treatment plants (WWTP), estimated to contribute 25–45% of all P in surface waters.A stream surrounded by soils and sediments with naturally elevated concentrations of As (> 200 mg/kg) and continuous entry of small capacity WWTP discharge was studied. The methods used were XRD, EPMA, bulk analyses, single extractions, and batch leaching experiments. Since 2013, the WWTP effluent supplies 7–23 mg/l of PO4 into the stream and an increased concentration of As (150–180 µg/l) due to everyday usage of As‑enriched wells water in the households. This study revealed that the fractionation of As and P in sediments changed due to exposure to treated wastewater. The adsorbed As fraction decreased by 9 %, whereas the adsorbed P fraction increased by 9 % in the downstream samples. As a result, the P‑retention capacity of the sediment decreased in the downstream samples from 16 % to 10–12 %. These findings are supported by a mineralogical study, which showed that P and As distribution within the Fe (hydr)oxides differed significantly between the samples taken upstream and downstream of the effluent discharge point. The samples upstream showed higher As and lower P median concentration (1.3 wt % of As2O5 and 0.8 of P2O5 wt %, respectively), while the opposite behavior was observed downstream: As 0.7 wt % of As2O5 and P 1.6 wt % of P2O5. These findings indicate that elevated phosphate is replaced by arsenate in the Fe (hydr)oxides, and the As is mobilized into the aqueous phase. Moreover, a detailed mineralogical investigation of samples exposed to the P-enriched effluent showed newly created Fe (hydr)oxide coatings significantly enriched in P (2O5), Ca (< 10.9 wt % CaO) while depleted in As (< 3.3 wt % As2O5).Our results showed that local sources of phosphate, such as WWTP, in areas with elevated concentrations of As can significantly impact As behavior and may be responsible for elevated concentrations of As in surface waters.Acknowledgments: This research was supported by the Grant Agency of Charles University (GAUK no. 790120), Czech Science Foundation (GAČR no. 22-27939S), and the Center for Geosphere Dynamics (UNCE/SCI/006).

Radioactive (radon) groundwaters are highly valued among mineral waters for their healing effects. Between 2005 and 2015, a large exploratory event for prospecting and documenting radon water springs took place in the crystalline area of Lugicum (Bohemian Massif) under Czech–Polish cooperation. For these purposes, an exploration method was developed as a combination of GIS (ArcMap 9.1–10.2) area preparation followed by field radiohydrogeochemical mapping at a scale of 1:10,000. The gamma indication method was optimized and used for the selection of water samples. A total of 2354 water sources were examined. Radon activity concentrations were measured at 660 sources found throughout the territory. Of those, 111 sources exhibited 222Rn activity above 1500 Bq/L and, thus, were categorized as sources of mineral radioactive waters according to Czech legislation. The highest 222Rn activity was found in the Michael spring near Nové Město pod Smrkem (up to 6237 Bq/L 222Rn). Many discovered sources with high balneological potential are significant and, therefore, are quickly becoming popular among the public.

One of the leading causes of As release from streambed sediments into freshwater systems is competition with phosphate. Among important sources of P to the fluvial ecosystems are wastewater treatment plants (WWTP), estimated to account for 25-45% of all P in surface waters. In this paper, long-term effects of discharged phosphorus from a small WWTP on the arsenic mobility were studied in an As-enriched fluvial system (approx. 240 mg/kg) in central Czech Republic. After 7 years of elevated P (≤7.7 mg/L) in the stream water, the total As decreased by 25% and the total P increased by 40% in the sediments downstream (at a distance of 66 m). The results of the chemical extractions and mineralogical analyses indicated that the changes in the concentration were mostly due to the sorption processes in the Fe (oxyhydr)oxides (goethite and hematite). In the downstream samples, the As in these phases decreased two-fold, and P was significantly enriched by 45-140%. Phosphorus was also found precipitated as newly formed Ca phosphates. The stream water monitoring indicated that the discharged P was either sequestered when the levels of dissolved P were high (2.3 mg/L) or released from the downstream sediments when these levels were low (∼1.5 mg/L). Meanwhile, As was continuously mobilized from the downstream sediments likely due to (i) the ongoing As desorption from the exterior parts of the Fe (oxyhydr)oxides at high aqueous P levels and (ii) the dissolution of As-bearing Ca phosphates at low dissolved P levels. These findings clearly demonstrate that point sources of P to streams and rivers, such as WWTP, may result in the permanent and long-term release of As from contaminated streambed sediments.

Cerium oxide nanoparticles (CeNPs) possess multiple redox enzyme mimetic activities in scavenging reactive oxygen species (ROS) as a potential biomedicine. These enzymatic activities of CeNPs are closely related to their surface oxidation state. Here we have reported a synthetic method to modify CeNPs’ surface oxidation state by changing the conformation of the poly(acrylic acid) (PAA) polymers adsorbed onto the CeNP surface. The synthesized PAA–CeNPs exhibited the same core size, morphology, crystal structure, and colloidal stability, with the only variation being their surface oxidation state (Ce3+ percentage). The modification mechanism can be attributed to the polymers chemisorbed onto the metal oxide surface forming a metal complexation structure. Such adsorption further modified CeNPs’ surface oxidation state in a temperature-dependent manner. The series of PAA–CeNPs exhibited multiple redox enzyme mimetic activities (superoxide dismutase, catalase, peroxidase, and oxidase) directly related to their surface oxidation state. In vitro experiments showed no cytotoxic effect of these PAA–CeNPs on the osteoblastic cell line SAOS-2 at high loadings. Microscopic images confirmed the internalization of PAA–CeNPs in the cells. All tested PAA–CeNPs can reduce the basal and hydrogen peroxide-induced intracellular ROS level in the cells, indicating their effective intracellular ROS scavenging effect. However, we did not observe a positive correlation between the CeNP surface oxidation state and their capacities to reduce the intracellular ROS levels. We propose that CeNPs can maintain a dynamic state of Ce3+/Ce4+ during their catalytic activities, exhibiting a non-linear correlation between the CeNP surface oxidation state and their effect on regulating the intracellular ROS level.

The Blovice accretionary complex, Bohemian Massif, hosts well-preserved basaltic blocks derived from an oceanic plate subducted beneath the northern active margin of Gondwana during late Neoproterozoic to early Cambrian. The major and trace element and Hf–Nd isotope systematics revealed two different suites, tholeiitic and alkaline, whose composition reflects different sources of melts within a back-arc basin setting. The former suite has composition similar to mid-ocean ridge basalts (MORB), yet with striking enrichment in large-ion lithophile elements (LILE) and Pb paralleled by depletion in Nb, in agreement with its derivation from depleted mantle fluxed by subduction-related fluids. In contrast, the latter suite has composition similar to ocean island basalts (OIB) with variable contribution of ancient, recycled crustal material. We argue that both suites represent volcanic members of Ocean Plate Stratigraphy (OPS) and indicate that the oceanic realm consumed by the Cadomian subduction was a complex mosaic of intra-oceanic subduction zones, volcanic island arcs, and back-arc basins with mantle plume impinging the spreading centre. Hence, the basalt geochemistry implies that two distinct domains of oceanic lithosphere may have existed off the Gondwana’s continental edge: an outboard domain, made up of old and less buoyant oceanic lithosphere (remnants of the Mirovoi Ocean surrounding former Rodinia?) that was steeply subducted and generated the back-arcs, and young, hot, and more buoyant oceanic lithosphere generated in the back-arcs and later involved in accretionary complexes as dismembered OPS. Perhaps the best recent analogy of this setting is the Izu Bonin–Mariana arc–Philippine Sea in the western Pacific.

This paper focuses on formation of subcalcic Cr-rich garnet (up to 14.25 wt% Cr2O3) in the model ultramafic system corresponding to natural harzburgite with the presence of REE-bearing fluid phase. The experiments were carried out using a “split-sphere” type multi-anvil high-pressure apparatus (BARS) at a pressure of 5 GPa and a temperature of 1300 °C. Natural serpentine, chromite, corundum and REE-carbonatite were used as starting components. Crystallization of garnet occurred in subsolidus conditions by the reaction of orthopyroxene and spinel in the presence of fluid phase. Composition of fluid was controlled by interaction of water released by decomposition of serpentine with carbonate. By using different amounts of carbonatite (0.5 and 1.5 wt%) as a source of calcium and REE, subcalcic Cr-rich garnets with up to 3.5 wt% CaO were crystallized, which are typical for inclusions of harzburgitic paragenesis in natural diamonds. The experiments demonstrated that the rare earth elements (REE) released from the initial carbonatite were transported by the fluid and were incorporated into the newly formed garnet. The distribution of REE in garnet revealed a vivid enrichment toward the heavy REE (HREE), showing the pattern with a very steep slope. These results confirmed high partitioning of HREE into garnet. The present study indicates that the mantle carbonatites, which contain very high proportions of light REE (LREE) to HREE, can play an important role as source material in formation of REE-rich fluids to crystallize garnets with typical REE patterns in mantle peridotites.

Ancient brass (aurichalcum) was a valued commodity in the Antiquity, notably because of its gold-like appearance. After mastering brass fabrication using the cementation procedure in the 1st century BC in the Mediterranean, this material became widely used by the Romans for coins, jewellery and other objects. Because of its visual qualities, it is believed that since this period, brass played an important role in diplomatic and economic contacts with indigenous communities, notably Celtic and Germanic tribes north of Danube and west of Rhine. To test this hypothesis, we performed for the first time the archaeometric and advanced statistical multivariate analysis of a suite of late Iron Age and Early Roman period (1st century BC – 1st century AD) brass and other copper-alloy objects from the territory of Bohemia to constrain their provenance. The new results for brass objects from this early phase of the massive occurrence of Roman aurichalcum in the Barbarian territories point to the ore deposits in the western Mediterranean or the Massif Central area in Gaul, consistent with historical events. These new findings underscore the great economic and political importance of the new and rich mineral resources in the Transalpine Gaul acquired due to Caesar's military campaigns

We present new experimental data on major and trace element partition coefficients (D) between clinopyroxene and a K-basaltic melt from Procida Island (Campi Flegrei Volcanic District, south Italy). Time-series experiments were conducted at 0.8 GPa and 1080–1250 °C aiming to investigate the role of the crystallization kinetics on trace elements partitioning behaviour at a pressure relevant for deep magmatic reservoirs. Results indicate that large ion lithophile elements (LILE) are incompatible (e.g., DSr ≤ 0.15), light rare elements (LREE; e.g., DLa ≤ 0.20) are always more incompatible than heavy rare elements (HREE), which in some cases result to be compatible with clinopyroxene (e.g., DDy = 1.40); high field strength elements (HFSE) are generally incompatible (DHFSE ≤ 0.8), while transition elements (TE) range from slightly incompatible (e.g., DV = 0.6) to highly compatible (e.g., DCr = 63). The calculated D values for LILEs, REEs, HFSEs, and TEs tend to decrease with the increase of temperature and to increase with increasing tetrahedrally-coordinated aluminium content, in agreement with the previous studies. Moreover, we observed the influence of the growth rate on the partition coefficients, with the highest DREE values calculated in the runs with the highest growth rate (~10−7 cm s−1), due to the less efficient rejection of incompatible elements during rapid crystal growth, that in this study is not linked to disequilibrium conditions, but to the presence of pre-existing nuclei. Additionally, the apparent increase in DREE values with time observed in some runs is not referable to a change in time but rather to the different degrees of polymerization, expressed as the ratios NBO/T of these melts, strictly related to a loss of Fe occurred during the experiments, and thus to a different melt viscosity. Finally, the application of the experimental clinopyroxene-melt partition coefficients highlights that the deepest step of the magmatic differentiation in the Campi Flegrei Volcanic District is represented by the fractionation of about 20–30% of a clinopyroxenitic mineral assemblage from a basaltic parental magma.

The Upper Silesian basin belongs to the largest industrial pollution sources in Europe and the city of Ostrava ranks among the worst-polluted urban areas in the European Union. To assess temporal and spatial trends in atmospheric pollution, we determined concentrations of S, Pb, Cu, Zn, As, Cd, Sb, and Al in snow in downtown Ostrava and at the Lysa Hora Mt. (LH), situated 33 km southeast. Snowpack surfaces were sampled in February 2011/2012, 2018, and 2019. At LH, we collected snow samples at four elevations (700, 900, 1100, and 1300 m) in order to quantify mountain slope gradients in the pollution that, in turn, might reflect vertical stratification of air masses in a region frequently affected by temperature inversions. 206Pb/207Pb and 208Pb/207Pb isotope ratios and back trajectories of air masses were used for pollution source apportionment. In year 1, there were clear-cut upslope decreases in concentrations of soluble pollutants. By year 3, the concentrations of soluble pollutants at LH decreased by 90% and the concentration gradients ceased to exist. Because annual precipitation totals at LH increase upslope by 75%, rates of deposition of soluble pollutants are now higher at the summit than those at the foot of the mountain. Hydrological control of deposition rates of soluble pollutants thus plays a more important role under lower pollution levels. Concentrations of soluble pollutants in Ostrava were up to 36 times higher compared with those at LH and also decreased by 90%. Lead isotopes indicated the continuing presence of gasoline Pb in the atmosphere, despite its ban in 2000.

The mineral, chemical and Pb-isotope composition were investigated in the host granite and low-temperature open-fracture fillings from the 100 m deep borehole PDM-1 located in the Melechov Massif of the Moldanubian Batholith. The fillings are dominated by limonite and clay-mineral (illite, kaolinite, montmorillonite, nontronite, chlorite) mixtures, accompanied by minor amounts of residual minerals from the parent rock (quartz, feldspars, zircon, monazite). Chemically contrasting fracture assemblages occur mainly at lesser depths (

The isotopic composition of lead ( 207 Pb/ 206 Pb, 208 Pb/ 206 Pb, and 210 Pb) in a recently formed galena from burning heaps after coal mining in Radvanice, Markousovice, and Rybnicek, the Lower Silesian basin, Czech Republic, was studied in detail. 210 Pb activity in galena varied from 135 ± 9 to 714 ± 22 Bq/g and calculated integral doses ranged from 2.21 × 10 11 to 6.11 × 10 11 α/g. The radioactivity of the galena causes micro-deformations in its crystal structure as indicated by the Williamson-Hall graphs, showing that the level of micro-strain depends on the length of time that galena samples were exposed to the radiation. However, the crystal structure of galena is affected very inhomogenously; according to TEM investigations there are domains of fully crystalline, polycrystalline, and fully metamict galena within one crystal. Inductively coupled plasma-mass spectrometry (ICP-MS) was used to determine the isotopic composition of the studied galena. The stable isotope ratios of Pb varied for 207 Pb/ 206 Pb from 0.8402 to 0.8435 and for 208 Pb/ 206 Pb from 2.0663 to 2.0836. The average ratios 207 Pb/ 206 Pb = 0.8312 and 208 Pb/ 206 Pb = 2.0421 were obtained for coal from the same localities. These isotope ratios show that there is no isotopic fractionation taking place during the coal burning and subsequent galena crystallization from hot gases.

The Ohře River has received contamination from metal mining and metallurgy (mainly Cu, Pb, Sn, U, Zn) over the previous five centuries. This contamination history has been poorly documented. Contamination has entered the river system in its middle reach, where the channel is incised and bedrock confined, which impedes overbank deposition. Our objective was to locate and describe a sedimentary record in this unfavourable depositional setting. Three former channel bars that have coalesced with the riverbank were revealed by examination of historical and current maps and a digital terrain model. Manual coring in the bar and in situ (handheld) X-ray fluorescence (XRF) spectroscopy provided data for developing a contamination chemostratigraphy, which was correlated with the mining history in the region. Detailed topographic examination of the bar and valley edge was important to understanding the evolution of one of the bars. Optically stimulated luminescence (OSL) dating was used to verify the timing of deposition. Handheld XRF for in situ analysis of element composition is efficient for studying contaminated sediment bodies with complex stratigraphy, which require extensive coring and stratigraphic correlation. Despite the unfavourable settings, the channel bars trapped sufficient sediment to produce a record that correlates with the history of contamination in the drainage basin. In the bar studied in greatest detail, we observed a surprising amount of contamination passing through the Ohře River channel (up to 300 mg kg−1 of Cu, 340 mg kg−1 of Pb and 630 mg kg−1 of Sn in fine sand and silt deposits) associated with a pollution climax in the sixteenth and seventeenth centuries. Modern contamination (Hg and U deposited in the nineteenth and twentieth centuries) was entrapped with low efficiency based on comparable concentrations of Hg and U located 90 km downstream. The efficacy of the use of historical maps and detailed fieldwork was demonstrated by identification of unique depositional meso-environments, which are rare in bedrock-confined fluvial systems. The contamination chemostratigraphy of the bar deposits was correlated with the local mining and pollution history and contributed to an understanding of the bar evolution. The approach used in our study may be applicable to other montane rivers with historic ore mining and processing in their basins.

Powdered samples of new and old gasoline catalysts (Pt, Pd, Rh) and new and old diesel (Pt) catalysts were subjected to a pH-static leaching procedure (pH 2-9) coupled with thermodynamic modeling using PHREEQC-3 to verify the release and mobility of PGEs (platinum group elements). PGEs were released under acidic conditions, mostly exhibiting L-shaped leaching patterns: diesel old: 5.47, 0.005, 0.02; diesel new: 68.5, 0.23, 0.11; gasoline old: 0.1, 11.8, 4.79; gasoline new 2.6, 25.2, 35.9 in mg kg(-1) for Pt, Pd and Rh, respectively. Only the new diesel catalyst had a strikingly different leaching pattern with elevated concentrations at pH 4, probably influenced by the dissolution of the catalyst carrier and washcoat. The pH-static experiment coupled with thermodynamic modeling was found to be an effective instrument for understanding the leaching behavior of PGEs under various environmental conditions, and indicated that charged Pt and Rh species may be adsorbed on the negatively charged surface of kaolinite or Mn oxides in the soil system, whereas uncharged Pd and Rh species may remain mobile in soil solutions.

The late Neoproterozoic Lecice black shales and an overlying siliciclastic succession, Bohemian Massif, were deposited in a marine environment on a volcanic arc and provide insights into palaeoenvironmental conditions at the former active margin of northern Gondwana. Field relationships integrated with major/trace element and Mo–Cr–S isotope systematics in two different sections (Stěchovice and Břežany) indicate complex depositional settings intimately connected with the waning activity of the underlying volcanic arc. The Stěchovice black shales represent a deeper part of the basin and were first deposited in weakly anoxic conditions (lower stratigraphic level) with limited terrigenous supply, as reflected by their higher total organic carbon (TOC) and U contents and positive δ53Cr, but negative δ34Spyrite values accompanied by late-stage silicification by arc-related fluids. An abrupt change to oxygenated conditions and increased terrigenous flux, characterized by lower TOC, U and Mo and coupled, negative δ53Cr and δ98Mo, is documented in the upper level of the same section. By contrast, the Břežany black shales were deposited in a shallower part of the basin and their composition (e.g., low metal contents, negative δ53Cr and δ98Mo) suggests oxygenated conditions. Furthermore, the extensive syn-to post-depositional silicification by low-temperature hydrothermal fluids was associated with Si and Ba enrichment and elevated bacterial productivity leading to higher organic matter input. The black shale deposition was terminated by arc uplift, which supplied vast amounts of terrigenous material to the basin and produced a thick flysch sequence deposited at oxygenated conditions. The estimated age of the Lecice black shales (~580–560 Ma) suggests that their deposition may be linked to interactions between global eustatic sea level changes in response to the late Neoproterozoic glaciations (Gaskiers, Farquar) and dynamic arc topography.

Correction for ‘Poly(acrylic acid)-mediated synthesis of cerium oxide nanoparticles with variable oxidation states and their effect on regulating the intracellular ROS level’ by Xiaohui Ju et al., J. Mater. Chem. B, 2021, 9, 7386–7400, DOI: 10.1039/D1TB00706H.

Collections of Cystoderma carcharias sporocarps were sampled from clean and smelter-polluted sites and analyzed for Ag, As, Cd, Cu, Pb, Se, and Zn contents. Concentrations of all elements were significantly higher in samples from the smelter-polluted area. Except for As and Pb, all elements were effectively accumulated in the sporocarps at both clean and polluted sites. With the highest concentration of 604 mg Cd kg−1, C. carcharias can be considered as Cd hyperaccumulator. As revealed by HPLC-ICPQQQMS analysis, the As species in sporocarps from clean and polluted areas involved besides the major arsenobetaine a variety of known and unknown arsenicals; the occurrence of dimethylarsinoylacetate and trimethylarsoniopropionate is reported for the first time for gilled fungi (Agaricales). Size-exclusion chromatography of C. carcharias extracts supported by sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE) and RP-HPLC data indicated that detoxification of intracellular Cd and Cu may largely rely on metallothioneins (MT) or MT-like peptides, not phytochelatins.

Silicified Agathoxylon -type wood of Late Palaeozoic age was characterized by means of cathodoluminescence (CL) and LA-ICP-MS of the quartz mass, which was found to contain wakefieldite, characterized by electron-microprobe (EMP) analysis, Raman microspectroscopy and X-ray diffraction. Although former organic matter is almost absent, plant anatomy served as the template for the quartz mass texture. Two generations of quartz mass were distinguished; the large proportion of the silicified wood consisting of brownish α-quartz with a dark reddish CL emission, and the minor portion of whitish ‘leached’ wood with a short-lived (transient) blue CL. On the outer edge, a silicified texture of formerly slightly humified wood also emits a dark reddish CL. Likely the wood specimen has been fossilized and diagenetically altered in several steps. The marginal part had been humified (reductively degraded) before the initial stages of silicification. The LA-ICP-MS analyses revealed chemical differences in all three distinct parts. The quartz mass relatively enriched in REEs and As and giving the dark reddish CL is interpreted as a primary diagenetic mineral mass. Whitish zones relatively depleted in U and V, and enriched in Al, Li, Rb, Cu, and Sr producing the blue CL would then be a secondary diagenetic overprint. An EMP/WDS analysis identified As-rich xenotime-(Y) and a solid solution of wakefieldite–(Ce) and wakefieldite–(Y), which locally enclose individual silicified tracheids. Wakefieldite, identified in silicified plant tissue for the first time, was most likely formed as a secondary mineral during post-depositional diagenesis. The mineral diagenesis did not erase the original anatomy of the wood.

The Berounka River is considered a relatively clean river, but recent studies have reported various levels of pollution. The purpose of this work is to identify anthropogenic pollution by metals (i.e. Pb, Zn, Cu) and magnetic particles in the sediments of that river and its tributaries. Samples were obtained from hand-drilled cores taken from representative areas within the fluvial system; in distal floodplains (overbank fines) and closer to the channel (laterally deposited sediments). Samples were subjected to analysis using mass magnetic susceptibility (MS), X-ray fluorescence spectrometry (XRF) and also by inductively coupled plasma mass spectrometer (ICP MS) which allowed for a determination of 206Pb/207Pb isotope ratios. Macroelement ratios (K/Ti and Ti/Al) were used to distinguish variegated sediment provenance in the Berounka system. Normalization of trace elements by Ti (in the case of trace elements) and by Fe (magnetic susceptibility) allowed us to establish lithogenic background functions of trace elements and magnetic susceptibility within these two geologically different areas. A pollution assessment of the study area was performed using magnetic susceptibility and local enrichment factors (LEFs) for the risk elements. By comparing 1/(LEF Pb) and Pb isotopic composition, the origins of Pb within the catchment were determined. This unique method was able to distinguish Pb from various origins. The upper parts of the floodplain cores contained higher levels of trace elements and magnetic particles (anthropogenically polluted), but samples taken from the cores in the active channel belt exhibited considerably higher concentrations of trace elements and magnetic particles than the upper parts of the floodplain cores and to much greater depths. We interpreted the deeper parts of the floodplain cores as a local lithogenic background. The upper parts of floodplain sediments hence showed moderate pollution (LEF of Pb and Zn ∼2, MS ∼2.5); whereas laterally deposited sediments showed significantly higher LEF values (LEF of Pb ∼6, Zn ∼9, MS ∼8). The analysis of the sediments confirmed that the Berounka River system contains higher concentrations of trace elements and magnetic particles than can be accounted for by natural geological processes. Our pollution assessment of the Berounka River and its tributaries demonstrated that their sediments are moderately polluted from sources situated on its tributaries: Ag–Pb mining near the city of Střibro in the Mže catchment; Pb–Zn mining in the Přibram ore district in the Litavka catchment and Fe ore processing and smelting in the Klabava catchment.

Fluvial architecture in conjunction with the morphology, petrographical, mineralogical and geochemical composition of intercalated paleosols of the Middle Moscovian upper Radnice Member of the continental Kladno-Rakovnik Basin, Czech Republic, were studied in order to decipher climatic signals in the eastern Pangea region during the Late Paleozoic Ice Age. Analysis of architectural elements reveals vertical changes from strongly amalgamated channel fills of bedload-dominated braided streams, to isolated ribbon-like meandering channel fills in mud-dominated floodplain strata. The resulting large scale fining upward cycles separated by laterally widespread bounding surfaces are interpreted as having been formed in response to allocyclic processes driven by variable intensities of precipitation which affected the density of vegetation cover across the landscape and, in turn, the amount and character of sediment supply. Bedload-dominated parts of the cycles were deposited during periods of low water tables and sparse vegetation, whereas periods of maximum precipitation resulted in higher water tables and a greater density of vegetation cover, which, in turn stabilized the floodplains and fixed streams to narrow meandering/anastomosing channels in mud-dominated floodplain strata. Associated paleosols resemble modern Vertisols, which form under seasonal precipitation in modern settings. However, coeval formation of inertinite-rich peat represented by histosols and gleyed low chroma Vertisols in the stratigraphically lowest paleosol succession occurred under overlapping marginal conditions for the climatically different types of soils (i.e., under a seasonal climate where precipitation exceeds evapotranspiration for 6 to 8 months out of the year). Mean annual precipitation calculated from the geochemistry of B horizons of Vertisols (CALMAG proxy) varies between 1815 and 1730 mm/yr.

This study describes two methods (Procedures-1 and -2) for the direct extraction of Au by an inorganic acid mixture (HClO4-HBr-HI-aqua regia) from complex sample matrices. Standard PTFE jars at 200 °C were used to decompose test portions of 0.5–1 g, with subsequent precise and accurate analysis by ICP-MS without any other preconcentration or separation. Procedure-1 decomposed samples effectively without the necessity of leaching with HF and was developed for dust samples from e-waste (electronic waste) processing; however, testing on geological reference materials showed very good results. The analyses of replicate decompositions (n = 5) from both procedures yielded very good precision (

The fluvial system of the Litavka River in the Czech Republic has been severely polluted by polymetallic ore mining and smelting that occurred mainly between the 1780s and 1970s. To decipher the mechanisms of the pollution transport pathways, we analysed river valley sediments from river headwaters upstream from the ore district through mining and smelting areas to downstream sites. We sampled recently inundated areas as well as sites just outside 100-year (Q100) inundation. In the river valley, it was necessary to distinguish anthropogenic alluvium (AA) floodplain sediments produced due to ore mining and processing. AA had changed K/Rb signal ratios (measured by energy dispersive X-ray fluorescence, ED XRF); Pb and Zn pollution; and 206 Pb/ 207 Pb isotope ratios. The main part of the primary pollution of the river system was deposited in 19th century and during the first half of the 20th century, a few kilometres far downstream from the primary pollution sources (waste deposits of ore mining processing and the smelter). AA has a Zn/Pb ratio of ~ 1.5 and a local enrichment factor (LEF) of up to ~ 160 for Pb and up to ~ 130 for Zn. The floodplain further downstream has received diluted primary pollution with the same Zn/Pb ratio and a LEF of up to ~ 80 for Pb and up to ~ 50 for Zn. Much less severe pollution is recognised in fallout-polluted soils at the river valley edges outside Q100 (Zn/Pb ~ 0.9, LEF ~ 7 for Pb and LEF ~ 2 for Zn). The secondary pollution currently exported from the watershed and floodplain is substantially enriched in Zn (Zn/Pb ~ 1.5–6). That is obviously a consequence of the higher mobility of Zn in the temporary reservoirs in the mining and smelting area and floodplain. We demonstrate that simple element ratios obtained by convenient laboratory XRF spectrometry can considerably help in deciphering the complex structure of floodplain fill as well as pollution transport routes because that method allows us to adequately process a large number of samples to characterise the complexity of the pollutant distribution in floodplains.

This work presents data for the radiogenic Pb isotopic ratios (206Pb/207Pb and 208Pb/206Pb) in nine biogenic certified reference materials (NIST SRM 1515, 1566b, 1570a, 1573a, 1575a; BCR 100, BCR 101, BCR 670 and IAEA 359), which are suitable for analytical quality control in environmental research. The results were obtained using three different types of ICP-based mass spectrometer (quadrupole-based/magnetic sector field single-collector ICP-MS instruments and a multi-collector ICP-MS) and applying different mass bias correction procedures (calibrator-sample bracketing and external Tl normalisation) with and without Pb separation from the matrix using ion exchange chromatography. In the majority of the samples, the measurements from all three of the ICP-MS instruments were in agreement within ± 0.1%, despite the lower analytical precision of the single-collector ICP-MS instruments. We demonstrate that the presence of the sample matrix did not significantly influence the Pb isotopic ratios measured by magnetic sector field ICP-MS, whereas the use of the two different mass bias corrections resulted in a systematic difference of 0.09% for the 208Pb/206Pb ratio. Ce travail presente des donnees concernant les rapports isotopiques du Pb radiogenique (Pb206/Pb207 et Pb208/Pb206) dans neuf materiaux biogenes de reference certifies (NIST SRM 1515, 1566b, 1570a, 1573a, 1575a; BCR 100, BCR 101, BCR 670 et de l’AIEA 359), qui sont appropries pour le controle de la qualite analytique dans le domaine de la recherche environnementale. Les resultats ont ete obtenus en utilisant trois types differents de spectrometre de masse de type ICP (ICP-MS quadripole/ ICP-MS a secteur magnetique mono-collecteur et multi-collecteur ICP-MS) avec differentes procedures de correction du biais en masse (« bracketing » echantillon-etalon et normalisation externe Tl) avec et sans separation du Pb de la matrice en utilisant une chromatographie echangeuse d'ions. Pour la majorite des echantillons, les mesures avec les trois instruments ICP-MS sont en accord a ± 0,1%, en depit de la precision analytique inferieure des ICP-MS a simple collecteur. Nous demontrons que la presence de la matrice de l’echantillon n'a pas d'influence significative sur les rapports isotopiques du plomb mesures par ICP-MS a secteur magnetique mono-collecteur, alors que l'utilisation des deux corrections de biais en masse differents abouti a une difference systematique de 0,09% pour le rapport Pb208/Pb206.

The petrography and mineral chemistry of the coarse-grained, weakly porphyritic (muscovite-) biotite Říčany granite (Variscan Central Bohemian Plutonic Complex, Bohemian Massif) were studied in order to assess the distribution of major and trace elements among its minerals, with consequences for granite petrogenesis and availability of geochemical species during supergene processes. It is demonstrated that chemistry-based approaches are the best suited for modal analyses of granites, especially methods taking into account compositions of whole-rock samples as well as their mineral constituents, such as constrained least-squares algorithm. They smooth out any local variations (mineral zoning, presence of phenocrysts, schlieren…) and are robust in respect to the presence of phenocrysts or fabrics. The study confirms the notion that the accessory phases play a key role in incorporation of many elements during crystallization of granitic magmas. Especially the REE seem of little value in petrogenetic modelling, unless the role of accessories is properly assessed and saturation models for apatite, zircon, monazite±rutile carefully considered. At the same time, the presence of several P-, Zr- and LREE-bearing phases may have some important consequences for saturation thermometry of apatite, zircon and monazite.

The approximately 1200 m thick Cracow Sandstone Series (Middle – early Late Pennsylvanian) in the Polish part of the Upper Silesian Coal Basin consists of 25–70 m thick fining up and laterally widespread fluvial cycles. The cycles are marked by alternating sheet-like sandstone bodies overlain by much thinner intervals dominated by mudstone and coal. These two-member cycles record the alternation of a sand-dominated fluvial braidplain and floodplain-dominated fluvial system with channels confined to narrow belts. The lateral persistence, internal architecture, and isochronous alternations suggest an allogenic origin for the cycles, possibly related to climate. This interpretation is supported by a three-stage evolution of pedogenic processes operating on floodplain deposits beginning with the formation of vertisols, followed later by gleying and, finally, termination by a Histosol (peat) formation. Such a succession of paleosols indicates a climatic shift from highly seasonal (Vertisol) to humid climate (coal) with the most seasonal part of the cycle likely represented by the sheet-like sandbody. The mechanistic link between climate and the cyclic pattern of strata is explained as climatically-driven variations in clastic supply, which was highest during periods of prominent seasonality. Short-term climatic oscillations generating cyclic patterns in the Cracow Sandstone Series are superimposed on a long-term climatic shift towards increased seasonality near the Middle – Late Pennsylvanian boundary. This is evidenced by the termination of peat formation in the Upper Silesian Basin as well as in some other coeval basins of the equatorial Pangea and is interpreted to represent a potentially regional climatic event.

Particles originating from the last major Eyjafjallajokull volcano eruption in April 2010 were subsequently found in settled dust samples collected in a suburban area of Prague, Czech Republic. These dust samples contained predominantly non-volcanic particulate matter of super-regional but mainly local origin. The highest proportion of the Eyjafjallajokull material recorded in the Prague daily dust samples reached 12% of the total lithic component mass. Volcanogenic particles, mostly glasses, were concentrated in particle size classes from 2.5 to 25 μm, but rare fragments of volcanic glasses up to 50 μm in diameter were also found. The most effective method for detection and identification of the volcanic ash particles were morpho-textural observations combined with energy dispersive and wavelength dispersive analysis of individual grains and X-ray powder diffraction. Because of the low percentage of volcanic ash particles in the total samples, the geochemical signal was rather weak although detectable in terms of selected trace elements and REE distributions. The mineralogy, particle size distributions, and geochemical compositions of the Prague samples were compared with reference materials sampled near the Eyjafjallajokull volcano.

The distribution of platinum group elements (PGE) was studied in the soils of municipal parks in two large industrial cities with different histories, Prague and Ostrava in the Czech Republic. Soil samples were taken from depths of 0–10, 10–20 and 20–30 cm and the Pd, Pt, Rh and Ir contents were studied in the individual samples following dokimastic separation into NiS using ICP MS. Higher PGE contents were determined in Prague; the highest contents were found in the centres of both cities because of the slower, stop-and-go movement of automobiles during which more PGE's are emitted. The maximum PGE contents found were for Pt in Prague (160 μg kg− 1), with lower contents of Pd (49 μg kg− 1), followed by Rh (3.9 μg kg− 1). Elevated PGE concentrations are observable in the topmost layers of most soils. At some locations, the maximum PGE concentrations were observed in deeper parts of the profile. On the basis of the maximum numbers of registered vehicles (1997) and assumption that new vehicles emit the highest amounts of PGE, the calculated velocity of migration of metals through the profile corresponded to 1.1–2.2 cm year− 1. The statistically lower PGE contents in areas under the tree crowns compared to open sites can be explained by the annual collection and removal of fallen biomass containing the captured catalyst particles.

Highly siderophile element (HSE – Re, Os, Ir, Ru, Rh, Pd, Pt, and Au) and S abundances, sulphide petrography and 187Os/188Os compositions of two distinct suites – Mg-lherzolite and Fe-dunite/wehrlite accompanied by pyroxenites from Horni Bory, Bohemian Massif, Czech Republic are reported. The Mg-lherzolite suite is enriched in IPGE (Os, Ir, and Ru), moderately depleted in Pd, Pt and S, and has osmium isotopic compositions similar to that of the Phanerozoic convecting mantle. Such a composition can be best explained by reaction between previously depleted peridotite and sulphur-undersaturated melt at low melt-rock ratios. This reaction was associated with precipitation of IPGE alloys and Pt–As. The Fe-dunite/wehrlite suite is depleted in IPGE, enriched in Pd, Pt, and S and has radiogenic osmium isotopic compositions. The origin of this suite reflects melt-rock reaction between peridotite and subduction-related melt at high melt/rock ratios resulting in breakdown of primary sulphides and their replacement by HSE-poor but 187Os-enriched sulphides. Mass-balance calculations and relations between HSE and S contents show that, while most of the Re is trapped in base metal sulphides (BMS), only up to 28% of the rest of the HSE (Os, Ir, Ru, Pd, Pt) are accommodated in BMS. Several Pt–As phases discovered in Mg-lherzolite and Fe-dunite/wehrlite and Os–Ru phase found in Mg-lherzolite suggesting complex behaviour of HSE during melt-rock reactions depending on melt composition and melt/rock ratios. The Re–Os data for the Fe-wehrlite/dunite and pyroxenite rocks yield an errorchon age of 334 ± 19 Ma, which is similar to the age of other high temperature/pressure rocks from Gfohl Nappe (Moldanubian Zone, Bohemian Massif); this age likely corresponds to the time of melt-rock reactions and subduction.

Purpose Regional contamination of southern Moravia (SE part of the Czech Republic) by trace metals and magnetic particles during the twentieth century was quantified in fluvial sediments of the Morava River. The influence of local pollution sources on regional contamination of the river sediments and the effect of sampling site heterogeneity were studied in sediment profiles with different lithologies.

Kasperske Hory, one of the largest gold deposits in the Bohemian Massif, is characterised by shear zone-related gold-bearing quartz veins at the tectonic boundary of the two metamorphic terranes of the Moldanubian Unit. Studies of the geology, mineral paragenesis, fluid inclusions and oxygen geothermometry have been carried out to determine the mineralisation events and alternative P–T–t model of this deposit. The pre-mineralisation stage is characterised by geochemical evidence of pegmatites (~ 700 °C and 1.1–0.45 GPa) and metamorphic structures resulting from deformation Dx + 1 at the regional metamorphic peak (650 °C and 0.5 GPa). The mineralisation in Dx + 2 began to develop from the formation of the Q1 and Q2 quartz veins (Stage I) under brittle-ductile conditions with the N–S extension; these quartz veins were filled mainly by apatite, plagioclase-1, muscovite and arsenopyrite-1. Revised and reinterpreted gechronological data indicate that the earliest quartz veins can be dated at 344 Ma. The Q3 veins were formed later under brittle to brittle-ductile conditions with crystallisation of plagioclase-2, arsenopyrite-2, scheelite, chlorite, pyrite and calcite (Stage II). The corresponding fluids of Stages I and II belong to the C-H-O-N system. The P–T conditions correspond to 590–520 °C and to 0.44–0.25 GPa for Stage I and 480–390 °C and ~ 0.2 GPa for Stage II. Stage III is characterised by the precipitation of younger quartz, chlorite, molybdenite, calcite, pyrrhotite-1, galena-1, native gold, bismuth, and other Bi-Te minerals; the associated aqueous fluids (salinity 1.5, 8 wt.% NaCl equiv.) follow fluid inclusion trails and were trapped at relatively low pressures and temperatures (290–180 °C and < 0.1 GPa). Stage IV is mainly dominated by carbonate and fluorite fillings of the open fractures and cracks. Arsenopyrite-1 and ‐2 and molybdenite are the main gold-bearing and gold-carrying ore phases at this deposit. The means of microanalysis indicate the presence of both micron-sized and probably submicron-sized particles of gold (~ 920/1000) in the fractures and fissures of the arsenopyrite-1 and structurally bound invisible gold in the arsenopyrite-2 crystal lattice (e.g., gold as Au(I)). Economic gold mineralisation (native-free gold flakes; 930/1000) is linked to Stage III.

International audience; A 1596-m-deep borehole (CS-1) located in the central part of the Cinovec (Zinnwald) granite cupola mineralized in Sn and W intersected zinnwaldite granite (ZG) followed by lithian annite ("protolithionite") granite (PG). These two types of granite are separated by a transition zone (TZ). We studied the chemical composition of major mineral phases (plagioclase, K-feldspar, micas) by EPMA and LA-ICP-MS analyses. The plagioclase composition corresponds to albite (Ab(99.6-91.1)) containing 0.09 to 0.18 wt.% Rb2O. Albite crystallized from the magma. K-feldspar is perthitic and shows an increase in Rb concentration (up to 0.83 wt.% Rb2O) in the apical part of the cupola. The partition coefficient K-D-Rb(Mi-Kfs) is constant throughout the cupola, indicating a systematic re-equilibration of these two minerals with fluid. Lithian annite occurs below -735 m. Its F content decreases with depth and from -940.5 m, OH exceeds F. Magnesium and Ti concentrations show a remarkable positive correlation with depth. The TZ and adjacent area are characterized by strong variations in the chemical composition of micas, reflecting the fluctuation of saturation-oversaturation of residual liquid by a F-rich fluid phase. The Rb concentration in zinnwaldite (up to 2 wt.% Rb2O) strongly increases in the apical part of the cupola owing to a significant transfer of volatiles. The chemical composition of mica evolves gradually from the TZ to the apical zone. The discovery of lithian annite included in quartz at -97 m indicates the formation of zinnwaldite by interaction of lithian annite with F-rich fluid. The octahedral site of lithian annite allows the incorporation of Sn, Nb, Ta and W, replacing Ti. Because of the lithian annite -> zinnwaldite transformation, these elements with higher ionic charges are expelled from the mica structure, transferred to the fluid phase and concentrated in the apical part of the cupola. The LA-ICP-MS analyses of the micas confirm this process. We envisage the transport of Sn, Nb, Ta and W in the form of fluorides and the precipitation of cassiterite by hydrolysis of SnF4. Tungsten was probably transported as H2WO4, resulting from the reaction of WF6 with H2O. A similar behavior of Nb and Ta is suggested. The hydrolysis of fluorides leads to a strong enrichment of fluid in HF, which induced albite instability and formation of greisens. Calculations show that the amounts of Sn and W released by the transformation lithian annite -> zinnwaldite transformation are close to the estimated reserves of these metals within the Cinovec cupola, corroborating the proposed metallogenic model.

* �Correspondingauthor Samples of naturally irradiated fluorite have been analyzed by means of X-ray powder diffraction analysis (XRPD), differential scanning calorimetry (DSC) and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The diffraction patterns of all irradiated samples show peak broadening caused by micro-strain, which was evaluated by Williamson-Hall method, and an increase in the unit cell parameter. The DSC analysis showed an exothermic peak at 273 °C corresponding to enthalpy change about 16 kJ·mol -1 . This value is an order of magnitude higher than calculated change due to unit cell volume increase that is only 2 kJ·mol -1 . The LA-ICP-MS did not show any significant substitu- tions, which might account for observed unit-cell parameter increase. The results have shown that high radiation doses lead to formation of defect clusters.

The Janska vein is one of the important veins of Březove Hory mining district (central Bohemia, Czech Republic). Base metals were mined here since 14th century and uranium ore during late 1950s. Uranium mineralization is younger than most of the base metal mineralization according to macroscopic and microscopic study. Most specimens of uraninite, obtained from archive, contain more or less abundant galena inclusions. Galena of this type is non-radiogenic as indicated by its Pb isotopic composition (ICP-MS). Its origin can be explained by remobilisation of the older base-metal mineralization during the younger, uranium-bearing mineralization event. The amount of radiogenic Pb in uraninite fluctuates from 48 up to 89.8 %. The age of theoretical end member of uraninite, calculated statistically from all measured data (for intersection 208Pb/206Pb = 0), is 269.8 err 20.3 Ma. The only uraninite grain without galena inclusions yielded an age of 263.2 err 8.9 Ma by chemical dating using electron microprobe. The calculated age of the uranium mineralization is in agreement with published data for other uranium deposits genetically associated with the Central Bohemian Plutonic Complex.