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Total organic carbon (TOC) contents in agricultural soil are presently receiving increased attention, not only because of their relationship to soil fertility, but also due to the sequestration of organic carbon in soil to reduce carbon dioxide emissions. In this research, the spatial patterns of TOC and its relationship with pH at the European scale were studied using hot spot analysis based on the agricultural soil results of the Geochemical Mapping of Agricultural Soil (GEMAS) project. The hot and cold spot maps revealed the overall spatial patterns showing a negative correlation between TOC contents and pH values in European agricultural soil. High TOC contents accompanying low pH values in the north-eastern part of Europe (e.g., Fennoscandia), and low TOC with high pH values in the southern part (e.g., Spain. Italy, Balkan countries). A special feature of co-existence of comparatively low TOC contents and low pH values in north-central Europe was also identified on hot and cold spot analysis maps. It has been found that these patterns are strongly related to the high concentration of SiO2 (quartz) in the coarse-textured glacial sediments in north-central Europe. The hot spot analysis was effective, therefore, in highlighting the spatial patterns of TOC in European agricultural soil and helpful to identify hidden patterns. (C) 2019 Elsevier B.V. All rights reserved.

Over 4000 agricultural and grazing land soil samples were collected for the “Geochemical Mapping of Agricultural and Grazing Land Soil of Europe” (GEMAS) project carried out by the EuroGeoSurveys Geochemistry Expert Group. The samples were collected in 33 European countries, covering 5.6 million km 2 at a density of 1 sample site per 2500 km 2 . All samples were analysed by ICP-MS following an aqua regia extraction. The European median Cd concentration is 0.182 mg/kg in agricultural soil and 0.197 mg/kg in grazing land soil (including eastern Ukraine). The Cd map demonstrates the existence of two different geochemical background regimes in northern and southern Europe, separated by the southern limit of the Quaternary glaciation. Cadmium shows two times higher background concentrations in the older and more weathered southern European soil than in northern European soil. The spatial distribution patterns of Cd in the collected soil samples are mainly governed by geology (parent material and mineralisation), as well as weathering, soil formation and climate since the last glaciation period. Locally, in several areas, the natural anomaly pattern is overprinted by anthropogenic emissions from former mining, ore processing and related metal industries. Some Cd anomalies can be attributed to urbanisation and the use of fertilisers. A comparison of the raw data Cd concentration map with its clr-transformed counterpart and selected single element ratio maps demonstrates that substantial additional information about sources and processes governing the distribution of Cd in agricultural soil at the European scale can be obtained. Results of a PCA, carried out following the classical approach (standardised) versus a PCA based on the statistically acceptable approach, using clr-transformed data, are quite comparable.

Two thousand one hundred and eight agricultural soils (0–20 cm depth) collected at a density of one sample per 2500 km2 under the auspices of the Geochemical Mapping of Agricultural Soils (GEMAS) project over most of the European continent have been analysed using the Mobile Metal Ion (MMI®) partial extraction technique with ICP-MS finish. For a number of elements, notably Ce, Ni, and Ca, coherent geogenic patterns have been observed which relate to underlying lithology. For Fe and Al, coherent patterns are also observed but the effects of weathering are evident, and provide a mechanism to explain the acidity of soils in high rainfall areas. Individual anomalies, many related to anthropogenic activity (mining, metallurgy, agriculture) have been observed for Ag, Au, Cu, Pb, Cd and Zn. Comparison of the results with aqua regia digestion and the equivalent National Geochemistry Survey of Australia (NGSA) provides insights into weathering processes and the concept of bioavailability. © 2015 AAG/The Geological Society of London.

During 2008 the GEochemical Mapping of Agricultural Soils (GEMAS) project collected 2108 agricultural (ploughed soil, Ap horizon, 0–20 cm) and 2023 grazing land soil samples (Gr, 0–10 cm) evenly spread over 33 European countries and covering an area of 5.6 million km2. The pH of all samples was determined by one single laboratory applying a 0.01 M CaCl2 extraction, and following a strict quality-control procedure. The resulting pH-value distributions for European Ap and Gr soil are both bimodal. Broad acidic modes, with pH between 4 and 6, and sharp alkaline modes, with pH between 7 and 8 due to the Ca2+ buffer system, are clearly separated. The European median pH is 5.8 for the GEMAS Ap soil samples and 5.5 for the GEMAS Gr soil samples. According to the pH distribution maps, Europe is separated into two main zones: northern Europe with generally lower pH values (Ap: 5.2, Gr: 4.8), dominated by acidic soils occurring in Fennoscandia, and southern Europe with higher pH values (Ap: 6.3, Gr: 5.9), dominated by carbonate rich soils. The separation line coincides with the southern border of the sediments of the last glaciation. The dominant factors controlling pH at the European scale are thus geology (crystalline bedrock) in combination with climate (temperature and precipitation). The GEMAS pH maps mainly reflect the natural site conditions on the European scale, whilst anthropogenic impact is hardly detectable. The GEMAS results provide a unique set of homogenous and spatially representative soil pH data for the continent. The data set defines a dependable continental-scale background, and offers the possibility to calibrate studies on more detailed scales.

Agricultural soil (Ap-horizon, 0–20 cm) samples were collected from 33 European countries as part of the GEMAS (GEochemical Mapping of Agricultural and grazing land Soil) soil-mapping project. The Mg data derived from total concentrations (XRF) and two acid digestion methods, aqua regia (AR) and Mobile Metal Ion (MMI®), were used to provide an overview of its spatial distribution in soil at the continental-scale. Magnesium is one of the most abundant elements in the Earth's crust and essential nutrient for plants and animals and its presence in soil is, therefore, important for soil quality evaluation. In this study, the geochemical behaviour of Mg in European agricultural soil was investigated in relation to a variety of soil parent materials, climatic zones, and landscapes. The chemical composition of soil reflects mostly the primary mineralogy of the source bedrock, and the superimposed effects of pre- and post-depositional chemical weathering, controlled by element mobility and formation of secondary phases such as clays. Low Mg concentrations in agricultural soil occur in regions with quartz-rich glacial sediments (Poland, Baltic States, N. Germany), and in soil developed on quartz-rich sandstone parent materials (e.g., central Sweden). High Mg concentrations occur in soil developed over mafic lithologies such as ophiolite belts and in carbonate-rich regions, including karst areas. The maximum extent of the last glaciation is well defined by a Mg concentration break, which is marked by low Mg concentrations in Fennoscandia and north-central Europe, and high Mg concentrations in Mediterranean region. Lithology of parent materials seems to play a key role in the Mg nutritional status of agricultural soil at the European scale. Influence from agricultural practice and use of fertilisers appears to be subordinate. Comparison of the continental-scale spatial distribution of Mg in agricultural soil by using the results from three analytical methods (XRF, AR and MMI®) provides complementary information about Mg mobility and its residence time in soil. Thus, allowing evaluation of soil weathering grade and impact of land use exploitation.

Geochemical studies that focus on environmental applications tend to approach the chemical elements as individual entities and may therefore offer only partial and sometimes biased interpretations of their distributions and behaviour. A potential alternative approach is to consider a compositional data analysis, where every element is part of a whole. In this study, an integrated methodology, which included compositional data analysis, multifractal data transformations and interpolation, as well as enrichment factor analysis, was applied to a geochemical dataset for the Campania region, in the south of Italy, focusing in particular on the behaviour, footprints and sources of a smaller pool of elements: Al, Na, K and P. The initial dataset included 3669 topsoil samples, collected at an average sampling density of 1 site per 2.3 km(2), and analyzed (after an aqua regia extraction) by a combination of ICP-AES and ICP-MS for 53 elements. Frequency based methods (Clr biplot, Enrichment Factor computation) and frequency spatial-method (fractal and multifractal plots) allowed identifying the relationships between the elements and their possible source patterns in Campania soils in relation to a natural occurring concentrations in geogenic material (rocks, soils and sediments) or human input. Results showed how the interpretation of concentration and behaviour of Al, Na, K and P was enhanced thanks to the application of data log-ratio transformation in univariate and multivariate analysis compared to the use of raw or log-normal data. Multivariate analyses with compositional biplot allowed the identification of four element associations and their potential association with the underling geology and/or human activities. When focusing on the smaller pool of elements (Al, P, K and Na), these relationships with the unique geology of the region, were largely confirmed by multifractal interpolated maps. However, when the local background was used for the calculation of the enrichment factor, the resulting interpolated maps allowed to identify smaller areas where the greater concentrations of P could not be possibly associated to a mineralisation (e.g., ultrapotassic rocks) but were more likely to be associated to anthropogenic input such as agriculture activities with potentially extensive use of phosphate fertilizers. The integrated approach of this study allowed a more robust qualitative and quantitative evaluation of elemental concentration, providing in particular new and vital information on the distribution and patterns of P in soils of the Campania region, but also a viable, more robust, methodological approach to regional environmental geochemistry studies.

Organochlorine pesticides (OCPs) are synthetic chemicals commonly used in agricultural activities to kill pests and are persistent organic pollutants (POPs). They can be detected in different environmental media, but soil is considered an important reservoir due to its retention capacity. Many different types of OCPs exist, which can have different origins and pathways in the environment. It is therefore important to study their distribution and behaviour in the environment, starting to build a picture of the potential human health risk in different contexts. This study aimed at investigating the regional distribution, possible sources and contamination levels of 24 OCP compounds in urban and rural soils from central and southern Italy. One hundred and forty-eight topsoil samples (0-20cm top layer) from 78 urban and 70 rural areas in 11 administrative regions were collected and analysed by gas chromatography-electron capture detector (GC-ECD). Total OCP residues in soils ranged from nd (no detected) to 1043ng/g with a mean of 29.91ng/g and from nd to 1914ng/g with a mean of 60.16ng/g in urban and rural area, respectively. Endosulfan was the prevailing OCP in urban areas, followed by DDTs, Drins, Methoxychlor, HCHs, Chlordane-related compounds and HCB. In rural areas, the order of concentrations was Drins>DDTs>Methoxychlor>Endosulfans>HCHs>Chlordanes>HCB. Diagnostic ratios and robust multivariate analyses revealed that DDT in soils could be related to historical application, whilst (illegal) use of technical DDT or dicofol may still occur in some urban areas. HCH residues could be related to both historical use and recent application, whilst there was evidence that modest (yet significant) application of commercial technical HCH may still be happening in urban areas. Drins and Chlordane compounds appeared to be mostly related to historical application, whilst Endosulfan presented a complex mix of results, indicating mainly historical origin in rural areas as well as potential recent applications on urban areas. Contamination levels were quantified by Soil Quality Index (SoQI), identifying high levels in rural areas of Campania and Apulia, possibly due to the intensive nature of some agricultural practices in those regions (e.g., vineyards and olive plantations). The results from this study (which is in progress in the remaining regions of Italy) will provide an invaluable baseline for OCP distribution in Italy and a powerful argument for follow-up studies in contaminated areas. It is also hoped that similar studies will eventually constitute enough evidence to push towards an institutional response for more adequate regulation as well as a full ratification of the Stockholm Convention.

We present Sr-87/Sr-86 isotope ratios for similar to 1200 selected soil samples, collected by the GEMAS consortium from grazing (Gr) and agricultural (Ap) soils in Europe with the aim to better understand the strontium isotope distribution in the bioavailable fraction of the top-soil and its potential for provenancing applications. Spatial analysis shows that there is a clear distinction between coastal (100 km) samples in their variance and that this variance is mirrored in the sodium concentration, suggesting an important but highly variable contribution from seaspray. We present two Sr-87/Sr-86 maps at 25 km x 25 km scale: one based solely on the measured data using a classical kriging approach and one based on a Random Forest model using complementary GEMAS data to predict the strontium isotope composition at the remaining 3000+ GEMAS sampling locations, including appropriate uncertainty assessment. Using a forensic Bayesian likelihood ratio approach, a tool was developed in R to create provenancing likelihood ratio maps. The maps delineate areas of high and low likelihood and allow investigators to direct their resources to areas of interest. For actual forensic case work either the measured or the modelled data can be used as reference data for the overall distribution of Sr-87/Sr-86 values in Europe. (C) 2019 Elsevier B.V. All tights reserved.

Organochlorine pesticides (OCPs) have the potential to concentrate in the marine environment and threaten the local marine life. Here, we present the results of a study of the contamination profiles, spatial distribution, possible sources, and potential ecological risk of OCPs in marine sediments from Gulfs of Naples and Salerno, Southern Italy. The total concentrations of OCPs ranged from 0.54 to 99.6 ng/g (average mean: AM = 7.80 +/- 16.3 ng/g). The concentration of OCPs from gulf of Salerno (AM = 9.20 +/- 20.7 ng/g) was higher than Naples (AM = 7.49 +/- 15.3 ng/g). The sediment levels of individual OCPs were (in sequence of concentration) dichlorodiphenyltrichloroethanes (DDTs, including p,p'-DDD, p,p'-DDE, o,p'-DDT and p,p'-DDT) > CHLs (heptachlor, heptachlor epoxide, trans-chlordane, and cis-chlordane) > hexachlorocyclohexanes (HCHs, including alpha-beta-gamma-and delta-HCH) > DRINs (aldrin, dieldrin, and endrin) > hexachlorobenzene (HCB) > SULPHs (alpha-endosulfan, beta-endosulfan, and endosulfan sulfate). DDTs and heptachlor were the highest in proportion among the OCPs. High concentrations of OCPs were observed in the coastal area especially near the cities of Naples and Salerno as a result of terrigenous supply. The occurrence of high residual levels of OCPs found in this study may be attributed to their historical application. Marine dynamics influence the distribution of OCPs, in particular the HCHs, as they are less lipophilic and more soluble. According to established sediment quality guidelines, DDTs may cause ecological risk.

This study assesses the distribution of Au, Ag, Pt, and Pd in the topsoils from the Campania Region (Southern Italy). The 13,600 km2 study area was divided using a 16 km2 grid in the suburban and agricultural areas, and a 4 km2 grid in urban areas and 2120 topsoil samples were analyzed by ICP-MS after an aqua regia digestion. The maximum concentrations of Pt and Pd were 278.1 and 431.9 ppb, respectively, however, >50% of samples analyzed during this study had concentrations of Pt and Pd below the instrumental detection limit. Gold and Ag concentrations ranged from 0.2 to 1278.6 ppb, and 2 to 8132 ppb, respectively. The geochemical data was first elaborated into dot maps to assess the relationship between the real concentrations across the region. Point data were subsequently classified using their statistical percentile thresholds (25th, 50th, 75th, 95th and 98th). A C–A fractal model was then applied to the data to assess their spatial distribution and determine thresholds representing changes in concentrations highlighting background/baseline and anomalous components. Major results indicate that: (1) application of C–A fractal model on multifractal gridded data allows the discrimination of geochemical anomalies from background concentrations; (2) Au, Ag, Pt, and Pd in Campania topsoils clearly reflect both natural and anthropogenic influences on their occurrence and distribution; (3) a clear relationship exists between the abrasion of automobile catalytic converters, the occurrence of PM10 aerosol particles, and elevated concentrations of Pt and Pd in soil; (4) the concentration of Ag and Au in the soils of the study area reflect differences in the origin of their source material in the volcanic products of northern (Roccamonfina) and central Campania (Campi Flegrei, Vesuvius); and (5) clear enrichment in Au and Ag are located corresponding to the main urban areas.

Digital image processing analysis was carried out on As in topsoils of the Campania Region (Italy) to recognise any unknown spatial patterns. The highest As concentration is related to topsoils developed on the NW–SE-trending carbonate massifs overlain by pyroclastic rocks where the highest spatial variability and gradient magnitude of As concentration and the highest fault density were also observed. High As concentrations were also found in topsoils over volcanic rocks which played a control on its distribution pattern. The low As values are associated with topsoils along large fluvial valleys where the activity of rivers disturbed the As pattern by transporting larger grain-sized stream sediments with low As concentrations.

Concern about health effect of Potentially Toxic Elements (PTEs) has led to an increasing global attention about their concentration levels in the environment. Soil geochemistry has been widely used as a tool for environment monitoring. This study investigates topsoil geochemistry of Campania region (Southern Italy) and (i) allows a reliable overview of the PTEs (As, Be, Cd, Co, Cr, Cu, Hg, Ni, Pb, Sb, Se, Sn, Tl, V and Zn) concentration in soils, (ii) enable the investigation of the main factors governing PTEs geochemical variation on a regional scale. Over 7300 topsoil samples were collected from the survey area, which occupies an area of about 13.600 km2. Samples were analyzed for pseudo-total content of 53 elements (major and trace elements) by ICP-MS after aqua regia digestion. Data analysis was performed taking into account both raw data and their compositional nature as a tool for the PTEs environmental evaluation and origin investigation. As, Be, Cu, Pb, Sn, Tl, V and Zn in soils of Campania region show higher median concentration levels than Italian and European ones. In addition, all PTEs exceed the residential/ recreational intervention limit (CSCA) set by Italian legislation. The variation structure of compositional data had been visualized using compositional (clr) biplots and displaying the individual sample observations according to their parent rock. Clr-biplot analysis allowed us to recognize geochemical processes controlling most of soil chemical signatures. Multivariate analysis has been performed and three principal components were determined. PC1 is controlled by enrichment of elements deriving from dominant parent rocks of the area (siliciclastics and volcanoclastics). On the other hand, PC1 reveals the presence of an elemental association dominated by Na, K, U, Th, Zr, Ti, Tl and Be (clr variables), which are pathfinder element of soils developed from volcanic parent material. The second (PC2) component well discriminates the geochemical mobility of the elements in soils. The third (PC3) component reveal the presence of an anthropogenic association (Hg, Sb, Pb, Sn, Au, Ag) which depict a marginal contribution in soil geochemistry of the study area. The generation of clr-biplot helped us in a deeper interpretation of single element spatial distribution patterns. As, Be, Sn, Tl and V spatial distribution shows dominance in soil developed from volcanic products of the main volcanic complexes. Our study showed that element such as Be, Sn and Tl naturally exceed the contamination thresholds in almost the entire territory, due to a quite elevated background concentration values. Hence, Campania region con not be considered entirely contaminated (at this scale) by such elements. Co, Cd, Cr and Ni are more abundant where siliciclastic parent rocks occur.

The concentrations of polycyclic aromatic hydrocarbons (PAHs) in soils from Caserta provincial territory, southern Italy, were systematically investigated along with their correlations with soil properties and health risk. The concentrations of ∑16PAHs ranged from 10.0 to 4191 ng/g, with a median (1 st quartile, Q1; 3rd quartile, Q3) of 28.5 (17.5–65.0) ng/g; Four-ring PAHs were the most abundant and contributed an average of ∼50.2% of the ∑16PAHs. Significant differences in the spatial distributions of PAHs in soil were observed, with higher levels of PAH contamination found in Caserta city and the surrounding areas. According to the positive matrix factorization (PMF) model, three sources were identified: chemical production and metal smelting, vehicle emissions, and coal/biomass combustion. Soil total organic carbon was significantly correlated with the concentration of total PAHs and the concentrations of PAHs with three-, four-, and five-rings. In contrast, only the concentration of ∑4DBPs (dibenzo(a,e)pyrene, dibenzo(a,h)pyrene, dibenzo(a,i)pyrene, dibenzo(a,l)pyrene) was well correlated with population density. The soil mass inventory of ∑16PAHs was estimated to be 6.87 metric tons (geometric mean). The ecological risks posed by PAHs in the study are negligible; however, health risks of exposure to soil-borne PAHs were identified based on a probabilistic risk model.

Uranium, thorium and potassium are distinguished in different compartments of the environmental media according to the inputs, the fate and the distribution patterns that occur in the ecosystems. Thus, an understanding of the sources patterns and behaviours of these elements in soils, their rock-soil relationships and potential toxicity or deficiency problems associated with them is nowadays a relevant concern for environmental protection and human health. A robust compositional computation analysis coupled with frequency spatial-method (Fractal model) is applied on 3 selected elements (U, Th and K), based on a large dataset of 7134 topsoil samples over the whole Campania region, and investigated elements concentrations were analysed (after aqua regia extraction) by inductively coupled plasma mass spectrometry (ICP-MS). In this survey, U concentrations ranged from 0.05 to 43.2 mg kg−1 with a mean value of 3.35 mg kg−1, Th concentrations ranged from 0.3 to 64.30 mg kg−1 with a mean values of 11.95 mg kg−1 and K concentrations ranged from 0.03 to 5.97% with a mean value of 0.68%. The mean values for U and Th are slightly above the mean crustal abundances, while K is slightly below them. Fractal mapping of Centred-log transformed (clr) data of investigated elements show that the U, Th and K geochemical anomalies can be ascribed to geology-related volcanic sources. Indeed, the highest values in soils were assessed in the surveyed alkaline magmatic areas in the central-western part of the region characterized by volcanic rocks, whereas lowest values are found in areas characterized by silico-clastic and carbonate deposits, occurring mostly in the southern and eastern part of the region. Evidence from this study showed that compositional data transformations such as clr transformation could help to avoid artefacts, prior to statistical computations.

Agricultural soil (Ap-horizon, 0–20 cm) samples were collected in Europe (33 countries, 5.6 million km2) as part of the GEMAS (GEochemical Mapping of Agricultural and grazing land Soil) soil-mapping project. The GEMAS survey area includes diverse groups of soil parent materials with varying geological history, a wide range of climate zones, and landscapes. The soil data have been used to provide a general view of U and Th mobility at the continental scale, using aqua regia and MMI® extractions. The U-Th distribution pattern is closely related to the compositional variation of the geological bedrock on which the soil is developed and human impact on the environment has not concealed these genuine geochemical features. Results from both extraction methods (aqua regia and MMI®) used in this study support this general picture. Ternary plots of several soil parameters have been used to evaluate chemical weathering trends. In the aqua regia extraction, some relative Th enrichment-U loss is related to the influence of alkaline and schist bedrocks, due to weathering processes. Whereas U enrichment-Th loss characterizes soils developed on alkaline and mafic bedrock end-members on one hand and calcareous rock, with a concomitant Sc depletion (used as proxy for mafic lithologies), on the other hand. This reflects weathering processes sensu latu, and their role in U retention in related soils. Contrary to that, the large U enrichment relative to Th in the MMI® extraction and the absence of end-member parent material influence explaining the enrichment indicates that lithology is not the cause of such enrichment. Comparison of U and Th to the soil geological parent material evidenced i) higher capability of U to be weathered in soils and higher resistance of Th to weathering processes and its enrichment in soils; and, ii) the MMI® extraction results show a greater affinity of U than Th for the bearing phases like clays and organic matter. The comparison of geological units with U anomalies in agricultural soil at the country scale (France) enables better understanding of U sources in the surficial environment and can be a useful tool in risk assessments.

A reliable overview of measured concentrations of TC, TN and TS, TOC/TN ratios, and their regional distribution patterns in agricultural soil at the continental scale and based on measured data has been missing - despite much previous work on local and the European scales. Detection and mapping of natural (ambient) background element concentrations and variability in Europe was the focus of this work. While total C and S data had been presented in the GEMAS atlas already, this work delivers more precise (lower limit of determination) and fully quantitative data, and for the first time high-quality TN data. Samples were collected from the uppermost 20 cm of ploughed soil (Ap horizon) at 2108 sites with an even sampling density of one site per 2500 km2 for one individual land-use class (agricultural) across Europe (33 countries). Laboratory-independent quality control from sampling to analysis guaranteed very good data reliability and accuracy. Total carbon concentrations ranged from 0.37 to 46.3 wt% (median: 2.20 wt%) and TOC from 0.40 to 46.0 wt% (median: 1.80 wt%). Total nitrogen ranged from 0.018 to 2.64 wt% (median: 0.169 wt%) and TS from 0.008 to 9.74 wt% (median: 0.034 wt%), all with large variations in most countries. The TOC/TN ratios ranged from 1.8 to 252 (median: 10.1), with the largest variation in Spain and the smallest in some eastern European countries. Distinct and repetitive patterns emerge at the European scale, reflecting mostly geogenic and longer-term climatic influence responsible for the spatial distribution of TC, TN and TS. Different processes become visible at the continental scale when examining TC, TN and TS concentrations in agricultural soil Europe-wide. This facilitates large-scale land-use management and allows specific areas (subregional to local) to be identified that may require more detailed research.

The GEMAS (geochemical mapping of agricultural soil) project collected 2108 Ap horizon soil samples from regularly ploughed fields in 33 European countries, covering 5.6 million km(2). The

This study shows the statistical and spatial distribution of Mo, Sn and W in topsoils of the Campania Region. Topsoil samples were collected based on a 16-km 2 and a 3.8-km 2 cell-sampling grid in the suburban and urban areas, respectively. Samples were analysed for Mo, Sn and W concentrations by ICP-MS after an aqua regia digestion. Multifractal methods and RGB (Red, Green, Blue) composite maps of untransformed and centred log-ratio (clr) transformed datasets have been used to recognize spatial patterns of the three elements. Continuous low-value zones were revealed in topsoils over siliciclastic rocks where rivers might have redistributed sediments with low concentrations. A molybdenum anomaly south of Mt Cervati can be related to lacustrine argillaceous sediments containing sulphide minerals. Tin hot spots and anomaly zones were revealed along the Volturno River and urban areas. Tungsten is the element out of the three which is best related to the presence of volcanic rocks belonging to the Neapolitan Potassic Province.

Clinopyroxene and olivine are ubiquitous phases in Somma-Vesuvius (SV) volcanics and for the first time they were systematically studied in several products younger than 40ka. In this manuscript chemical compositions (major, trace and rare earth elements) of a large set of olivine and clinopyroxene crystals from selected rock samples are presented and discussed. Fourteen pumice samples from Plinian pyroclastic deposits as well as three scoriae and eight lava samples from inter-Plinian deposits were collected. A representative number of olivine and clinopyroxene crystals (n~50) were selected for each sample and analysed by electron microprobe and laser ablation inductively coupled plasma mass spectrometer, resulting in a large database, which is now available to the scientific community. All studied eruptive products contain olivine and clinopyroxene crystals spanning a wide range of compositions. Olivines show Fo content varying from 91 to 68, while clinopyroxenes display Mg# ranging from 93 to 71. In samples younger than A.D. 79, the more evolved (Mg#82–72) clinopyroxene crystals show clear Ca enrichment (~23.5–24.5wt% CaO) with respect to those from older samples (before-A.D.79, ~23–21wt% CaO). The results corroborate disequilibrium between olivine, clinopyroxene and the hosting melt, and an increasing role of carbonate assimilation in SV magma evolution in the last 2ka. The database here produced is thought as a share product that makes available mineral data and can be used for further studies by researchers to investigate geochemical evolution of the SV system.

This review paper is intended to be a guideline to novices on how to conduct research on silicate melt inclusions in volcanic environments, which analytical techniques are more suitable to gather the desired data and the major pitfalls scientist may encounter. Silicate melt inclusions (SMIs) are small quantities of silicate melt that are trapped in minerals during their growth or crystallization. They contain liquids formed in equilibrium with their host minerals and therefore record the liquid line of descent of magmatic systems. Upon trapping, SMIs become ideally closed to the surrounding environment, and behave as time capsules, giving important information about processes that originated magmas and the nature of their mantle source. A melt inclusions investigation is composed of several steps: (1) a detailed petrographic study to characterize and select representative SMIs, with the aim of identifying Melt Inclusions Assemblages (MIA), the only reliable tool to assess that SMIs obey Roedder's rules and have not re-equilibrated following entrapment; (2) a careful preparation of samples for re-heating experiments and microanalysis; (3) high temperature studies in order to homogenize the SMIs and be able to perform chemical analysis; (4) interpretation of SMIs data, which should always be compared with bulk rock composition and relevant experimentally derived liquid compositions. We suggest that the search for good SMI candidates for study will be achieved by good petrographic analysis of SMIs and detailed petrographic information (size, shape, appearance, position relative to the host and other SMI within the same host). If the goal of a SMIs study is to determine volatile concentrations, assessing the relative time of trapping among SMIs is of paramount importance, as it allows understanding if the variation in volatile concentrations is consistent with a certain magmatic physical–chemical process. Researchers that choose to work with SMIs face several challenges. SMIs are not always hosted in all samples or they can be difficult to recognize (mostly due to their small size). Additionally, due several processes, such as post-entrapment crystallization, boundary layer and sampling melt heterogeneity at the micron scale, they may not be representative of the original trapped melt composition.

Objectives. Higher natural concentrations of lithium in drinking water may be associated with lower local rates of suicide. Methods. Lithium concentrations in drinking water were assayed by mass spectrometry at 145 sites in Italy, and compared with reported local suicide rates for men and women between 1980 and 2011. Results. Lithium concentrations in drinking water averaged 5.28 [CI: 4.08–6.48] μg/L (0.761 [0.588–0.934] μEq/L) and ranged from 0.110 to 60.8 μg/L (1.58 to 8.76 μEq/L). Lithium concentrations and local suicide rates were not significantly inversely related, except in 1980–1989, particularly among women. Conclusions. A proposed association between trace lithium concentrations in drinking water and risk of suicide was only partially supported, and mechanisms for potential clinical effects of trace levels of lithium are unknown.

The use of bottled mineral waters use is increasingly becoming popular and the need for better knowledge of their chemical composition is a key issue for defining their quality, particularly for those elements that are not monitored on a regular basis. The link between geology and water chemistry is well known and can lead to extreme differences in element distribution and is an issue that needs to be addressed. Such an opportunity has been provided by a project of the EuroGeoSurvey Geochemistry Expert Group aimed at the characterization of groundwater geochemistry using bottled mineral waters purchased in supermarkets all over Europe. On these waters pH, conductivity and concentrations of 69 elements and ions were measured at the BGR geochemical laboratories. On a total of 1785 “samples”, 158 represent waters bottled in Italy in 126 different sites scattered throughout the country. Most of the purchased mineral water is packaged in PET bottles. In this paper, the dataset concerning Italy has been used to provide an overview on the relationship between natural concentration of the determined chemical elements in groundwater and geo-lithological features. These relationships have been investigated mostly taking into account the surface geology and other information available on water sources. Application of R-Mode factor analysis to the data set allowed the determination of the possible relationship between the distribution of individual elements and lithology or other surface enrichment phenomena. In particular waters draining through volcanic rocks are enriched in elements such as As, B, Br − , Cl − , Cs, I, K, Li, Na, NO 3 − , PO 4 3− , Rb, Sc, SiO 2 , Sr, Te, Ti, and V up to 3 orders of magnitude higher than waters draining through other lithologies. REE and Y show significant difference in median concentration due to interaction of waters with plutonic rocks. Many elements have a large spread of concentrations, which reflects natural variations and interaction with particular lithologies. One of the five R-mode factor analysis associations, recognized as being representative of elements analysed shows high nitrate and V loadings along with As, PO 4 3− and Se. The latter association probably reflects a sign of anthropogenic contribution in some aquifers in volcano-sedimentary or silico-clastic deposits and in intensively cultivated areas.

The eruptive styles of Mt. Somma-Vesuvius vary dramatically and appear to correlate with pre-eruptive magma compositions. Explosive eruptions occurring in the past 3550 years involved magmas enriched in H2O, Cl, S, F, and P and characterized by elevated (S/Cl). To interpret volatile exsolution and magmatic degassing, we have determined the solubilities of H2O and Cl for melts of natural Mt. Somma-Vesuvius phonolite and phonotephrite in hydrothermal experiments conducted at 500 and 2000 bars and temperatures of 946–1166°C. The solubility of Cl in phonolite melts is a complex function of pressure and the assemblage of volatile phases. For melts with low H2O contents and saturated in hypersaline liquid, Cl solubility decreases marginally with decreasing pressure; whereas, Cl solubility increases with decreasing pressure with vapor plus hypersaline liquid stable. Chlorine solubility in hypersaline liquid-saturated melts also varies strongly with melt composition; the Cl content of phonolite melt is approximately one-half that of phonotephrite melt at both pressures. Differentiation of the Cl-enriched Mt. Somma-Vesuvius magmas occurred via crystallization and fractionation of clinopyroxene, olivine, plagioclase, and other phenocrysts. Crystallization increased the volatile abundances of residual fractions of melt while simultaneously reducing Cl solubility, and this increased the potential for pre-eruptive saturation of compositionally evolved magmas in one or more volatile phases. Comparison of the experimental results with the pre-eruptive abundances of volatiles in Mt. Somma-Vesuvius magmas (determined from melt inclusions) and with modeled Cl solubilities in H2O-poor, hypersaline liquid-saturated melts indicates that many compositionally evolved magmas did exsolve or would have exsolved hypersaline liquid (with or without vapor) initially. The passively-erupted, lava- and scoria-forming magmas were more likely to exsolve hypersaline liquid (with or without vapor); whereas, the H2O-enriched, explosively erupting, pumice-forming magmas were more likely to exsolve vapor (with or without hypersaline liquid). Prior experimental investigations have argued that the H2O and Cl concentrations of silicate melt, aqueous vapor, and hypersaline liquid should be invariant as crystallization occurs at constant pressure and temperature. However, the ascent, crystallization, and differentiation of magmas in nature involves simultaneous changes in bulk melt composition, temperature, and pressure, and the solvus for vapor plus brine (i.e., hypersaline liquid) varies as a function of each of these variables. Consequently, the solubilities of H2O and Cl in vapor- plus hypersaline liquid-saturated magmas, undergoing ascent and compositional evolution, will not be fixed by the phase assemblage. Instead, the volatile concentrations of vapor and hypersaline liquid will and do change during eruptive and pre-eruptive magmatic degassing.

Fluid and melt inclusions and geochemical features of alkali syenite, mafic, and ultramafic cumulate xenoliths in the last ignimbritic event (volcanism up to 300 ky.b.P.) at the island of Ventotene in the Pontine archipelago (Gaeta Gulf) were investigated to establish the genesis and evolution of the fluids trapped in the inclusions. Ranges in lead isotopic compositions of the xenoliths as a group are narrow: 206Pb/204Pb:18.778–18.864; 207Pb/204Pb:15.641–15.701; 208Pb/204Pb:38.858–39.090; the values overlap among the groups, implying that the xenoliths are closely related. The xenoliths straddle the best-fit line describing the regional NW-SE variation of values for uranogenic Pb in volcanic rocks from the Roman alkaline province. The similarity between the xenoliths and volcanic rocks permits the interpretation that the xenoliths are representative of the source region of the volcanic rocks, residues after partial melting of the source region or fractional crystallization of the volcanic rocks, or even that the xenoliths represent assimilants obtained during the evolution of the magmas that produced the volcanic rocks. Xenoliths belonging to the ultramafic-mafic cumulate group contain only silicate melt inclusions ± vapor bubble ± droplets of an opaque phase and rarely some CO2 trapped in silicate melt inclusions. Xenoliths in the alkali syenite group have three types of fluid inclusions: (1) single phase vapor and silicate melt inclusions; (2) two-phase silicate melt + salt, silicate melt + CO2 (V), aqueous (L + V), and silicate melt + vapor inclusions, and (3) three-phase and multiphase inclusions: CO2 (L) + CO2 (V) + H2O; silicate melt + saline melt + H2O ± birefringent or opaque trapped minerals; H2O + salt + silicate glass ± birefringent trapped minerals. During heating experiments, melting of salt occurs at temperatures from 565 to 815°C, depending on the water content of the inclusions. Homogenization of the vapor bubble occurs from 850–1160°C, and complete melting of the silicate glass at about 950°C. The highly variable proportions of the individual phases in the silicate melt + salt + H2O inclusions and the coexistence of silicate melt + CO2 inclusions indicates immiscibility during the crystallization of the magma. Primary and secondary CO2 inclusions in the alkali syenite suite indicate lower densities (from 0.10 to 0.22 g/cm3) than those resulting from primary CO2 inclusions in the gabbroic suite (from 0.34 to 0.42 g/cm3). The P-T trajectory of the probable fluid evolution path shows that the crystallization of gabbro occurred between ∼1 and 1.4 kbars, whereas alkali syenite crystallized between ∼200 and 400 bars. The secondary H2O inclusions in alkali syenite were trapped in the later stages of the hydrothermal process and at much lower temperatures (130–290°C), but at pressures relatively close to those of alkali syenite crystallization. The almost isobaric conditions during the final stage of the fluid evolution path are explained by the very shallow emplacement of the alkali syenite intrusive body.

Studies into the use of fissile elements and uranium for the production of atomic weapons in particular and of energy in general were initially kept a strict secret when research was begun during the second world war. Even after the war, until 1952, the U.S.A., which possessed almost all the scientific and technological information on the refining and uses of uranium, kept its knowledge even from its most loyal allies. The MacMahon Act forbade the U.S.A. from giving any help, which included the transfer of information and technology, to any other country.