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The large-scale Yaogangxian W deposit, located in central of the Nanling metallogenic belt, South China, comprises independent quartz vein-type and skarn-type W mineralization. Wolframite-bearing quartz veins occur invariably in metasandstone and slate to the northwest of the Yaogangxian granitic intrusion, whereas scheelite-skarn are mainly hosted by the limestone to the east. The vertical extension of single wolframite-bearing quartz vein can reach up to 1000 m and we focused on the vein samples collected from the deepest level (26 level) which likely recorded early magmatic fluids. For skarn mineralization, two scheelite precipitation stages were recognized, namely scheelite-1 in retrograde stage and scheelite-2 from sulfide-stage. To reveal the fluid sources and characteristics of two mineralizing systems, detailed petrography and microthermometry analyses were carried out on fluid inclusion assemblages (FIA) in scheelite, wolframite and their coexisting quartz. Fluid compositions were obtained from individual fluid inclusion (FI) in ore and gangue minerals via laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) analysis. These data aid elucidation on the source and nature of fluids in the two distinct W mineralization styles. The chemical compositions of FIs hosted in wolframite and scheelite points to a common magmatic source. The fluid in the scheelite ore section exhibits lower As and B than the wolframite ore section, indicating that boiling may have occurred at early skarn stage. Fluid evolution in the two mineralizing systems suggest that formation of diverse W mineralization styles is mainly controlled by different host lithology and fluid processes. In the wolframite ore section, ore-forming fluid recorded in the deepest level of vein show elevated As, B, K and Rb contents than previously reported ore-forming fluid obtained from the tip of the vein. This likely indicate absence of intensive fluid immiscibility in the deep during wolframite formation, which may rather be accompanied by fluid-rock interaction. In the scheelite ore section, constant injection of meteoric water is revealed. FI hosted in scheelite-1 and 2 exhibit similar compositions, and the lower K content in scheelite-2 fluid is thought to be caused by sericitization in the retrograde stage skarn. The Mo content of scheelite decreased from the retrograde stage to sulfide-stage, indicating a decrease in oxygen fugacity. Based on these conclusion and previous geological and geochronological studies, we propose a metallogenic model of the coupled wolframite-quartz vein and scheelite-skarn mineralization.

Everything in and on the Earth - mineral, animal and vegetable - is made from one, or generally some combination of, the natural chemical elements occurring in the rocks of the Earth’s crust and the surficial materials derived from them. Everything that is grown, or made, depends upon the availability of the appropriate elements. The existence, quality and survival of life depends upon the availability of elements in the correct proportions and combinations. Because natural processes and human activities are continuously modifying the chemical composition of our environment, it is important to determine the present abundance and spatial distribution of the elements across the Earth’s surface in a much more systematic manner than has been attempted hitherto” (Darnley et al., 1995). Although such a global database is urgently needed for multi-purpose use, the systematic attempt is still in its infancy because of the non-existence of a manual of comprehensive and standardised methods of sampling and other supporting procedures. The current ‘International Union of Geological Sciences Manual of Standard Methods for Establishing the Global Geochemical Reference Network’ fills this gap. The Manual follows the concept of 7356 Global Terrestrial Network grid cells of 160x160 km, covering the land surface of Earth, with five random sites within each grid cell for the collection of samples. This allows the establishment of the standardised Global Geochemical Reference Network with respect to rock, residual soil, humus, overbank sediment, stream water, stream sediment and floodplain sediment. Apart from the instructions for the collection of samples, the Manual covers sample preparation and storage, development of reference materials, geoanalytical methods, quality control procedures, geodetic and parametric levelling of existing geochemical data sets, data conditioning for the generation of time-independent geochemical data, management of data and map production, and finally project management. The methods described herein, apart from their use for Establishing the Global Geochemical Reference Network, can be used in other geochemical surveys at any mapping scale.

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.

Sources of anthropogenic environmental pollution are widespread, not only as a result of industrial activities, but also due to recreational facilities. Outdoor shooting ranges, involving millions of people everywhere in the world, can produce several negative effects on environment and public health. The area of a dismissed outdoor shooting range in Campania region (Southern Italy) has been declared unsuitable for agricultural and forest-pastoral production by the Italian Ministry of Agricultural, Food and Forestry Resources, due to an extensive long term (approximately 10 years of activity) soil contamination associated with Pb, Sb, PAHs, dioxins, PCBs and C> 12 hydrocarbons. In the framework of a site characterization plan aiming at its reclamation, the shooting range area was surveyed by means of i) proximal sensors (such as EMI - Electromagnetic Induction - and Gamma Ray - dose rate, K, eU, eTh - spectroscopy) for indirect, cost effective and rapid measurements at field scale, to identify homogeneous zones in terms of soil degradation; ii) ultrasonic penetrometry to evaluate both soil compaction rate and depth of occurring hard layers, iii) direct investigations by means of hand drillings to preliminary characterize the soil down to the presence of a hardened, impenetrable layer; iv) direct XRF measurements on the soils sampled at different depths, to assess the total content of some potentially toxic metals (PTE); v) chemical analyses of PAHs compounds on topsoil samples collected on the basis of the regular grid across the study area. Apparent electrical conductivity (ECa) map, consistently with the Gamma Ray dose rate map, evidenced three key zones, wide bands North-South oriented. Cone index data, obtained by ultrasonic penetrometer measurements, indicated the presence of a very dense, hard and impenetrable to hand hauger layer, recognised as travertine rock, from 25 to more than 55 cm of depth, and dipping northward. Sandy soils, frequently enriched of coarse fragments, were identified to a variable depth from 25 to 80 cm of depth. Elemental analyses, carried out with the portable XRF analyzer on soil sampled until the travertine layer, showed a high contamination by Pb (greater than 1000 mg/kg) and Sb (greater than 30 mg/kg) in the first 15 cm of depth, at approximately 90 m from the shooting platforms. Concentrations of 13 PAHs compounds determined on 32 topsoil samples showed the highest values close to the firing lanes where a huge amount of shooting target and fragments were present. Data were analyzed by means of GIS and multivariate analysis was completed jointly considering compositional and non-compositional variables to explore hidden potential relationships among involved parameters.

Geochemical systems are complex and the analysis of the shape of the frequency distribution of elements and chemical species often informs about the variability and dispersion related to the underlying dynamics. However, when compositional data are used it is incorrect to investigate concentrations in the Euclidean space. Distribution analysis is aimed at focusing on real coordinates, which can be obtained by applying some appropriate log-ratio transformation. In particular, distributional analysis for compositional data can be applied to isometric coordinates, called balances, obtained through partition of a multi-element data set. As an alternative the same investigation can be performed on indices such as the robust Mahalanobis distance after having ranked log-ratio compositions with respect to some reference composition (i.e. average Earth crust) and having obtained a sort of “measure of change”. By considering this second new perspective, the chemical composition of topsoils of the Campania Region (Southern Italy) was investigated by analysing the concentrations of Al, As, B, Ba, Ca, Co, Cr, Cu, Fe, K, La, Mg, Mn, Mo, Na, Ni, P, Pb, Sr, Th, Ti, V and Zn, in mg/kg, determined on > 3500 samples. Results reveal the presence of complex processes governed by interaction-dominant dynamics where self-organisation appears to play some role.

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.

International audience; 2108 agricultural soil samples (Ap-horizon, 0–20 cm) were collected in Europe (33 countries, area 5.6 million km2) as part of the recently completed GEMAS (GEochemical Mapping of Agricultural and grazing land Soil) soil mapping project. GEMAS soil data have been used to provide a general view of element origin and mobility with a main focus on source parent material (and source rocks) at the continental scale, either by reference to average crustal abundances or to normalized patterns of element mobility during weathering processes. The survey area covers a large territory with diverse types of soil parent materials, with distinct geological history and a wide range of climate zones, and landscapes.To normalize the chemical composition of European agricultural soil, mean values and standard deviation of the selected elements have been compared to model compositions of the upper continental crust (UCC) and mean European river suspended sediment. Some elements are enriched relative to the UCC (Al, P, Pb, Zr,) whereas others, such as Mg, Na and Sr are depleted. The concept of the UCC extended normalization pattern has been applied to selected elements. The mean values of Rb, K, Y, Ti, Al, Si, Zr, Ce and Fe are very similar to the values from the UCC model, even when standard deviations indicate slight enrichment or depletion. Zirconium has the best fit to the UCC model using both mean value and standard deviation. Lead and Cr are enriched in European soil when compared to the UCC model, but their standard deviation values span a large, particularly towards very low values, which can be interpreted as a lithological effect.GEMAS soil data have been normalized to Al and Na, taking into account the main lithologies of the UCC, in order to discriminate provenance sources. Additionally, sodium normalization highlights variations related to the soluble and insoluble behavior of some elements (e.g., K, Rb versus Ti, Al, Si, V, Y, Zr, Ba, and La, respectively), their reactivity (e.g, Fe, Mn, Zn) and association with carbonates (e.g., Ca and Sr). Maps of Europe showing the spatial distribution of normalized compositions and element ratios reveal difficulties with the use of classical element ratios because of the large lithological differences in compositions of soil parent material. The ratio maps and color composite images extracted from the GEMAS data can help to discriminate the main lithologies in Europe at the regional scale but need to be used with caution due to the complexity of superimposed processes responsible for the soil chemical composition.

Soil geochemistry is often investigated by considering a large number of variables, including major, minor and trace elements. Some of the variables are usually highly correlated due to coherent geochemical behaviour, but the effect of anthropic factors tends to increase data variability, sometimes obscuring natural relationships governing their distributions. In this framework it may be difficult to identify geochemical features linked to natural phenomena as well as to separate geogenic anomaly from the anthropogenic ones. Consequently the identification of background/baseline values may be seriously compromised. However, knowledge about these reference terms is fundamental to manage and protect natural resources on different scales. Moreover, adequate estimations of background/baseline values are possible only if a sufficient number of chemical analyses are stored in complex repositories. In this contribution the multi-element data archive of the Campania Region (Southern Italy) was explored from the CoDA (Compositional Data Analysis) multivariate perspective to characterise its structure. The archive contains abundance data of Al, As, B, Ba, Ca, Co, Cr, Cu, Fe, K, La, Mg, Mn, Mo, Na, Ni, P, Pb, Sr, Th, Ti, V and Zn (mg/kg) determined in 3535 new topsoils as well as information on coordinates, geology and land cover. Under CoDA the proportionality features of abundance data are fully taken into account enhancing their relative multivariate behaviour in the correct sample space. Results indicate that the structure of the whole matrix appears to be constituted by a core that geographically is mainly given by topsoils developed on volcanic materials and several outlier compositions whose origin is different. Anomalous compositions can originate from the robust barycentre all around when the following conditions are present: 1) high Na–K volcanic products, 2) limestones and dolostones with their terrigenous component, 3) flysch deposits or 4) fertiliser contribution. The (1 × D) robust barycentre of the whole dataset together with the variation array of the core represents the most frequent (1 × D) multi-element vector as well as the proportionality relationships among its components. It might be considered a compositional baseline.

Indium is a very rare element, which is usually not reported in geochemical data sets. It is classified as a critical metal, with important applications in the electronics industry, especially in the production of solar panels and liquid-crystal displays (LCDs).Over 4000 samples of agricultural and grazing land soil have been collected for the "Geochemical Mapping of Agricultural and Grazing Land Soil of Europe" (GEMAS) project, carried out by the EuroGeoSurveys Geochemistry Expert Group. Indium concentrations in soil have been analysed using aqua regia extraction followed by ICP-MS. Median values of In for both land use types are nearly identical, 0.0176. mg/kg for agricultural soil and 0.0177. mg/kg for grazing land soil.The spatial distribution patterns of In in European soil are mainly controlled by geology and the presence of Zn and Sn mineralisation. The preference of In to accumulate in the fine-grained fraction of soil with high clay content dominates the major anomaly patterns on the geochemical maps. In the Mediterranean region, secondary In enrichment is visible in karst areas. A notable feature of the In spatial distribution is the large difference between northern and southern Europe, with median values of 0.012 and 0.021. mg. In/kg, respectively, suggesting that, in addition to lithology, weathering and climate are important factors influencing In soil enrichment over time. © 2015 Elsevier B.V.

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.