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The compositions of soils and their parent materials were studied within one of the most northern land areas of the world — the island of Alexandra Land of the Franz Josef Land archipelago. Contents of 65 trace and major elements were determined using atomic emission spectrometry (ICP-AES) and inductively coupled plasma spectrometry (ICP-MS). Other analyzed characteristics included soil pH, particle-size distribution and contents of carbon and nitrogen. The bedrock had an alkaline pH, whereas the soil pH ranged from weakly acid to alkaline. The textural class of the soils predominantly corresponded to sandy loam. The contents of clay and silt increased with depth due to the migration of these fractions with groundwater. The studied soils were formed on basalts with high contents of MgO, Fe2O3, TiO2, Cu, Co, V, Ni, Cr, Zn, and low contents of Pb and Hg. The present study confirms that the FJL basalts are similar to the Siberian Platform basalts in composition and belong to the continental basalt series. The composition of soils was generally similar to that of the bedrock. Compared to other Arctic archipelagos (i.e., Svalbard, Severnaya Zemlya), the soils of Alexandra Land are characterized by increased contents of Cu, Mn, Co, and Fe and reduced contents of Hg, Pb, and Cd. The median concentrations (mg kg−1) of trace elements in the soils were as follows: Cu—142, Zn—100, Ni—72, Pb—2.4, Cd—0.1, and Hg—0.0052. The low contents of Hg, Pb, and Cd in the soils are indicative of low inputs of these elements from both long-range transport and local sources of pollutants. [ABSTRACT FROM AUTHOR]

This geochemical survey was conducted in an area of 2.4 km2 near Ténès, a portion of an area which covers 800 km2 traditionally associated with mining activities. A total of 1270 soil and 114 rocks samples were collected. The soil samples were analyzed for Ni, Co, Ti, V, Cr, Mo, Zr, Cu, Pb, Ag, Bi, Zn, Sn, Be, Sr, Ba, and F and the rocks samples for Cu, Ag. To characterize the mineralization in this area, statistical and geostatistical techniques were used. With the exception of Co, the statistical analysis indicated that the frequency distribution of the analyzed parameters for these soils was not normal. With grids of 100 × 20 m soil geochemistry gives excellent results. Extremely superimposed anomalies in Cu and Ag aligned on the same direction faults N–S crossing the area. Based on correlation and PCA analysis the results of these geochemical associated are as follows: Cu–Zn–Cd–As (Sb–Bi) constituents of sulfide mineralization and Cr–Mo (Ti–V–Zr) appears to be lithologically related to the presence of magmatic rocks. In rock geochemistry, the geostatistical techniques (Variography and Kriging map) results outline superimposed anomalies in copper and silver. [ABSTRACT FROM AUTHOR]

The state of Ohio has a long history of industrial pollution over numerous decades. Scientific investigations of the sources and impacts of this pollution are becoming increasingly common, particularly in the southwest region of the state, with a strong focus of recent studies being carried out within the context of air, urban soil and sediment quality, and aquatic environments. A key supporting issue in these, and future pollution investigations, is understanding the contribution from, and background concentrations of, natural geogenic materials. A glacial till sampled from Peffer Park, a publicly accessible site in Butler County southwest Ohio, was studied in detail to characterize its mineralogical and geochemical properties. The till sampled, a result of Wisconsin-aged glaciation, represents the regionally extensive glacial drift across the region and is the ideal candidate for targeting in efforts to quantify the background, geogenic environment. Samples were characterized for their elemental abundances using ICP-OES and ICP-MS, while mineralogy was investigated using powder X-ray diffraction, transmission electron microscopy, X-ray computed tomography, and reflective spectroscopy. Chemically, the till sampled is akin to the Earth's bulk continental crust with characteristic light REE (LREE) enrichment and depleted middle/heavy REE signatures. Of the 39 minor and trace elements analyzed, 74% (n = 29) vary by less than 10 ppm between the 20 sites sampled, and of the ten major element oxides, there is a < 3 wt. % variation with a < 1 wt. % variation observed for seven of the major element oxides. All standard deviations (reported at 2σ) are < 1. Major minerals detected by powder XRD include illite, chlorite (ripidolite), quartz, calcite, dolomite and feldspar minerals with lesser amounts of amphibole, consistent with inferences from bulk chemistry. X-ray computed tomography on a selected sample highlights five orders of magnitude variation with respect to particle size, which is demonstrably skewed toward fine particle size. Accompanying reflective spectral features are dominated by signatures from the high clay mineral (e.g., illite) and carbonate contents, consistent with inferred source materials from the regionally extensive Ordovician stratigraphy associated with the Cincinnati Arch and the ancient crystalline continental basement of Canada. Through a wide variety of analytical techniques, it is demonstrated that the Peffer Park till of southwest Ohio has a remarkably low variation in composition and is highly representative of the geogenic background of this region of the USA. Its characteristics reported here therefore justify its use and application as a broad environmental reference material for the Midwest. [ABSTRACT FROM AUTHOR]

The Marahiq area represents a portion of the Pan-African belt from the Neoproterozoic age in south Egypt and includes metamorphosed ultramafic rocks, metavolcanic rocks, and granodiorite pluton. The area is characterized by the ancient abandoned Au mine and the recent active talc mines. The present paper provides a preliminary assessment of stream sediments for gold (Au) placer and environmental hazard. Steam sediments from 36 stations were analyzed using ICP-MS for determining the concentration of 53 elements. Various statistical techniques, graphical representations, a set of complementary sediment quality assessment methods, and different mapping methods have been applied. The results showed that Au and the investigated elements were influenced by long history of the ancient mining activities and weathering processes, leading to elevate Au and some heavy metal(loid)s concentrations and exhibit enrichment ratios as follows: Te > As > Au > Cu > Cd > Co > Ni > V. Whereas Cd, Co, and V were attributed to geogenic origin, As, Au, Cu, Ni, and Te were derived from anthropogenic mining activities. It is found that the anomalies of Au and the element of interest are indicative of Au placer and point out a new perspective Au-sulfide mineralization hosted along the favorable tectonic zones that were the main source of Au placer. Both As and Te are good pathfinders to explore Au placer and related mineralization. Environmentally, the excess of As, Cu, Ni, and Te could generate moderate levels of contamination and low level of ecological risk in the sediments. Although As, Cu and Ni posed medium-low potentially adverse effects and low toxicity levels, they cannot cause harmful influences on biological life. Accordingly, streambed sediments are considered as safe and acceptable as inoffensive materials for environmental management. Overall, this study is as reference values for governmental organizations for appraising future environmental pollution in the area. Also, it is fruitful for Au placer and promising with success for Au exploration along the shear zones and strike-slip faults. [ABSTRACT FROM AUTHOR]

During large constructions of roads or structures, unexpected acid rock drainage (ARD) can be caused by local mineralization containing sulfides in the geology. The potential of ARD occurrence of a certain area sometimes must be assessed before initiation of any engineering earth works. However, it is difficult to assess the entire area through collecting rock samples and predicting the potential by laboratory tests, such as the acid-base accounting method. In this study, a new prediction protocol using a geochemical exploration survey technique of stream sediment is proposed. Sediment samples were collected at the case study area where a large development is expected in the future, and the contents of some major and heavy metal elements were compared according to the major geologies of the sampling points. The modified geoaccumulation indices ( I) of Fe, Pb and As could indicate a possible zone of pyrophyllite mineralization, which may cause the occurrence of ARD at the study area. Using the enrichment index of the three elements relative to the median values of the area, a high potential zone of ARD could be designated, which was in agreement with the laboratory ARD prediction tests of the rock samples. In the other areas with different mineralization processes, other metallic elements can be selected as indicators of the ARD potential. Likewise, the potential of the occurrence of ARD at an area can be assessed by evaluating the geochemical distributions and drawing the indicator elements for ARD through a stream sediment survey. [ABSTRACT FROM AUTHOR]

Because of the risk of diminishing supplies of rare earth elements (REEs) worldwide due to China's dominance over REE supply, the necessity of developing domestic resources of REE has been realized in other countries. To explore new ore bodies, a geochemical survey was conducted at one existing carbonatite REE deposit in the Hongcheon area of Korea. Proper sampling strategies and baseline data for the interpretation of the results were determined through a pilot study conducted in the area. Enrichment in the concentration of light REE (LREE) over that of heavy REE, which is typical in carbonatite-type deposits, was observed in stream sediments and heavy mineral samples collected during the geochemical survey. Maximum concentrations of LREE were 2,299 and 27,798 mg/kg for stream sediments and heavy minerals, respectively. Among LREEs, La and Ce are the dominant components of all REEs, comprising approximately 68 % of mean concentrations. Considering the distribution pattern of La + Ce contents and the associations with the existing outcropping ore bodies, the zone of prospective REE mineralization was determined to be in the south-western part of the area. A detailed follow-up soil survey of the zone found even higher concentrations of La and Ce (2,450 and 3,100 mg/kg, respectively), and suggested the possible extension of the existing ore bodies. Likewise, a systematic geochemical survey for REE is feasible for locating concealed ore bodies in the area, where the mineralization is mostly covered with soil, and rock outcrops are scarce. [ABSTRACT FROM AUTHOR]

Preliminary geochemical mapping was carried out within urban areas in Tampere Central Region, Finland, to gain a better understanding of element concentrations in urban soil and to provide information on baselines in soil within urban centres for soil contamination assessment purposes. The soil samples were taken from central city parks, day-care centres and school yards, and residential areas. Various sampling depths have generally been used in urban geochemical surveys. The aim of this study was to compare the results from two commonly used sample types taken from the same sites in urban soil: single samples of minerogenic topsoil from the 0-25 cm layer and composite samples of minerogenic topsoil from a depth of 0-2 cm. The concentrations of most of the studied trace elements showed a significant correlation between samples from 0 to 2 and 0 to 25 cm, but element concentrations differed between the two studied sample depths. For most of the studied elements, the median concentrations were higher in the 0-25 cm samples, but anomalous concentrations were more often found in the 0-2 cm samples. Some elements had elevated concentrations when compared with the Finnish guideline values for soil contamination assessment. This study did not conclusively establish whether a sampling depth of 0-2 or 0-25 cm should be recommended for similar studies in the future. Selection of the sampling depth in geochemical studies greatly depends on the aim of the project. In order to determine the upper limits of geochemical baseline variation, the deeper sampling depth appears to be more feasible. However, for the preliminary health risk assessment of areas with sensitive land uses, e.g. children's playgrounds, samples from 0-2 cm depth are considered informative. Such samples may also be used to indicate local sources of dusting creating site-specific hotspots of potentially harmful elements in urban topsoil. [ABSTRACT FROM AUTHOR]

Groundwater is the most important source of water supply in Sidi Bouzid plain located in central Tunisia. Proper understanding of the geochemical evolution of groundwater is important for sustainable development of water resources in this region. A hydrogeochemical survey was conducted on the Mio-Plio-Quaternary aquifer system using stable isotopes, radiocarbon, tritium and major elements, in order to evaluate the groundwater chemistry patterns and the main mineralization processes occurring in this system. The chemical data indicate that dissolution of evaporate minerals and evaporation are the main processes controlling groundwater mineralization. The isotopic data show that groundwater in the study area is a mixture of recent shallow waters located upstream and along Wadi Al Fakka bed and paleowaters located towards plain limits and discharge areas. Low H and C contents are observed in major part of the plain indicating that recharge of the aquifer occurs mainly through direct infiltration at Wadi Al Fakka while there is no evidence of significant recharge in major part of the plain and mountains piedmonts. [ABSTRACT FROM AUTHOR]

Soil carbon sequestration plays an essential role in mitigating CO increases and the global greenhouse effect. This paper calculates soil organic carbon (SOC) storage changes during the course of industrialization and urbanization in Yangtze Delta region, China, based on the data of the second national soil survey (1982-1985) and the regional geochemical survey (2002-2005), with the help of remote sensing images acquired in periods of 1980, 2000, 2005. The results show that soils in the top 0-20 and 0-100 cm depth in this region demonstrate the carbon sink effect from the early 1980s to the early 2000s. The SOC storage in 0-20 cm depth has resulted in increase from 213.70 to 238.65 Tg, which corresponds to the SOC density increase from 2.94 ± 1.08 to 3.28 ± 0.92 kg m, and mean carbon sequestration storage and rate are 1.25 Tg a, 17.14 g m a, respectively. The SOC storage in 0-100 cm depth has resulted in increase from 690.26 to 792.65 Tg, which corresponds to the SOC density increase from 9.48 ± 4.22 to 10.89 ± 3.42 kg m, and mean carbon sequestration storage and rate are 5.12 Tg a, 70.32 g m a, respectively. Urban area in Yangtze Delta region, China, increased more than 3,000 km and the urban growth patterns circled the central city region in the past 20 years. The SOC densities in 0-20 cm depth decrease gradually along urban-suburban-countryside and the urban topsoil is slightly enriched with SOC. Compared to the data of the second national soil survey in the early 1980s, the mean SOC density in urban area increased by 0.76 kg m, or up 25.85% in the past 20 years. With the characteristics of SOC storage changes offered, land-use changes, farming system transition and ecological city construction are mainly attributed to SOC storage increases. Because of lower SOC content in this region, it is assumed that the carbon sink effect will go on in the future through improved soil management. [ABSTRACT FROM AUTHOR]

This paper deals with the integration of electrical resistivity tomography and geochemical methods for studying four different fire-prone landfills. Landfill gas composition (CH4, H2S, O2, CO, CO2) and subsurface temperature were measured with the constant net 50 × 50 m from the depth 10–60 cm. 28 electrical resistivity tomography lines were surveyed, while Wenner and Sclumberger electrode arrays were employed for all measurements. At the studied sites the landfill gas and temperature measurements mapped gas and temperature anomalies over underground fire sources. 2D electrical resistivity tomography lines, performed over these anomalies, showed these fire sources as high-resistivity zones. The joint employment of the electrical imaging and geochemical survey seems to be a useful tool in carrying out diagnostic investigations at fire-prone landfills. [ABSTRACT FROM AUTHOR]

Chemical and isotopic composition of groundwaters and rain waters in the Sisseb el Alem basin (Tunisia) was monitored to obtain a hydrologic and geochemical characterization of the aquifers. The studied aquifers are the only water resource for domestic and irrigation use in the basin. Two aquifers have been identified by hydrogeologic data, one, shallower, flowing in Plio-Quaternary sediments, the other, deeper, in Miocenic–Oligocenic sediments. Although this area is intensively farmed with widespread fertiliser use and settlements are unsewered, groundwater in the area is relatively uncontaminated by land-use activities. The chemical and isotopic compositions of the sampled waters, which have a meteoric origin, are largely controlled by both the geological signatures of their drainage area and by evaporative processes and water–rock interaction (reverse cationic exchange) phenomena. Geochemical data suggest, on the basis of the Na/Cl, Cl/SO4 ratios and concentrations of Li, Sr, and Mn, that a hydraulic connection exists between two distinctive aquifers. One strongly influenced by Lake Saadine water characterised by Na/Cl > 1, high Cl/SO4 and Li, Sr, and Mn > 0.1 meq/l, the other, deeper, characterised by Na/Cl < 1, low and near constant Cl/SO4 and Li, Sr, and Mn < 0.1 meq/l. Despite relatively high salinity and SAR values, all sampled waters are suitable for irrigation in well-draining soils. The isotopic composition of the rain waters highlights the importance of evaporation in controlling the composition of the groundwater. [ABSTRACT FROM AUTHOR]

La Trucha is a small (~ 1.9 km2), mountainous (~ 1300 m a.s.l.) granitic drainage basin, demonstrative of hundreds of second-order basins in the Achala Batholith of the Sierras Pampeanas of Córdoba, Argentina. Dominated by physical weathering and a weathering-limited denudation regime, the coarse- and fine-grained regolith has shown scant geochemical differences with the country rock. Erosion and sediment transport mainly occurs during torrential rain events (austral summer), whereas surface waters classify as dilute (750 < TΣ+ < 375 µeq L−1) or very dilute (375 < TΣ+ < 185 µeq L−1) water types. The dynamics of chemical weathering at La Trucha was approached through the use of major dissolved chemical components, comparing the performance of different methodologies in its assessment: mineral stability diagrams (i.e., chemical equilibria), the RE chemical weathering index, ternary diagrams, and PHREEQC inverse modeling. The latter approach allowed to probe into subtleties of the geochemical processes indicating that, besides the morphological dependency on mineral hydrolysis/dissolution or precipitation, there is a marked seasonal control that promotes or limits the occurrence of geochemical reactions. [ABSTRACT FROM AUTHOR]

The original article has been published inadvertently with some missed footnotes for Tables 2, 3, 4, 5, 6 and 8, and missed letters in the caption of Table 7. [ABSTRACT FROM AUTHOR]