Preparation and Characterisation of Two Geochemical Reference Materials: DG‐H (Granite) and AM‐H (Amphibolite) from the Himalayan Orogenic Belt

Two geochemical reference materials of Himalayan origin named DG‐H (a granite) and AM‐H (an amphibolite) prepared by the Wadia Institute of Himalayan Geology Dehradun are described. Both samples were collected from the NW Himachal Himalaya in India. With the participation of analysts from more than forty international laboratories, element determination data collected during the past 10 years for characterisation of the samples was processed to assign working values using statistical procedures in use for this purpose. Earlier work published on these samples is incorporated in the present communication making it an updated document. The typical chemical and petrological characteristics of these two samples may prove useful for method validation and calibration of analytical instruments used for analysing similar rock types, and for widening the analytical range of several analytical methods used for geochemical analysis.     

Use of lichens in detecting environmental risk and in geochemical prospecting

This paper provides data on variations in the contents of As, Sb, Ni, V, Pb, Cu, Cr, Au, Zn, Sc, and Al, measured in the thalli of a saxicolous lichen species,Xanthoria calcicola Ochsner s.l., collected in northeastern Sicily, near an industrial zone and along a belt crossing areas of known ores containing sulfides of heavy metals. A total of 91 lichen samples were collected on roof tiles (39) and on rocks (52). In the industrial zone, analysis of lichen thalli revealed high contents of nickel and vanadium, decreasing at increasing distances from the source of contamination. The results have also revealed the versatility ofXanthoria calcicola in geochemical prospecting for heavy metals such as Pb, Zn, As, Au, Sb, Ni, V, and Cu. The contents of these elements in the analyzed lichens highlight the same geochemical associations observed in prospecting surveys on samples of river sediments and identify similar anomalies. Interpretation of data in terms of enrichment factors (EFs) turned out to be particularly useful.     

Mineralogical and spectroscopic characterization,and potential environmental use of limestone from the Abiod formation,Tunisia

Limestone beds of the Late Cretaceous Abiod formation (Campanian-Maastrichtian system) are fundamentally important for the economic growth of the raw material sector in Tunisia. However, little attention has been paid to the detailed physical and chemical properties of the Abiod limestone. Nine limestone samples collected from the Abiod formation outcropping in the areas of Bizerte, Gafsa and Gabes, Tunisia, as well as their separated clay fractions, were characterized using different techniques, such as XRF, XRD, FTIR and TG/DTA. XRF showed the chemical composition of the limestone in which calcium carbonate was the main constituent, and silica, iron and magnesium were the impurities. XRD also confirmed the presence of small amounts of clay minerals and quartz along with sharp peaks of calcite. FTIR spectra indicated that the limestone was mainly composed of CaCO₃ in the form of calcite, as identified by its main characteristic absorption bands. These data were in agreement with XRD and XRF analysis data. The TG/DTA curves of the limestone samples, showing a close similarity to that of pure calcium carbonate, exhibited an endothermic peak between 600 and 760°C, with the maximum near 750°C. Moreover, FTIR spectra of clay fraction samples indicated high silica content in some samples. Especially the samples SD1 and SD2 collected in the northern area showed higher amounts of silica compared with those of AS1, AS2, CHB, ZNC, SND, MKM and GBS collected from southern districts. However, among the latter seven samples, one could recognize two groups based on the clay mineral investigations: (1) limestone with minor amounts of smectite and mixed layer minerals of smectite/illite (AS1 and 2, CHB, ZNC, SND and GBS) and (2) limestone with smectite, kaolinite and apatite (SND and MKM). Differences in these mineralogical and chemical characteristics should be considered when limestone from the Abiod formation is utilized as a medium for heavy metal removal from wastewater.     

Contemporary archaeomagnetic results and the accuracy of archaeomagnetic dates

When multiple archaeomagnetic samples are collected from the same site or component, it is tempting to look for evidence of temporal differences between the collected features. This paper addresses the issue of the practical limits to confidently identifying temporal differences based on archaeomagnetic sample information. Three controlled data sets suggest that when the specimen polar projections of the samples compared have substantially overlapping ranges and when sample mean projections are less than five degrees apart, statistical comparisons do not support conclusions about probable age differences. These results suggest that temporal differences less than 50 to 100 years (depending on the rate of directional change in the geomagnetic field) between features within a site or component will be difficult to confidently identify. Additional analysis leads to the hypothesis, however, that the averaged results from sets of archaeomagnetic samples might provide the basis for making fine scale temporal distinctions between sites or components from which multiple archaeomagnetic samples have been collected.     

Origine du matériel altéré et hétérogénéité du matériel originel de la météorite Foum Tatahouine (Tunisie) : éléments traces et isotopes du SrOrigin of altered material and heterogeneity of original material in the Foum Tatahouine meteorite (Tunisia): Trace elements and Sr isotopes

Foum Tatahouine is one of the rare meteorites that allow studying weathering effects since their fall on Earth. The comparison between clasts collected the very day of the fall (1931) and in 1994 showed some chemical modifications. We report data obtained on samples collected in 2000. The purpose of this study is: (1) to define (REE, Sr isotopes) the terrestrial weathering origin that is to be found in soil carbonates, (2) to show (Sr, Rb, REE) that the weathering effects are small on centimetre-sized samples, and (3) to emphasise (HREE) Foum Tatahouine samples heterogeneity. To cite this article: Y. Bentahila et al., C. R. Geoscience 334 (2002) 267–272.     

Anthropogenic influences on toxic metals in water and sediment samples collected from industrially polluted Cuddalore coast,Southeast coast of India

The present study was carried out to investigate the impact of anthropogenic influences on Cuddalore coast, Southeast coast of India, with regard to physicochemical parameters and heavy metal concentration in the surface water and sediment samples of the study area. The samples were collected in different seasons of the year (January–December 2010) and analysed for physicochemical parameters (Temperature, pH, salinity, nitrate, nitrite, ammonia, phosphate and silicate) and heavy metals (Cd, Cu, Pb and Zn) using standard methods. Results showed that physicochemical characteristics and heavy metals concentration in the samples of the study area were varied seasonally and spatially. The concentrations of heavy metals in water and sediment samples of the study area were higher in the monsoon season compared with those of other seasons. The heavy metal concentration in collected samples was found to be above WHO standards. The order of heavy metals in water and sediment samples was Pb > Cu > Cd > Zn. The heavy metal data were analysed through widely using multivariate statistical methods including principle component analysis (PCA) and cluster analysis (CA). CA classified the sampling sites into three clusters based on contamination sources and season. The PCA revealed that the season has a huge impact on the levels, types and distribution of metals found in water and sediment samples. The study also shows the main basis of heavy metals pollution at Cuddalore coast is land based anthropogenic inputs as a result of discharging of waste from industries, municipal, agricultural activities and sewage into estuarine regions, which carries the wastes into coastal area during tidal action. Statistical analyses and experimental data revealed that the Cuddalore coast may cause health risk to the recreational users and fisher folk, ultimately warrants environmental quality management to control heavy metal contamination.     

深圳大沙河河水与海水关系的水文化学识别

为了解深圳沿岸河口处海水与河水的混合关系,在大沙河下游靠近河口段密集取17件河水样,依据其水化学数据,分析了主要离子Ca、Mg、Na、K、SO4、HCO3与Cl的关系,Br与Cl的关系以及piper三线图解,在研究区河段从上游至入海口,对河水样品有如下认识:(1)上游4个样品(Cl<100mg/L)接受降水和地下水的补给;(2)4个样品(150mg/L     

Dust deposition in the central Mediterranean (Tyrrhenian and Adriatic Seas): Relationships with marine sediments and riverine input

Major (Al, Ca, Fe, Mg, Mn, Si) and minor (Cd, Pb, Zn) elements of aeolian dust samples collected onboard ship around Italy were analysed, and the concentrations of metal in the dusts were in good agreement with previously published data from the Mediterranean Sea.
The elemental composition of dust samples collected in four subareas (Adriatic, Ionian, Tyrrhenian, and Sicily Channel) was compared with the composition of marine deep sediments obtained in the same regions: Mn, Al, Cd and Zn contents differentiated between the four areas in both sets of samples, suggesting a possible 'geochemical signature' of the atmospheric crustal contribution in marine deep sediments.
An estimate of the relative contribution of atmospheric dry deposition of Cd, Pb and Zn and riverine discharge indicates that: (a) the metals deposited from the atmosphere to the Adriatic basin are a small fraction (2–5%) of those discharged by the Po and Adige rivers; (b) almost the same amounts of Cd, Pb and Zn are delivered to the Tyrrhenian Sea by the atmosphere and by the Arno and Tiber Rivers.     

Interpreting data dispersion and “inverted” dates in apatite (U-Th)/He and fission-track datasets: An example from the US midcontinent

New apatite (U-Th)/He (AHe) and apatite fission-track (AFT) data were acquired for cratonic basement samples from an 80 m span of drillcore in northeastern Kansas. The short depth interval over which the samples were collected indicates that they should have undergone thermal histories that would be indistinguishable using low temperature thermochronometry techniques. Individual AHe dates from four samples range from 99 to 464 Ma. Three samples yield dates <300 Ma that display a correlation with apatite eU (9-34 ppm) and a weaker correlation with grain size. eU concentration maps of apatites from these samples reveal low to moderate zonation in eU. Results for a fourth sample are characterized by dates >300 Ma, higher eU (39-113 ppm), and substantial data dispersion uncorrelated with eU and grain size. These apatites have strong and variable eU zonation. AFT dates for five samples range from 242 to 291 Ma. The sample with the highest eU apatites and oldest AHe dates yields the youngest AFT results. These results are “inverted”, with AHe dates distinctly older than the corresponding AFT date.We explore both the causes of data dispersion and the overall compatibility of this cratonic dataset. We find that geologically reasonable thermal histories can (1) explain the distribution of the moderate eU AHe data when accounting for the influence of radiation damage, grain size, and eU zonation on apatite He diffusivity, (2) reproduce the observed dispersion in the high eU AHe data when using a viable range of eU zonation and grain size, and (3) explain the AFT data for the same samples. The AHe and AFT data are mutually consistent, and viable thermal histories successfully predict the observed pattern of older AHe than AFT dates for the high eU apatites. Together these results suggest that appropriately accounting for the known controls on apatite He diffusivity can explain the observed dispersion and “inverted” AHe and AFT results in some thermochronometry datasets. A range of AHe dates should be especially common in cratonic data, because small differences in apatite He diffusivity are amplified by the thermal histories that typify cratonic settings. We use these results to develop some guidelines for interpreting dispersed AHe datasets. First, date-eU and date-grain size correlations should be evaluated, and if these patterns occur they can be used to better resolve the thermal history. Second, for samples that yield inexplicably large dispersion of AHe dates uncorrelated with eU and crystal size, the appropriate strategy is either to reject these samples from the suite used for thermal history interpretation or to acquire additional data to help decipher the significance of the age distribution.     

Application of statistical methods to study seasonal variation in the mine contaminants in soil and groundwater of Goa, India

 Soil and groundwater samples were collected during two seasons, premonsoon (April 1990) and postmonsoon (December 1990), and analyzed for major elements (Na, Mg, Al, Si, P, K, Ca, Ti, Mn and Fe), trace elements (Ni, Pb, Co, Cr and Zn) and water parameters (pH, conductivity, acidity, alkalinity, hardness, Cl and SO₄). All the data were subjected to linear discriminant analysis and partial correlation analysis in order to understand the seasonal variation in the data. It was observed from the Mahalanobis generalized distance that in both soil and groundwater samples there was a large difference in the concentration level of premonsoon and postmonsoon data. Linear discriminant functions were calculated to distinguish between premonsoon and postmonsoon samples. From the partial correlation coefficient analysis of soil samples, dominance of chemical weathering and precipitation of atmospheric fallout during monsoon were inferred. In the case of the water samples, high conductivity and high hardness in the postmonsoon samples as well as atmospheric fallout of Pb and Ni during the premonsoon period was suggested from partial correlation of water samples. Received: 19 September 1995 · Accepted: 12 December 1995     

Grain-size distributions of pyroclastic deposits

A multivariate statistical technique (principal component analysis) has been used to investigate the granulometric features of 414 samples of pyroclastic rocks: 216 samples were collected from areas of recent and active volcanism in Central and Southern Italy; data for the remaining 198 samples were obtained from the literature and relate to products from Somma-Vesuvio, Mount St Helens and the Japanese volcanic arc. The analysis offers an improved means of discriminating pyroclastic deposits using their grain-size characteristics.     

Geochemical and mineralogical pattern recognition and modeling with a Bayesian approach to hydrothermal gold deposits

The Bayesian approach is an effective method of identifying the probability of mineralogical and geochemical type (MGT) mineralization of trace elements in galena, pyrite and other distributions in ore mineralization. Monomineralic samples have been identified using a computer-based Bayesian method and exploration geochemical techniques of Au deposits for MGT. In order to employ the method, a data bank was used consisting of the results of analysis of more than 12,000 monomineralic samples collected from the main hydrothermal Au deposits in Tajikistan (a territory of CIS). The Bayesian approach applied to geochemical data, such as posterior probabilities and discriminant analysis, provide numerical and graphical means through which the relationships between the trace elements and samples can be studied. The method used here, along with GIS, to find MGT can be used as geochemical indicators of regions with Au mineralization. The results of analyzing 100 monomineralic samples of pyrite from the Au–Ag Shkolnoe deposit (Tajikistan) show a multi-MGT anomaly superposition which is a combination of three MGT: (1) Au–Ag type (85% and more), (2) Au–sulfide-polymetallic type (46%), and (3) Au–sulfide type (40%). Mineralogical and geochemical maps (MGM) can be drawn based on results of MGT anomalies in a GIS environment. These maps can replace traditional metallogenic maps. The advantage of MGM substitutions is that a qualitative tool is replaced by a quantitative one. This helps one to make optimal managerial and more economical decisions.     

Mercury accumulation in snow on the Idaho National Engineering and Environmental Laboratory and surrounding region,southeast Idaho,USA

Snow was sampled and analyzed for total mercury (THg) on the Idaho National Engineering and Environmental Laboratory (INEEL) and surrounding region prior to the start-up of a large (9-11 g/h) gaseous mercury emission source. The objective was to determine the effects of the source on local and regional atmospheric deposition of mercury. Snow samples collected from 48 points on a polar grid near the source had THg concentrations that ranged from 4.71 to 27.26 ng/L; snow collected from regional background sites had THg concentrations that ranged from 0.89 to 16.61 ng/L. Grid samples had higher concentrations than the regional background sites, which was unexpected because the source was not operating yet. Emission of Hg from soils is a possible source of Hg in snow on the INEEL. Evidence from Hg profiles in snow and from unfiltered/filtered split samples supports this hypothesis. Ongoing work on the INEEL is investigating Hg fluxes from soils and snow.     

http://www.sciencedirect.com/science/article/pii/S1674987112000886

Six national-scale, or near national-scale, geochemical data sets for soils or stream sediments exist for the United States. The earliest of these, here termed the ‘Shacklette’ data set, was generated by a U.S. Geological Survey (USGS) project conducted from 1961 to 1975. This project used soil collected from a depth of about 20 cm as the sampling medium at 1323 sites throughout the conterminous U.S. The National Uranium Resource Evaluation Hydrogeochemical and Stream Sediment Reconnaissance (NURE-HSSR) Program of the U.S. Department of Energy was conducted from 1975 to 1984 and collected either stream sediments, lake sediments, or soils at more than 378,000 sites in both the conterminous U.S. and Alaska. The sampled area represented about 65% of the nation. The Natural Resources Conservation Service (NRCS), from 1978 to 1982, collected samples from multiple soil horizons at sites within the major crop-growing regions of the conterminous U.S. This data set contains analyses of more than 3000 samples. The National Geochemical Survey, a USGS project conducted from 1997 to 2009, used a subset of the NURE-HSSR archival samples as its starting point and then collected primarily stream sediments, with occasional soils, in the parts of the U.S. not covered by the NURE-HSSR Program. This data set contains chemical analyses for more than 70,000 samples. The USGS, in collaboration with the Mexican Geological Survey and the Geological Survey of Canada, initiated soil sampling for the North American Soil Geochemical Landscapes Project in 2007. Sampling of three horizons or depths at more than 4800 sites in the U.S. was completed in 2010, and chemical analyses are currently ongoing. The NRCS initiated a project in the 1990s to analyze the various soil horizons from selected pedons throughout the U.S. This data set currently contains data from more than 1400 sites. This paper (1) discusses each data set in terms of its purpose, sample collection protocols, and analytical methods; and (2) evaluates each data set in terms of its appropriateness as a national-scale geochemical database and its usefulness for national-scale geochemical mapping.     

Assessment of suspended particulate pollution in the Bhadra River catchment,Southern India: an environmental magnetic approach

Open-cast mining generates sediment in river systems at globally significant scales. One of the challenges in attributing measured sediment loads to upstream mining activities is establishing the source of sediments that are a mixture of natural and mining-based materials. The environmental magnetic data (mass-specific magnetic susceptibility, anhysteretic remanent magnetisation, isothermal remanent magnetisation and inter-parametric ratios) on 57 samples of suspended sediment from the Bhadra River in the Sahyadri (the Western Ghat) of India have been used in this study. Samples were collected upstream, adjacent to and downstream of Kudremukh, a mountainous and high rainfall site where the largest mechanised open-cast mine in south Asia was located. Graphical and multivariate analyses and modelling of the data show that on average ~29% of the river suspended load downstream of the mine is derived from mining and allied activities at Kudremukh although the mine occupies less than 5% of the catchment. The contribution of primary ore is the maximum (18%), followed by transitional hard weathered ore (7%) and weathered ore (4%). The model has done a fairly good job of unmixing; the sum of errors is <1 for 40 samples, 1–4,254 for five samples and >71,000 for four samples. Modelling of samples with small mass seems to produce large errors. This investigation demonstrates the utility of environmental magnetic data, which can be obtained in a simple and rapid manner, and the unmixing of such data in identifying the contribution of mining activities to the total suspended sediment load.     

慕士塔格卡尔塔马克冰川作用区的水文与水化学特征

利用2003年6月1日~8月25日实测的水文数据,分析了慕士塔格峰卡尔塔马克冰川融水径流的变化特征.卡尔塔马克冰川融水径流主要集中在6~8月,其存在着明显的日变化过程,融水径流受控于温度及降水要素.同时,对8月10~23日采集的冰川径流样品及部分降水样品的pH、EC(电导率)和主要离子(Na⁺,K⁺,Ca²⁺,Mg²⁺,Cl^-,NO₃^-,SO₄^2-,未检测降水样品的离子含量)的测定结果进行了分析讨论.径流样品略偏碱性,pH和EC呈正相关关系.SO₄^2-和Ca²⁺是所测离子中主导的阴阳离子.除NO₃^-外,样品中各离子含量具有一致的变化特征;各离子浓度与流量或水位具有相反的变化趋势.初步讨论了离子的来源,结果表明冰川融水中化学物质组分主要来源于地表.     

Comparative study of As,Cd, Cu,Cr, Mg,Mn, Ni,Pb and Zn concentrations between sediment and water from estuary and port

The contents of As, Cd, Cu, Cr, Mg, Mn, Ni, Pb and Zn have been determined in sediment and water samples from Valle de las Garzas estuary and Port Manzanillo (Colima, Mexico) using ICP-AES. The concentrations of these elements were used for a comparative study to determine the distribution of heavy metals and to evaluate which elements reflect natural or anthropogenic backgrounds. For this purpose, seven sampling points were selected: Four of them correspond to the lagoon, and three were situated in the port. Statistical analysis of the mineral content was assessed. Initially, data comparison was assessed by statistical tests for each variable. Principal component analysis was then applied considering the influence of all variables at the same time by obtaining the distribution of samples according to their scores in the principal component space. In this way, four studies were carried out: (1) study of sediments collected during the dry season; (2) study of sediments collected during the rainy season; (3) comparative study between sediments from rainy and dry season; and (4) study of water composition collected during rainy season. From the results of the performed analyses, it can be concluded that metals distribution pattern reflected natural and anthropogenic backgrounds (e.g., sediments from the lagoon, situated at the beginning of the rain channel, presented high contents of Zn and Cu, perhaps related to anthropogenic activities or the influence of igneous sediments).     

Source of salinity in the groundwater of Lenjanat Plain,Isfahan, Iran

The present study aimed at identifying the salinity source in the groundwater of Lenjanat Plain. To do so, non-isotopic geochemical methods were employed: groundwater samples were collected seasonally from 33 wells widespread in the area, and physicochemical parameters as well as major and minor elements were measured in the 132 samples. The data collected from the field and laboratory measurements were interpreted through statistical and hydrogeochemical graphs, mass ratios and saturation indexes obtained from modeling. The results revealed that hydrogeochemical properties of the study aquifer were controlled by rock/water interactions including ion exchange, dissolution of evaporation deposits (halite and gypsum) and precipitation/dissolution of carbonates. Based on the values of Cl/Br ratio in Lenjanat groundwater (329–4,492), dissolution of evaporation deposits in aquifer was the main cause for groundwater salinity. Considering the Lenjanat groundwater geochemical properties, the data confirm the reported Cl/Br ratios for groundwater affected by the dissolution of evaporation deposits (Cl/Br > 300) and overlaps with the range of Cl/Br ratios for domestic sewage effluent groundwater. Selecting the best chemical components and their ratios in non-isotopic geochemical methods provides an accurate distinction between sources of groundwater salinity.     

Assessment of geochemical and sedimentological characteristics of atmospheric dust in Shiraz,southwest Iran

Geogenic dust is commonly believed to be one of the most important environmental problems in the Middle East.The present study investigated the geochemical characteristics of atmospheric dust particles in Shiraz City(south of Iran).Atmospheric dust samples were collected through a dry collector method by using glass trays at 10 location sites in May 2018.Elemental composition was analysed through inductively coupled plasma optical emission spectrometry.Meteorological data showed that the dustiest days were usually in spring and summer,particularly in April.X-ray diffraction analysis of atmospheric dust samples indicated that the mineralogical composition of atmospheric dust was calcite+dolomite(24%)palygorskite(18%)quartz(14%)muscovite(13%)albite(11%)kaolinite(7%)gypsum(7%)zircon=anatase(3%).The high occurrence of palygorskite(16%-23%) could serve as a tracer of the source areas of dust storms from the desert of Iraq and Saudi Arabia to the South of Iran.Scanning electron microscopy indicated that the sizes of the collected dust varied from 50 μm to0.8 μm,but 10 μm was the predominant size.The atmospheric dust collected had prismatic trigonal-rhombohedral crystals and semi-rounded irregular shapes.Moreover,diatoms were detected in several samples,suggesting that emissions from dry-bed lakes,such as Hoor Al-Azim Wetland(located in the southwest of Iran),also contributed to the dust load.Backward trajectory simulations were performed at the date of sampling by using the NOAA HYSPLIT model.Results showed that the sources of atmospheric dust in the study area were the eastern area of Iraq,eastern desert of Saudi Arabia,Kuwait and Khuzestan Province.The Ca/Al ratio of the collected samples(1.14) was different from the upper continental crust(UCC) value(UCC=0.37),whereas Mg/A1(0.29),K/Al(0.22) and Ti/Al(0.07) ratios were close to the UCC value(0.04).This condition favours desert calcisols as the main mineral dust sources.Analysis of the crustal enrichment factor(EF_(crustal)) revealed geogenic sources for V,Mo,Pb,Sr,Cu and Zn(2),whereas anthropogenic sources affected As,Cd,Cr and Ni.     

Limestone Provenance in Roman Lime‐Volcanic Ash Mortars from the Villa dei Quintili,Rome

Roman mortars were collected from the Villa dei Quintili in Rome, an archaeological site consisting of numerous edifices from nine construction phases dating from the 2nd century A.D. to modern times. A multianalytical approach was used on 34 mortar samples to infer the evolution of production techniques over time and to identify the source area of calcareous raw materials used in the preparation of the lime. Optical microscopy, scanning electron microscopy coupled with an energy‐dispersive system, and laser ablation inductively coupled plasma mass spectrometry were used to study the samples. The major and trace element data were compared with the compositions of two types of limestone samples (Calcare Massiccio and Calcare Maiolica) collected from the Cornicolani Mountains. The results suggest that the technological practices and the calcareous raw materials used for lime production remained unchanged over the time period considered (2nd century A.D. to 3rd century A.D.). The compositions of lime‐related particles in the mortars match those of Calcare Maiolica, which suggests its use as raw material for lime production. On the whole, the results are in agreement with data from existing literature regarding both the use by Roman builders of specific raw materials for the mortars’ production and the relative supply area.