Geochemical exploration for uranium

International Nuclear Information System (INIS)

1988-01-01

This Technical Report is designed mainly to introduce the methods and techniques of uranium geochemical exploration to exploration geologists who may not have had experience with geochemical exploration methods in their uranium programmes. The methods presented have been widely used in the uranium exploration industry for more than two decades. The intention has not been to produce an exhaustive, detailed manual, although detailed instructions are given for a field and laboratory data recording scheme and a satisfactory analytical method for the geochemical determination of uranium. Rather, the intention has been to introduce the concepts and methods of uranium exploration geochemistry in sufficient detail to guide the user in their effective use. Readers are advised to consult general references on geochemical exploration to increase their understanding of geochemical techniques for uranium

Geochemical reanalysis of historical U.S. Geological Survey sediment samples from the northeastern Alaska Range, Healy, Mount Hayes, Nabesna, and Tanacross quadrangles, Alaska

Science.gov (United States)

Werdon, Melanie B.; Granitto, Matthew; Azain, Jaime S.

2015-01-01

The State of Alaska’s Strategic and Critical Minerals (SCM) Assessment project, a State-funded Capital Improvement Project (CIP), is designed to evaluate Alaska’s statewide potential for SCM resources. The SCM Assessment is being implemented by the Alaska Division of Geological & Geophysical Surveys (DGGS), and involves obtaining new airborne-geophysical, geological, and geochemical data. As part of the SCM Assessment, thousands of historical geochemical samples from DGGS, U.S. Geological Survey (USGS), and U.S. Bureau of Mines archives are being reanalyzed by DGGS using modern, quantitative, geochemical-analytical methods. The objective is to update the statewide geochemical database to more clearly identify areas in Alaska with SCM potential. The USGS is also undertaking SCM-related geologic studies in Alaska through the federally funded Alaska Critical Minerals cooperative project. DGGS and USGS share the goal of evaluating Alaska’s strategic and critical minerals potential and together created a Letter of Agreement (signed December 2012) and a supplementary Technical Assistance Agreement (#14CMTAA143458) to facilitate the two agencies’ cooperative work. Under these agreements, DGGS contracted the USGS in Denver to reanalyze historical USGS sediment samples from Alaska. For this report, DGGS funded reanalysis of 670 historical USGS sediment samples from the statewide Alaska Geochemical Database Version 2.0 (AGDB2; Granitto and others, 2013). Samples were chosen from the northeastern Alaska Range, in the Healy, Mount Hayes, Nabesna, and Tanacross quadrangles, Alaska (fig. 1). The USGS was responsible for sample retrieval from the National Geochemical Sample Archive (NGSA) in Denver, Colorado through the final quality assurance/quality control (QA/QC) of the geochemical analyses obtained through the USGS contract lab. The new geochemical data are published in this report as a coauthored DGGS report, and will be incorporated into the statewide geochemical

A soil sampling reference site: The challenge in defining reference material for sampling

International Nuclear Information System (INIS)

De Zorzi, Paolo; Barbizzi, Sabrina; Belli, Maria; Fajgelj, Ales; Jacimovic, Radojko; Jeran, Zvonka; Sansone, Umberto; Perk, Marcel van der

2008-01-01

In the frame of the international SOILSAMP project, funded and coordinated by the Italian Environmental Protection Agency, an agricultural area was established as a reference site suitable for performing soil sampling inter-comparison exercises. The reference site was characterized for trace element content in soil, in terms of the spatial and temporal variability of their mass fraction. Considering that the behaviour of long-lived radionuclides in soil can be expected to be similar to that of some stable trace elements and that the distribution of these trace elements in soil can simulate the distribution of radionuclides, the reference site characterised in term of trace elements, can be also used to compare the soil sampling strategies developed for radionuclide investigations

A soil sampling reference site: The challenge in defining reference material for sampling

Energy Technology Data Exchange (ETDEWEB)

De Zorzi, Paolo [Agenzia per la Protezione dell' Ambiente e per i Servizi Tecnici (APAT), Servizio Metrologia Ambientale, Via di Castel Romano, Rome 100-00128 (Italy)], E-mail: paolo.dezorzi@apat.it; Barbizzi, Sabrina; Belli, Maria [Agenzia per la Protezione dell' Ambiente e per i Servizi Tecnici (APAT), Servizio Metrologia Ambientale, Via di Castel Romano, Rome 100-00128 (Italy); Fajgelj, Ales [International Atomic Energy Agency (IAEA), Agency' s Laboratories Seibersdorf, Vienna A-1400 (Austria); Jacimovic, Radojko; Jeran, Zvonka; Sansone, Umberto [Jozef Stefan Institute, Jamova 39, Ljubljana 1000 (Slovenia); Perk, Marcel van der [Department of Physical Geography, Utrecht University, P.O. Box 80115, TC Utrecht 3508 (Netherlands)

2008-11-15

In the frame of the international SOILSAMP project, funded and coordinated by the Italian Environmental Protection Agency, an agricultural area was established as a reference site suitable for performing soil sampling inter-comparison exercises. The reference site was characterized for trace element content in soil, in terms of the spatial and temporal variability of their mass fraction. Considering that the behaviour of long-lived radionuclides in soil can be expected to be similar to that of some stable trace elements and that the distribution of these trace elements in soil can simulate the distribution of radionuclides, the reference site characterised in term of trace elements, can be also used to compare the soil sampling strategies developed for radionuclide investigations.

A soil sampling reference site: the challenge in defining reference material for sampling.

Science.gov (United States)

de Zorzi, Paolo; Barbizzi, Sabrina; Belli, Maria; Fajgelj, Ales; Jacimovic, Radojko; Jeran, Zvonka; Sansone, Umberto; van der Perk, Marcel

2008-11-01

In the frame of the international SOILSAMP project, funded and coordinated by the Italian Environmental Protection Agency, an agricultural area was established as a reference site suitable for performing soil sampling inter-comparison exercises. The reference site was characterized for trace element content in soil, in terms of the spatial and temporal variability of their mass fraction. Considering that the behaviour of long-lived radionuclides in soil can be expected to be similar to that of some stable trace elements and that the distribution of these trace elements in soil can simulate the distribution of radionuclides, the reference site characterised in term of trace elements, can be also used to compare the soil sampling strategies developed for radionuclide investigations.

‘Sampling the reference set’ revisited

NARCIS (Netherlands)

Berkum, van E.E.M.; Linssen, H.N.; Overdijk, D.A.

1998-01-01

The confidence level of an inference table is defined as a weighted truth probability of the inference when sampling the reference set. The reference set is recognized by conditioning on the values of maximal partially ancillary statistics. In the sampling experiment values of incidental parameters

Quantitative determination of 210Po in geochemical samples

International Nuclear Information System (INIS)

Dyck, W.; Bristow, Q.

1984-01-01

To test the usefulness of 210 Po in soils as a means of detecting buried U mineralization, methods for the determination of 210 Po were investigated and adapted for routine production of 210 Po data from geochemical samples. A number of conditions affecting autodeposition and detection of 210 Po were investigated. The optimum area of deposition with a 450 mm 2 solid state detector was found to be 300 mm 2 . Convenience dictated room temperature over-night deposition times, although increased temperature increased speed and efficiency of deposition. A clear inverse relationship was observed between volume of solution and deposition efficiency with stirring times of less than 2 hours. For routine analysis, soil and rock powders were dissolved by leaching 1 g samples in teflon beakers successively with conc. HNO 3 , HF, and HNO 3 -HClO 4 , evaporating the solution to dryness between leaches, and taking the residue up in 20 mL 0.5 M HCl. The 210 Po was deposited on 19 mm diameter Ni discs and counted with an alpha spectrometer system employing 450 mm 2 ruggedized surface barrier detectors. The method achieved 90 percent recovery of 210 Po from solution and a detection efficiency of 30 percent. With a counting time of 3 hours, the method is capable of detecting 0.2 pCi of 210 Po per gram of sample

Sample size of the reference sample in a case-augmented study.

Science.gov (United States)

Ghosh, Palash; Dewanji, Anup

2017-05-01

The case-augmented study, in which a case sample is augmented with a reference (random) sample from the source population with only covariates information known, is becoming popular in different areas of applied science such as pharmacovigilance, ecology, and econometrics. In general, the case sample is available from some source (for example, hospital database, case registry, etc.); however, the reference sample is required to be drawn from the corresponding source population. The required minimum size of the reference sample is an important issue in this regard. In this work, we address the minimum sample size calculation and discuss related issues. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Reference samples for the earth sciences

Science.gov (United States)

Flanagan, F.J.

1974-01-01

A revised list of reference samples of interest to geoscientists has been extended to include samples for the agronomist, the archaeologist and the environmentalist. In addition to the source from which standard samples may be obtained, references or pertinent notes for some samples are included. The number of rock reference samples is now almost adequate, and the variety of ore samples will soon be sufficient. There are very few samples for microprobe work. Oil shales will become more important because of the outlook for world petroleum resources. The dryland equivalent of a submarine basalt might be useful in studies of sea-floor spreading and of the geochemistry of basalts. The Na- and K-feldspars of BCS (British Chemical Standards-Bureau of Analysed Samples), NBS (National Bureau of Standards), and ANRT (Association Kationale de la Recherche Technique) could serve as trace-element standards if such data were available. Similarly, the present NBS flint and plastic clays, as well as their predecessors, might be useful for archaeological pottery studies. The International Decade for Ocean Exploration may stimulate the preparation of ocean-water standards for trace elements or pollutants and a standard for manganese nodules. ?? 1974.

Establishing geochemical background levels of selected trace elements in areas having geochemical anomalies: The case study of the Orbetello lagoon (Tuscany, Italy)

International Nuclear Information System (INIS)

Romano, Elena; Bergamin, Luisa; Croudace, Ian W.; Ausili, Antonella; Maggi, Chiara; Gabellini, Massimo

2015-01-01

The determination of background concentration values (BGVs) in areas, characterised by the presence of natural geochemical anomalies and anthropogenic impact, appears essential for a correct pollution assessment. For this purpose, it is necessary to establish a reliable method for determination of local BGVs. The case of the Orbetello lagoon, a geologically complex area characterized by Tertiary volcanism, is illustrated. The vertical concentration profiles of As, Cd, Cr, Cu, Hg, Ni, Pb and Zn were studied in four sediment cores. Local BGVs were determined considering exclusively samples not affected by anthropogenic influence, recognized by means of multivariate statistics and radiochronological dating ( 137 Cs and 210 Pb). Results showed BGVs well-comparable with mean crustal or shale values for most of the considered elements except for Hg (0.87 mg/kg d.w.) and As (16.87 mg/kg d.w.), due to mineralization present in the catchment basin draining into the lagoon. - Highlights: • Pollution assessment in areas with geochemical anomalies needs local reference values. • A new method for the determination of background values (BGV) was established. • Geochemical data from unpolluted samples of sediment cores were used. • Statistics and geochronology were applied to recognize unpolluted sediments. • Anthropogenically influenced samples were not considered for BGV determination. - A method including multivariate statistics and radiochronological dating is proposed for determining local background values for trace elements using analytical data form sediment cores

Large sample neutron activation analysis of a reference inhomogeneous sample

International Nuclear Information System (INIS)

Vasilopoulou, T.; Athens National Technical University, Athens; Tzika, F.; Stamatelatos, I.E.; Koster-Ammerlaan, M.J.J.

2011-01-01

A benchmark experiment was performed for Neutron Activation Analysis (NAA) of a large inhomogeneous sample. The reference sample was developed in-house and consisted of SiO 2 matrix and an Al-Zn alloy 'inhomogeneity' body. Monte Carlo simulations were employed to derive appropriate correction factors for neutron self-shielding during irradiation as well as self-attenuation of gamma rays and sample geometry during counting. The large sample neutron activation analysis (LSNAA) results were compared against reference values and the trueness of the technique was evaluated. An agreement within ±10% was observed between LSNAA and reference elemental mass values, for all matrix and inhomogeneity elements except Samarium, provided that the inhomogeneity body was fully simulated. However, in cases that the inhomogeneity was treated as not known, the results showed a reasonable agreement for most matrix elements, while large discrepancies were observed for the inhomogeneity elements. This study provided a quantification of the uncertainties associated with inhomogeneity in large sample analysis and contributed to the identification of the needs for future development of LSNAA facilities for analysis of inhomogeneous samples. (author)

The outlier sample effects on multivariate statistical data processing geochemical stream sediment survey (Moghangegh region, North West of Iran)

International Nuclear Information System (INIS)

Ghanbari, Y.; Habibnia, A.; Memar, A.

2009-01-01

In geochemical stream sediment surveys in Moghangegh Region in north west of Iran, sheet 1:50,000, 152 samples were collected and after the analyze and processing of data, it revealed that Yb, Sc, Ni, Li, Eu, Cd, Co, as contents in one sample is far higher than other samples. After detecting this sample as an outlier sample, the effect of this sample on multivariate statistical data processing for destructive effects of outlier sample in geochemical exploration was investigated. Pearson and Spear man correlation coefficient methods and cluster analysis were used for multivariate studies and the scatter plot of some elements together the regression profiles are given in case of 152 and 151 samples and the results are compared. After investigation of multivariate statistical data processing results, it was realized that results of existence of outlier samples may appear as the following relations between elements: - true relation between two elements, which have no outlier frequency in the outlier sample. - false relation between two elements which one of them has outlier frequency in the outlier sample. - complete false relation between two elements which both have outlier frequency in the outlier sample

Application of integrated Landsat, geochemical and geophysical data in mineral exploration

International Nuclear Information System (INIS)

Conradsen, K.; Nilsson, G.; Thyrsted, T.; Gronlands Geologiske Undersogelse, Copenhagen, Denmark)

1985-01-01

In South Greenland (20000 sq. km) a remote sensing investigation is executed in connection with uranium exploration. The investigation includes analysis of Landsat data, conversion of geological, geochemical and geophysical data to image format compatible with Landsat images, and analysis of the total set of integrated data. The available geochemical data consisted of samples from 2000 sites, analyzed for U, K, Rb, Sr, Nb, Ga, Y, and Fe. The geophysical data comprised airborne gamma-spectrometric measurements and aeromagnetic data. The interpolation routines consisted of a kriging procedure for the geochemical data and a minimum curvature routine for the geophysical data. The analysis of the integrated data set is at a preliminary stage. As example a composite image showing Landsat channel 7, magnetic values, and Fe values as respectively intensity, hue and saturation is analyzed. It reveals alkaline intrusions and basaltic layers as anomalies while other anomalies cannot be accounted for on the basis of the present geological knowledge. 12 references

Regional geochemical maps of the Tonopah 1 degree by 2 degrees Quadrangle, Nevada, based on samples of stream sediment and nonmagnetic heavy-mineral concentrate

Science.gov (United States)

Nash, J.T.; Siems, D.F.

1988-01-01

This report is part of a series of geologic, geochemical, and geophysical maps of the Tonopah 1° x 2° quadrangle, Nevada, prepared during studies of the area for the Conterminous United States Mineral Assessment Program (CUSMAP). Included here are 21 maps showing the distributions of selected elements or combinations of elements. These regional geochemical maps are based on chemical analyses of the minus-60 mesh (0.25 mm) fraction of stream-sediment samples and the nonmagnetic heavy-mineral concentrate derived from stream sediment. Stream sediments were collected at 1,217 sites. Our geochemical studies of mineralized rock samples provide a framework for evaluating the results from stream sediments.

TAPIR--Finnish national geochemical baseline database.

Science.gov (United States)

Jarva, Jaana; Tarvainen, Timo; Reinikainen, Jussi; Eklund, Mikael

2010-09-15

In Finland, a Government Decree on the Assessment of Soil Contamination and Remediation Needs has generated a need for reliable and readily accessible data on geochemical baseline concentrations in Finnish soils. According to the Decree, baseline concentrations, referring both to the natural geological background concentrations and the diffuse anthropogenic input of substances, shall be taken into account in the soil contamination assessment process. This baseline information is provided in a national geochemical baseline database, TAPIR, that is publicly available via the Internet. Geochemical provinces with elevated baseline concentrations were delineated to provide regional geochemical baseline values. The nationwide geochemical datasets were used to divide Finland into geochemical provinces. Several metals (Co, Cr, Cu, Ni, V, and Zn) showed anomalous concentrations in seven regions that were defined as metal provinces. Arsenic did not follow a similar distribution to any other elements, and four arsenic provinces were separately determined. Nationwide geochemical datasets were not available for some other important elements such as Cd and Pb. Although these elements are included in the TAPIR system, their distribution does not necessarily follow the ones pre-defined for metal and arsenic provinces. Regional geochemical baseline values, presented as upper limit of geochemical variation within the region, can be used as trigger values to assess potential soil contamination. Baseline values have also been used to determine upper and lower guideline values that must be taken into account as a tool in basic risk assessment. If regional geochemical baseline values are available, the national guideline values prescribed in the Decree based on ecological risks can be modified accordingly. The national geochemical baseline database provides scientifically sound, easily accessible and generally accepted information on the baseline values, and it can be used in various

Geochemical features of the elemental composition of meadowsweet (Filipendula ulmaria (L).Maxim) in Kemerovo Oblast

Science.gov (United States)

Zhdanov, V. A.; Sobolev, I. S.; Baranovskaya, N. V.; Kolesnikova, E. A.; Chernenkaya, E. V.; Yalaltdinova, A. R.

2016-09-01

Biogeochemical sampling of the aboveground part of meadowsweet (Fillipendula Ulmaria (L). Maxim) allowed us to study ecological and geochemical features of 10 regions in Kemerovo Oblast, including both natural and man-made landscapes. The content of 55 elements in the plant is determined by ICP-MS. Statistical analysis of the results allowed us to establish the effect of the soil mineral composition and the mining region specificity on the elemental composition of meadowsweet, to reveal significant positive correlations of the elements and to establish a statistically significant difference in the studied areas on the basis of the content of some elements. Sample reference to one of the clusters, followed by an assessment of their geochemical features is determined by the K-average method.

Methodological approaches in estimating anomalous geochemical field structure

International Nuclear Information System (INIS)

Gavrilov, R; Rudmin, M

2015-01-01

Mathematical statistic methods were applied to analyze the core samples from vertical expendable wells in Chertovo Koryto gold ore field. The following methods were used to analyse gold in samples: assay tests and atomic absorption method (AAS), while emission spectrum semiquantative method was applied to identify traces. The analysis of geochemical association distribution in one central profile demonstrated that bulk metasomatic aureoles are characteristic of concentric zonal structure. The distribution of geochemical associations is correlated to the hydrothermal stages of mineral formation identified in this deposit. It was proved that the processed geochemical data by factor and cluster analyses provided additional information on the anomalous geochemical field structure in gold- bearing black-shale strata. Such methods are effective tools in interpretating specific features of geochemical field structures in analogous potential ore-bearing areas

Application of cluster analysis to geochemical compositional data for identifying ore-related geochemical anomalies

Science.gov (United States)

Zhou, Shuguang; Zhou, Kefa; Wang, Jinlin; Yang, Genfang; Wang, Shanshan

2017-12-01

Cluster analysis is a well-known technique that is used to analyze various types of data. In this study, cluster analysis is applied to geochemical data that describe 1444 stream sediment samples collected in northwestern Xinjiang with a sample spacing of approximately 2 km. Three algorithms (the hierarchical, k-means, and fuzzy c-means algorithms) and six data transformation methods (the z-score standardization, ZST; the logarithmic transformation, LT; the additive log-ratio transformation, ALT; the centered log-ratio transformation, CLT; the isometric log-ratio transformation, ILT; and no transformation, NT) are compared in terms of their effects on the cluster analysis of the geochemical compositional data. The study shows that, on the one hand, the ZST does not affect the results of column- or variable-based (R-type) cluster analysis, whereas the other methods, including the LT, the ALT, and the CLT, have substantial effects on the results. On the other hand, the results of the row- or observation-based (Q-type) cluster analysis obtained from the geochemical data after applying NT and the ZST are relatively poor. However, we derive some improved results from the geochemical data after applying the CLT, the ILT, the LT, and the ALT. Moreover, the k-means and fuzzy c-means clustering algorithms are more reliable than the hierarchical algorithm when they are used to cluster the geochemical data. We apply cluster analysis to the geochemical data to explore for Au deposits within the study area, and we obtain a good correlation between the results retrieved by combining the CLT or the ILT with the k-means or fuzzy c-means algorithms and the potential zones of Au mineralization. Therefore, we suggest that the combination of the CLT or the ILT with the k-means or fuzzy c-means algorithms is an effective tool to identify potential zones of mineralization from geochemical data.

Identification of hydrologic and geochemical pathways using high frequency sampling, REE aqueous sampling and soil characterization at Koiliaris Critical Zone Observatory, Crete

Energy Technology Data Exchange (ETDEWEB)

Moraetis, Daniel, E-mail: moraetis@mred.tuc.gr [Department of Environmental Engineering, Technical University of Crete, 73100 Chania (Greece); Stamati, Fotini; Kotronakis, Manolis; Fragia, Tasoula; Paranychnianakis, Nikolaos; Nikolaidis, Nikolaos P. [Department of Environmental Engineering, Technical University of Crete, 73100 Chania (Greece)

2011-06-15

Highlights: > Identification of hydrological and geochemical pathways within a complex watershed. > Water increased N-NO{sub 3} concentration and E.C. values during flash flood events. > Soil degradation and impact on water infiltration within the Koiliaris watershed. > Analysis of Rare Earth Elements in water bodies for identification of karstic water. - Abstract: Koiliaris River watershed is a Critical Zone Observatory that represents severely degraded soils due to intensive agricultural activities and biophysical factors. It has typical Mediterranean soils under the imminent threat of desertification which is expected to intensify due to projected climate change. High frequency hydro-chemical monitoring with targeted sampling for Rare Earth Elements (REE) analysis of different water bodies and geochemical characterization of soils were used for the identification of hydrologic and geochemical pathways. The high frequency monitoring of water chemical data highlighted the chemical alterations of water in Koiliaris River during flash flood events. Soil physical and chemical characterization surveys were used to identify erodibility patterns within the watershed and the influence of soils on surface and ground water chemistry. The methodology presented can be used to identify the impacts of degraded soils to surface and ground water quality as well as in the design of methods to minimize the impacts of land use practices.

A comparison of iron oxide-rich joint coatings and rock chips as geochemical sampling media in exploration for disseminated gold deposits

Science.gov (United States)

Crone, W.; Larson, L.T.; Carpenter, R.H.; Chao, T.T.; Sanzolone, R.F.

1984-01-01

We evaluated the effectiveness of iron oxide-rich fracture coatings as a geochemical sampling medium for disseminated gold deposits, as compared with conventional lithogeochemical methods, for samples from the Pinson mine and Preble prospect in southeastern Humboldt County, Nevada. That disseminated gold mineralization is associated with Hg, As, and Sb is clearly demonstrated in these deposits for both fracture coatings and rock chip samples. However, the relationship is more pronounced for fracture coatings. Fracture coatings at Pinson contain an average of 3.61, 5.13, 14.37, and 3.42 times more Au, As, Sb and Hg, respectively, than adjacent rock samples. At Preble, fracture coatings contain 3.13, 9.72, 9.18, and 1.85 times more Au, As, Sb and Hg, respectively, than do adjacent rock samples. Geochemical anomalies determined from fracture coatings are thus typically more intense than those determined from rock samples for these elements. The sizes of anomalies indicated by fracture coatings are also somewhat larger, but this is less obvious. In both areas, Sb anomalies are more extensive in fracture coatings. At Preble, some Hg and Au anomalies are also more extensive in fracture coatings. In addition to halos formed by the Hg, As and Sb, high values for Au/Ag and Zn/(Fe + Mn) are closely associated with gold mineralization at the Pinson mine. The large enhancement in geochemical response afforded by fracture coatings indicates a definite potential in the search for buried disseminated gold deposits. ?? 1984.

Regional geochemical maps of uranium in Northern Scotland. Environmental and economic considerations

International Nuclear Information System (INIS)

Plant, J.

1978-01-01

The Institute of Geological Studies geochemical mapping programme is outlined. The natural levels of uranium in rocks, soils and waters are discussed. Some practical details of geochemical mapping are given. Applications of geochemical maps of uranium in Scotland are considered: economic applications and medical geography and agriculture. A list of 38 references is appended. (U.K.)

Radioactive waste isolation in salt: peer review of the Office of Nuclear Waste Isolation's Geochemical Program Plan

International Nuclear Information System (INIS)

Harrison, W.; Seitz, M.; Fenster, D.; Lerman, A.; Brookins, D.; Tisue, M.

1984-02-01

Describe the management program for coordinating subcontractors and their work, and integrating research results. Appropriate flowcharts should be included. Provide more information on the overall scope of the program. For each subcontractor, provide specific workscopes that indicate whether analytical activities are developmental or routine, approximate number of analyses to be made, and something of the adequacy of the analyses to meet program goals. Indicate interfaces with other earth-science disciplines like hydrology and with other groups doing relevant geochemical research and engineering design. Address the priorities for each activity or group of activities. High priority should be given to early development of a geochemical statement of what constitutes suitable salt for a repository. Reference standard procedures for sampling, sample preservation, and sample analysis wherever appropriate or, if not appropriate, indicate that any deviations from standard procedures will be documented. Ensure that appropriate quality assurance procedures will be followed for the procedures listed above. Include specific procedures for the choice, verification, validation, and documentation of computer codes related to the geochemical aspects of repository performance assessment. Include activities addressing regional hydrochemistry and make clear that each principal hydrogeologic unit at each site will be studied geochemically. Indicate that proposed plans for obtaining hydrogeochemical data will be included in each site characterization plan. Describe how site geochemical stability will be handled, especially with respect to dissolution, postemplacement geochemistry, human influences, and climatic variations. Minor recommendations and suggested improvements in the text of the plan are given in Sec. 5

The geochemical atlas of Alaska, 2016

Science.gov (United States)

Lee, Gregory K.; Yager, Douglas B.; Mauk, Jeffrey L.; Granitto, Matthew; Denning, Paul; Wang, Bronwen; Werdon, Melanie B.

2016-06-21

A rich legacy of geochemical data produced since the early 1960s covers the great expanse of Alaska; careful treatment of such data may provide significant and revealing geochemical maps that may be used for landscape geochemistry, mineral resource exploration, and geoenvironmental investigations over large areas. To maximize the spatial density and extent of data coverage for statewide mapping of element distributions, we compiled and integrated analyses of more than 175,000 sediment and soil samples from three major, separate sources: the U.S. Geological Survey, the National Uranium Resource Evaluation program, and the Alaska Division of Geological & Geophysical Surveys geochemical databases. Various types of heterogeneity and deficiencies in these data presented major challenges to our development of coherently integrated datasets for modeling and mapping of element distributions. Researchers from many different organizations and disparate scientific studies collected samples that were analyzed using highly variable methods throughout a time period of more than 50 years, during which many changes in analytical techniques were developed and applied. Despite these challenges, the U.S. Geological Survey has produced a new systematically integrated compilation of sediment and soil geochemical data with an average sample site density of approximately 1 locality per 10 square kilometers (km2) for the entire State of Alaska, although density varies considerably among different areas. From that compilation, we have modeled and mapped the distributions of 68 elements, thus creating an updated geochemical atlas for the State.

Geochemical Exploration Techniques Applicable in the Search for Copper Deposits

Science.gov (United States)

Chaffee, Maurice A.

1975-01-01

Geochemical exploration is an important part of copper-resource evaluation. A large number of geochemical exploration techniques, both proved and untried, are available to the geochemist to use in the search for new copper deposits. Analyses of whole-rock samples have been used in both regional and local geochemical exploration surveys in the search for copper. Analyses of mineral separates, such as biotite, magnetite, and sulfides, have also been used. Analyses of soil samples are widely used in geochemical exploration, especially for localized surveys. It is important to distinguish between residual and transported soil types. Orientation studies should always be conducted prior to a geochemical investigation in a given area in order to determine the best soil horizon and the best size of soil material for sampling in that area. Silty frost boils, caliche, and desert varnish are specialized types of soil samples that might be useful sampling media. Soil gas is a new and potentially valuable geochemical sampling medium, especially in exploring for buried mineral deposits in arid regions. Gaseous products in samples of soil may be related to base-metal deposits and include mercury vapor, sulfur dioxide, hydrogen sulfide, carbon oxysulfide, carbon dioxide, hydrogen, oxygen, nitrogen, the noble gases, the halogens, and many hydrocarbon compounds. Transported materials that have been used in geochemical sampling programs include glacial float boulders, glacial till, esker gravels, stream sediments, stream-sediment concentrates, and lake sediments. Stream-sediment sampling is probably the most widely used and most successful geochemical exploration technique. Hydrogeochemical exploration programs have utilized hot- and cold-spring waters and their precipitates as well as waters from lakes, streams, and wells. Organic gel found in lakes and at stream mouths is an unproved sampling medium. Suspended material and dissolved gases in any type of water may also be useful

Geologic Mapping and Paired Geochemical-Paleomagnetic Sampling of Reference Sections in the Grande Ronde Basalt: An Example from the Bingen Section, Columbia River Gorge, Washington

Science.gov (United States)

Sawlan, M.; Hagstrum, J. T.; Wells, R. E.

2011-12-01

We have completed comprehensive geochemical (GC) and paleomagnetic (PM) sampling of individual lava flows from eight reference stratigraphic sections in the Grande Ronde Basalt (GRB), Columbia River Basalt Group [Hagstrum et al., 2009, GSA Ann. Mtg, Portland (abst); Hagstrum et al., 2010, AGU Fall Mtg, San Francisco (abst)]. These sections, distributed across the Columbia Plateau and eastern Columbia River Gorge, contain as many as 30 flows, are up to 670 m thick, span upper magneto-stratigraphic zones R2 and N2, and, in some locations, also contain one or more N1 flows. In concert with GC and PM sampling, we have carried out detailed geologic mapping of these sections, typically at a scale of 1:3,000 to 1:5,000, using GPS, digital imagery from the National Aerial Imagery Program (NAIP), and compilation in GIS. GRB member and informal unit names of Reidel et al. [1989, GSA Sp. Paper 239] generally have been adopted, although two new units are identified and named within the N2 zone. Notably, a distinctive PM direction for intercalated lavas of several lower N2 units indicates coeval eruption of compositionally distinct units; this result contrasts with the scenario of serial stratigraphic succession of GRB units proposed by Reidel et al. [1989]. Our objectives in the mapping include: Confirming the integrity of the stratigraphic sequences by documenting flow contacts and intraflow horizons (changes in joint patterns or vesicularity); assessing fault displacements; and, establishing precisely located samples in geologic context such that selected sites can be unambiguously reoccupied. A geologic map and GC-PM data for the Bingen section, along the north side of the Columbia River, are presented as an example of our GRB reference section mapping and sampling. One of our thicker sections (670 m) along which 30 flows are mapped, the Bingen section spans 7 km along WA State Hwy 14, from near the Hood River Bridge ESE to Locke Lake. This section cuts obliquely through a

Geochemical baseline studies of soil in Finland

Science.gov (United States)

Pihlaja, Jouni

2017-04-01

The soil element concentrations regionally vary a lot in Finland. Mostly this is caused by the different bedrock types, which are reflected in the soil qualities. Geological Survey of Finland (GTK) is carrying out geochemical baseline studies in Finland. In the previous phase, the research is focusing on urban areas and mine environments. The information can, for example, be used to determine the need for soil remediation, to assess environmental impacts or to measure the natural state of soil in industrial areas or mine districts. The field work is done by taking soil samples, typically at depth between 0-10 cm. Sampling sites are chosen to represent the most vulnerable areas when thinking of human impacts by possible toxic soil element contents: playgrounds, day-care centers, schools, parks and residential areas. In the mine districts the samples are taken from the areas locating outside the airborne dust effected areas. Element contents of the soil samples are then analyzed with ICP-AES and ICP-MS, Hg with CV-AAS. The results of the geochemical baseline studies are published in the Finnish national geochemical baseline database (TAPIR). The geochemical baseline map service is free for all users via internet browser. Through this map service it is possible to calculate regional soil baseline values using geochemical data stored in the map service database. Baseline data for 17 elements in total is provided in the map service and it can be viewed on the GTK's web pages (http://gtkdata.gtk.fi/Tapir/indexEN.html).

The Lyman alpha reference sample

DEFF Research Database (Denmark)

Hayes, M.; Östlin, G.; Schaerer, D.

2013-01-01

We report on new imaging observations of the Lyman alpha emission line (Lyα), performed with the Hubble Space Telescope, that comprise the backbone of the Lyman alpha Reference Sample. We present images of 14 starburst galaxies at redshifts 0.028

Geochemical reanalysis of historical U.S. Geological Survey sediment samples from the Inmachuk, Kugruk, Kiwalik, and Koyuk River drainages, Granite Mountain, and the northern Darby Mountains, Bendeleben, Candle, Kotzebue, and Solomon quadrangles, Alaska

Science.gov (United States)

Werdon, Melanie B.; Granitto, Matthew; Azain, Jaime S.

2015-01-01

The State of Alaska’s Strategic and Critical Minerals (SCM) Assessment project, a State-funded Capital Improvement Project (CIP), is designed to evaluate Alaska’s statewide potential for SCM resources. The SCM Assessment is being implemented by the Alaska Division of Geological & Geophysical Surveys (DGGS), and involves obtaining new airborne-geophysical, geological, and geochemical data. As part of the SCM Assessment, thousands of historical geochemical samples from DGGS, U.S. Geological Survey (USGS), and U.S. Bureau of Mines archives are being reanalyzed by DGGS using modern, quantitative, geochemical-analytical methods. The objective is to update the statewide geochemical database to more clearly identify areas in Alaska with SCM potential. The USGS is also undertaking SCM-related geologic studies in Alaska through the federally funded Alaska Critical Minerals cooperative project. DGGS and USGS share the goal of evaluating Alaska’s strategic and critical minerals potential and together created a Letter of Agreement (signed December 2012) and a supplementary Technical Assistance Agreement (#14CMTAA143458) to facilitate the two agencies’ cooperative work. Under these agreements, DGGS contracted the USGS in Denver to reanalyze historical USGS sediment samples from Alaska. For this report, DGGS funded reanalysis of 653 historical USGS sediment samples from the statewide Alaska Geochemical Database Version 2.0 (AGDB2; Granitto and others, 2013). Samples were chosen from an area covering portions of the Inmachuk, Kugruk, Kiwalik, and Koyuk river drainages, Granite Mountain, and the northern Darby Mountains, located in the Bendeleben, Candle, Kotzebue, and Solomon quadrangles of eastern Seward Peninsula, Alaska (fig. 1). The USGS was responsible for sample retrieval from the National Geochemical Sample Archive (NGSA) in Denver, Colorado through the final quality assurance/quality control (QA/QC) of the geochemical analyses obtained through the USGS contract

Geochemical Constraints for Mercury's PCA-Derived Geochemical Terranes

Science.gov (United States)

Stockstill-Cahill, K. R.; Peplowski, P. N.

2018-05-01

PCA-derived geochemical terranes provide a robust, analytical means of defining these terranes using strictly geochemical inputs. Using the end members derived in this way, we are able to assess the geochemical implications for Mercury.

Estimation of individual reference intervals in small sample sizes

DEFF Research Database (Denmark)

Hansen, Ase Marie; Garde, Anne Helene; Eller, Nanna Hurwitz

2007-01-01

In occupational health studies, the study groups most often comprise healthy subjects performing their work. Sampling is often planned in the most practical way, e.g., sampling of blood in the morning at the work site just after the work starts. Optimal use of reference intervals requires...... from various variables such as gender, age, BMI, alcohol, smoking, and menopause. The reference intervals were compared to reference intervals calculated using IFCC recommendations. Where comparable, the IFCC calculated reference intervals had a wider range compared to the variance component models...

Leachate Geochemical Results for Ash Samples from the June 2007 Angora Wildfire Near Lake Tahoe in Northern California

Science.gov (United States)

Hageman, Philip L.; Plumlee, Geoffrey S.; Martin, Deborah A.; Hoefen, Todd M.; Adams, Monique; Lamothe, Paul J.; Todorov, Todor I.; Anthony, Michael W.

2008-01-01

This report releases leachate geochemical data for ash samples produced by the Angora wildfire that burned from June 24 to July 2, 2007, near Lake Tahoe in northern California. The leaching studies are part of a larger interdisciplinary study whose goal is to identify geochemical characteristics and properties of the ash that may adversely affect human health, water quality, air quality, animal habitat, endangered species, debris flows, and flooding hazards. The leaching study helps characterize and understand the interactions that occur when the ash comes in contact with rain or snowmelt, and helps identify the constituents that may be mobilized as run-off from these materials. Similar leaching studies were conducted on ash and burned soils from the October 2007 southern California wildfires (Hageman and others, 2008; Plumlee and others, 2007).

Geochemical prospect ion results of Treinta y Tres aerial photo

International Nuclear Information System (INIS)

Zeegers, H.; Bonnefoy, D.; Garau, M.; Spangenberg, J.

1981-01-01

This report shows the geochemical prospect ion results carried out within the framework of the multielemental geochemical strategy. The samples were studied by e spectrometry in the laboratories of Orleans.

The Lyα Reference Sample

DEFF Research Database (Denmark)

Ostlin, Goran; Hayes, Matthew; Duval, Florent

2014-01-01

The Lyα Reference Sample (LARS) is a substantial program with the Hubble Space Telescope (HST) that provides a sample of local universe laboratory galaxies in which to study the detailed astrophysics of the visibility and strength of the Lyαline of neutral hydrogen. Lyα is the dominant spectral...... are produced (whether or not they escape), we demanded an Hα equivalent width W(Hα) ≥100 Å. The final sample of 14 galaxies covers far-UV (FUV, λ ~ 1500 Å) luminosities that overlap with those of high-z Lyα emitters (LAEs) and Lyman break galaxies (LBGs), making LARS a valid comparison sample. We present......) but strongly asymmetric Lyα emission. Spectroscopy from the Cosmic Origins Spectrograph on board HST centered on the brightest UV knot shows a moderate outflow in the neutral interstellar medium (probed by low ionization stage absorption features) and Lyα emission with an asymmetric profile. Radiative transfer...

Instrumental neutron activation analysis of geochemical samples by k{sub 0} standardization method using short lived nuclides

Energy Technology Data Exchange (ETDEWEB)

Oura, Yasuji; Kanzaki, Chinatsu; Ebihara, Mitsuru [Tokyo Metropolitan Univ., Graduate School of Science, Tokyo (Japan)

2003-03-01

Mg, Al, Ca, Ti, V, and Mn contents in geochemical and cosmochemical samples were analyzed by both k{sub 0} standardization INAA and conventional INAA by a comparison method. The contents of Mg, Al, and Mn by k{sub 0} method were consistent with recommended values and ones by comparison methods. For Ti and V their values are slightly higher than recommended ones. The values by k{sub 0} method were reliable within {+-}10%. (author)

A Spatially Constrained Multi-autoencoder Approach for Multivariate Geochemical Anomaly Recognition

Science.gov (United States)

Lirong, C.; Qingfeng, G.; Renguang, Z.; Yihui, X.

2017-12-01

Separating and recognizing geochemical anomalies from the geochemical background is one of the key tasks in geochemical exploration. Many methods have been developed, such as calculating the mean ±2 standard deviation, and fractal/multifractal models. In recent years, deep autoencoder, a deep learning approach, have been used for multivariate geochemical anomaly recognition. While being able to deal with the non-normal distributions of geochemical concentrations and the non-linear relationships among them, this self-supervised learning method does not take into account the spatial heterogeneity of geochemical background and the uncertainty induced by the randomly initialized weights of neurons, leading to ineffective recognition of weak anomalies. In this paper, we introduce a spatially constrained multi-autoencoder (SCMA) approach for multivariate geochemical anomaly recognition, which includes two steps: spatial partitioning and anomaly score computation. The first step divides the study area into multiple sub-regions to segregate the geochemical background, by grouping the geochemical samples through K-means clustering, spatial filtering, and spatial constraining rules. In the second step, for each sub-region, a group of autoencoder neural networks are constructed with an identical structure but different initial weights on neurons. Each autoencoder is trained using the geochemical samples within the corresponding sub-region to learn the sub-regional geochemical background. The best autoencoder of a group is chosen as the final model for the corresponding sub-region. The anomaly score at each location can then be calculated as the euclidean distance between the observed concentrations and reconstructed concentrations of geochemical elements.The experiments using the geochemical data and Fe deposits in the southwestern Fujian province of China showed that our SCMA approach greatly improved the recognition of weak anomalies, achieving the AUC of 0.89, compared

Geochemical homogeneity of tuffs at the potential repository level, Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Peterman, Zell E.; Cloke, Paul

2001-01-01

In a potential high-level radioactive waste repository at Yucca Mountain, Nevada, radioactive waste and canisters, drip shields protecting the waste from seepage and from rock falls, the backfill and invert material of crushed rock, the host rock, and water and gases contained within pores and fractures in the host rock together would form a complex system commonly referred to as the near-field geochemical environment. Materials introduced into the rock mass with the waste that are designed to prolong containment collectively are referred to as the Engineered Barrier System, and the host rock and its contained water and gases compose the natural system. The interaction of these component parts under highly perturbed conditions including temperatures well above natural ambient temperatures will need to be understood to assess the performance of the potential repository for long-term containment of nuclear waste. The geochemistry and mineralogy of the rock mass hosting the emplacement drifts must be known in order to assess the role of the natural system in the near-field environment. Emplacement drifts in a potential repository at Yucca Mountain would be constructed in the phenocryst-poor member of the Topopah Spring Tuff which is composed of both lithophysal and nonlithophysal zones. The chemical composition of the phenocryst-poor member has been characterized by numerous chemical analyses of outcrop samples and of core samples obtained by surface-based drilling. Those analyses have shown that the phenocryst-poor member of the Topopah Spring Tuff is remarkably uniform in composition both vertically and laterally. To verify this geochemical uniformity and to provide rock analyses of samples obtained directly from the potential repository block, major and trace elements were analyzed in core samples obtained from drill holes in the cross drift, which was driven to provide direct access to the rock mass where emplacement drifts would be constructed

Data precision of X-ray fluorescence (XRF) scanning of discrete samples with the ITRAX XRF core-scanner exemplified on loess-paleosol samples

Science.gov (United States)

Profe, Jörn; Ohlendorf, Christian

2017-04-01

XRF-scanning is the state-of-the-art technique for geochemical analyses in marine and lacustrine sedimentology for more than a decade. However, little attention has been paid to data precision and technical limitations so far. Using homogenized, dried and powdered samples (certified geochemical reference standards and samples from a lithologically-contrasting loess-paleosol sequence) minimizes many adverse effects that influence the XRF-signal when analyzing wet sediment cores. This allows the investigation of data precision under ideal conditions and documents a new application of the XRF core-scanner technology at the same time. Reliable interpretations of XRF results require data precision evaluation of single elements as a function of X-ray tube, measurement time, sample compaction and quality of peak fitting. Ten-fold measurement of each sample constitutes data precision. Data precision of XRF measurements theoretically obeys Poisson statistics. Fe and Ca exhibit largest deviations from Poisson statistics. The same elements show the least mean relative standard deviations in the range from 0.5% to 1%. This represents the technical limit of data precision achievable by the installed detector. Measurement times ≥ 30 s reveal mean relative standard deviations below 4% for most elements. The quality of peak fitting is only relevant for elements with overlapping fluorescence lines such as Ba, Ti and Mn or for elements with low concentrations such as Y, for example. Differences in sample compaction are marginal and do not change mean relative standard deviation considerably. Data precision is in the range reported for geochemical reference standards measured by conventional techniques. Therefore, XRF scanning of discrete samples provide a cost- and time-efficient alternative to conventional multi-element analyses. As best trade-off between economical operation and data quality, we recommend a measurement time of 30 s resulting in a total scan time of 30 minutes

Statistical interpretation of geochemical data

International Nuclear Information System (INIS)

Carambula, M.

1990-01-01

Statistical results have been obtained from a geochemical research from the following four aerial photographies Zapican, Carape, Las Canias, Alferez. They have been studied 3020 samples in total, to 22 chemical elements using plasma emission spectrometry methods.

Reference Priors For Non-Normal Two-Sample Problems

NARCIS (Netherlands)

Fernández, C.; Steel, M.F.J.

1997-01-01

The reference prior algorithm (Berger and Bernardo, 1992) is applied to locationscale models with any regular sampling density. A number of two-sample problems is analyzed in this general context, extending the dierence, ratio and product of Normal means problems outside Normality, while explicitly

Geochemical signature of land-based activities in Caribbean coral surface samples

Science.gov (United States)

Prouty, N.G.; Hughen, K.A.; Carilli, J.

2008-01-01

Anthropogenic threats, such as increased sedimentation, agrochemical run-off, coastal development, tourism, and overfishing, are of great concern to the Mesoamerican Caribbean Reef System (MACR). Trace metals in corals can be used to quantify and monitor the impact of these land-based activities. Surface coral samples from the MACR were investigated for trace metal signatures resulting from relative differences in water quality. Samples were analyzed at three spatial scales (colony, reef, and regional) as part of a hierarchical multi-scale survey. A primary goal of the paper is to elucidate the extrapolation of information between fine-scale variation at the colony or reef scale and broad-scale patterns at the regional scale. Of the 18 metals measured, five yielded statistical differences at the colony and/or reef scale, suggesting fine-scale spatial heterogeneity not conducive to regional interpretation. Five metals yielded a statistical difference at the regional scale with an absence of a statistical difference at either the colony or reef scale. These metals are barium (Ba), manganese (Mn), chromium (Cr), copper (Cu), and antimony (Sb). The most robust geochemical indicators of land-based activities are coral Ba and Mn concentrations, which are elevated in samples from the southern region of the Gulf of Honduras relative to those from the Turneffe Islands. These findings are consistent with the occurrence of the most significant watersheds in the MACR from southern Belize to Honduras, which contribute sediment-laden freshwater to the coastal zone primarily as a result of human alteration to the landscape (e.g., deforestation and agricultural practices). Elevated levels of Cu and Sb were found in samples from Honduras and may be linked to industrial shipping activities where copper-antimony additives are commonly used in antifouling paints. Results from this study strongly demonstrate the impact of terrestrial runoff and anthropogenic activities on coastal water

Use of reference samples for more accurate RBS analyses

International Nuclear Information System (INIS)

Lanford, W.A.; Pelicon, P.; Zorko, B.; Budnar, M.

2002-01-01

While one of the primary assets of RBS analysis is that it is quantitative without use of reference samples, for certain types of analyses the precision of the method can be improved by measuring RBS spectra of unknowns relative to the RBS spectra of a similar known sample. The advantage of such an approach is that one can reduce (or eliminate) the uncertainties that arise from error in the detector solid angle, beam current integration efficiency, scattering cross-section, and stopping powers. We have used this approach extensively to determine the composition (x) of homogeneous thin films of TaN x using as reference samples films of pure Ta. Our approach is to measure R=(Ta count) unknown /(Ta count) standard and use RUMP to determine the function x(R). Once the function x(R) has been determined, this approach makes it easy to analyze many samples quickly. Other analyses for which this approach has proved useful are determination of the composition (x) of WN x , SiO x H y and SiN x H y , using W, SiO 2 and amorphous Si as reference samples, respectively

Geochemical signature of radioactive waste: oil NORM

International Nuclear Information System (INIS)

Costa, Gilberto T. de Paula; Costa-de-Moura, Jorge; Gomes, Carlos de Almeida; Sampaio, Emidio A. Lopes

2017-01-01

The Brazilian Nuclear Agency (CNEN) rules all nuclear activity in Brazil as demanded by the Federal Constitution, articles 21, XXIII, and 177, V, and by the Federal Acts 4.118/62 and 10.308/2001. Therefore, the CNEN is responsible for any radioactive waste disposal in the country. Oil Naturally Occurring Radioactive Materials (Oil NORM) in this paper refers to waste coming from oil exploration. Oil NORM has called much attention during the last decades, mostly because it is not possible to determine its primary source due to the actual absence of regulatory control mechanism. There is no efficient regulatory tool which allows determining the origin of such NORM wastes even among those facilities under regulatory control. This fact may encourage non-authorized radioactive material transportation, smuggling and terrorism. The aim of this project is to provide a geochemical signature for each oil NORM waste using its naturally occurring isotopic composition to identify its origin. The here proposed method is a specific geochemical modeling of oil sludge NORM samples which are analyzed for radioisotopes normally present in oil pipes, such as 228 Ac, 214 Bi and 214 Pb. The activity ratios are plotted in scatter diagrams. This method was successfully tested with data of different sources obtained from analysis reports from the Campos Basin/Brazil and from literature. (author)

Geochemical signature of radioactive waste: oil NORM

Energy Technology Data Exchange (ETDEWEB)

Costa, Gilberto T. de Paula; Costa-de-Moura, Jorge; Gomes, Carlos de Almeida; Sampaio, Emidio A. Lopes, E-mail: gilberto.costa@cnen.gov.br, E-mail: jcmoura@cnen.gov.br, E-mail: cgomes@cnen.gov.br [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil). Div. de Controle de Rejeitos e Transporte de Materiais Radioativos

2017-07-01

The Brazilian Nuclear Agency (CNEN) rules all nuclear activity in Brazil as demanded by the Federal Constitution, articles 21, XXIII, and 177, V, and by the Federal Acts 4.118/62 and 10.308/2001. Therefore, the CNEN is responsible for any radioactive waste disposal in the country. Oil Naturally Occurring Radioactive Materials (Oil NORM) in this paper refers to waste coming from oil exploration. Oil NORM has called much attention during the last decades, mostly because it is not possible to determine its primary source due to the actual absence of regulatory control mechanism. There is no efficient regulatory tool which allows determining the origin of such NORM wastes even among those facilities under regulatory control. This fact may encourage non-authorized radioactive material transportation, smuggling and terrorism. The aim of this project is to provide a geochemical signature for each oil NORM waste using its naturally occurring isotopic composition to identify its origin. The here proposed method is a specific geochemical modeling of oil sludge NORM samples which are analyzed for radioisotopes normally present in oil pipes, such as {sup 228}Ac, {sup 214}Bi and {sup 214}Pb. The activity ratios are plotted in scatter diagrams. This method was successfully tested with data of different sources obtained from analysis reports from the Campos Basin/Brazil and from literature. (author)

Multi-elemental analysis of aqueous geochemical samples by quadrupole inductively coupled plasma-mass spectrometry (ICP-MS)

Science.gov (United States)

Wolf, Ruth E.; Adams, Monique

2015-01-01

Typically, quadrupole inductively coupled plasma-mass spectrometry (ICP-MS) is used to determine as many as 57 major, minor, and trace elements in aqueous geochemical samples, including natural surface water and groundwater, acid mine drainage water, and extracts or leachates from geological samples. The sample solution is aspirated into the inductively coupled plasma (ICP) which is an electrodeless discharge of ionized argon gas at a temperature of approximately 6,000 degrees Celsius. The elements in the sample solution are subsequently volatilized, atomized, and ionized by the ICP. The ions generated are then focused and introduced into a quadrupole mass filter which only allows one mass to reach the detector at a given moment in time. As the settings of the mass analyzer change, subsequent masses are allowed to impact the detector. Although the typical quadrupole ICP-MS system is a sequential scanning instrument (determining each mass separately), the scan speed of modern instruments is on the order of several thousand masses per second. Consequently, typical total sample analysis times of 2–3 minutes are readily achievable for up to 57 elements.

A geochemical atlas of North Carolina, USA

Science.gov (United States)

Reid, J.C.

1993-01-01

A geochemical atlas of North Carolina, U.S.A., was prepared using National Uranium Resource Evaluation (NURE) stream-sediment data. Before termination of the NURE program, sampling of nearly the entire state (48,666 square miles of land area) was completed and geochemical analyses were obtained. The NURE data are applicable to mineral exploration, agriculture, waste disposal siting issues, health, and environmental studies. Applications in state government include resource surveys to assist mineral exploration by identifying geochemical anomalies and areas of mineralization. Agriculture seeks to identify areas with favorable (or unfavorable) conditions for plant growth, disease, and crop productivity. Trace elements such as cobalt, copper, chromium, iron, manganese, zinc, and molybdenum must be present within narrow ranges in soils for optimum growth and productivity. Trace elements as a contributing factor to disease are of concern to health professionals. Industry can use pH and conductivity data for water samples to site facilities which require specific water quality. The North Carolina NURE database consists of stream-sediment samples, groundwater samples, and stream-water analyses. The statewide database consists of 6,744 stream-sediment sites, 5,778 groundwater sample sites, and 295 stream-water sites. Neutron activation analyses were provided for U, Br, Cl, F, Mn, Na, Al, V, Dy in groundwater and stream water, and for U, Th, Hf, Ce, Fe, Mn, Na, Sc, Ti, V, Al, Dy, Eu, La, Sm, Yb, and Lu in stream sediments. Supplemental analyses by other techniques were reported on U (extractable), Ag, As, Ba, Be, Ca, Co, Cr, Cu, K, Li, Mg, Mo, Nb, Ni, P, Pb, Se, Sn, Sr, W, Y, and Zn for 4,619 stream-sediment samples. A small subset of 334 stream samples was analyzed for gold. The goal of the atlas was to make available the statewide NURE data with minimal interpretation to enable prospective users to modify and manipulate the data for their end use. The atlas provides only

The Geochemical Databases GEOROC and GeoReM - What's New?

Science.gov (United States)

Sarbas, B.; Jochum, K. P.; Nohl, U.; Weis, U.

2017-12-01

The geochemical databases GEOROC (http: georoc.mpch-mainz.gwdg.de) and GeoReM (http: georem.mpch-mainz.gwdg.de) are maintained by the Max Planck Institute for Chemistry in Mainz, Germany. Both online databases became crucial tools for geoscientists from different research areas. They are regularly upgraded by new tools and new data from recent publications obtained from a wide range of international journals. GEOROC is a collection of published analyses of volcanic rocks and mantle xenoliths. Since recently, data for plutonic rocks are added. The analyses include major and trace element concentrations, radiogenic and non-radiogenic isotope ratios as well as analytical ages for whole rocks, glasses, minerals and inclusions. Samples come from eleven geological settings and span the whole geological age scale from Archean to Recent. Metadata include, among others, geographic location, rock class and rock type, geological age, degree of alteration, analytical method, laboratory, and reference. The GEOROC web page allows selection of samples by geological setting, geography, chemical criteria, rock or sample name, and bibliographic criteria. In addition, it provides a large number of precompiled files for individual locations, minerals and rock classes. GeoReM is a database collecting information about reference materials of geological and environmental interest, such as rock powders, synthetic and natural glasses as well as mineral, isotopic, biological, river water and seawater reference materials. It contains published data and compilation values (major and trace element concentrations and mass fractions, radiogenic and stable isotope ratios). Metadata comprise, among others, uncertainty, analytical method and laboratory. Reference materials are important for calibration, method validation, quality control and to establish metrological traceability. GeoReM offers six different search strategies: samples or materials (published values), samples (GeoReM preferred

Geochemical Data Package for Performance Assessment Calculations Related to the Savannah River Site

Energy Technology Data Exchange (ETDEWEB)

Kaplan, Daniel I. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2016-07-22

The Savannah River Site (SRS) disposes of low-level radioactive waste (LLW) and stabilizes high-level radioactive waste (HLW) tanks in the subsurface environment. Calculations used to establish the radiological limits of these facilities are referred to as Performance Assessments (PA), Special Analyses (SA), and Composite Analyses (CA). The objective of this document is to revise existing geochemical input values used for these calculations. This work builds on earlier compilations of geochemical data (2007, 2010), referred to a geochemical data packages. This work is being conducted as part of the on-going maintenance program of the SRS PA programs that periodically updates calculations and data packages when new information becomes available. Because application of values without full understanding of their original purpose may lead to misuse, this document also provides the geochemical conceptual model, the approach used for selecting the values, the justification for selecting data, and the assumptions made to assure that the conceptual and numerical geochemical models are reasonably conservative (i.e., bias the recommended input values to reflect conditions that will tend to predict the maximum risk to the hypothetical recipient). This document provides 1088 input parameters for geochemical parameters describing transport processes for 64 elements (>740 radioisotopes) potentially occurring within eight subsurface disposal or tank closure areas: Slit Trenches (ST), Engineered Trenches (ET), Low Activity Waste Vault (LAWV), Intermediate Level (ILV) Vaults, Naval Reactor Component Disposal Areas (NRCDA), Components-in-Grout (CIG) Trenches, Saltstone Facility, and Closed Liquid Waste Tanks. The geochemical parameters described here are the distribution coefficient, Kd value, apparent solubility concentration, k_s value, and the cementitious leachate impact factor.

Regional geochemical baselines for Portuguese shelf sediments

International Nuclear Information System (INIS)

Mil-Homens, M.; Stevens, R.L.; Cato, I.; Abrantes, F.

2007-01-01

Metal concentrations (Al, Cr, Cu, Ni, Pb and Zn) from the DGM-INETI archive data set have been examined for sediments collected during the 1970s from 267 sites on the Portuguese shelf. Due to the differences in the oceanographic and sedimentological settings between western and Algarve coasts, the archive data set is split in two segments. For both shelf segments, regional geochemical baselines (RGB) are defined using aluminium as a reference element. Seabed samples recovered in 2002 from four distinct areas of the Portuguese shelf are superimposed on these models to identify and compare possible metal enrichments relative to the natural distribution. Metal enrichments associated with anthropogenic influences are identified in three samples collected nearby the Tejo River and are characterised by the highest enrichment factors (EF; EF Pb Zn < 4). EF values close to 1 suggest a largely natural origin for metal distributions in sediments from the other areas included in the study. - Background metal concentrations and their natural variability must be established before assessing anthropogenic impacts

Baseline geochemical data for stream sediment and surface water samples from Panther Creek, the Middle Fork of the Salmon River, and the Main Salmon River from North Fork to Corn Creek, collected prior to the severe wildfires of 2000 in central Idaho

Science.gov (United States)

Eppinger, Robert G.; Briggs, Paul H.; Brown, Zoe Ann; Crock, James G.; Meier, Allen; Theodorakos, Peter M.; Wilson, Stephen A.

2001-01-01

In 1996, the U.S. Geological Survey conducted a reconnaissance baseline geochemical study in central Idaho. The purpose of the baseline study was to establish a 'geochemical snapshot' of the area, as a datum for monitoring future change in the geochemical landscape, whether natural or human-induced. This report presents the methology, analytical results, and sample descriptions for water, sediment, and heavy-mineral concentrate samples collected during this geochemical investigation. In the summer of 2000, the Clear Creek, Little Pistol, and Shellrock wildfires swept across much of the area that was sampled. Thus, these data represent a pre-fire baseline geochemical dataset. A 2001 post- fire study is planned and will involve re-sampling of the pre-fire baseline sites, to allow for pre- and post-fire comparison.

Determination of toxic trace elements in body fluid reference samples

International Nuclear Information System (INIS)

Gills, T.E.; McClendon, L.T.; Maienthal, E.J.; Becker, D.A.; Durst, R.A.; LaFleur, P.D.

1974-01-01

The measurement of elemental concentration in body fluids has been widely used to give indication of exposures to certain toxic materials and/or a measure of body burden. To understand fully the toxicological effect of these trace elements on our physiological system, meaningful analytical data are required along with accurate standards or reference samples. The National Bureau of Standards has prepared for the National Institute for Occupational Safety and Health (NIOSH) a number of reference samples containing selected toxic trace elements in body fluids. The reference samples produced include mercury in urine at three concentration levels, five elements (Se, Cu, As, Ni and Cr) in freeze-dried urine at two levels, fluorine in freeze-dried urine at two levels and lead in blood at two concentration levels. These reference samples have been found to be extremely useful for the evaluation of field and laboratory analytical methods for the analysis of toxic trace elements. In particular the use of at least two calibration points (i.e., ''normal'' and ''elevated'' levels) for a given matrix provides a more positive calibration for most analytical techniques over the range of interest for occupational toxicological levels of exposure. (U.S.)

Overview of geochemical modeling needs for nuclear waste management

International Nuclear Information System (INIS)

Isherwood, D.J.; Wolery, T.J.

1985-01-01

Geochemical modeling needs for nuclear waste management are discussed with an emphasis on data base development and computer code. Other areas for future research include: precipitation kinetics, fixed fugacity, sorption, glasslt. slashwater interactions, redox disequilibrium and kinetics, radiolysis, solid solutions, and isotopic fractionation. 15 references

Estimation of reference intervals from small samples: an example using canine plasma creatinine.

Science.gov (United States)

Geffré, A; Braun, J P; Trumel, C; Concordet, D

2009-12-01

According to international recommendations, reference intervals should be determined from at least 120 reference individuals, which often are impossible to achieve in veterinary clinical pathology, especially for wild animals. When only a small number of reference subjects is available, the possible bias cannot be known and the normality of the distribution cannot be evaluated. A comparison of reference intervals estimated by different methods could be helpful. The purpose of this study was to compare reference limits determined from a large set of canine plasma creatinine reference values, and large subsets of this data, with estimates obtained from small samples selected randomly. Twenty sets each of 120 and 27 samples were randomly selected from a set of 1439 plasma creatinine results obtained from healthy dogs in another study. Reference intervals for the whole sample and for the large samples were determined by a nonparametric method. The estimated reference limits for the small samples were minimum and maximum, mean +/- 2 SD of native and Box-Cox-transformed values, 2.5th and 97.5th percentiles by a robust method on native and Box-Cox-transformed values, and estimates from diagrams of cumulative distribution functions. The whole sample had a heavily skewed distribution, which approached Gaussian after Box-Cox transformation. The reference limits estimated from small samples were highly variable. The closest estimates to the 1439-result reference interval for 27-result subsamples were obtained by both parametric and robust methods after Box-Cox transformation but were grossly erroneous in some cases. For small samples, it is recommended that all values be reported graphically in a dot plot or histogram and that estimates of the reference limits be compared using different methods.

Development of standard reference samples for diffractometry

International Nuclear Information System (INIS)

Galvao, Antonio de Sant'Ana

2011-01-01

In this work, samples of standard reference materials for diffractometry of polycrystals were developed. High-purity materials were submitted to mechanical and thermal treatments in order to present the adequate properties to be used as high-quality standard reference materials for powder diffraction, comparable to the internationally recognized produced by the USA National Institute of Standards and Technology NIST, but at lower costs. The characterization of the standard materials was performed by measurements in conventional X-ray diffraction diffractometers, high resolution neutron diffraction and high-resolution synchrotron diffraction. The lattice parameters were calculated by extrapolation of the values obtained from each X-ray reflection against cos 2 θ by the Least-Squares Method. The adjustments were compared to the values obtained by the Rietveld Method, using program GSAS. The materials thus obtained were the α-alumina, yttrium oxide, silicon, cerium oxide, lanthanum hexaboride and lithium fluoride. The standard reference materials produced present quality similar or, in some cases, superior to the standard reference materials produced and commercialized by the NIST. (author)

Manual hierarchical clustering of regional geochemical data using a Bayesian finite mixture model

International Nuclear Information System (INIS)

Ellefsen, Karl J.; Smith, David B.

2016-01-01

Interpretation of regional scale, multivariate geochemical data is aided by a statistical technique called “clustering.” We investigate a particular clustering procedure by applying it to geochemical data collected in the State of Colorado, United States of America. The clustering procedure partitions the field samples for the entire survey area into two clusters. The field samples in each cluster are partitioned again to create two subclusters, and so on. This manual procedure generates a hierarchy of clusters, and the different levels of the hierarchy show geochemical and geological processes occurring at different spatial scales. Although there are many different clustering methods, we use Bayesian finite mixture modeling with two probability distributions, which yields two clusters. The model parameters are estimated with Hamiltonian Monte Carlo sampling of the posterior probability density function, which usually has multiple modes. Each mode has its own set of model parameters; each set is checked to ensure that it is consistent both with the data and with independent geologic knowledge. The set of model parameters that is most consistent with the independent geologic knowledge is selected for detailed interpretation and partitioning of the field samples. - Highlights: • We evaluate a clustering procedure by applying it to geochemical data. • The procedure generates a hierarchy of clusters. • Different levels of the hierarchy show geochemical processes at different spatial scales. • The clustering method is Bayesian finite mixture modeling. • Model parameters are estimated with Hamiltonian Monte Carlo sampling.

Reference waste form, basalts, and ground water systems for waste interaction studies

Energy Technology Data Exchange (ETDEWEB)

Deju, R.A.; Ledgerwood, R.K.; Long, P.E.

1978-09-01

This report summarizes the type of waste form, basalt, and ground water compositions to be used in theoretical and experimental models of the geochemical environment to be simulated in studying a typical basalt repository. Waste forms to be used in the experiments include, and are limited to, glass, supercalcine, and spent unreprocessed fuel. Reference basalts selected for study include the Pomona member and the Umtanum Unit, Shwana Member, of the Columbia River Basalt Group. In addition, a sample of the Basalt International Geochemical Standard (BCR-1) will be used for cross-comparison purposes. The representative water to be used is of a sodium bicarbonate composition as determined from results of analyses of deep ground waters underlying the Hanford Site. 12 figures, 13 tables.

Reference waste form, basalts, and ground water systems for waste interaction studies

International Nuclear Information System (INIS)

Deju, R.A.; Ledgerwood, R.K.; Long, P.E.

1978-09-01

This report summarizes the type of waste form, basalt, and ground water compositions to be used in theoretical and experimental models of the geochemical environment to be simulated in studying a typical basalt repository. Waste forms to be used in the experiments include, and are limited to, glass, supercalcine, and spent unreprocessed fuel. Reference basalts selected for study include the Pomona member and the Umtanum Unit, Shwana Member, of the Columbia River Basalt Group. In addition, a sample of the Basalt International Geochemical Standard (BCR-1) will be used for cross-comparison purposes. The representative water to be used is of a sodium bicarbonate composition as determined from results of analyses of deep ground waters underlying the Hanford Site. 12 figures, 13 tables

Initial geochemical characteristics of fluid fine tailings in an oil sands end pit lake

Energy Technology Data Exchange (ETDEWEB)

Dompierre, Kathryn A. [Department of Civil and Geological Engineering, University of Saskatchewan, Saskatoon, Saskatchewan, Canada S7N 5A9 (Canada); Lindsay, Matthew B.J., E-mail: matt.lindsay@usask.ca [Department of Geological Sciences, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2 (Canada); Cruz-Hernández, Pablo [Department of Geology, University of Huelva, Campus ‘El Carmen’, E-21071 Huelva (Spain); Halferdahl, Geoffrey M. [Environmental Research and Development, Syncrude Canada Limited, Edmonton, Alberta T6N 1H4 (Canada)

2016-06-15

Geochemical characteristics of fluid fine tailings (FFT) were examined in Base Mine Lake (BML), which is the first full-scale demonstration oil sands end pit lake (EPL) in northern Alberta, Canada. Approximately 186 Mm{sup 3} of FFT was deposited between 1994 and 2012, before BML was established on December 31, 2012. Bulk FFT samples (n = 588) were collected in July and August 2013 at various depths at 15 sampling sites. Temperature, solid content, electrical conductivity (EC), pH, Eh and alkalinity were measured for all samples. Detailed geochemical analyses were performed on a subset of samples (n = 284). Pore-water pH decreased with depth by approximately 0.5 within the upper 10 m of the FFT. Major pore-water constituents included Na (880 ± 96 mg L{sup −1}) and Cl (560 ± 95 mg L{sup −1}); Ca (19 ± 4.1 mg L{sup −1}), Mg (11 ± 2.0 mg L{sup −1}), K (16 ± 2.3 mg L{sup −1}) and NH{sub 3} (9.9 ± 4.7 mg L{sup −1}) were consistently observed. Iron and Mn concentrations were low within FFT pore water, whereas SO{sub 4} concentrations decreased sharply across the FFT–water interface. Geochemical modeling indicated that FeS{sub (s)} precipitation was favoured under SO{sub 4}-reducing conditions. Pore water was also under-saturated with respect to gypsum [CaSO{sub 4}·2H{sub 2}O], and near saturation with respect to calcite [CaCO{sub 3}], dolomite [CaMg(CO{sub 3}){sub 2}] and siderite [FeCO{sub 3}]. X-ray diffraction (XRD) suggested that carbonate-mineral dissolution largely depleted calcite and dolomite. X-ray absorption near edge structure (XANES) spectroscopy revealed the presence of FeS{sub (s)}, pyrite [FeS{sub 2}], and siderite. Carbonate-mineral dissolution and secondary mineral precipitation have likely contributed to FFT dewatering and settlement. However, the long-term importance of these processes within EPLs remains unknown. These results provide a reference for assessing the long-term geochemical evolution of oil sands EPLs, and offer

Geochemical Parameters Required from the SKB Site Characterisation Programme

International Nuclear Information System (INIS)

Bath, Adrian

2002-01-01

SKB has described its approach to site characterisation in a number of Technical Reports. One of the scientific topics in which specific information requirements and priorities are set out is geochemistry. This report for SKI examines critically whether the geochemical parameters identified in the SKB programme documents will be adequate for safety and regulatory requirements. It also examines some of the details of parameter requirements and interpretation tools that will be necessary to convert site investigation data into knowledge about chemical conditions and groundwater movements. The SKB strategy for geochemical data focuses on a small number of 'suitability indicators', primarily dissolved oxygen, pH and salinity. Their parameter requirements aim to assess those primary characteristics, as well as to acquire a wider range of data that will support those assessments and provide a broader understanding of candidate areas. An initial observation in this review that, though it is a primary suitability indicator, dissolved oxygen apparently will not be measured and instead will be inferred from other redox indicators. This raises a number of issues about sampling and monitoring measures, analytical data reliability and sensitivity, and the degree of confidence in geochemical understanding. A geochemical programme involves reconnaissance by desk study and acquisition of new data at levels of details that are appropriate to the stage of site investigations. As early as possible, a conceptual model of a candidate area should help to define the objectives of geochemical measurements on both rock and groundwater samples. It is recommended that parameters requirements should be defined and considered not only in terms of isolated measurements but more in terms of addressing broader objectives that relate to safety and also to geoscientific understanding. The safety priorities remain (e.g. dissolved oxygen) but will then be supported by an understanding of processes

Geochemical Parameters Required from the SKB Site Characterisation Programme

Energy Technology Data Exchange (ETDEWEB)

Bath, Adrian [Intellisci Ltd., Loughborough (United Kingdom)

2002-01-01

SKB has described its approach to site characterisation in a number of Technical Reports. One of the scientific topics in which specific information requirements and priorities are set out is geochemistry. This report for SKI examines critically whether the geochemical parameters identified in the SKB programme documents will be adequate for safety and regulatory requirements. It also examines some of the details of parameter requirements and interpretation tools that will be necessary to convert site investigation data into knowledge about chemical conditions and groundwater movements. The SKB strategy for geochemical data focuses on a small number of 'suitability indicators', primarily dissolved oxygen, pH and salinity. Their parameter requirements aim to assess those primary characteristics, as well as to acquire a wider range of data that will support those assessments and provide a broader understanding of candidate areas. An initial observation in this review that, though it is a primary suitability indicator, dissolved oxygen apparently will not be measured and instead will be inferred from other redox indicators. This raises a number of issues about sampling and monitoring measures, analytical data reliability and sensitivity, and the degree of confidence in geochemical understanding. A geochemical programme involves reconnaissance by desk study and acquisition of new data at levels of details that are appropriate to the stage of site investigations. As early as possible, a conceptual model of a candidate area should help to define the objectives of geochemical measurements on both rock and groundwater samples. It is recommended that parameters requirements should be defined and considered not only in terms of isolated measurements but more in terms of addressing broader objectives that relate to safety and also to geoscientific understanding. The safety priorities remain (e.g. dissolved oxygen) but will then be supported by an understanding of

Geochemical characteristics of peat from two raised bogs of Germany

Science.gov (United States)

Mezhibor, A. M.

2016-11-01

Peat has a wide range of applications in different spheres of human activity, and this is a reason for a comprehensive study. This research represents the results of an ICP-MS study of moss and peat samples from two raised bogs of Germany. Because of the wide use of sphagnum moss and peat, determining their geochemical characteristics is an important issue. According to the results obtained, we can resume that the moss samples from Germany are rich in Cu, As, Y, Zr, Nb, and REE. The geochemical composition of the bogs reflects the regional environmental features and anthropogenic influence.

Mineralogical, geochemical and radiological characterisation of Selmo Formation in Batman area, Turkey.

Science.gov (United States)

Isik, Umit; Damla, Nevzat; Akkoca, Dicle Bal; Cevik, Uğur

2012-06-01

This work deals with the mineralogical, geochemical and radiological characterisations of Selmo Formation in Batman neighbourhood. The upper Miocene-Pliocene Selmo Formation is common in the centre of Batman and composed of carbonated sandy claystones and silty-sandy stone lenses. The common whole minerals of the samples are quartz, feldspars, calcite and dolomite. The clay minerals are smectite, illite, chlorite and mixed-layer clay (chlorite-smectite). The geochemical mean values of the samples are 51.7% SiO(2); 12.6% Al(2)O(3); 6.2% Fe(2)O(3); 3.6% MgO; 6.3% CaO; 1.1% Na(2)O; 1.7% K(2)O; 0.8% TiO(2); 0.2% P(2)O(5); 0.1% MnO; and 0.03% Cr(2)O(3). In addition, baseline maps for the concentrations of each radionuclide, the radium equivalent activity and the outdoor gamma dose rate distributions have been plotted for the study area. The mean activity concentrations of (226)Ra, (232)Th, (40)K and (137)Cs were determined to be 32, 24, 210 and 9 Bq kg(-1), respectively. The assessments of the radiological hazard indices, such as radium equivalent activity, absorbed dose rate in air, annual effective dose equivalent, excess lifetime cancer risk, external hazard index and internal hazard index, were calculated and compared with the internationally accepted reference values. This study shows that the concentrations of radioactivities in the measured samples were within the recommended safety limits and did not pose to be any significant source of radiation hazard.

Orientation geochemical survey for uranium exploration using 230Th

International Nuclear Information System (INIS)

Xia Dingliang.

1985-01-01

The distribution of 230 Th in soils, rocks and ores and its relationship with respect to uranium ore formation are discussed for its possible use in geochemical exploration for U. 230 Th, U and Ra, being members of the same decay series, are different in their geochemical behavior upon which the study is orientated. Twenty uranium deposits and occurrences located in western and southern Hunan province are tested. Geochemical data obtained are comprehensively correlated. It is suggested that 230 Th is useful not only in U-Ra disequilibrium study but also in understanding the geochemical evolution of U ores. The data aid to interpret the genesis of uranium deposits and to assess the radioactive anomalies and uranium-bearing zones. Therefore, it can be adopted as a tool for searching in deep-buried uranium ores. The field procedure is rather simple and flexible to meet any geological environment. It is easy to read out and is less influnced by any kind of interference. In case of disequilibrium caused by oxidation and reduction during the period of ore formation it still gives good indication compared with that of radiometry, radonmetry and geochemical sampling for U

Geochemical characterization of Parana Basin volcanic rocks: petrogenetic implications

International Nuclear Information System (INIS)

Marques, L.S.

1988-01-01

A detailed study of the geochemical characteristics of Parana Basin volcanic rocks is presented. The results are based on the analyses of major and trace elements of 158 samples. Ninety three of these volcanic samples belong to 8 flow sequences from Rio Grande do Sul and Santa Catarina States. The remaining sixty five samples are distributed over the entire basin. In order to study the influence of crustal contamination processes in changing chemical characteristics of the volcanic rocks, 47 samples representative of the crystalline basement of the southern and southeastern Parana Basin were also analysed. Several petrogenetic models were tested to explain the compocional variability of the volcanic rocks, in particular those of southern region. The results obtained sugest an assimilation-fractional crystallization process as viable to explain the differences of both the chemical characteristics and Sr isotope initial ratios observed in basic and intermediate rocks. A model involving melting processes of basic material, trapped at the base of the crust, with composition similar to low and high TiO 2 basalts appears to be a possibility to originate the Palmas and Chapeco acid melts, respectively. The study of ''uncontaminated'' or poorly contaminated low TiO 2 basic rocks from the southern, central and northern regions shows the existence of significant differences in the geochemical charactetistics according to their geographical occurrence. A similar geochemical diversity is also observed in high TiO 2 basalts and Chapeco volcanics. Differences in incompatible element ratios between low and high TiO 2 ''uncontaminated'' or poorly contaminated basalts suggest that they could have been produced by different degrees of melting in a garnet peridotite source. Geochemical and isotopic (Sr and Nd) data also support the view that basalts from northern and southern regions of Parana Basin originated from mantle source with different composition. (author) [pt

Review of geochemical measurement techniques for a nuclear waste repository in bedded salt

International Nuclear Information System (INIS)

Knauss, K.G.; Steinborn, T.L.

1980-01-01

A broad, general review is presented of geochemical measurement techniques that can provide data necessary for site selection and repository effectiveness assessment for a radioactive waste repository in bedded salt. The available measurement techniques are organized according to the parameter measured. The list of geochemical parameters include all those measurable geochemical properties of a sample whole values determine the geochemical characteristics or behavior of the system. For each technique, remarks are made pertaining to the operating principles of the measurement instrument and the purpose for which the technique is used. Attention is drawn to areas where further research and development are needed

Semi-detailed uranium geochemical survey in Northwestern Samar (27 March 1979 - 4 July 1979)

International Nuclear Information System (INIS)

Santos, G. Jr.; Ogena, M.; Tauli, G.

1980-04-01

A uranium geochemical survey was conducted to delineate in detail the uranium prospective area(s) in northwestern Samar. A total of 805 stream sediments and 1.115 water samples were obtained from the target areas from uranium analysis. Geochemical anomalies were indicated in San Isidro and Mauo. Geochemical correlations between uranium and trace elements (Pb, Ag, Ni, Cu, Co, Zn and Mn) were generally poor. (ELC)

Quest to identify geochemical risk factors associated with chronic kidney disease of unknown etiology (CKDu) in an endemic region of Sri Lanka-a multimedia laboratory analysis of biological, food, and environmental samples.

Science.gov (United States)

Levine, Keith E; Redmon, Jennifer Hoponick; Elledge, Myles F; Wanigasuriya, Kamani P; Smith, Kristin; Munoz, Breda; Waduge, Vajira A; Periris-John, Roshini J; Sathiakumar, Nalini; Harrington, James M; Womack, Donna S; Wickremasinghe, Rajitha

2016-10-01

The emergence of a new form of chronic kidney disease of unknown etiology (CKDu) in Sri Lanka's North Central Province (NCP) has become a catastrophic health crisis. CKDu is characterized as slowly progressing, irreversible, and asymptomatic until late stages and, importantly, not attributed to diabetes, hypertension, or other known risk factors. It is postulated that the etiology of CKDu is multifactorial, involving genetic predisposition, nutritional and dehydration status, exposure to one or more environmental nephrotoxins, and lifestyle factors. The objective of this limited geochemical laboratory analysis was to determine the concentration of a suite of heavy metals and trace element nutrients in biological samples (human whole blood and hair) and environmental samples (drinking water, rice, soil, and freshwater fish) collected from two towns within the endemic NCP region in 2012 and 2013. This broad panel, metallomics/mineralomics approach was used to shed light on potential geochemical risk factors associated with CKDu. Based on prior literature documentation of potential nephrotoxins that may play a role in the genesis and progression of CKDu, heavy metals and fluoride were selected for analysis. The geochemical concentrations in biological and environmental media areas were quantified. Basic statistical measurements were subsequently used to compare media against applicable benchmark values, such as US soil screening levels. Cadmium, lead, and mercury were detected at concentrations exceeding US reference values in many of the biological samples, suggesting that study participants are subjected to chronic, low-level exposure to these elements. Within the limited number of environmental media samples, arsenic was determined to exceed initial risk screening and background concentration values in soil, while data collected from drinking water samples reflected the unique hydrogeochemistry of the region, including the prevalence of hard or very hard water, and

Statistical characterization of a large geochemical database and effect of sample size

Science.gov (United States)

Zhang, C.; Manheim, F.T.; Hinde, J.; Grossman, J.N.

2005-01-01

The authors investigated statistical distributions for concentrations of chemical elements from the National Geochemical Survey (NGS) database of the U.S. Geological Survey. At the time of this study, the NGS data set encompasses 48,544 stream sediment and soil samples from the conterminous United States analyzed by ICP-AES following a 4-acid near-total digestion. This report includes 27 elements: Al, Ca, Fe, K, Mg, Na, P, Ti, Ba, Ce, Co, Cr, Cu, Ga, La, Li, Mn, Nb, Nd, Ni, Pb, Sc, Sr, Th, V, Y and Zn. The goal and challenge for the statistical overview was to delineate chemical distributions in a complex, heterogeneous data set spanning a large geographic range (the conterminous United States), and many different geological provinces and rock types. After declustering to create a uniform spatial sample distribution with 16,511 samples, histograms and quantile-quantile (Q-Q) plots were employed to delineate subpopulations that have coherent chemical and mineral affinities. Probability groupings are discerned by changes in slope (kinks) on the plots. Major rock-forming elements, e.g., Al, Ca, K and Na, tend to display linear segments on normal Q-Q plots. These segments can commonly be linked to petrologic or mineralogical associations. For example, linear segments on K and Na plots reflect dilution of clay minerals by quartz sand (low in K and Na). Minor and trace element relationships are best displayed on lognormal Q-Q plots. These sensitively reflect discrete relationships in subpopulations within the wide range of the data. For example, small but distinctly log-linear subpopulations for Pb, Cu, Zn and Ag are interpreted to represent ore-grade enrichment of naturally occurring minerals such as sulfides. None of the 27 chemical elements could pass the test for either normal or lognormal distribution on the declustered data set. Part of the reasons relate to the presence of mixtures of subpopulations and outliers. Random samples of the data set with successively

A geostatistical method applied to the geochemical study of the Chichinautzin Volcanic Field in Mexico

Science.gov (United States)

Robidoux, P.; Roberge, J.; Urbina Oviedo, C. A.

2011-12-01

The origin of magmatism and the role of the subducted Coco's Plate in the Chichinautzin volcanic field (CVF), Mexico is still a subject of debate. It has been established that mafic magmas of alkali type (subduction) and calc-alkali type (OIB) are produced in the CVF and both groups cannot be related by simple fractional crystallization. Therefore, many geochemical studies have been done, and many models have been proposed. The main goal of the work present here is to provide a new tool for the visualization and interpretation of geochemical data using geostatistics and geospatial analysis techniques. It contains a complete geodatabase built from referred samples over the 2500 km2 area of CVF and its neighbour stratovolcanoes (Popocatepetl, Iztaccihuatl and Nevado de Toluca). From this database, map of different geochemical markers were done to visualise geochemical signature in a geographical manner, to test the statistic distribution with a cartographic technique and highlight any spatial correlations. The distribution and regionalization of the geochemical signatures can be viewed in a two-dimensional space using a specific spatial analysis tools from a Geographic Information System (GIS). The model of spatial distribution is tested with Linear Decrease (LD) and Inverse Distance Weight (IDW) interpolation technique because they best represent the geostatistical characteristics of the geodatabase. We found that ratio of Ba/Nb, Nb/Ta, Th/Nb show first order tendency, which means visible spatial variation over a large scale area. Monogenetic volcanoes in the center of the CVF have distinct values compare to those of the Popocatepetl-Iztaccihuatl polygenetic complex which are spatially well defined. Inside the Valley of Mexico, a large quantity of monogenetic cone in the eastern portion of CVF has ratios similar to the Iztaccihuatl and Popocatepetl complex. Other ratios like alkalis vs SiO2, V/Ti, La/Yb, Zr/Y show different spatial tendencies. In that case, second

Drowning in Geochemical Data: The Good, the bad, and the Ugly

Science.gov (United States)

Hofmann, A. W.; Goldstein, S. L.

2008-12-01

Geochemical databases are placing unprecedented amounts of geochemical data at the fingertips of professionals and students. How these data are being used is taking an increasingly important role in shaping our thinking about the Earth. Databases have helped to expose (and eventually kill?) some long- cherished myths, such as the idea of the well-homogenized upper-mantle reservoir, and and they have made geochemical data accessible to geophysicists and enabled them to look at geochemistry with fresh eyes, leading to genuinely new insights. Yet, their very accessibility also makes them "dangerous tools" in the hands of the inexperienced. Statistical treatment of masses of geochemical data without, or with excessive, filtering can yield all sorts of "answers" we would probably be better off without. Data that are severely flawed (due to alteration or poor analytical quality, errors in published data, or errors during data entry) might not be easily identified by, say, a geodynamicist. Other dangers stem from overrepresentation of over-sampled locations and the general, but faulty, assumption of random sampling of the Earth. We will show examples where raw downloads of data from databases without extensive screening can yield data collections where the garbage swamps the useful information. We will also show impressive but meaningless correlations, e.g. upper-mantle temperature versus atmospheric temperature. The lesson is that screening is necessary. On the other hand, sound database compilations now demonstrate that average incompatible-element concentrations in global MORB are two to five times higher than published estimates. This fundamentally changes 30-year-old geochemical mass balance estimates of the mantle. OIBs are fundamentally similar to MORBs but are isotopically shifted, on average, to more "enriched" values. Mantle geochemistry is now fully consistent with dynamic models of "whole-mantle" circulation, with the likely exception of a relatively small

Geochemical sensitivity analysis: Identification of important geochemical parameters for performance assessment studies

International Nuclear Information System (INIS)

Siegel, M.; Guzowski, R.; Rechard, R.; Erickson, K.

1986-01-01

The EPA Standard for geologic disposal of high level waste requires demonstration that the cumulative discharge of individual radioisotopes over a 10,000 year period at points 5 kilometers from the engineered barrier system will not exceed the limits prescribed in 40 CFR Part 191. The roles of the waste package, engineered facility, hydrogeology and geochemical processes in limiting radionuclide releases all must be considered in calculations designed to assess compliance of candidate repositories with the EPA Standard. In this talk, they will discuss the geochemical requirements of calculations used in these compliance assessments. In addition, they will describe the complementary roles of (1) simple models designed to bound the radionuclide discharge over the widest reasonable range of geochemical conditions and scenarios and (2) detailed geochemical models which can provide insights into the actual behavior of the radionuclides in the ground water. Finally, they will discuss development of sensitivity/uncertainty techniques designed to identify important site-specific geochemical parameters and processes using data from a basalt formation

Research needs for coupling geochemical and flow models for nuclear waste isolation

International Nuclear Information System (INIS)

Pearson, F.J. Jr.

1985-01-01

An overview of coupling geochemical and flow models for nuclear waste disposal is presented and research needs are discussed. Topics considered include, chemical effects on flow, fluid and rock properties, pressure effects, water-rock equilibria, and reaction kinetics. 25 references

Geochemical orientation for mineral exploration in the Hashemite Kingdom of Jordan

Science.gov (United States)

Overstreet, W.C.; Grimes, D.J.; Seitz, J.F.

1982-01-01

This report is a supplement to previous accounts of geochemical exploration conducted in the Hashemite Kingdom of Jordan by the Natural Resources Authority of the Royal Government of Jordan and the U.S. Geological Survey. The field work on which this report is based was sponsored by the U.S. Agency for International Development, U.S. Department of State. Procedures used in collecting various kinds of rocks, ores, slags, eluvial and alluvial sediments, heavy-mineral concentrates, and organic materials for use as geochemical sample media are summarized, as are the laboratory procedures followed for the analysis of these sample materials by semiquantitative spectrographic, atomic absorption, fluorometric, and X-ray diffraction methods. Geochemical evaluations of the possibilities for economic mineral deposits in certain areas are presented. The results of these preliminary investigations open concepts for further use in geochemical exploration in the search for metallic mineral deposits in Jordan. Perhaps the most desirable new activity would be hydrogeochemical exploration for uranium and base metals, accompanied by interpretation of such remote-sensing data as results of airborne radiometric surveys and computer-enhanced LANDSAT imagery. For more conventional approaches to geochemical exploration, however, several fundamental problems regarding proper choice of geochemical sample media for different geologic and geographic parts of the Country must be solved before effective surveys can be made. The present results also show that such common geochemical exploration techniques as the determination of the trace-element contents of soils, plant ash, and slags have direct application also toward the resolution of several archaeological problems in Jordan. These include the relation of trace-elements chemistry of local soils to the composition of botanic remains, the trace-elements composition of slags to the technological development of the extractive metallurgy of

The geochemical profile of Mn, Co, Cu and Fe in Kerteh Mangrove Forest, Terengganu

International Nuclear Information System (INIS)

Kamaruzzaman, B.Y.; Antotina, A.; Airiza, Z.; Syalindran, S.; Ong, M.C.

2007-01-01

The geochemical profile of Kerteh mangrove sediments was analyzed for the vertical and horizontal distribution. The 100 cm core sediment sample and 15 surface sediments samples were taken from the field. The geochemical elements of Mn, Co, Cu and Fe of the sediments were analyzed. Geochemical proxy of Mn, Co, Cu and Fe were analyzed by using Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). The mean concentrations of Mn, Co, Cu and Fe for the vertical distribution were 210.18 μg/ g, 15.55 μg/ g, 43.65 μg/ g and 1.88 μg/ g respectively. on the other hand, the mean concentrations of the geochemical elements for horizontal distributions were 230.50 μg/ g for Mn, 17.57 μg/ g for Co, 43.381 μg/ g for Cu and 2.93 μg/ g for Fe. Enrichment factor and normalization was used to point out the level of pollution. The EF and the normalization indicated that all the geochemical elements were from the natural sources. (author)

Concerning evaluation of eco-geochemical background in remediation strategy

Science.gov (United States)

Korobova, Elena; Romanov, Sergey

2015-04-01

plants and animals (Kovalsky, 1974; Letunova, Kovalsky, 1978, Ermakov, 1999). Obtained zones of different eco-geochemical risk need particular strategy basing on maximum possible correspondence to the natural geochemical conditions. For example, the assessment of effects of the nuclear accident in any case needs taking into account the synergetic results of ionizing radiation in different eco-geochemical conditions. In this respect the most contaminated areas should be withdrawn from living but some spatial arable lands can be used for seeds or technical crops production. The less contaminated areas still used in agriculture need shifting to fodder or species giving non-contaminated products (e.g. oil). Wet meadows of superaqueous landscapes with a relatively high radionuclide transfer to the plants should be excluded from grazing but other areas with lower transfer to forage may be used. In all the cases the resultant remediation should achieve first of all the maximum decrease of the summary negative health effect for the residents or working personnel. References Vernadsky V.I., 1926. Biosphere. Leningrad, Nauch. khim.-tekhn. izd-vo, 147 p. Vernadsky V.I., 1960. Selected works, Vol. 5. Moscow, izd-vo AN SSSR, 422 p. Kovalsky V.V., 1974. Geochemical ecology. Moscow, Nauka, Letunova S.V., Kovalsky V.V., 1978. Geochemical ecology of microorganisms. Moscow, Nauka, 148 pp. Ermakov V.V., 1999.Geochemical ecology as a result of the system-based study of the biosphere. Problems of biogeochemistry and geochemical ecology. Transactions of the Biogeochem. Lab., 23, Moscow, Nauka, 152-182.

Geochemical investigation of UMTRAP designated site at Durango, Colorado

International Nuclear Information System (INIS)

Markos, G.; Bush, K.J.

1983-09-01

This report is the result of a geochemical investigation of the former uranium mill and tailings site at Durango, Colorado. This is one in a series of site specific geochemical investigations performed on the inactive uranium mill tailings included in the UMTRA Project. The objectives of the investigation are to characterize the geochemistry, to determine the contaminant distribution resulting from the former milling activities and tailings, and to infer chemical pathways and transport mechanisms from the contaminant distribution. The results will be used to model contaminant migration and to develop criteria for long-term containment media such as a cover system which is impermeable to contaminant migration. This report assumes a familiarity with the hydrologic conditions of the site and the geochemical concepts underlying the investigation. The results reported are based on a one-time sampling of waters and solid material from the background, the area adjacent to the site, and the site. The solid samples are water extracted remove easily soluble salts and acids extracted to remove cabonates and hydroxides. The water extracts and solid samples were analyzed for the major and trace elements. A limited number of samples were analyzed for radiological components. The report includes the methods of sampling, sample processing, analysis, and data interpretation. Three major conclusions are: (1) carbonate salts and low TDS characterize the tailings; (2) the adjacent area and raffinate ponds contain contaminants deposited by a single event of fluid permeation of the soils; and (3) the Animas River adjacent to the site has elevated gross alpha activity attributed to 226 Ra in the sediments derived from the tailings or milling activities

Soil Iodine Determination in Deccan Syneclise, India: Implications for Near Surface Geochemical Hydrocarbon Prospecting

International Nuclear Information System (INIS)

Mani, Devleena; Kumar, T. Satish; Rasheed, M. A.; Patil, D. J.; Dayal, A. M.; Rao, T. Gnaneshwar; Balaram, V.

2011-01-01

The association of iodine with organic matter in sedimentary basins is well documented. High iodine concentration in soils overlying oil and gas fields and areas with hydrocarbon microseepage has been observed and used as a geochemical exploratory tool for hydrocarbons in a few studies. In this study, we measure iodine concentration in soil samples collected from parts of Deccan Syneclise in the west central India to investigate its potential application as a geochemical indicator for hydrocarbons. The Deccan Syneclise consists of rifted depositional sites with Gondwana–Mesozoic sediments up to 3.5 km concealed under the Deccan Traps and is considered prospective for hydrocarbons. The concentration of iodine in soil samples is determined using ICP-MS and the values range between 1.1 and 19.3 ppm. High iodine values are characteristic of the northern part of the sampled region. The total organic carbon (TOC) content of the soil samples range between 0.1 and 1.3%. The TOC correlates poorly with the soil iodine (r 2 < 1), indicating a lack of association of iodine with the surficial organic matter and the possibility of interaction between the seeping hydrocarbons and soil iodine. Further, the distribution pattern of iodine compares well with two surface geochemical indicators: the adsorbed light gaseous hydrocarbons (methane through butane) and the propane-oxidizing bacterial populations in the soil. The integration of geochemical observations show the occurrence of elevated values in the northern part of the study area, which is also coincident with the presence of exposed dyke swarms that probably serve as conduits for hydrocarbon microseepage. The corroboration of iodine with existing geological, geophysical, and geochemical data suggests its efficacy as one of the potential tool in surface geochemical exploration of hydrocarbons. Our study supports Deccan Syneclise to be promising in terms of its hydrocarbon prospects.

Geochemical studies of potential source minerals of radon: case studies in Hungary

Energy Technology Data Exchange (ETDEWEB)

Rajnai, G.; Nagy-Balogh, J.; Gal-Solymos, K.; Konc, Z.; Breitner, D.; Barabas, A.; Szabo, C. [Eotvos Univ., Lithosphere Fluid Research Lab, Dept. of Petrology and Geochemistry, Budapest (Hungary); Barabas, A. [Eotvos Univ., Dept. of Geophysics, Budapest (Hungary)

2006-07-01

In Hungary, during the past decade five distinct regions have been chosen to find possible explanations of the uncommonly high radon background radiation values. The main aim of the research is to study U- and Th-bearing minerals in petrographic and geochemical characters. Besides the microscopic techniques, whole rock and in situ geochemical analytical methods were applied to determine the bulk U and Th content of the studied geological samples. We assume that some of the radon measured is related to the U and Th contents of the samples. (authors)

The role of atomic absorption spectrometry in geochemical exploration

Science.gov (United States)

Viets, J.G.; O'Leary, R. M.

1992-01-01

In this paper we briefly describe the principles of atomic absorption spectrometry (AAS) and the basic hardware components necessary to make measurements of analyte concentrations. Then we discuss a variety of methods that have been developed for the introduction of analyte atoms into the light path of the spectrophotometer. This section deals with sample digestion, elimination of interferences, and optimum production of ground-state atoms, all critical considerations when choosing an AAS method. Other critical considerations are cost, speed, simplicity, precision, and applicability of the method to the wide range of materials sampled in geochemical exploration. We cannot attempt to review all of the AAS methods developed for geological materials but instead will restrict our discussion to some of those appropriate for geochemical exploration. Our background and familiarity are reflected in the methods we discuss, and we have no doubt overlooked many good methods. Our discussion should therefore be considered a starting point in finding the right method for the problem, rather than the end of the search. Finally, we discuss the future of AAS relative to other instrumental techniques and the promising new directions for AAS in geochemical exploration. ?? 1992.

Geochemical and biogeochemical investigations in national parks [Badania geochemiczne i biogeochemiczne w parkach narodowych

Science.gov (United States)

Migaszewski, Z.M.; Lamothe, P.J.; Crock, J.G.

1998-01-01

National parks hold a key position among nature protection areas including a diversity of resources - natural, cultural, recreational and scenic. These "inviolable sanctuaries" are simultaneosuly ecologic knots and pristine nature refuges due to the presence of a number of unique plant and animal species. These species make up a natural gene bank. Classically, the level of biologic degradation in national parks is determined on the basis of qualitative and quantitative studies of plant bioindicators. Their scope encompasses phytosociologic survey the purpose of which is to identify floral assemblages with a detailed list of species to record future changes in their number. The best biomonitors of air quality are epiphytic lichens, ground mosses and conifers. Geochemical and biogeochemical investigations are widely performed in the U.S.A. to evaluate the degree of pollution in the nature protection areas including national parks (Gough et al., 1988a, b; Crock et al., 1992a, 1993; Jackson et al., 1995). Variability of element concentrations in soils and plants is assessed by using unbalanced, nested analysis-of-variance (ANOVA). It enables obtaining important statistical information with a minimum number of samples. In some cases a combined grid and barbell sampling design is applied (Jackson et al., 1995). In specific mountainous parks a method of 2-3 transects parallel to the extent of range (crest) is recommended. To determine the impact of a single pollution source on a given park, traverse sampling beginning near the emitter is used (Crock et al., 1992, 1993). The obtained results are a "snapshot" of chemical composition of soils and plant bioindicators that can be a reference for any future changes in the concentration level of chemical elements and organics. In addition, baseline element and organics composition of the media mentioned above can be compared with that obtained for geochemical atlases of polluted urban and industrial areas. Geochemical and

Stream-sediment geochemical exploration for uranium in Narigan area Central Iran

International Nuclear Information System (INIS)

Yazdi, M.; Khoshnoodi, K.; Kavand, M.; Ashteyani, A. R.

2009-01-01

Uranium deposits of Iran occur mainly in the Central Iran zone. Several uranium deposits have been discovered in this zone. The Narigan area is one of the most important uranium mineralized area in this zone. The uranium bearing sequences in this area are contained in the plutonic to volcanic rocks of Narigan which intruded to the Pre-Cambrian pyroclastics rocks. Plutonic and volcanic rocks are granite, rhyolite and volcanoclastic. Diabasic dykes have been intruded to these igneous rocks. The plutonic and volcanic rocks have been covered by Cretaceous limestones which seem to be youngest the rocks in this area. The aim of our project is to develop a regional exploration strategy for uranium in these igneous rocks. A grid-based sampling was planned following the results of the previous geochemical mapping at a scale of 1:100,000, integrated with geophysical data and alteration zones and outcrop of intrusive rocks. The following results are based on geological, and stream geochemical explorations in 1:20000 scale of this area. During this study 121 samples were collected from the stream sediments of <80 mesh for final sampling. Ten percent of the samples were used for checking laboratories errors. The samples were collected according to conventional methods from 30-40 cm depth of stream sediments. Finally, geochemical and radiometric data were combined and the results introduced 3 anomalies in the Narigan area

Geochemical Interactions and Viral-Prokaryote Relationships in Freshwater Environments

Science.gov (United States)

Kyle, J. E.; Ferris, G.

2009-05-01

Viral and prokaryotic abundances were surveyed throughout southern Ontario aquatic habitats to determine relationships with geochemical parameters in the natural environment. Surface water samples were collected from acid mine drainage in summer of 2007 and 2008 and from circum-neutral pH environments in October to November 2008. Site determination was based on collecting samples from various aquatic habitats (acid mine drainage, lakes, rivers, tributaries, wetlands) with differing bedrock geology (limestone and shale dominated vs granitic Canadian Shield) to obtain a range of geochemical conditions. At each site, measurements of temperature, pH, and Eh were conducted. Samples collected for microbial counts and electron imaging were preserved to a final concentration of 2.5 % (v/v) glutaraldehyde. Additional sample were filtered into 60 mL nalgene bottles and amber EPA certified 40 mL glass vials to determine chemical constituents and dissolved organic carbon (DOC), respectively. Water was also collected to determine additional physiochemical parameters (dissolved total iron, ferric iron, nitrate, sulfate, phosphate, alkalinity, and turbidity). All samples were stored at 4 °C until analysis. Viral and prokaryotic abundance was determined by staining samples with SYBR Green I and examining with a epifluorescence microscope under blue excitation. Multiple regression analysis using stepwise backwards regression and general linear models revealed that viral abundance was the most influential predictor of prokaryotic abundance. Additional predictors include pH, sulfate, phosphate, and magnesium. The strength of the model was very strong with 90 % of the variability explained (R2 = 0.90, p < 0.007). This is the first report, to our knowledge, of viruses exhibiting such strong controls over prokaryotic abundance in the natural environment. All relationships are positively correlated with the exception of Mg, which is negatively correlated. Iron was also noted as a

Uruguay Mining inventory. Florida fotoplano geochemical prospecting results

International Nuclear Information System (INIS)

Zeegers, H.; Artignan, D.; Vairon, P.

1982-01-01

This work is about the geochemical prospecting carried out in Florida fotoplano within the framework of Uruguay Mining inventory. In this work were covered 660 km2 obtaining 752 samples for study which were analyzed by Plasma Emission Spectrometry in Orleans BRGM laboratories

Phosphated minerals to be used as radioactive reference materials

International Nuclear Information System (INIS)

Braganca, M.J.C.S.; Tauhata, L.; Clain, A.F.; Moreira, I.

2003-01-01

The production and the supplying of certified reference materials, or deliberated contaminated materials containing natural radionuclides for laboratories which analyses environmental samples are fundamentals for the correct measurements of their radioactive levels. This analysis quality represents a important step for the safeguards of the population health, and quality control of the imported and exported products, such as minerals, agricultural and raw materials. The phosphate rocks, containing significant concentrations of thorium, and used as raw material and fertilizers justified a study for better characterization and distinction to be used cas certified reference radioactive materials. Therefore, samples from the two carboanalytical-alkaline chimneys (Araxa and Catalao), and one from metasedimentar origin (Patos de Minas), distant 100 km from each other, were collected and chemical and cholecystographic characterized by optical emission, X-ray diffraction and fluorescence. The element concentrations were determined by neutron activation analysis, ICP-MS and ICP-AES. The results, after multivariate statistical analysis and study of correlations among elements, have shown geochemical similarities of the phosphates from Araxa and Catalao, and differences from Patos de Minas, despite of the geographic proximity. The concentration of thorium between 200 and 500 (mg/g) allows to use such minerals as reference materials

Geochemical Investigations of Groundwater Stability

International Nuclear Information System (INIS)

Bath, Adrian

2006-05-01

palaeohydrogeological conditions. It is likely that inland areas have had longer durations of post-glacial fresh water infiltration than coastal areas, possibly causing greater degrees of dilution and dispersion of preexisting groundwaters and thus overprinting their hydrochemical and isotopic 'fingerprints'. Lower post-glacial hydraulic gradients relative to inland sites may account for the occurrence of more relict cold-climate water at coastal sites. Some general observations are based on rather thin evidence and therefore speculative. Firstly, it seems that glacial melt water penetrated many hundreds of metres and in some places to at least 1,000 m depth. However the low remaining proportions of melt water and of much older saline Shield water suggest that melt water flux did not fully displace pre-existing groundwaters at these depths. Secondly, where there has been post-glacial infiltration of palaeo-Baltic sea water, the density stratification or compartmentalisation effect coupled with low hydraulic gradient has reduced rates of subsequent fresh water circulation after shoreline recession. There are many uncertainties in interpreting these geochemical indicators in terms of the penetration depths of glacial melt waters and the degree to which they replace preexisting groundwaters, of other aspects of groundwater stability, and of comparisons between inland and coastal groundwater systems. Uncertainties derive partly from the reliability of groundwater samples as being representative of in situ conditions, and partly from the non-uniqueness of interpretative models. Future investigations using these approaches need to improve sampling, to make conjunctive use of geochemical and isotopic indicators which have varying timescales and sensitivities, and to integrate these indicators with palaeohydrogeological modelling to support the development of reliable groundwater flow and solute transport models for Performance Assessment

Applications of prospecting geochemical techniques to the search for and to the study of uranium deposits in metropolitan France

International Nuclear Information System (INIS)

Grimbert, Arnold

1957-01-01

After having recalled facts which leaded the CEA to use new geochemical techniques for the prospecting of uranium deposits through sampling and analysis of soils and waters, the author describes the organisation and methods implemented for this prospecting activity: team composition for sampling and analysis, role of each engineer and technician in the prospecting stages (preliminary study, routine prospecting, result interpretation), sampling and analysis processes. He also reports campaigns of geochemical prospecting: study of the La Chapelle Largeau deposit (objectives, geological context, preliminary study, routine prospecting, study of geochemical anomalies), tactical research on Verneix indices (study of radioactivity anomaly discovered by radio-prospecting), strategical searches in a non prospected area in the South of Avallon. The author discusses the issues of efficiency and cost price of this geochemical prospecting technique in soils and in waters. Appendices present the equipment and operation modality for soil sampling, and for soil sample preparation, and principles, equipment and products for soil analysis and for water analysis [fr

Methods for geochemical analysis

Science.gov (United States)

Baedecker, Philip A.

1987-01-01

The laboratories for analytical chemistry within the Geologic Division of the U.S. Geological Survey are administered by the Office of Mineral Resources. The laboratory analysts provide analytical support to those programs of the Geologic Division that require chemical information and conduct basic research in analytical and geochemical areas vital to the furtherance of Division program goals. Laboratories for research and geochemical analysis are maintained at the three major centers in Reston, Virginia, Denver, Colorado, and Menlo Park, California. The Division has an expertise in a broad spectrum of analytical techniques, and the analytical research is designed to advance the state of the art of existing techniques and to develop new methods of analysis in response to special problems in geochemical analysis. The geochemical research and analytical results are applied to the solution of fundamental geochemical problems relating to the origin of mineral deposits and fossil fuels, as well as to studies relating to the distribution of elements in varied geologic systems, the mechanisms by which they are transported, and their impact on the environment.

Some results of NURE uranium geochemical studies

International Nuclear Information System (INIS)

Price, V. Jr.

1979-01-01

Some technical developments of the National Uranium Resource Evaluation Program which are of general application in geochemical exploration are being studied. Results of stream water and suspended and bottom sediment analyses are compared for an area near Williamsport, Pennsylvania. Variations of uranium content of water samples with time in the North Carolina Piedmont are seen to correlate with rainfall. Ground water samples from coastal and piedmont areas were analyzed for helium. All media sampled provide useful information when properly analyzed and interpreted as part of a total geological analysis of an area

Uruguay Mining inventory. Minas fotoplano geochemical prospecting results

International Nuclear Information System (INIS)

Zeegers, H.; Artignan, D.; Vairon, P.

1982-01-01

This work is about the geochemical prospecting carried out in Minas fotoplano within the framework of Uruguay Mining inventory. In this work were covered 380 km2 obtaining with 433 samples for study which were analized by Plasma Emission Spectrometry in Orleans BRGM laboratories

Pilot studies for the North American Soil Geochemical Landscapes Project - Site selection, sampling protocols, analytical methods, and quality control protocols

Science.gov (United States)

Smith, D.B.; Woodruff, L.G.; O'Leary, R. M.; Cannon, W.F.; Garrett, R.G.; Kilburn, J.E.; Goldhaber, M.B.

2009-01-01

In 2004, the US Geological Survey (USGS) and the Geological Survey of Canada sampled and chemically analyzed soils along two transects across Canada and the USA in preparation for a planned soil geochemical survey of North America. This effort was a pilot study to test and refine sampling protocols, analytical methods, quality control protocols, and field logistics for the continental survey. A total of 220 sample sites were selected at approximately 40-km intervals along the two transects. The ideal sampling protocol at each site called for a sample from a depth of 0-5 cm and a composite of each of the O, A, and C horizons. The Ca, Fe, K, Mg, Na, S, Ti, Ag, As, Ba, Be, Bi, Cd, Ce, Co, Cr, Cs, Cu, Ga, In, La, Li, Mn, Mo, Nb, Ni, P, Pb, Rb, Sb, Sc, Sn, Sr, Te, Th, Tl, U, V, W, Y, and Zn by inductively coupled plasma-mass spectrometry and inductively coupled plasma-atomic emission spectrometry following a near-total digestion in a mixture of HCl, HNO3, HClO4, and HF. Separate methods were used for Hg, Se, total C, and carbonate-C on this same size fraction. Only Ag, In, and Te had a large percentage of concentrations below the detection limit. Quality control (QC) of the analyses was monitored at three levels: the laboratory performing the analysis, the USGS QC officer, and the principal investigator for the study. This level of review resulted in an average of one QC sample for every 20 field samples, which proved to be minimally adequate for such a large-scale survey. Additional QC samples should be added to monitor within-batch quality to the extent that no more than 10 samples are analyzed between a QC sample. Only Cr (77%), Y (82%), and Sb (80%) fell outside the acceptable limits of accuracy (% recovery between 85 and 115%) because of likely residence in mineral phases resistant to the acid digestion. A separate sample of 0-5-cm material was collected at each site for determination of organic compounds. A subset of 73 of these samples was analyzed for a suite of

Parent-Adolescent Cross-Informant Agreement in Clinically Referred Samples

DEFF Research Database (Denmark)

Rescorla, Leslie A; Ewing, Grace; Ivanova, Masha Y

2017-01-01

To conduct international comparisons of parent-adolescent cross-informant agreement in clinical samples, we analyzed ratings on the Child Behavior Checklist (CBCL) and Youth Self-Report (YSR) for 6,762 clinically referred adolescents ages 11-18 from 7 societies (M = 14.5 years, SD = 2.0 years; 51...

Panay carborne radiometric and geochemical surveys

International Nuclear Information System (INIS)

Santos, G. Jr.

1981-09-01

A carborne radiometric survey and stream sediments collection were conducted in Panay and Guimaras Islands. An area in Nabas, Aklan, situated in the northwestern tip of Panay (Buruanga Peninsula) which indicated 2 to 3 times above background radioactivity was delineated. Uranium content in the stream sediment samples collected from Buruanga Peninsula was generally higher than those obtained in other parts of the island. Radioactivity measurements and uranium content in stream sediments were found to be within background levels. It is recommended that follow-up radiometric and geochemical surveys be undertaken in Buruanga Peninsula and additional stream sediments samples be collected in Panay to achieve better sampling density and coverage. (author)

Reconnaissance geochemical survey for uranium and related industrial minerals in Cebu Island

International Nuclear Information System (INIS)

Reyes, R.Y.; Ramos, A.F.; Magsambol, W.N.; Hernandez, E.

1989-03-01

Consistent with the program of evaluating the nuclear mineral resource potential and related industrial minerals of the Philippines, a reconnaissance geochemical survey was conducted in Cebu with considerable success. The total area covered by the survey was about 5,088 sq. kms. The survey consisted of systematic collection of 857 geochemical stream and water and heavy mineral samples, and measurement of radioactivity in over 352 stations. The average sampling density was about one set of samples per 15 to 30 sq. kms. All solid samples were analyzed for U, Cu, Pb, Zn, Mn, Ag, Co and Ni. Uranium, radon and conductivity were measured on most water samples collected. A total of 4,518 elemental determinations were involved. All field and analytical data were treated by statistics, and the computed parameters data were correlated with the geology of the area to establish anomalous zones. Four areas were delineated for possible uranium mineralization. Of the areas, the Mandaue river area is the most interesting for uranium. The contact zone between the diorite and the sedimentary rocks in this area appears to be a favorable geological environment for uranium mineralization. The other anomalous uranium values were found to be related with the guano and phosphate deposits. Uranium was also shown to be independent of the other seven elements in the geologic environment of Cebu. No definite elemental association could be established at present. This study also marks the thorough utilization of Q'GAS, Cadplot and Autocad, all microcomputer-based programs/systems, in the evaluation and interpretation of exploration-oriented geochemical and geological data, and with more significance in the sense that computer generated quality geochemical maps were produced, a first in the country. (Author). Appendices (23); 23 figs; 13 refs.; 4 tabs

Predictive geochemical mapping using environmental correlation

International Nuclear Information System (INIS)

Wilford, John; Caritat, Patrice de; Bui, Elisabeth

2016-01-01

The distribution of chemical elements at and near the Earth's surface, the so-called critical zone, is complex and reflects the geochemistry and mineralogy of the original substrate modified by environmental factors that include physical, chemical and biological processes over time. Geochemical data typically is illustrated in the form of plan view maps or vertical cross-sections, where the composition of regolith, soil, bedrock or any other material is represented. These are primarily point observations that frequently are interpolated to produce rasters of element distributions. Here we propose the application of environmental or covariate regression modelling to predict and better understand the controls on major and trace element geochemistry within the regolith. Available environmental covariate datasets (raster or vector) representing factors influencing regolith or soil composition are intersected with the geochemical point data in a spatial statistical correlation model to develop a system of multiple linear correlations. The spatial resolution of the environmental covariates, which typically is much finer (e.g. ∼90 m pixel) than that of geochemical surveys (e.g. 1 sample per 10-10,000 km 2 ), carries over to the predictions. Therefore the derived predictive models of element concentrations take the form of continuous geochemical landscape representations that are potentially much more informative than geostatistical interpolations. Environmental correlation is applied to the Sir Samuel 1:250,000 scale map sheet in Western Australia to produce distribution models of individual elements describing the geochemical composition of the regolith and exposed bedrock. As an example we model the distribution of two elements – chromium and sodium. We show that the environmental correlation approach generates high resolution predictive maps that are statistically more accurate and effective than ordinary kriging and inverse distance weighting interpolation

Geochemical Investigations of Groundwater Stability

Energy Technology Data Exchange (ETDEWEB)

Bath, Adrian [Intellisci Ltd., Loughborough (United Kingdom)

2006-05-15

local palaeohydrogeological conditions. It is likely that inland areas have had longer durations of post-glacial fresh water infiltration than coastal areas, possibly causing greater degrees of dilution and dispersion of preexisting groundwaters and thus overprinting their hydrochemical and isotopic 'fingerprints'. Lower post-glacial hydraulic gradients relative to inland sites may account for the occurrence of more relict cold-climate water at coastal sites. Some general observations are based on rather thin evidence and therefore speculative. Firstly, it seems that glacial melt water penetrated many hundreds of metres and in some places to at least 1,000 m depth. However the low remaining proportions of melt water and of much older saline Shield water suggest that melt water flux did not fully displace pre-existing groundwaters at these depths. Secondly, where there has been post-glacial infiltration of palaeo-Baltic sea water, the density stratification or compartmentalisation effect coupled with low hydraulic gradient has reduced rates of subsequent fresh water circulation after shoreline recession. There are many uncertainties in interpreting these geochemical indicators in terms of the penetration depths of glacial melt waters and the degree to which they replace preexisting groundwaters, of other aspects of groundwater stability, and of comparisons between inland and coastal groundwater systems. Uncertainties derive partly from the reliability of groundwater samples as being representative of in situ conditions, and partly from the non-uniqueness of interpretative models. Future investigations using these approaches need to improve sampling, to make conjunctive use of geochemical and isotopic indicators which have varying timescales and sensitivities, and to integrate these indicators with palaeohydrogeological modelling to support the development of reliable groundwater flow and solute transport models for Performance Assessment.

Mining inventory of Uruguay. Polanco fotoplano geochemical prospecting results

International Nuclear Information System (INIS)

Zeegers, H; Artignan, D; Vairon, P

1982-01-01

This work is about the geochemical prospecting carried out in Polanco fotoplano within the framework of Uruguay Mining inventory . In this work were covered 660 km2 obtaining 685 samples for study which were analyzed by Plasma Emission Spectrometry in Orleans BRGM laboratories

Gender differences on the Five to Fifteen questionnaire in a non-referred sample with inattention and hyperactivity-impulsivity and a clinic-referred sample with hyperkinetic disorder

DEFF Research Database (Denmark)

Lambek, Rikke; Trillingsgaard, Anegen; Kadesjö, Björn

2010-01-01

The aim of the present study was to examine gender differences in children with inattention, hyperactivity, and impulsivity on the Five to Fifteen (FTF) parent questionnaire. First, non-referred girls (n = 43) and boys (n = 51) with problems of attention and hyperactivity-impulsivity and then cli......The aim of the present study was to examine gender differences in children with inattention, hyperactivity, and impulsivity on the Five to Fifteen (FTF) parent questionnaire. First, non-referred girls (n = 43) and boys (n = 51) with problems of attention and hyperactivity...... questionnaire. Secondly, it was examined whether the application of gender mixed norms versus gender specific norms would result in varying proportions of clinic-referred children with HKD being identified as impaired on the subdomains of the FTF questionnaire. Based on results it was concluded that the use...... of a gender mixed normative sample may lead to overestimation of impairment in boys with HKD, but the type of sample applied to define impairment on the FTF should depend on the purpose for applying the questionnaire....

Uranium exploration data and global geochemical baselines: The need for co-ordinated action

International Nuclear Information System (INIS)

Darnley, A.G.

1997-01-01

Public concern about environmental problems continues. In order to assess the magnitude of potential problems it is necessary to have comprehensive information. The absence of quantitative geochemical data to map the surface composition of the earth is one of the major information gaps in present day environmental science. An IAEA Technical Committee meeting held in November 1993 reviewed the uses of uranium exploration data for environmental purposes. Most attention was focussed on data involving radiation measurements. Uranium exploration programmes conducted since 1970 in many countries collected a considerable amount of geochemical survey data, providing information about the distribution of non-radioactive elements in the natural environment. Canada is one of several countries where such data provided the foundation for national geochemical mapping; other countries could benefit from similar actions. Increasing importance is being attached by governments to the need to enact effective environmental legislation concerning ''safe levels'' of many chemical substances. Such legislation requires geochemical variations in the natural environment. It is becoming necessary to make quantitative comparisons of element abundances across national boundaries, and from continent to continent. In 1995 the IAEA, with other organizations, supported UNESCO to publish a report concerned with the establishment of a Global Geochemical Reference Network. This is designed to provide a framework to connect all types of geochemical survey, to move towards international compatibility of data. The report contains recommendations relating to the standardization of field and laboratory methods; the use of the most sensitive analytical techniques; and standardization of data management. Ground and airborne gamma ray spectrometry, and nuclear laboratory techniques are all discussed. Following the publication of the report, the International Union of Geological Sciences has now established a

Geochemical landscapes of the conterminous United States; new map presentations for 22 elements

Science.gov (United States)

Gustavsson, N.; Bolviken, B.; Smith, D.B.; Severson, R.C.

2001-01-01

Geochemical maps of the conterminous United States have been prepared for seven major elements (Al, Ca, Fe, K, Mg, Na, and Ti) and 15 trace elements (As, Ba, Cr, Cu, Hg, Li, Mn, Ni, Pb, Se, Sr, V, Y, Zn, and Zr). The maps are based on an ultra low-density geochemical survey consisting of 1,323 samples of soils and other surficial materials collected from approximately 1960-1975. The data were published by Boerngen and Shacklette (1981) and black-and-white point-symbol geochemical maps were published by Shacklette and Boerngen (1984). The data have been reprocessed using weighted-median and Bootstrap procedures for interpolation and smoothing.

Geochemical Data for Samples Collected in 2007 Near the Concealed Pebble Porphyry Cu-Au-Mo Deposit, Southwest Alaska

Science.gov (United States)

Fey, David L.; Granitto, Matthew; Giles, Stuart A.; Smith, Steven M.; Eppinger, Robert G.; Kelley, Karen D.

2008-01-01

In the summer of 2007, the U.S. Geological Survey (USGS) began an exploration geochemical research study over the Pebble porphyry copper-gold-molydenum (Cu-Au-Mo) deposit in southwest Alaska. The Pebble deposit is extremely large and is almost entirely concealed by tundra, glacial deposits, and post-Cretaceous volcanic and volcaniclastic rocks. The deposit is presently being explored by Northern Dynasty Minerals, Ltd., and Anglo-American LLC. The USGS undertakes unbiased, broad-scale mineral resource assessments of government lands to provide Congress and citizens with information on national mineral endowment. Research on known deposits is also done to refine and better constrain methods and deposit models for the mineral resource assessments. The Pebble deposit was chosen for this study because it is concealed by surficial cover rocks, it is relatively undisturbed (except for exploration company drill holes), it is a large mineral system, and it is fairly well constrained at depth by the drill hole geology and geochemistry. The goals of the USGS study are (1) to determine whether the concealed deposit can be detected with surface samples, (2) to better understand the processes of metal migration from the deposit to the surface, and (3) to test and develop methods for assessing mineral resources in similar concealed terrains. This report presents analytical results for geochemical samples collected in 2007 from the Pebble deposit and surrounding environs. The analytical data are presented digitally both as an integrated Microsoft 2003 Access? database and as Microsoft 2003 Excel? files. The Pebble deposit is located in southwestern Alaska on state lands about 30 km (18 mi) northwest of the village of Illiamna and 320 km (200 mi) southwest of Anchorage (fig. 1). Elevations in the Pebble area range from 287 m (940 ft) at Frying Pan Lake just south of the deposit to 1146 m (3760 ft) on Kaskanak Mountain about 5 km (5 mi) to the west. The deposit is in an area of

Uruguay Mining inventory. Las Animas fotoplano geochemical prospecting results

International Nuclear Information System (INIS)

Zeegers, H.; Spangenberg, J.

1981-01-01

This work is about the geochemical prospecting carried out in Las Animas fotoplano within the framework of Uruguay Mining inventory. In this work were covered 660 km2 obtaining 738 samples for study which were analyzed by Plasma Emission Spectrometry in Orleans BRGM laboratories.

Coupled geochemical and solute transport code development

International Nuclear Information System (INIS)

Morrey, J.R.; Hostetler, C.J.

1985-01-01

A number of coupled geochemical hydrologic codes have been reported in the literature. Some of these codes have directly coupled the source-sink term to the solute transport equation. The current consensus seems to be that directly coupling hydrologic transport and chemical models through a series of interdependent differential equations is not feasible for multicomponent problems with complex geochemical processes (e.g., precipitation/dissolution reactions). A two-step process appears to be the required method of coupling codes for problems where a large suite of chemical reactions must be monitored. Two-step structure requires that the source-sink term in the transport equation is supplied by a geochemical code rather than by an analytical expression. We have developed a one-dimensional two-step coupled model designed to calculate relatively complex geochemical equilibria (CTM1D). Our geochemical module implements a Newton-Raphson algorithm to solve heterogeneous geochemical equilibria, involving up to 40 chemical components and 400 aqueous species. The geochemical module was designed to be efficient and compact. A revised version of the MINTEQ Code is used as a parent geochemical code

Geochemical and sedimentological signature of catastrophic saltwater inundations (tsunami), New Zealand

International Nuclear Information System (INIS)

Chague-Goff, C.; Goff, J.R.

1999-01-01

Three tidal marshes in Able Tasman National Par, New Zealand, were studied using geochemical, sedimentological and radiometric dating techniques. Charcoal and plant material samples were taken from one core in each inlet for 14 C analysis. radiocarbon ages were converted to dendrocalibrated years . All samples produced a terrestrial 13 C signal. Near surface samples were date d by measuring 137 Cs. A 1700 year record of catastrophic saltwater inundations (CSI) events (Tsunami) was produced. Up to four such events were identified, with ruptures of one or more of the Wellington, Wairarapa and Alpine Faults being the most likely tsunamigenic source. CSI signatures include: peaks in Fe and/or S, a peak in fines and contemporaneous or delayed peaks in organic content and/or loss on ignition (LOI). Geochemical data in association with grain size analyses proved to be a valuable tool in the interpretation of these events

Evaluation of Skin Surface as an Alternative Source of Reference DNA Samples: A Pilot Study.

Science.gov (United States)

Albujja, Mohammed H; Bin Dukhyil, Abdul Aziz; Chaudhary, Abdul Rauf; Kassab, Ahmed Ch; Refaat, Ahmed M; Babu, Saranya Ramesh; Okla, Mohammad K; Kumar, Sachil

2018-01-01

An acceptable area for collecting DNA reference sample is a part of the forensic DNA analysis development. The aim of this study was to evaluate skin surface cells (SSC) as an alternate source of reference DNA sample. From each volunteer (n = 10), six samples from skin surface areas (forearm and fingertips) and two traditional samples (blood and buccal cells) were collected. Genomic DNA was extracted and quantified then genotyped using standard techniques. The highest DNA concentration of SSC samples was collected using the tape/forearm method of collection (2.1 ng/μL). Cotton swabs moistened with ethanol yielded higher quantities of DNA than swabs moistened with salicylic acid, and it gave the highest percentage of full STR profiles (97%). This study supports the use of SSC as a noninvasive sampling technique and as a extremely useful source of DNA reference samples among certain cultures where the use of buccal swabs can be considered socially unacceptable. © 2017 American Academy of Forensic Sciences.

Determination of geochemical and natural radioactivity characteristics in Bilecik Marble, Turkey

Science.gov (United States)

Yerel Kandemir, Suheyla; Ozbay, Nurgul

2014-05-01

Natural stones are one of the oldest known building materials. There are more than 400 natural stone in Turkey. Recently, the demand for the natural stone types in markets has been increasing rapidly. For this reason, the geochemical and natural radioactivity characteristics of natural stone are very important. Bilecik province is located at the northwest part of Turkey and it is surrounded by Sakarya, Bursa, Eskisehir and Kutahya city. Bilecik is one of the important marble industry regions of Turkey. Thus, the geochemical and natural radioactivity characteristics of Bilecik marble are very important. In this study, Bilecik marble was collected to determine the geochemistry and natural radioactivity. Then, analyses of geochemical and natural radioactivity in the marble samples are interpreted. ACKNOWLEDGMENT This study is supported by Bilecik Seyh Edebali University scientific project (Project Number =2011-02-BIL.03-04).

Assessment of diagenetic alteration of dinosaur eggshells through petrography and geochemical analysis

Science.gov (United States)

Enriquez, M. V.; Eagle, R.; Eiler, J. M.; Tripati, A. K.; Ramirez, P. C.; Loyd, S. J.; Chiappe, L.; Montanari, S.; Norell, M.; Tuetken, T.

2012-12-01

Carbonate clumped isotope analysis of fossil eggshells has the potential to constrain both the physiology of extinct animals and, potentially, paleoenvironmental conditions, especially when coupled with isotopic measurements of co-occurring soil carbonates. Eggshell samples from both modern vertebrates and Cretaceous Hadrosaurid, Oviraptorid, Titanosaur, Hypselosaurus, Faveoolithus, dinosaur fossils have been collected from Auca Mahuevo, Argentina and Rousett, France, amongst other locations, for geochemical analysis to determine if isotopic signatures could be used to indicate warm- or cold-bloodedness. In some locations soil carbonates were also analyzed to constrain environmental temperatures. In order to test the validity of the geochemical results, an extensive study was undertaken to establish degree of diagenetic alteration. Petrographic and cathodoluminescence characterization of the eggshells were used to assess diagenetic alteration. An empirical 1-5 point scale was used to assign each sample an alteration level, and the observations were then compared with the geochemical results. Specimens displayed a wide range of alteration states. Some of which were well preserved and others highly altered. Another group seemed to be structural intact and only under cathodoluminescence was alteration clearly observed. In the majority of samples, alteration level was found to be predictably related to geochemical results. From specimens with little evidence for diagenesis, carbonate clumped isotope signatures support high (37-40°C) body temperature for Titanosaurid dinosaurs, but potentially lower body temperatures for other taxa. If these data do, in fact, represent original eggshell growth temperatures, these results support variability in body temperature amongst Cretaceous dinosaurs and potentially are consistent with variations between adult body temperature and size — a characteristic of 'gigantothermy'.

Hydrogeological and geochemical monitoring system for deep disposal in rock mass

International Nuclear Information System (INIS)

Itoh, K.; Otsuka, Y.; Ohi, Y.

1996-01-01

For investigation and construction of deep underground disposal site, it is very important to monitor three dimensional hydrogeological and geochemical condition for long term in all stages of investigation, construction and management. In deep geological disposal site, permeability of rock mass should be extremely lower than conventional civil engineering field, and natural piezometric pressure should be much higher than conventional groundwater monitoring in civil engineering. So, pressure measuring device should have wide measuring range and high precision especially for interference hydraulic test in investigation stage. And, simultaneous pressure measurement in plural points would be required for cost minimization. Recently, some kinds of multi-point pressure monitoring system has been presented. However, most of all system requires borehole with large diameter, and for utilization in plural boreholes, centralized sensor control is very difficult. And, in groundwater sampling for geochemical investigation, it is important to keep original chemical condition through sampling and transportation from sampling depth to surface. For these purposes, the authors have developed multi well multi point piezometric pressure measuring device, and groundwater sampling system for 1,000m depth. (author)

Archean crust-mantle geochemical differentiation

Science.gov (United States)

Tilton, G. R.

Isotope measurements on carbonatite complexes and komatiites can provide information on the geochemical character and geochemical evolution of the mantle, including the sub-continental mantle. Measurements on young samples establish the validity of the method. These are based on Sr, Nd and Pb data from the Tertiary-Mesozoic Gorgona komatiite and Sr and Pb data from the Cretaceous Oka carbonatite complex. In both cases the data describe a LIL element-depleted source similar to that observed presently in MORB. Carbonatite data have been used to study the mantle beneath the Superior Province of the Canadian Shield one billion years (1 AE) ago. The framework for this investigation was established by Bell et al., who showed that large areas of the province appear to be underlain by LIL element-depleted mantle (Sr-85/Sr-86=0.7028) at 1 AE ago. Additionally Bell et al. found four complexes to have higher initial Sr ratios (Sr-87/Sr-86=0.7038), which they correlated with less depleted (bulk earth?) mantle sources, or possibly crustal contamination. Pb isotope relationships in four of the complexes have been studied by Bell et al.

Archean crust-mantle geochemical differentiation

Science.gov (United States)

Tilton, G. R.

1983-01-01

Isotope measurements on carbonatite complexes and komatiites can provide information on the geochemical character and geochemical evolution of the mantle, including the sub-continental mantle. Measurements on young samples establish the validity of the method. These are based on Sr, Nd and Pb data from the Tertiary-Mesozoic Gorgona komatiite and Sr and Pb data from the Cretaceous Oka carbonatite complex. In both cases the data describe a LIL element-depleted source similar to that observed presently in MORB. Carbonatite data have been used to study the mantle beneath the Superior Province of the Canadian Shield one billion years (1 AE) ago. The framework for this investigation was established by Bell et al., who showed that large areas of the province appear to be underlain by LIL element-depleted mantle (Sr-85/Sr-86=0.7028) at 1 AE ago. Additionally Bell et al. found four complexes to have higher initial Sr ratios (Sr-87/Sr-86=0.7038), which they correlated with less depleted (bulk earth?) mantle sources, or possibly crustal contamination. Pb isotope relationships in four of the complexes have been studied by Bell et al.

Petrologic and geochemical characterization of the Topopah Spring Member of the Paintbrush Tuff: outcrop samples used in waste package experiments

International Nuclear Information System (INIS)

Knauss, K.G.

1984-06-01

This report summarizes characterization studies conducted with outcrop samples of Topopah Spring Member of the Paintbrush Tuff (Tpt). In support of the Waste Package Task within the Nevada Nuclear Waste Storage Investigation (NNWSI), Tpt is being studied both as a primary object and as a constituent used to condition water that will be reacted with waste form, canister, or packing material. These studies directly or indirectly support NNWSI subtasks concerned with waste package design and geochemical modeling. To interpret the results of subtask experiments, it is necessary to know the exact nature of the starting material in terms of the intial bulk composition, mineralogy, and individual phase geochemistry. 31 figures, 5 tables

Petrologic and geochemical characterization of the Topopah Spring Member of the Paintbrush Tuff: outcrop samples used in waste package experiments

Energy Technology Data Exchange (ETDEWEB)

Knauss, K.G.

1984-06-01

This report summarizes characterization studies conducted with outcrop samples of Topopah Spring Member of the Paintbrush Tuff (Tpt). In support of the Waste Package Task within the Nevada Nuclear Waste Storage Investigation (NNWSI), Tpt is being studied both as a primary object and as a constituent used to condition water that will be reacted with waste form, canister, or packing material. These studies directly or indirectly support NNWSI subtasks concerned with waste package design and geochemical modeling. To interpret the results of subtask experiments, it is necessary to know the exact nature of the starting material in terms of the intial bulk composition, mineralogy, and individual phase geochemistry. 31 figures, 5 tables.

Integration of remote sensing and geochemical data in the mineral evaluation of the Yucca Mountain Addition, Nevada

International Nuclear Information System (INIS)

Feldman, S.C.; Castor, S.B.; Tingley, J.V.

1996-01-01

In 1989 the U.S. Department of Energy filed an application with the U.S. Bureau of Land Management for an administrative land withdrawal of about 4,300 acres bordering the western edge of the Nevada Test Site (NTS) and the southern edge of the Nellis Air Force Range. This area, which is referred to as the Yucca Mountain Addition, includes approximately 400 acres that are being considered as part of a potential repository for high-level nuclear waste at Yucca Mountain. A study of the geology and mineral deposits is required for a land withdrawal request under federal law. The Yucca Mountain Addition mineral evaluation was accomplished in late 1989 by field examination, sample collection, geochemical analysis, the analysis of satellite remote sensing data, and the collection of rock spectra in the field. Data from the Yucca Mountain Addition and from mining districts in the area were collected and analyzed, and the two data sets were then compared. The evaluation was limited to surficial data both at the Yucca Mountain Addition and in the mining districts. Evidence from both geochemical and remote sensing analyses indicate that the potential for mineral deposits is low in the Yucca Mountain Addition

Uranium Content in the Geological Samples of Different River Valleys in the Dauki fault Belt of Jaintiapur

International Nuclear Information System (INIS)

Chowdhury, Minhaz ul Islam; Ahmed Monir; Bhuiyan Abu Daiyan; Akon Eunus

1996-01-01

Thirty four geological samples that include six radioactive rock samples, four soil samples, two ooze samples,twelve stream-sediment samples and ten water samples, collected during a field survey in Jaintiapur area of the Dauki fault belt, oriented to the study on probable mobility of uranium either as detritus or in aquatic solution through the region, have been investigated with fluorimeter so as to find out content of uranium in the samples. The investigation aims at determining geochemical significance on uranium occurrence prevailing in the area. In general, the content of uranium in the rock samples lies in average distribution of geochemical interest. However, 194 ppm of uranium content in the gross material of the rock sample, collected from Lalakhal anomaly that records 1500 cps in situ, bears geochemical significance. But, the anomaly being associated with a cross -bedding, the presence of uranium may be inferred as an accumulation in placer sediment transported from a nearby source, Despite absence of in situ radiometric anomalies in the overall geological formations other than the Tipam and the Dupitila Sandstone members as encountered in the traverse of Sari valley , the area, in general, appears to be potential for possible occurrence of uranium. The transported stream sediments ooze and surface run-off water, as collected from the Rangapani, the Sari and even the Nayagang show geochemically significant distribution of uranium. Laboratory analyses of soil samples refers to dispersion of U bearing materials in the soil along the major channels.Uranium content in the surface run-off water of the Sari, the Rangapani and the Nayagang that have originated from the uranium bearing Meghalayan hills strongly support previous inference on mobility of uranium in aquatic solution through the geological formations of the area for possible formation of secondary uranium deposits. Eventually, prevailing geological evidences advocate that the area may be brought

Quality assurance and quality control of geochemical data—A primer for the research scientist

Science.gov (United States)

Geboy, Nicholas J.; Engle, Mark A.

2011-01-01

Geochemistry is a constantly expanding science. More and more, scientists are employing geochemical tools to help answer questions about the Earth and earth system processes. Scientists may assume that the responsibility of examining and assessing the quality of the geochemical data they generate is not theirs but rather that of the analytical laboratories to which their samples have been submitted. This assumption may be partially based on knowledge about internal and external quality assurance and quality control (QA/QC) programs in which analytical laboratories typically participate. Or there may be a perceived lack of time or resources to adequately examine data quality. Regardless of the reason, the lack of QA/QC protocols can lead to the generation and publication of erroneous data. Because the interpretations drawn from the data are primary products to U.S. Geological Survey (USGS) stakeholders, the consequences of publishing erroneous results can be significant. The principal investigator of a scientific study ultimately is responsible for the quality and interpretation of the project's findings, and thus must also play a role in the understanding, implementation, and presentation of QA/QC information about the data. Although occasionally ignored, QA/QC protocols apply not only to procedures in the laboratory but also in the initial planning of a research study and throughout the life of the project. Many of the tenets of developing a sound QA/QC program or protocols also parallel the core concepts of developing a good study: What is the main objective of the study? Will the methods selected provide data of enough resolution to answer the hypothesis? How should samples be collected? Are there known or unknown artifacts or contamination sources in the sampling and analysis methods? Assessing data quality requires communication between the scientists responsible for designing the study and those collecting samples, analyzing samples, treating data, and

Proceedings of the workshop on geochemical modeling

International Nuclear Information System (INIS)

1986-01-01

The following collection of papers was presented at a workshop on geochemical modeling that was sponsored by the Office of Civilian Radioactive Waste Management Program at the Lawrence Livermore National Laboratory (LLNL). The LLNL Waste Management Program sponsored this conference based on their belief that geochemical modeling is particularly important to the radioactive waste disposal project because of the need to predict the consequences of long-term water-rock interactions at the proposed repository site. The papers included in this volume represent a subset of the papers presented at the Fallen Leaf Lake Conference and cover a broad spectrum of detail and breadth in a subject that reflects the diverse research interests of the conference participants. These papers provide an insightful look into the current status of geochemical modeling and illustrate how various geochemical modeling codes have been applied to problems of geochemical interest. The emphasis of these papers includes traditional geochemical modeling studies of individual geochemical systems, the mathematical and theoretical development and refinement of new modeling capabilities, and enhancements of data bases on which the computations are based. The papers in this proceedings volume have been organized into the following four areas: Geochemical Model Development, Hydrothermal and Geothermal Systems, Sedimentary and Low Temperature Environments, and Data Base Development. The participants of this symposium and a complete list of the talks presented are listed in the appendices

Proceedings of the workshop on geochemical modeling

Energy Technology Data Exchange (ETDEWEB)

1986-01-01

The following collection of papers was presented at a workshop on geochemical modeling that was sponsored by the Office of Civilian Radioactive Waste Management Program at the Lawrence Livermore National Laboratory (LLNL). The LLNL Waste Management Program sponsored this conference based on their belief that geochemical modeling is particularly important to the radioactive waste disposal project because of the need to predict the consequences of long-term water-rock interactions at the proposed repository site. The papers included in this volume represent a subset of the papers presented at the Fallen Leaf Lake Conference and cover a broad spectrum of detail and breadth in a subject that reflects the diverse research interests of the conference participants. These papers provide an insightful look into the current status of geochemical modeling and illustrate how various geochemical modeling codes have been applied to problems of geochemical interest. The emphasis of these papers includes traditional geochemical modeling studies of individual geochemical systems, the mathematical and theoretical development and refinement of new modeling capabilities, and enhancements of data bases on which the computations are based. The papers in this proceedings volume have been organized into the following four areas: Geochemical Model Development, Hydrothermal and Geothermal Systems, Sedimentary and Low Temperature Environments, and Data Base Development. The participants of this symposium and a complete list of the talks presented are listed in the appendices.

Reference volumetric samples of gamma-spectroscopic sources

International Nuclear Information System (INIS)

Taskaev, E.; Taskaeva, M.; Grigorov, T.

1993-01-01

The purpose of this investigation is to determine the requirements for matrices of reference volumetric radiation sources necessary for detector calibration. The first stage of this determination consists in analysing some available organic and nonorganic materials. Different sorts of food, grass, plastics, minerals and building materials have been considered, taking into account the various procedures of their processing (grinding, screening, homogenizing) and their properties (hygroscopy, storage life, resistance to oxidation during gamma sterilization). The procedures of source processing, sample preparation, matrix irradiation and homogenization have been determined. A rotation homogenizing device has been elaborated enabling to homogenize the matrix activity irrespective of the vessel geometry. 33 standard volumetric radioactive sources have been prepared: 14 - on organic matrix and 19 - on nonorganic matrix. (author)

Introduction to selected references on fossil fuels of the central and southern Appalachian basin: Chapter H.1 in Coal and petroleum resources in the Appalachian basin: distribution, geologic framework, and geochemical character

Science.gov (United States)

Ruppert, Leslie F.; Lentz, Erika E.; Tewalt, Susan J.; Román Colón, Yomayra A.; Ruppert, Leslie F.; Ryder, Robert T.

2014-01-01

The Appalachian basin contains abundant coal and petroleum resources that have been studied and extracted for at least 150 years. In this volume, U.S. Geological Survey (USGS) scientists describe the geologic framework and geochemical character of the fossil-fuel resources of the central and southern Appalachian basin. Separate subchapters (some previously published) contain geologic cross sections; seismic profiles; burial history models; assessments of Carboniferous coalbed methane and Devonian shale gas; distribution information for oil, gas, and coal fields; data on the geochemistry of natural gas and oil; and the fossil-fuel production history of the basin. Although each chapter and subchapter includes references cited, many historical or other important references on Appalachian basin and global fossil-fuel science were omitted because they were not directly applicable to the chapters.

Geochemical investigation of UMTRAP designated site at Salt Lake City, Utah

International Nuclear Information System (INIS)

Markos, G.; Bush, K.J.

1983-09-01

This report is the result of a geochemical investigation of the former uranium mill and tailings site at Salt Lake City, Utah. This is one in a series of site specific geochemical investigations performed on the inactive uranium mill tailings included in the Uranium Mill Tailings Remedial Action Project. The objectives of the investigation are to characterize the geochemistry, to determine the contaminant distribution resulting from the former milling activities and tailings, and to infer chemical pathways and transport mechanisms from the contaminant distribution. The results will be used to model contaminant migration and to develop criteria for long-term containment media such as a cover system which is impermeable to contaminant migration. This report assumes a familiarity with the hydrologic conditions of the site and the geochemical concepts underlying the investigation. The results reported are based on a one-time sampling of waters and solid material from the background, the area adjacent to the site, and the site. The solid samples were water extracted to remove easily soluble salts and acid extracted to remove carbonates and hydroxides. The water extracts and solid samples were anlyzed for the major and trace elements. The report includes the methods of sampling, sample processing, analysis, and data interpretation. Four major conclusions are: (1) sediments in the ditches and creeks adjacent to the site contain tailings, however, the waters were generally not contaminated; (2) tailings are mixed with the soils within a meter below the tailings in some locations, however, water-soluble contaminants decrease to below background levels within 30 cm below the tailings; (3) there has not been significant acid seepage into the soils below the tailings; and (4) salt crusts on the tailings contain trace elements, with the elements that form chloride complexes having the greatest accumulation

Adult health study reference papers. Selection of the sample. Characteristics of the sample

Energy Technology Data Exchange (ETDEWEB)

Beebe, G W; Fujisawa, Hideo; Yamasaki, Mitsuru

1960-12-14

The characteristics and selection of the clinical sample have been described in some detail to provide information on the comparability of the exposure groups with respect to factors excluded from the matching criteria and to provide basic descriptive information potentially relevant to individual studies that may be done within the framework of the Adult Health Study. The characteristics under review here are age, sex, many different aspects of residence, marital status, occupation and industry, details of location and shielding ATB, acute radiation signs and symptoms, and prior ABCC medical or pathology examinations. 5 references, 57 tables.

Geochemical computer codes. A review

International Nuclear Information System (INIS)

Andersson, K.

1987-01-01

In this report a review of available codes is performed and some code intercomparisons are also discussed. The number of codes treating natural waters (groundwater, lake water, sea water) is large. Most geochemical computer codes treat equilibrium conditions, although some codes with kinetic capability are available. A geochemical equilibrium model consists of a computer code, solving a set of equations by some numerical method and a data base, consisting of thermodynamic data required for the calculations. There are some codes which treat coupled geochemical and transport modeling. Some of these codes solve the equilibrium and transport equations simultaneously while other solve the equations separately from each other. The coupled codes require a large computer capacity and have thus as yet limited use. Three code intercomparisons have been found in literature. It may be concluded that there are many codes available for geochemical calculations but most of them require a user that us quite familiar with the code. The user also has to know the geochemical system in order to judge the reliability of the results. A high quality data base is necessary to obtain a reliable result. The best results may be expected for the major species of natural waters. For more complicated problems, including trace elements, precipitation/dissolution, adsorption, etc., the results seem to be less reliable. (With 44 refs.) (author)

Geochemical characteristics of the Permian sedimentary rocks from Qiangtang Basin: Constraints for paleoenvironment and paleoclimate

Directory of Open Access Journals (Sweden)

Junjie Hu

2017-01-01

Full Text Available Qiangtang Basin is expected to become important strategic petroleum exploitation area in China. However, little research has been done on the Permian strata in this area. This paper presents Lower Permian Zhanjin Formation geochemical data from the Jiaomuri area, reconstructing the paleo-depositional environment and providing information for further petroleum exploration. The geochemical characteristics of 19 samples were investigated. These geochemical samples show a developed mud flat characteristic with light rich clay content. The geological data were used to constrain the paleoredox environment, which proved that these sediments were deposited mainly beneath a slightly oxic water column with relatively low paleoproductivity as evidenced by the P/Ti (mean of 0.07 and Ba/Al (mean of 20.5. Palaeoclimate indexes such as the C-value (0.24-1.75 and Sr/Cu (1.28-11.58 reveal a humid climatic condition during Zhanjin Formation sediment deposition. The ω(LaN/ω(YbN ratio values indicate a fast sedimentary rate during the deposition period.

Geochemical mapping of Anheung, Wonju and Eomjeong sheets (1:50,000)

Energy Technology Data Exchange (ETDEWEB)

Lee, Jin Soo; Seo, Hyo Joon; Shin, Seong Cheon; Chi, Se Jung; Kim, Seong Jae [Korea Inst. of Geology Mining and Materials, Taejon (Korea, Republic of)

1995-12-01

A geochemical mapping was undertaken on the three quadrangles of the Anheung, Wonju and Eomjeong sheets (1:50,000, new edition) in the southwestern Taebaeg Mineralized Belt. The survey area, ca. 1,900 km{sup 2}, is covered mostly by Jurassic granites and Precambrian metamorphic rocks, and partly by Cambro-Ordovician limestones and the Cretaceous igneous and sedimentary rocks. Light mineral stream sediments and water samples, totally 751 for each media, were collected from active channels of primary or secondary order with a mean sampling density of 1/2.4 km{sup 2}. Geochemical maps were made on 17 elements (i.e., Ag, Al, As, Ba, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Sr, V, W, Zn) for stream sediments. Geochemical distribution maps for water samples were independently made on major and minor components (i.e., Na, K, Li, Si, Ca, Mg, Al, As, B, Ba, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Sr, V, Zn, F{sup -}, Cl{sup -}, NO{sub 3}{sup -}, NO{sub 2}{sup -}, PO{sub 4}{sup 3-}, SO{sub 4}{sup 2-}, HCO{sub 3}{sup -}) and other physico-chemical properties (i.e., Electric Conductivity, Total Dissolved Solids, pH, Dissolved Oxygen). Analysis was carried out by Ion Coupled Plasma Spectrometry and Ion Chromatography. Geochemical anomalies were evaluated based upon geological and other field information. The Ag-As, Cu-Pb-Zn and W-Mo anomalies of stream sediments in the northern Anheung and southern Eomjeong sheets indicate a contamination derived from mining districts. Pb-Zn anomalies from southeastern area in the Eomjeong sheet may suggest a potential of polymetallic deposits near Mesozoic granites intruding the Ogcheon strata. High concentrations of Ca, Na, K, Cl{sup -} and NO{sub 3}{sup -} in stream waters around Chungju and Wonju imply a strong pollution over urban districts and stock farms. (author). 57 refs., 70 figs.

In-Situ Systematic Error Correction for Digital Volume Correlation Using a Reference Sample

KAUST Repository

Wang, B.

2017-11-27

The self-heating effect of a laboratory X-ray computed tomography (CT) scanner causes slight change in its imaging geometry, which induces translation and dilatation (i.e., artificial displacement and strain) in reconstructed volume images recorded at different times. To realize high-accuracy internal full-field deformation measurements using digital volume correlation (DVC), these artificial displacements and strains associated with unstable CT imaging must be eliminated. In this work, an effective and easily implemented reference sample compensation (RSC) method is proposed for in-situ systematic error correction in DVC. The proposed method utilizes a stationary reference sample, which is placed beside the test sample to record the artificial displacement fields caused by the self-heating effect of CT scanners. The detected displacement fields are then fitted by a parametric polynomial model, which is used to remove the unwanted artificial deformations in the test sample. Rescan tests of a stationary sample and real uniaxial compression tests performed on copper foam specimens demonstrate the accuracy, efficacy, and practicality of the presented RSC method.

In-Situ Systematic Error Correction for Digital Volume Correlation Using a Reference Sample

KAUST Repository

Wang, B.; Pan, B.; Lubineau, Gilles

2017-01-01

The self-heating effect of a laboratory X-ray computed tomography (CT) scanner causes slight change in its imaging geometry, which induces translation and dilatation (i.e., artificial displacement and strain) in reconstructed volume images recorded at different times. To realize high-accuracy internal full-field deformation measurements using digital volume correlation (DVC), these artificial displacements and strains associated with unstable CT imaging must be eliminated. In this work, an effective and easily implemented reference sample compensation (RSC) method is proposed for in-situ systematic error correction in DVC. The proposed method utilizes a stationary reference sample, which is placed beside the test sample to record the artificial displacement fields caused by the self-heating effect of CT scanners. The detected displacement fields are then fitted by a parametric polynomial model, which is used to remove the unwanted artificial deformations in the test sample. Rescan tests of a stationary sample and real uniaxial compression tests performed on copper foam specimens demonstrate the accuracy, efficacy, and practicality of the presented RSC method.

Geochemical characteristics of Lower Jurassic source rocks in the Zhongkouzi Basin

Science.gov (United States)

Niu, Haiqing; Han, Xiaofeng; Wei, Jianshe; Zhang, Huiyuan; Wang, Baowen

2018-01-01

Zhongkouzi basin is formed in Mesozoic and Cenozoic and developed on the Hercynian folded belt, the degree of exploration for oil and gas is relatively low hitherto. In order to find out the geochemical characteristics of the source rocks and the potentials for hydrocarbon generation. The research result shows that by analysis the geochemical characteristics of outcrop samples and new core samples in Longfengshan Group, Longfengshan Group are most developed intervals of favorable source rocks. They are formed in depression period of the basin when the sedimentary environments is salt water lacustrine and the water is keeping stable; The organic matter abundance is middle-higher, the main kerogen type is II1-II2 and few samples act as III type, The organic matter maturity is low maturity to medium maturity. The organic matter maturity of the source rock from eastern part of the basin is higher than in the western region. The source rock of Longfengshan Group are in the hydrocarbon generation threshold. The great mass of source rocks are matured and in the peak stage of oil generation.

Geochemical prospecting for uranium and thorium deposits

International Nuclear Information System (INIS)

Boyle, R.W.

1980-01-01

A brief review of analytical geochemical prospecting methods for uranium and thorium is given excluding radiometric techniques, except those utilized in the determination of radon. The indicator (pathfinder) elements useful in geochemical surveys are listed for each of the types of known uranium and thorium deposits; this is followed by sections on analytical geochemical surveys based on rocks (lithochemical surveys), unconsolidated materials (pedochemical surveys), natural waters and sediments (hydrochemical surveys), biological materials (biogeochemical surveys) and gases (atmochemical surveys). All of the analytical geochemical methods are applicable in prospecting for thorium and uranium, particularly where radiometric methods fail due to attenuation by overburden, water, deep leaching and so on. Efficiency in the discovery of uranium and/or thorium orebodies is promoted by an integrated methods approach employing geological pattern recognition in the localization of deposits, analytical geochemical surveys, and radiometric surveys. (author)

Geochemical approach to evaluate deforest of mangroves

OpenAIRE

Ishiga, Hiroaki; Diallo, Ibrahima M'bemba; Bah Mamadou Lamine Malick,; Ngulimi. Faustine Miguta,; Magai. Paschal Justin,; Shati Samwel Stanley,

2016-01-01

Processes of mangrove deforest related human activities were examined. To evaluate changes of soil feature, multielements geochemical compositions of mangrove muds and soils of deforest were analyzed. To describe present situation of the mangrove, Conakry in Guinea, Dar es Salaam in Tanzania, Sundarbans of Bangladesh and Nago in Okinawa of Japan were selected. Soil samples of the forests were evaluated enrichment of biologically concentrated heavy metals such as Zn, Cu and Fe, and TS (total s...

DNA-based methods of geochemical prospecting

Energy Technology Data Exchange (ETDEWEB)

Ashby, Matthew [Mill Valley, CA

2011-12-06

The present invention relates to methods for performing surveys of the genetic diversity of a population. The invention also relates to methods for performing genetic analyses of a population. The invention further relates to methods for the creation of databases comprising the survey information and the databases created by these methods. The invention also relates to methods for analyzing the information to correlate the presence of nucleic acid markers with desired parameters in a sample. These methods have application in the fields of geochemical exploration, agriculture, bioremediation, environmental analysis, clinical microbiology, forensic science and medicine.

Characterisation of a reference site for quantifying uncertainties related to soil sampling

International Nuclear Information System (INIS)

Barbizzi, Sabrina; Zorzi, Paolo de; Belli, Maria; Pati, Alessandra; Sansone, Umberto; Stellato, Luisa; Barbina, Maria; Deluisa, Andrea; Menegon, Sandro; Coletti, Valter

2004-01-01

An integrated approach to quality assurance in soil sampling remains to be accomplished. - The paper reports a methodology adopted to face problems related to quality assurance in soil sampling. The SOILSAMP project, funded by the Environmental Protection Agency of Italy (APAT), is aimed at (i) establishing protocols for soil sampling in different environments; (ii) assessing uncertainties associated with different soil sampling methods in order to select the 'fit-for-purpose' method; (iii) qualifying, in term of trace elements spatial variability, a reference site for national and international inter-comparison exercises. Preliminary results and considerations are illustrated

Influence of secular trends and sample size on reference equations for lung function tests.

Science.gov (United States)

Quanjer, P H; Stocks, J; Cole, T J; Hall, G L; Stanojevic, S

2011-03-01

The aim of our study was to determine the contribution of secular trends and sample size to lung function reference equations, and establish the number of local subjects required to validate published reference values. 30 spirometry datasets collected between 1978 and 2009 provided data on healthy, white subjects: 19,291 males and 23,741 females aged 2.5-95 yrs. The best fit for forced expiratory volume in 1 s (FEV(1)), forced vital capacity (FVC) and FEV(1)/FVC as functions of age, height and sex were derived from the entire dataset using GAMLSS. Mean z-scores were calculated for individual datasets to determine inter-centre differences. This was repeated by subdividing one large dataset (3,683 males and 4,759 females) into 36 smaller subsets (comprising 18-227 individuals) to preclude differences due to population/technique. No secular trends were observed and differences between datasets comprising >1,000 subjects were small (maximum difference in FEV(1) and FVC from overall mean: 0.30- -0.22 z-scores). Subdividing one large dataset into smaller subsets reproduced the above sample size-related differences and revealed that at least 150 males and 150 females would be necessary to validate reference values to avoid spurious differences due to sampling error. Use of local controls to validate reference equations will rarely be practical due to the numbers required. Reference equations derived from large or collated datasets are recommended.

Geochemical investigations at Maxey Flats radioactive waste disposal site

International Nuclear Information System (INIS)

Dayal, R.; Pietrzak, R.F.; Clinton, J.

1984-09-01

As part of the NRC efforts to develop a data base on source term characteristics for low level wastes, Brookhaven National Laboratory (BNL) has produced and analyzed a large amount of data on trench leachate chemistry at existing shallow land burial sites. In this report, we present the results of our investigations at the Maxey Flats, Kentucky disposal site. In particular, data on trench leachate chemistry are reviewed and discussed in terms of mechanisms and processes controlling the composition of trench solutes. Particular emphasis is placed on identifying both intra- and extra-trench factors and processes contributing to source term characteristics, modifications, and uncertainties. BNL research on the Maxey Flats disposal site has provided important information not only on the source term characteristics and the factors contributing to uncertainties in the source term but also some generic insights into such geochemical processes and controls as the mechanics of leachate formation, microbial degradation and development of anoxia, organic complexation and radionuclide mobility, redox inversion and modification of the source term, solubility constraints on solute chemistry, mineral authigenesis, corrosion products and radionuclide scavenging, and the role of organic complexants in geochemical partitioning of radionuclides. A knowledge of such processes and controls affecting the geochemical cycling of radionuclides as well as an understanding of the important factors that contribute to variability and uncertainties in the source term is essential for evaluating the performance of waste package and the site, making valid predictions of release for dose calculations, and for planning site performance monitoring as well as remedial actions. 43 references, 47 figures, 30 tables

Geochemical maps of stream sediments in central Colorado, from New Mexico to Wyoming

Science.gov (United States)

Eppinger, Robert G.; Giles, Stuart A.; Klein, Terry L.

2015-01-01

The U.S. Geological Survey has completed a series of geologic, mineral resource, and environmental assessment studies in the Rocky Mountains of central Colorado, from Leadville eastward to the range front and from New Mexico to the Wyoming border. Regional stream-sediment geochemical maps, useful for assessing mineral resources and environmental effects of historical mining activities, were produced as part of the study. The data portrayed in this 56-parameter portfolio of landscape geochemical maps serve as a geochemical baseline for the region, indicate element abundances characteristic of various lithologic terranes, and identify gross anthropogenic effects of historical mining. However, although reanalyzed in this study by modern, sensitive methods, the majority of the stream-sediment samples were collected in the 1970s. Thus, metal concentrations portrayed in these maps represent stream-sediment geochemistry at the time of collection.

Updated Reference Model for Heat Generation in the Lithosphere

Science.gov (United States)

Wipperfurth, S. A.; Sramek, O.; Roskovec, B.; Mantovani, F.; McDonough, W. F.

2017-12-01

Models integrating geophysics and geochemistry allow for characterization of the Earth's heat budget and geochemical evolution. Global lithospheric geophysical models are now constrained by surface and body wave data and are classified into several unique tectonic types. Global lithospheric geochemical models have evolved from petrological characterization of layers to a combination of petrologic and seismic constraints. Because of these advances regarding our knowledge of the lithosphere, it is necessary to create an updated chemical and physical reference model. We are developing a global lithospheric reference model based on LITHO1.0 (segmented into 1°lon x 1°lat x 9-layers) and seismological-geochemical relationships. Uncertainty assignments and correlations are assessed for its physical attributes, including layer thickness, Vp and Vs, and density. This approach yields uncertainties for the masses of the crust and lithospheric mantle. Heat producing element abundances (HPE: U, Th, and K) are ascribed to each volume element. These chemical attributes are based upon the composition of subducting sediment (sediment layers), composition of surface rocks (upper crust), a combination of petrologic and seismic correlations (middle and lower crust), and a compilation of xenolith data (lithospheric mantle). The HPE abundances are correlated within each voxel, but not vertically between layers. Efforts to provide correlation of abundances horizontally between each voxel are discussed. These models are used further to critically evaluate the bulk lithosphere heat production in the continents and the oceans. Cross-checks between our model and results from: 1) heat flux (Artemieva, 2006; Davies, 2013; Cammarano and Guerri, 2017), 2) gravity (Reguzzoni and Sampietro, 2015), and 3) geochemical and petrological models (Rudnick and Gao, 2014; Hacker et al. 2015) are performed.

Appliance of geochemical engineering in radioactive waste disposal

International Nuclear Information System (INIS)

Li Shuang; Zhang Chengjiang; Ni Shijun; Li Kuanliang

2008-01-01

The basic foundation of applying geochemical engineering to control environment, common engineering models of disposal radioactive waste and the functions of the engineering barriers are introduced in this paper. The authors take the geochemical engineering barrier materiel research of a radioactive waste repository as an example to explain the appliance of geochemical engineering in the disposal of radioactive waste. And the results show that it can enhance the security of the nuclear waste repository if we use geochemical engineering barrier. (authors)

Effect of source integration on the geochemical fluxes from springs

International Nuclear Information System (INIS)

Frisbee, Marty D.; Phillips, Fred M.; White, Art F.; Campbell, Andrew R.; Liu, Fengjing

2013-01-01

Geochemical fluxes from watersheds are typically defined using mass-balance methods that essentially lump all weathering processes operative in a watershed into a single flux of solute mass measured in streamflow at the watershed outlet. However, it is important that we understand how weathering processes in different hydrological zones of a watershed (i.e., surface, unsaturated, and saturated zones) contribute to the total geochemical flux from the watershed. This capability will improve understanding of how geochemical fluxes from these different zones may change in response to climate change. Here, the geochemical flux from weathering processes occurring solely in the saturated zone is investigated. This task, however, remains exceedingly difficult due to the sparsity of subsurface sampling points, especially in large, remote, and/or undeveloped watersheds. In such cases, springflow is often assumed to be a proxy for groundwater (defined as water residing in fully saturated geologic formations). However, springflow generation may integrate different sources of water including, but not limited to, groundwater. The authors’ hypothesis is that long-term estimates of geochemical fluxes from groundwater using springflow proxies will be too large due to the integrative nature of springflow generation. Two conceptual models of springflow generation are tested using endmember mixing analyses (EMMA) on observations of spring chemistries and stable isotopic compositions in a large alpine watershed in the San Juan Mountains of southwestern Colorado. In the “total springflow” conceptual model, springflow is assumed to be 100% groundwater. In the “fractional springflow” conceptual model, springflow is assumed to be an integration of different sources of water (e.g., groundwater, unsaturated flow, preferential flow in the soil, etc.) and groundwater is only a fractional component. The results indicate that groundwater contributions in springflow range from 2% to 100

A review of airborne particle sampling with special reference to long-lived radioactive dust

International Nuclear Information System (INIS)

Bigu, J.

1990-03-01

This report reviews some basic aspects related to the sampling of airborne particles with special reference to Long-Lived Radioactive Dust (LLRD). The report covers a number of areas of practical interest such as the production of aerosols, the dynamics of suspended particles, the physical and chemical characteristics and properties of dust clouds, and the inhalation and measurement of dust. It is followed with a brief review of dust sampling instrumentation, and with a short account of the work done on LLRD in Canada with a few references to work done outside this country. (34 figs., 7 tabs., 117 refs.)

Use of multiple attributes decision-making Technique for Order Preference by Similarity to Ideal Solution (TOPSIS for Ghare-Gheshlagh calcite in determination of optimum geochemical sampling sites

Directory of Open Access Journals (Sweden)

Mansour Rezaei Azizi

2015-04-01

for green, white and pink calcites were varied 0.087, 0.247 and 0.997 respectively. The low amounts of Eu anomaly for green and white calcites attributed to low rock/fluid ratio (Nesbitt et al., 1990 and relatively more pH value (Cheng et al., 2013, however, increasing the Eu anomaly may be due to high rock/fluid ratio and less pH value. Ce anomalies are 0.0241, 0.0113 and 0.0131 in pink, white and green calcites respectively. The most negative Ce anomaly values show that calcite have precipitated under reduction conditions (Nesbitt et al., 1990. Discussion Recently, multiple attributes decision-making techniques help scientist to solve decision-making problems related to various controlling factors (Zhijun et al., 2013. One of these techniques is a Technique for Order Preference by Similarity to Ideal Solution (TOPSIS which is a quantitative weighted method (Momenei 2006. The identified criteria are CaO abundant in solution (C1, Eu anomaly (C2, Ce anomaly (C3, Sr abundant (C4 and volume (C5. The Index-Rock matrix also includes A1, A2 and A3 alternatives; as pink, green and white calcite respectively. The weighted normalized decision matrix can be calculated by multiplying the normalized evaluation matrix with its associated weight to obtain the result. The result show that Eu anomaly, volume, Sr abundant and Ce anomaly in order have higher role to investigate the geochemical study of area. Calculation of the relative closeness to the ideal solution (Cl * for pink, green and white calcites are 0.837, 0.445 and 0.157 respectively. It can be deduced that the most preferable calcite to be sampled for investigating geochemically are pink and green calcites. References Cheng, D.L., Jiang-haob, L., Shou-pengc, Z., Lianga, L., Zhao-bina, Y., Guo-lina, G. and Tinga, L., 2013. Geochemical characteristics of calcite and dolomite in sandstone of Dongying Sinking, Shandong Province, China. Procedia Earth and Planetary Science, 7(4: 504 – 507. Eftekharnezhad, J., 1973

Selection of reference genes for tissue/organ samples on day 3 fifth-instar larvae in silkworm, Bombyx mori.

Science.gov (United States)

Wang, Genhong; Chen, Yanfei; Zhang, Xiaoying; Bai, Bingchuan; Yan, Hao; Qin, Daoyuan; Xia, Qingyou

2018-06-01

The silkworm, Bombyx mori, is one of the world's most economically important insect. Surveying variations in gene expression among multiple tissue/organ samples will provide clues for gene function assignments and will be helpful for identifying genes related to economic traits or specific cellular processes. To ensure their accuracy, commonly used gene expression quantification methods require a set of stable reference genes for data normalization. In this study, 24 candidate reference genes were assessed in 10 tissue/organ samples of day 3 fifth-instar B. mori larvae using geNorm and NormFinder. The results revealed that, using the combination of the expression of BGIBMGA003186 and BGIBMGA008209 was the optimum choice for normalizing the expression data of the B. mori tissue/organ samples. The most stable gene, BGIBMGA003186, is recommended if just one reference gene is used. Moreover, the commonly used reference gene encoding cytoplasmic actin was the least appropriate reference gene of the samples investigated. The reliability of the selected reference genes was further confirmed by evaluating the expression profiles of two cathepsin genes. Our results may be useful for future studies involving the quantification of relative gene expression levels of different tissue/organ samples in B. mori. © 2018 Wiley Periodicals, Inc.

Regional geochemical prospecting of uranium in the Amazon region

International Nuclear Information System (INIS)

Zenker, A.O.; Hohn, H.

1982-01-01

A regional geochemical prospecting program for uranium in the Serra dos Carajas area, south of Para, was performed by NUCLEBRAS using stream sediment samples obtained from other companies acting in this area. The results of the survey are presented compared to regional geology and an aerial total count map. The different data showed a good correlation, particularly in areas mapped regionally as granitic rocks. (Author) [pt

Establishing nursery estuary otolith geochemical tags for Sea Bass (Dicentrarchus labrax): Is temporal stability estuary dependent?

Science.gov (United States)

Ryan, Diarmuid; Wögerbauer, Ciara; Roche, William

2016-12-01

The ability to determine connectivity between juveniles in nursery estuaries and adult populations is an important tool for fisheries management. Otoliths of juvenile fish contain geochemical tags, which reflect the variation in estuarine elemental chemistry, and allow discrimination of their natal and/or nursery estuaries. These tags can be used to investigate connectivity patterns between juveniles and adults. However, inter-annual variability of geochemical tags may limit the accuracy of nursery origin determinations. Otolith elemental composition was used to assign a single cohort of 0-group sea bass Dicentrarchus labrax to their nursery estuary thus establishing an initial baseline for stocks in waters around Ireland. Using a standard LDFA model, high classification accuracies to nursery sites (80-88%) were obtained. Temporal stability of otolith geochemical tags was also investigated to assess if annual sampling is required for connectivity studies. Geochemical tag stability was found to be strongly estuary dependent.

The isotope X-ray fluorescence analysis and its application in geochemical investigations in Greenland

International Nuclear Information System (INIS)

Kunzendorf, H.

1973-01-01

The applicability of the isotope X-ray fluorescence analysis (IRFA) in the geochemical exploration was investigated. Detection limits of about 0.1% for the elements Ti, Zr, Nb, Mo and La+Ce were achieved in terrain measurements. Detection limits of 0.05% were found in the analysis of Cr, Ni, Cu, Zn, Zr, Nb, Mo, La+Ce and Pb in finely grinded rock samples. Geochemical investigations were carried out in the Ilimaussag-Intrusion in south Greenland as well as on the Mo deposits Malmbjerg and the heavy mineral occurence 'kote 800' in East Greenland. The use of portable IRFA equipment proved to be particularly suitable in the analysis of bed rocks, loose rock samples such as moraine material, in the semi-quantitative analysis of heavy mineral concentrates, the analysis of bored cores during the boring programme, as well as the analysis of finely grinded rock samples. (ORU) [de

Izu-Bonin rear-arc magmatism: Geochemical investigation of volcanoclastic material

OpenAIRE

Sæbø, Andreas

2017-01-01

Studied samples from the Izu Bonin rear arc show a distinct geochemical pattern that resemble the modern continental crust. In contrast to the volcanic front, samples from the Izu Bonin rear arc show enrichment of LREE (La, Ce, Pr, Nd) and higher K2O at a given SiO2. This suggest that processes leading up to the geochemistry observed in the rear arc is fundamental in creating the modern continental crust. Additional isotopic and trace element analysis from volcanic material rec...

Petrological, geochemical and isotopic characteristics of lignite and calcified lignite from mining area Pesje, Velenje Basin, Slovenia

Science.gov (United States)

Vrabec, Mirijam; Markič, Miloš; Vrabec, Marko; Jaćimović, Radojko; Kanduč, Tjaša

2014-05-01

Lignite (organic rich) and calcified lignite (inorganic rich) samples from excavation field -50c mining area Pesje, Velenje Basin, Slovenia were investigated. During geological and structural mapping lignite and calcified lignite samples were systematically taken for determination of their petrological, geochemical and isotopic characteristics. Lignite is composed of fine detritical gelified matrix. At least five different types of calcified lignite were recognized forming laminations, calcifications after wood, petrified wood and complete replacements of lignite with carbonate. All measured parameters so far indicate geochemical processes during sedimentation of the Velenej Basin. After macroscopic description samples were split to organic and inorganic component (Ward, 1984) and powdered in an agate mortar for geochemical and isotopic analyses. Major and trace elements (As, B, Ba, Cd, Co, Cr, Cu, Hg, Mn, Mo, Sb, Se, Th, U, Zn) in these samples were determined by instrumental neutron activation analysis (INAA) using k-0 standardization method (Jaćimović et al, 2002). The isotopic composition of carbon and nitrogen was determined using a Europa 20-20 continuous flow IRMS ANCA-SL preparation module. A 1 mg amount of a sample was weighed in a tin capsule for carbon and 10 mg for nitrogen analysis. Samples for carbon analyses were pretreated with 1 M HCl to remove carbonates. Carbonate samples from carbonate-rich strata and calcified xylite were first roasted at 450 deg C (Krantz et al., 1987). Three miligrams of carbonate sample was transformed into CO2 by reaction with anhydrous H3PO4 at 55 deg C under vacuum (McCrea, 1950) and measured with GV 2003 isotope ratio mass spectrometer. Measured isotopic composition of oxygen as VPDB values was recalculated to the VSMOW reference standard to enable the comparison with data from other coal basins. SEM/EDXS of carbonate rich sediments was performed with JEOL JSM 5800 electron microanalyzer scanning electron microscope

Geochemical modeling: a review

International Nuclear Information System (INIS)

Jenne, E.A.

1981-06-01

Two general families of geochemical models presently exist. The ion speciation-solubility group of geochemical models contain submodels to first calculate a distribution of aqueous species and to secondly test the hypothesis that the water is near equilibrium with particular solid phases. These models may or may not calculate the adsorption of dissolved constituents and simulate the dissolution and precipitation (mass transfer) of solid phases. Another family of geochemical models, the reaction path models, simulates the stepwise precipitation of solid phases as a result of reacting specified amounts of water and rock. Reaction path models first perform an aqueous speciation of the dissolved constituents of the water, test solubility hypotheses, then perform the reaction path modeling. Certain improvements in the present versions of these models would enhance their value and usefulness to applications in nuclear-waste isolation, etc. Mass-transfer calculations of limited extent are certainly within the capabilities of state-of-the-art models. However, the reaction path models require an expansion of their thermodynamic data bases and systematic validation before they are generally accepted

Geochemical modeling: a review

Energy Technology Data Exchange (ETDEWEB)

Jenne, E.A.

1981-06-01

Two general families of geochemical models presently exist. The ion speciation-solubility group of geochemical models contain submodels to first calculate a distribution of aqueous species and to secondly test the hypothesis that the water is near equilibrium with particular solid phases. These models may or may not calculate the adsorption of dissolved constituents and simulate the dissolution and precipitation (mass transfer) of solid phases. Another family of geochemical models, the reaction path models, simulates the stepwise precipitation of solid phases as a result of reacting specified amounts of water and rock. Reaction path models first perform an aqueous speciation of the dissolved constituents of the water, test solubility hypotheses, then perform the reaction path modeling. Certain improvements in the present versions of these models would enhance their value and usefulness to applications in nuclear-waste isolation, etc. Mass-transfer calculations of limited extent are certainly within the capabilities of state-of-the-art models. However, the reaction path models require an expansion of their thermodynamic data bases and systematic validation before they are generally accepted.

Chemical elements in the environment: multi-element geochemical datasets from continental to national scale surveys on four continents

Science.gov (United States)

Caritat, Patrice de; Reimann, Clemens; Smith, David; Wang, Xueqiu

2017-01-01

During the last 10-20 years, Geological Surveys around the world have undertaken a major effort towards delivering fully harmonized and tightly quality-controlled low-density multi-element soil geochemical maps and datasets of vast regions including up to whole continents. Concentrations of between 45 and 60 elements commonly have been determined in a variety of different regolith types (e.g., sediment, soil). The multi-element datasets are published as complete geochemical atlases and made available to the general public. Several other geochemical datasets covering smaller areas but generally at a higher spatial density are also available. These datasets may, however, not be found by superficial internet-based searches because the elements are not mentioned individually either in the title or in the keyword lists of the original references. This publication attempts to increase the visibility and discoverability of these fundamental background datasets covering large areas up to whole continents.

NOAA and MMS Marine Minerals Geochemical Database

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Marine Minerals Geochemical Database was created by NGDC as a part of a project to construct a comprehensive computerized bibliography and geochemical database...

A preliminary study on the geochemical environment for deep geological disposal of high level radioactive waste in Korea

International Nuclear Information System (INIS)

Kim, Chun Soo; Bae, Dae Seok; Kim, Kyung Su; Koh, Yong Kwon; Park, Byoung Yun

2000-03-01

Geochemical study on the groundwater from crystalline rocks (granite and gneiss) for the deep geological disposal of high-level radioactive waste was carried out in order to elucidate the hydrogeochemical and isotope characteristics and geochemical evolution of the groundwater. Study areas are Jungwon, Chojeong, Youngcheon and Yusung for granite region, Cheongyang for gneiss region, and Yeosu for volcanic region. Groundwaters of each study areas weree sampled and analysed systematically. Groundwaters can be grouped by their chemistry and host rock. Origin of the groundwater was proposed by isotope ( 18 O, 2 H, 13 C, 34 S, 87 Sr, 15 N) studies and the age of groundwater was inferred from their tritium contents. Based ont the geochemical and isotope characteristics, the geochemical evolutions of each types of groundwater were simulated using SOLVEQ/CHILLER and PHREEQC programs

Use of partial dissolution techniques in geochemical exploration

Science.gov (United States)

Chao, T.T.

1984-01-01

Application of partial dissolution techniques to geochemical exploration has advanced from an early empirical approach to an approach based on sound geochemical principles. This advance assures a prominent future position for the use of these techniques in geochemical exploration for concealed mineral deposits. Partial dissolution techniques are classified as single dissolution or sequential multiple dissolution depending on the number of steps taken in the procedure, or as "nonselective" extraction and as "selective" extraction in terms of the relative specificity of the extraction. The choice of dissolution techniques for use in geochemical exploration is dictated by the geology of the area, the type and degree of weathering, and the expected chemical forms of the ore and of the pathfinding elements. Case histories have illustrated many instances where partial dissolution techniques exhibit advantages over conventional methods of chemical analysis used in geochemical exploration. ?? 1984.

Geochemical modeling of uranium mill tailings: a case study

International Nuclear Information System (INIS)

Peterson, S.R.; Felmy, A.R.; Serne, R.J.; Gee, G.W.

1983-08-01

Liner failure was not found to be a problem when various acidic tailings solutions leached through liner materials for periods up to 3 y. On the contrary, materials that contained over 30% clay showed a decrease in permeability with time in the laboratory columns. The decreases in permeability noted above are attributed to pore plugging resulting from the precipitation of minerals and solids. This precipitation takes place due to the increase in pH of the tailings solution brought about by the buffering capacity of the soil. Geochemical modeling predicts, and x-ray characterization confirms, that precipitation of solids from solution is occurring in the acidic tailings solution/liner interactions studied. X-ray diffraction identified gypsum and alunite group minerals, such as jarosite, as having precipitated after acidic tailings solutions reacted with clay liners. The geochemical modeling and experimental work described above were used to construct an equilibrium conceptual model consisting of minerals and solid phases. This model was developed to represent a soil column. A computer program was used as a tool to solve the system of mathematical equations imposed by the conceptual chemical model. The combined conceptual model and computer program were used to predict aqueous phase compositions of effluent solutions from permeability cells packed with geologic materials and percolated with uranium mill tailings solutions. An initial conclusion drawn from these studies is that the laboratory experiments and geochemical modeling predictions were capable of simulating field observations. The same mineralogical changes and contaminant reductions observed in the laboratory studies were found at a drained evaporation pond (Lucky Mc in Wyoming) with a 10-year history of acid attack. 24 references, 5 figures 5 tables

Qualitative and quantitative analysis of environmental samples by laser-induced breakdown spectrometry

International Nuclear Information System (INIS)

Zorov, N B; Popov, A M; Zaytsev, S M; Labutin, T A

2015-01-01

The key achievements in the determination of trace amounts of components in environmental samples (soils, ores, natural waters, etc.) by laser-induced breakdown spectrometry are considered. Unique capabilities of this method make it suitable for rapid analysis of metals and alloys, glasses, polymers, objects of cultural heritage, archaeological and various environmental samples. The key advantages of the method that account for its high efficiency are demonstrated, in particular, a small amount of analyzed material, the absence of sample preparation, the possibility of local and remote analysis of either one or several elements. The use of chemometrics in laser-induced breakdown spectrometry for qualitative sample classification is described in detail. Various approaches to improving the figures of merit of quantitative analysis of environmental samples are discussed. The achieved limits of detection for most elements in geochemical samples are critically evaluated. The bibliography includes 302 references

Geochemical Characterization of the Upper and Middle Floridan Aquifer System, South Florida

Science.gov (United States)

Mirecki, J.; Richardson, E.; Bennett, M.; Hendel, J.

2008-05-01

Our study focus is to characterize the water quality and geochemical environment of the Floridan Aquifer System (FAS) throughout the regional flowpath. A synoptic survey of 21 wells (n=15, upper FAS; n=6 middle FAS) was supplemented by additional samples (n=11) obtained during exploratory well development at 4 aquifer storage recovery (ASR) pilot sites. Synoptic survey samples were analyzed intensively, yielding a dataset that consists of major and trace dissolved constituents (including metals), stable isotopes (δ18O, δ13C, δD, δ34S in sulfate and sulfide), carbon species (carbonate alkalinity and organic carbon), uranium-series radionuclides, nutrients, and selected microbes and pathogens. The objectives of this study are three-fold: 1) to provide baseline water-quality and geochemical information prior to initiation of ASR activities that are part of the Comprehensive Everglades Restoration Plan; 2) to quantify the major controls on geochemical evolution along upper and middle FAS flowpaths using geochemical modeling methods; and 3) to identify areas where water- quality may limit the feasibility of ASR methods in the FAS. Preliminary interpretations water quality changes along the regional FAS flowpath can be summarized as follows. Concentrations of dissolved constituents increase from north to south along the flow path; generally, the upper FAS has lower total dissolved solids than the middle FAS at locations where well pairs were analyzed. The redox environment changes from oxic to strongly anoxic, very close to the recharge area. Redox measurements, dissolved iron, sulfide, and sulfur isotope data are consistent with sulfate-reducing conditions. Uranium-series isotope concentrations and activities generally are below regulatory criteria, with few exceptions in both the upper and middle FAS. Areas with greater radionuclide activity occur primarily at distal flowpath locations or at the coast.

Geochemical and mineralogical characteristics of Lithomargic clay

African Journals Online (AJOL)

Administrator

Geochemical and mineralogical characteristics of Lithomargic clay. GEOCHEMICAL AND .... tries, as filling material in the pulp and paper, toothpaste and paint industries as well ..... tions very vital to human health and other ac- tivities of man.

Petrographic and geochemical data for Cenozoic volcanic rocks of the Bodie Hills, California and Nevada

Science.gov (United States)

du Bray, Edward A.; John, David A.; Box, Stephen E.; Vikre, Peter G.; Fleck, Robert J.; Cousens, Brian L.

2013-04-23

Petrographic and geochemical data for Cenozoic volcanic rocks of the Bodie Hills, California and Nevada // // This report presents petrographic and geochemical data for samples collected during investigations of Tertiary volcanism in the Bodie Hills of California and Nevada. Igneous rocks in the area are principally 15–6 Ma subduction-related volcanic rocks of the Bodie Hills volcanic field but also include 3.9–0.1 Ma rocks of the bimodal, post-subduction Aurora volcanic field. Limited petrographic results for local basement rocks, including Mesozoic granitoid rocks and their metamorphic host rocks, are also included in the compilation. The petrographic data include visual estimates of phenocryst abundances as well as other diagnostic petrographic criteria. The geochemical data include whole-rock major oxide and trace element data, as well as limited whole-rock isotopic data.

Geochemical dispersion of uranium near prospects in Pennsylvania

International Nuclear Information System (INIS)

Rose, A.W.; Schmiermund, R.L.; Mahar, D.L.

1977-06-01

The geochemical dispersion of U was investigated near sedimentary uranium prospects in eastern and north-central Pennsylvania. Near Jim Thorpe, known uranium occurrences in the Catskill Fm. are limited to the base of the Duncannon member. At Penn Haven Junction, roll-type U deposits with appreciable Pb and Se are localized adjacent to an oxidized tongue of channel-filling conglomeratic sandstone. The channel and encircling U occurrences furnish a large target for geochemical exploration. Selective extractions show that the organic, Fe-oxide, sand and silt fractions of stream sediments are the major hosts for U in stream sediments. Fe-oxides have a greater affinity for U than organic matter but are less abundant. The U content of organic matter is about 10 5 times the U content of stream water. Stream sediments furnish a representative sample of the average content of U, Zn, Cu, and major elements in soils of a drainage basin in north-central Pennsylvania, so a semiquantitative appraisal of weathering uranium occurrences can be made from stream sediments in climates and topography like Pennsylvania. The flux of uranium leaving the basin in solution is about equal to that leaving as sediment. Uranium is considerably less mobile than Ca and Na. A new method of extracting uranium from water samples, using a liquid ion exchanger (Amberlite LA-1), shows promise for simple field application

A >100 Ma Mantle Geochemical Record: Retiring Mantle Plumes may be Premature

Science.gov (United States)

Konter, J. G.; Hanan, B. B.; Blichert-Toft, J.; Koppers, A. A.; Plank, T.; Staudigel, H.

2006-12-01

Hotspot volcanism has long been attributed to mantle plumes, but in recent years suggestions have been made that plate tectonic processes, such as extension, can account for all hotspot tracks. This explanation involves a profoundly less dynamic lower mantle, which justifies a critical evaluation before the plume model is dismissed. Such an evaluation has to involve a wide range of geochemical, geological, and geophysical techniques, broadly investigating the products of volcanism as well as the underlying lithosphere and mantle. We argue here that the combined geological record and geochemistry of intraplate volcanoes holds some important clues that help us decide between models of plume-like upwelling versus passive upwelling with lithospheric extension. The best of these integrated datasets can be obtained from the long seamount chains in the Pacific Ocean. A new combined dataset of trace element and isotopic compositions, along with modern 40Ar/39Ar ages from seamounts in the Gilbert Ridge, Tokelau chain, and West Pacific Seamount Province (WPSP) provides a record of current to Cretaceous volcanism in the South Pacific. We have reconstructed the eruptive locations of the seamounts using a range of absolute plate motion models, including some models with hotspot motion and others that use the Indo-Atlantic hotspot reference frame. Our results show that the backtracked locations consistently form clusters (300km radius) around the active ends of the Macdonald, Rurutu and Rarotonga hotspot chains, while closely matching their distinct C-HIMU and C-EM1 signatures. The oldest WPSP seamounts (older than 100 Ma) form the only exception and backtrack, with larger uncertainty, to north of Rarotonga. Therefore, the mantle currently underlying the Cook-Austral islands has produced volcanoes in three geochemically distinct areas for at least 100 m.y. Furthermore, we find the shortest mantle residence time, 0.6 Ga, for a source of mixed recycled DMM and an EM1-like

METHYL MERCURY PRODUCTION IN NATURAL-COLLECTED SEDIMENT WITH DIFFERENT GEOCHEMICAL PARAMETERS

Directory of Open Access Journals (Sweden)

Markus T. Lasut

2010-06-01

Full Text Available Production of methyl mercury (MeHg has been shown in laboratory experiments using mercuric chloride (HgCl2 compound released into natural-collected sediments with different geochemical conditions. While the HgCl2 concentration was 30 µl of 113 ppm of HgCl2, the geochemical conditions [pH, salinity, total organic content (TOC, sulfur] of sampled sediments were A: 8.20, 0.00 ppt, 1.97%, and 0.92 ppt, respectively; B: 7.90, 2.00 ppt, 4.69%, and 1.98 ppt, respectively; and C: 8.20, 24.00 ppt, 1.32 %, and 90.90 ppt, respectively. A control was set with no HgCl2. Samples and control were incubated in room temperature of 27 ± 1 °C. Observations were done along 9 days with interval of 3 days. While total Hg was measured using mercury analyzer with Cold Vapor-Atomic Absorbtion Spectrophometer (CV-AAS system, MeHg was measured by using a gas chromatograph with ECD detector after extracted by dithizone-sodium sulfide extraction method. The result shows that MeHg was found in both treatment and control experiments. The concentrations of the MeHg varied according to the geochemical condition of the sampled sediments. Peak production of MeHg occurred on the third day; however, the production was not significantly affected by the incubation time. Optimum production was found inversely related to the pH, in which highest and lowest the pH formed an ineffectively methylated mercury species. The TOC was significantly correlated to the optimum production. Salinity and sulfate contents were found not correlated to the optimum of MeHg production.   Keywords: Methyl mercury; methylation process; sediment; biogeochemistry

Analytical results and sample locality map for rock, stream-sediment, and soil samples, Northern and Eastern Coloado Desert BLM Resource Area, Imperial, Riverside, and San Bernardino Counties, California

Science.gov (United States)

King, Harley D.; Chaffee, Maurice A.

2000-01-01

INTRODUCTION In 1996-1998 the U.S. Geological Survey (USGS) conducted a geochemical study of the Bureau of Land Management's (BLM) 5.5 million-acre Northern and Eastern Colorado Desert Resource Area (usually referred to as the NECD in this report), Imperial, Riverside, and San Bernardino Counties, southeastern California (figure 1). This study was done in support of the BLM's Coordinated Management Plan for the area. This report presents analytical data from this study. To provide comprehensive coverage of the NECD, we compiled and examined all available geochemical data, in digital form, from previous studies in the area, and made sample-site plots to aid in determining where sample-site coverage and analyses were sufficient, which samples should be re-analyzed, and where additional sampling was needed. Previous investigations conducted in parts of the current study area included the National Uranium Resource Evaluation (NURE) program studies of the Needles and Salton Sea 1? x 2? quadrangles; USGS studies of 12 BLM Wilderness Study Areas (WSAs) (Big Maria Mountains, Chemehuevi Mountains, Chuckwalla Mountains, Coxcomb Mountains, Mecca Hills, Orocopia Mountains, Palen-McCoy, Picacho Peak, Riverside Mountains, Sheephole Valley (also known as Sheep Hole/Cadiz), Turtle Mountains, and Whipple Mountains); and USGS studies in the Needles and El Centro 1? x 2? quadrangles done during the early 1990s as part of a project to identify the regional geochemistry of southern California. Areas where we did new sampling of rocks and stream sediments are mainly in the Chocolate Mountain Aerial Gunnery Range and in Joshua Tree National Park, which extends into the west-central part of the NECD, as shown in figure 1 and figure 2. This report contains analytical data for 132 rock samples and 1,245 stream-sediment samples collected by the USGS, and 362 stream-sediment samples and 189 soil samples collected during the NURE program. All samples are from the Northern and Eastern Colorado

Proceedings of 13. International Geochemical Exploration Symposium. 2. Brazilian Geochemical Congress

International Nuclear Information System (INIS)

1989-01-01

Some works about geochemistry are presented, including themes about geochemical exploration, lithogeochemistry and isotope geochemistry, environmental geochemistry, analyical geochemistry, geochemistry of carbonatites and rare earth elements and organic geochemistry. (C.G.C.) [pt

A preliminary study on the geochemical environment for deep geological disposal of high level radioactive waste in Korea

Energy Technology Data Exchange (ETDEWEB)

Kim, Chun Soo; Bae, Dae Seok; Kim, Kyung Su; Koh, Yong Kwon; Park, Byoung Yun

2000-03-01

Geochemical study on the groundwater from crystalline rocks (granite and gneiss) for the deep geological disposal of high-level radioactive waste was carried out in order to elucidate the hydrogeochemical and isotope characteristics and geochemical evolution of the groundwater. Study areas are Jungwon, Chojeong, Youngcheon and Yusung for granite region, Cheongyang for gneiss region, and Yeosu for volcanic region. Groundwaters of each study areas weree sampled and analysed systematically. Groundwaters can be grouped by their chemistry and host rock. Origin of the groundwater was proposed by isotope ({sup 18}O, {sup 2}H, {sup 13}C, {sup 34}S, {sup 87}Sr, {sup 15}N) studies and the age of groundwater was inferred from their tritium contents. Based ont the geochemical and isotope characteristics, the geochemical evolutions of each types of groundwater were simulated using SOLVEQ/CHILLER and PHREEQC programs.

A national-scale geochemical and mineralogical survey of soils of the conterminous United States

International Nuclear Information System (INIS)

Smith, David B.; Cannon, William F.; Woodruff, Laurel G.

2011-01-01

Highlights: → Sampling for national-scale soil geochemical and mineralogical survey completed for conterminous USA. → Natural variation for most elements is approximately three orders of magnitude. → Composition of soil parent material is the major controlling factor. → Climate (average annual precipitation) is also an important controlling factor for some elements. → Sample archive (4800 sites) available for future investigations. - Abstract: In 2007, the US Geological Survey initiated a low-density (1 site per 1600 km 2 , c. 4800 sites) geochemical and mineralogical survey of soils of the conterminous USA. The ideal sampling protocol at each site includes a sample from 0-5 cm depth, a composite of the soil A horizon, and a sample from the soil C horizon. The 3 , HClO 4 and HF. Separate methods are used for As, Hg, Se and total C on this same size fraction. The major mineralogical components are determined by a quantitative X-ray diffraction method. Sampling was completed in 2010 with chemical and mineralogical analysis currently underway. Preliminary results for a swath from the central USA to Florida clearly show the effects of soil parent material and climate on the chemical and mineralogical composition of soils. A sample archive will be established and made available for future investigations.

Report on the geological-geochemical research carried out within the area of geochemical anomaly P7, Vathyrema, Drama Department

International Nuclear Information System (INIS)

Stavropoulos, Athanasios.

1982-08-01

The investigated area covering about 30 km 2 is situated in the crystalline massive of Rhodope (north of Drama deparment, E. Macedonia) where granitoids constitute its main petrological type. The geological-geochemical and radiometric investigations carried out so far in the area have localized a large number of places with high values of γ-radiation (1.000 - 15.000 c/s), as well as high concentrations of uranium (50-500 ppm). The uranium mineralization within the zone of oxidation is expressed by the uranium mineral autunite, accompanied by intensive hematitization-limonitization and chloritization-kaolinization, and additionally by small spots and veinlets of pyrite and galena. It seems that tectonic control exists on the uranium mineralization, since most of the anomalous concentrations of uranium are sitting along mylonite zones rich in chlorite and kaolin. There have been discerned seven more anomalous part areas which will have to be covered by geochemical stream sediment sampling (phase 3), as well as geological mapping (scale 1:5.000). The results from the research conducted within the concerned anomaly lead us to the conclusion that this area is very promising and possibilities of localization of uranium payable concentrations are very high. (N.Ch.)

Evaluation of Botanical Reference Materials for the Determination of Vanadium in Biological Samples

DEFF Research Database (Denmark)

Heydorn, Kaj; Damsgaard, Else

1982-01-01

Three botanical reference materials prepared by the National Bureau of Standards have been studied by neutron activation analysis to evaluate their suitability with respect to the determination of vanadium in biological samples. Various decomposition methods were applied in connection with chemic....... A reference value of 1.15 mg/kg of this material is recommended, based on results from 3 different methods. All three materials are preferable to SRM 1571 Orchard Leaves, while Bowen's Kale remains the material of choice because of its lower concentration....

Testing and sampling of deep brine aquifers in the Palo Duro Basin, West Texas

International Nuclear Information System (INIS)

Deyling, M.A.

1984-01-01

The US Department of Energy is investigating the Palo Duro Basin of West Texas along with locations in Nevada, Washington, Utah, Mississippi and Louisiana as potential sites for storage of high-level nuclear waste. Ten wells have been drilled to depths between 3000 and 8300 feet. Testing and sampling of deep test zones requires advance planning and analysis of what must be obtained from the well. Various alternatives are available depending on data needs. In this particular instance, both hydrologic and geochemical data were required. The methods chosen were field proven methods used in the oil field industry for many years. Short term testing has included conventional oil-field-type drill stem tests and drill stem equipment with surface pressure readout. Long term testing has consisted of a series of production and recovery tests. Fluid sampling was performed in two stages. The first was at the well head under an imposed pressure of several hundred psi. The second fluid samples were collected downhole at the production zone under pressures close to ambient pressure. The geochemical data and hydrologic data can be used as independent checks on each other in many cases. Test results from the well along with examination of recovered core provided maximum data for each well. 5 references, 8 figures

Geochemical signatures of tephras from Quaternary Antarctic Peninsula volcanoes

OpenAIRE

Kraus,Stefan; Kurbatov,Andrei; Yates,Martin

2013-01-01

In the northern Antarctic Peninsula area, at least 12 Late Plelstocene-Holocene volcanic centers could be potential sources of tephra layers in the region. We present unique geochemical fingerprints for ten of these volcanoes using major, trace, rare earth element, and isotope data from 95 samples of tephra and other eruption products. The volcanoes have predominantly basaltic and basaltic andesitic compositions. The Nb/Y ratio proves useful to distinguish between volcanic centers located on ...

Statistical tables and charts showing geochemical variation in the Mesoproterozoic Big Creek, Apple Creek, and Gunsight formations, Lemhi group, Salmon River Mountains and Lemhi Range, central Idaho

Science.gov (United States)

Lindsey, David A.; Tysdal, Russell G.; Taggart, Joseph E.

2002-01-01

The principal purpose of this report is to provide a reference archive for results of a statistical analysis of geochemical data for metasedimentary rocks of Mesoproterozoic age of the Salmon River Mountains and Lemhi Range, central Idaho. Descriptions of geochemical data sets, statistical methods, rationale for interpretations, and references to the literature are provided. Three methods of analysis are used: R-mode factor analysis of major oxide and trace element data for identifying petrochemical processes, analysis of variance for effects of rock type and stratigraphic position on chemical composition, and major-oxide ratio plots for comparison with the chemical composition of common clastic sedimentary rocks.

Field-based tests of geochemical modeling codes: New Zealand hydrothermal systems

International Nuclear Information System (INIS)

Bruton, C.J.; Glassley, W.E.; Bourcier, W.L.

1993-12-01

Hydrothermal systems in the Taupo Volcanic Zone, North Island, New Zealand are being used as field-based modeling exercises for the EQ3/6 geochemical modeling code package. Comparisons of the observed state and evolution of the hydrothermal systems with predictions of fluid-solid equilibria made using geochemical modeling codes will determine how the codes can be used to predict the chemical and mineralogical response of the environment to nuclear waste emplacement. Field-based exercises allow us to test the models on time scales unattainable in the laboratory. Preliminary predictions of mineral assemblages in equilibrium with fluids sampled from wells in the Wairakei and Kawerau geothermal field suggest that affinity-temperature diagrams must be used in conjunction with EQ6 to minimize the effect of uncertainties in thermodynamic and kinetic data on code predictions

Data for the geochemical investigation of UMTRAP designated site at Monument Valley, Arizona

International Nuclear Information System (INIS)

Markos, G.; Bush, K.J.

1983-09-01

This report contains the geochemical data and the methods of data collection from the former tailings site at Monument Valley, Arizona. Data are from a one-time sampling of waters and solid material from the background, the area adjacent to the site, and the site. Selected solid samples are water extracted to remove easily soluble salts. The waters and extracts of solid samples were analyzed for selected major and trace elements. 3 refs., 2 figs., 1 tab

Site study plan for geochemical analytical requirements and methodologies: Revision 1

International Nuclear Information System (INIS)

1987-12-01

This site study plan documents the analytical methodologies and procedures that will be used to analyze geochemically the rock and fluid samples collected during Site Characterization. Information relating to the quality aspects of these analyses is also provided, where available. Most of the proposed analytical procedures have been used previously on the program and are sufficiently sensitive to yield high-quality analyses. In a few cases improvements in analytical methodology (e.g., greater sensitivity, fewer interferences) are desired. Suggested improvements to these methodologies are discussed. In most cases these method-development activities have already been initiated. The primary source of rock and fluid samples for geochemical analysis during Site Characterization will be the drilling program, as described in various SRP Site Study Plans. The Salt Repository Project (SRP) Networks specify the schedule under which the program will operate. Drilling will not begin until after site ground water baseline conditions have been established. The Technical Field Services Contractor (TFSC) is responsible for conducting the field program of drilling and testing. Samples and data will be handled and reported in accordance with established SRP procedures. A quality assurance program will be utilized to assure that activities affecting quality are performed correctly and that the appropriate documentation is maintained. 28 refs., 9 figs., 14 tabs

Geochemical studies of the sediments of Barreiras group, Itaborai region-RJ, Brazil

International Nuclear Information System (INIS)

Neves, M.C.G.P.

1983-01-01

It is purpused to study the lead, copper, chromium, manganese, vanadium and zinc geochemical bahavior of the clays obtained from outcrop samples of Barreiras group and weathered Pre-Cambriam situated at Itaborai region, in Rio de Janeiro State, Brazil. Field and laboratory description, grain size analyses, X-ray diffraction, emission spectrography, X-ray fluorescence, atomic absorption, transmission electronic microscopy and pH tests were applied to twenty-two samples selected. (Author) [pt

The IUGS/IAGC Task Group on Global Geochemical Baselines

Science.gov (United States)

Smith, David B.; Wang, Xueqiu; Reeder, Shaun; Demetriades, Alecos

2012-01-01

The Task Group on Global Geochemical Baselines, operating under the auspices of both the International Union of Geological Sciences (IUGS) and the International Association of Geochemistry (IAGC), has the long-term goal of establishing a global geochemical database to document the concentration and distribution of chemical elements in the Earth’s surface or near-surface environment. The database and accompanying element distribution maps represent a geochemical baseline against which future human-induced or natural changes to the chemistry of the land surface may be recognized and quantified. In order to accomplish this long-term goal, the activities of the Task Group include: (1) developing partnerships with countries conducting broad-scale geochemical mapping studies; (2) providing consultation and training in the form of workshops and short courses; (3) organizing periodic international symposia to foster communication among the geochemical mapping community; (4) developing criteria for certifying those projects whose data are acceptable in a global geochemical database; (5) acting as a repository for data collected by those projects meeting the criteria for standardization; (6) preparing complete metadata for the certified projects; and (7) preparing, ultimately, a global geochemical database. This paper summarizes the history and accomplishments of the Task Group since its first predecessor project was established in 1988.

Toward a better understanding of the complex geochemical processes governing subsurface contaminant transport

International Nuclear Information System (INIS)

Puls, R.W.

1990-01-01

Identification and understanding of the geochemical processes, including ion exchange, precipitation, organic partitioning, chemisorption, aqueous complexation, and colloidal stability and transport, controlling subsurface contamination is essential for making accurate predictions of the fate and transport of these constituents. Current approaches to quantify the effect of these processes primarily involve laboratory techniques, including the use of closed static systems (batch experiments) where small amounts of aquifer solids or minerals are contacted with an aqueous phase containing the components of interest for relatively short durations; and dynamic systems (column experiments) where a larger segment of the aquifer is investigated by analyzing the breakthrough profiles of reactive and non-reactive species. Both approaches are constrained by differences in scale, alteration of media during sample collection and use, and spatial variability. More field reactivity studies are needed to complement established laboratory approaches for the determination of retardation factors and scaling factors, corroboration of batch and column results, and validation of sampling techniques. These studies also serve to accentuate areas of geochemical process research where data deficiencies exist, such as the kinetics of adsorption-desorption, metal-organic-mineral interactions, and colloidal mobility. The advantages and disadvantages of the above approaches are discussed in the context of achieving a more completely integrated approach to geochemical transport experiments, with supportive data presented from selected studies. (Author) (16 refs., 4 figs., 2 tabs.)

Reconnaissance Geochemical Study

African Journals Online (AJOL)

distribution patterns. The geochemical distribution maps of the elements reveal that Cu, Pb, Zn, Co, Sc, Ni, Cr, .... After filtration, the leached solutions were diluted with ultra ...... some other rare earth elements in the study area. The occurrence ...

Identification and assembly of genomes and genetic elements in complex metagenomic samples without using reference genomes.

Science.gov (United States)

Nielsen, H Bjørn; Almeida, Mathieu; Juncker, Agnieszka Sierakowska; Rasmussen, Simon; Li, Junhua; Sunagawa, Shinichi; Plichta, Damian R; Gautier, Laurent; Pedersen, Anders G; Le Chatelier, Emmanuelle; Pelletier, Eric; Bonde, Ida; Nielsen, Trine; Manichanh, Chaysavanh; Arumugam, Manimozhiyan; Batto, Jean-Michel; Quintanilha Dos Santos, Marcelo B; Blom, Nikolaj; Borruel, Natalia; Burgdorf, Kristoffer S; Boumezbeur, Fouad; Casellas, Francesc; Doré, Joël; Dworzynski, Piotr; Guarner, Francisco; Hansen, Torben; Hildebrand, Falk; Kaas, Rolf S; Kennedy, Sean; Kristiansen, Karsten; Kultima, Jens Roat; Léonard, Pierre; Levenez, Florence; Lund, Ole; Moumen, Bouziane; Le Paslier, Denis; Pons, Nicolas; Pedersen, Oluf; Prifti, Edi; Qin, Junjie; Raes, Jeroen; Sørensen, Søren; Tap, Julien; Tims, Sebastian; Ussery, David W; Yamada, Takuji; Renault, Pierre; Sicheritz-Ponten, Thomas; Bork, Peer; Wang, Jun; Brunak, Søren; Ehrlich, S Dusko

2014-08-01

Most current approaches for analyzing metagenomic data rely on comparisons to reference genomes, but the microbial diversity of many environments extends far beyond what is covered by reference databases. De novo segregation of complex metagenomic data into specific biological entities, such as particular bacterial strains or viruses, remains a largely unsolved problem. Here we present a method, based on binning co-abundant genes across a series of metagenomic samples, that enables comprehensive discovery of new microbial organisms, viruses and co-inherited genetic entities and aids assembly of microbial genomes without the need for reference sequences. We demonstrate the method on data from 396 human gut microbiome samples and identify 7,381 co-abundance gene groups (CAGs), including 741 metagenomic species (MGS). We use these to assemble 238 high-quality microbial genomes and identify affiliations between MGS and hundreds of viruses or genetic entities. Our method provides the means for comprehensive profiling of the diversity within complex metagenomic samples.

Geochemical modelling: what phenomena are missing

International Nuclear Information System (INIS)

Jacquier, P.

1989-12-01

In the framework of safety assessment of radioactive waste disposal, retention phenomena are usually taken into account by the Kd concept. It is well recognized that this concept is not enough for safety assessment models, because of the several and strong assumptions which are involved in this kind of representation. One way to have a better representation of the retention phenomena, is to substitute for this Kd concept an explicit description of geochemical phenomena and then couple transport codes with geochemical codes in a fully or a two-step procedure. We use currently such codes, but the scope of this paper is to display the limits today of the geochemical modelling in connection with sites analysis for deep disposal. In this paper, we intend to give an overview of phenomena which are missing in the geochemical models, or which are not completely introduced in the models. We can distinguish, on one hand phenomena for which modelling concepts exist such as adsorption/desorption and, on the other hand, phenomena for which modelling concepts do not exist for the moment such as colloids, and complexation by polyelectrolyte solutions (organics). Moreover we have to take care of very low concentrations of radionuclides, which can be expected from the leaching processes in the repository. Under those conditions, some reactions may not occur. After a critical review of the involved phenomena, we intend to stress the main directions of the wishful evolution of the geochemical modelling. This evolution should improve substantially the quality of the above-mentioned site assessments

Remote Raman - laser induced breakdown spectroscopy (LIBS) geochemical investigation under Venus atmospheric conditions

Energy Technology Data Exchange (ETDEWEB)

Clegg, Sanuel M [Los Alamos National Laboratory; Barefield, James E [Los Alamos National Laboratory; Humphries, Seth D [Los Alamos National Laboratory; Wiens, Roger C [Los Alamos National Laboratory; Vaniman, D. T. [Los Alamos National Laboratory; Sharma, S. K. [UNIV OF HAWAII; Misra, A. K. [UNIV OF HAWAII; Dyar, M. D. [MT. HOLYOKE COLLEGE; Smrekar, S. E. [JET PROPULSION LAB.

2010-12-13

The extreme Venus surface temperatures ({approx}740 K) and atmospheric pressures ({approx}93 atm) create a challenging environment for surface missions. Scientific investigations capable of Venus geochemical observations must be completed within hours of landing before the lander will be overcome by the harsh atmosphere. A combined remote Raman - LIBS (Laser Induced Breakdown Spectroscopy) instrument is capable of accomplishing the geochemical science goals without the risks associated with collecting samples and bringing them into the lander. Wiens et al. and Sharma et al. demonstrated that both analytical techniques can be integrated into a single instrument capable of planetary missions. The focus of this paper is to explore the capability to probe geologic samples with Raman - LIBS and demonstrate quantitative analysis under Venus surface conditions. Raman and LIBS are highly complementary analytical techniques capable of detecting both the mineralogical and geochemical composition of Venus surface materials. These techniques have the potential to profoundly increase our knowledge of the Venus surface composition, which is currently limited to geochemical data from Soviet Venera and VEGA landers that collectively suggest a surface composition that is primarily tholeiitic basaltic with some potentially more evolved compositions and, in some locations, K-rich trachyandesite. These landers were not equipped to probe the surface mineralogy as can be accomplished with Raman spectroscopy. Based on the observed compositional differences and recognizing the imprecise nature of the existing data, 15 samples were chosen to constitute a Venus-analog suite for this study, including five basalts, two each of andesites, dacites, and sulfates, and single samples of a foidite, trachyandesite, rhyolite, and basaltic trachyandesite under Venus conditions. LIBS data reduction involved generating a partial least squares (PLS) model with a subset of the rock powder standards to

Coupling of transport and geochemical models

International Nuclear Information System (INIS)

Noy, D.J.

1986-01-01

This report considers mass transport in the far-field of a radioactive waste repository, and detailed geochemical modelling of the ground-water in the near-field. A parallel approach to this problem of coupling transport and geochemical codes is the subject of another CEC report (ref. EUR 10226). Both studies were carried out in the framework of the CEC project MIRAGE. (Migration of radionuclides in the geosphere)

History and progress of the North American Soil Geochemical Landscapes Project, 2001-2010

Science.gov (United States)

Smith, David B.; Cannon, William F.; Woodruff, Laurel G.; Rivera, Francisco Moreira; Rencz, Andrew N.; Garrett, Robert G.

2012-01-01

In 2007, the U.S. Geological Survey, the Geological Survey of Canada, and the Mexican Geological Survey initiated a low-density (1 site per 1600 km2, 13323 sites) geochemical and mineralogical survey of North American soils (North American Soil Geochemical Landscapes Project). Sampling and analytical protocols were developed at a series of workshops in 20032004 and pilot studies were conducted from 20042007. The ideal sampling protocol at each site includes a sample from 05 cm depth, a composite of the soil A horizon, and a sample from the soil C horizon. The 3, HClO4, and HF. Separate methods are used for As, Hg, Se, and total C on this same size fraction. The major mineralogical components are determined by a quantitative X-ray diffraction method. Sampling in the conterminous U.S. was completed in 2010 (c. 4800 sites) with chemical and mineralogical analysis currently underway. In Mexico, approximately 66% of the sampling (871 sites) had been done by the end of 2010 with completion expected in 2012. After completing sampling in the Maritime provinces and portions of other provinces (472 sites, 7.6% of the total), Canada withdrew from the project in 2010. Preliminary results for a swath from the central U.S. to Florida clearly show the effects of soil parent material and climate on the chemical and mineralogical composition of soils. A sample archive will be established and made available for future investigations.

Geochemical modelling baseline compositions of groundwater

DEFF Research Database (Denmark)

Postma, Diederik Jan; Kjøller, Claus; Andersen, Martin Søgaard

2008-01-01

and variations in water chemistry that are caused by large scale geochemical processes taking place at the timescale of thousands of years. The most important geochemical processes are ion exchange (Valreas and Aveiro) where freshwater solutes are displacing marine ions from the sediment surface, and carbonate......Reactive transport models, were developed to explore the evolution in groundwater chemistry along the flow path in three aquifers; the Triassic East Midland aquifer (UK), the Miocene aquifer at Valreas (F) and the Cretaceous aquifer near Aveiro (P). All three aquifers contain very old groundwaters...... dissolution (East Midlands, Valreas and Aveiro). Reactive transport models, employing the code PHREEQC, which included these geochemical processes and one-dimensional solute transport were able to duplicate the observed patterns in water quality. These models may provide a quantitative understanding...

Extension of the EQ3/6 computer codes to geochemical modeling of brines

Energy Technology Data Exchange (ETDEWEB)

Jackson, K.J.; Wolery, T.J.

1984-10-23

Recent modifications to the EQ3/6 geochemical modeling software package provide for the use of Pitzer's equations to calculate the activity coefficients of aqueous species and the activity of water. These changes extend the range of solute concentrations over which the codes can be used to dependably calculate equilibria in geochemical systems, and permit the inclusion of ion pairs, complexes, and undissociated acids and bases as explicit component species in the Pitzer model. Comparisons of calculations made by the EQ3NR and EQ6 compuer codes with experimental data confirm that the modifications not only allow the codes to accurately evaluate activity coefficients in concentrated solutions, but also permit prediction of solubility limits of evaporite minerals in brines at 25/sup 0/C and elevated temperatures. Calculations for a few salts can be made at temperatures up to approx. 300/sup 0/C, but the temperature range for most electrolytes is constrained by the availability of requisite data to values less than or equal to 100/sup 0/C. The implementation of Pitzer's equations in EQ3/6 allows application of these codes to problems involving calculation of geochemical equilibria in brines; such as evaluation of the chemical environment which might be anticipated for nuclear waste canisters located in a salt repository. 26 references, 3 figures, 1 table.

Petroleum geochemical responses to reservoir rock properties

Energy Technology Data Exchange (ETDEWEB)

Bennett, B.; Larter, S.R. [Calgary Univ., AB (Canada)

2008-07-01

Reservoir geochemistry is used to study petroleum basin development, petroleum mixing, and alterations. In this study, polar non-hydrocarbons were used as proxies for describing reservoir properties sensitive to fluid-rock interactions. A core flood experiment was conducted on a Carboniferous siltstone core obtained from a site in the United Kingdom. Core samples were then obtained from a typical upper shoreface in a North Sea oilfield. The samples were extracted with a dichloromethane and methanol mixture. Alkylcarbazoles and alkylfluorenones were then isolated from the samples. Compositional changes along the core were also investigated. Polar non hydrocarbons were studied using a wireline gamma ray log. The strongest deflections were observed in the basal coarsening upwards unit. The study demonstrated the correlations between molecular markers, and indicated that molecular parameters can be used to differentiate between clean sand units and adjacent coarsening upward muddy sand sequences. It was concluded that reservoir geochemical parameters can provide an independent response to properties defined by petrophysical methods. 6 refs., 2 figs.

Virtual reconstruction of modern and fossil hominoid crania: consequences of reference sample choice.

Science.gov (United States)

Senck, Sascha; Bookstein, Fred L; Benazzi, Stefano; Kastner, Johann; Weber, Gerhard W

2015-05-01

Most hominin cranial fossils are incomplete and require reconstruction prior to subsequent analyses. Missing data can be estimated by geometric morphometrics using information from complete specimens, for example, by using thin-plate splines. In this study, we estimate missing data in several virtually fragmented models of hominoid crania (Homo, Pan, Pongo) and fossil hominins (e.g., Australopithecus africanus, Homo heidelbergensis). The aim is to investigate in which way different references influence estimations of cranial shape and how this information can be employed in the reconstruction of fossils. We used a sample of 64 three-dimensional digital models of complete human, chimpanzee, and orangutan crania and a set of 758 landmarks and semilandmarks. The virtually knocked out neurocranial and facial areas that were reconstructed corresponded to those of a real case found in A.L. 444-2 (A. afarensis) cranium. Accuracy of multiple intraspecies and interspecies reconstructions was computed as the maximum square root of the mean squared difference between the original and the reconstruction (root mean square). The results show that the uncertainty in reconstructions is a function of both the geometry of the knockout area and the dissimilarity between the reference sample and the specimen(s) undergoing reconstruction. We suggest that it is possible to estimate large missing cranial areas if the shape of the reference is similar enough to the shape of the specimen reconstructed, though caution must be exercised when employing these reconstructions in subsequent analyses. We provide a potential guide for the choice of the reference by means of bending energy. © 2015 Wiley Periodicals, Inc.

Characterization of primary geochemical haloes for gold exploration at the Huanxiangwa gold deposit, China

NARCIS (Netherlands)

Wang, Changming; Carranza, E.J.M; Zhang, Shouting; Zhang, Jing; Liu, Xiaoji Liu; Zhang, Da; Sun, Xiang; Duan, Cunji

2013-01-01

Recognition of primary geochemical haloes is one of the most important tools for exploring undiscovered mineral resources. This tool is being routinely applied in exploration programs at the Huanxiangwa gold deposit, Xiong'er Mountains, China. Sampling of unweathered rock for multi-element analysis

Geochemical investigation of UMTRAP designated site at Grand Junction, Colorado

International Nuclear Information System (INIS)

Markos, G.; Bush, K.J.

1983-09-01

This report is the result of a geochemical investigation of the former uranium mill and tailings site at Grand Junction, Colorado. The objectives of the investigation are to characterize the geochemistry, to determine the contaminant distribution resulting from the former milling activities and tailings, and to infer chemical pathways and transport mechanisms from the contaminant distribution. The results should be used to model contaminant migration and to develop criteria for long-term containment media, such as a cover system which is impermeable to contaminant migration. This report assumes a familiarity with the hydrologic conditions of the site and the geochemical concepts underlying the investigation. The results reported are based on a sampling of waters in two seasons and solid material from the background, the area adjacent to the site, and the site. The solid samples were water extracted to remove easily soluble salts and acid extracted to remove carbonates and hydroxides. The water extracts and solid samples were analyzed for the major and trace elements. A limited number of samples were analyzed for radiological components. The report includes the methods of sampling, sample processing, analysis, and data interpretation. Four major conclusions are: (1) trace element concentrations in shallow subsurface waters adjacent to the tailings temporally vary up to an order of magnitude; (2) the riverbank soils and borehole waters are contaminated with uranium, radium, and trace elements from discharge of tailings solids and solutions during the active time of the mill; however, the movement of contaminants toward the Colorado River does not appear to be significant; (3) the Colorado River adjacent to the tailings is not contaminated; and (4) trace metals have accumulated at both the tailings/cover and tailings/soil interface because of precipitation reactions caused by chemical differences between the two materials

Geochemical and geophysical investigations, and fluid inclusion studies in the exploration area of Zafarghand (Northeast Isfahan, Iran

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Zahra Alaminia

2017-11-01

Full Text Available Introduction Urumieh-Dokhtar Magmatic Arc (UDMA is a good prospective area for Cu, Cu-Mo and Cu-Au deposits (Fig. 1A and B. The Zafarghand district is located in the central part of the UDMA and the northeastern Isfahan. The present study concerns geological observations, alteration investigations, geochemical data and fluid inclusion studies. The purpose of the research is to identify geochemical anomalies and source of metals in this area. Geochemical anomalies for mineralizing elements and element associations were identified by using statistical analysis methods. Additionally, these results together suggest a site for exploration drilling in this study area. Materials and methods We collected 186 samples (rock along multi-cross sections oriented perpendicular to the strike of the South -Ardestan fault (Fig. 2.Trace element concentrations were determined by the ICP-MS technique in Amdel laboratory (Australia. Thin sections and doubly polished sections (100–200 µm thick from quartz veins were prepared from samples collected from the Zafarghand district in the University of Isfahan. Heating and freezing experiments on fluid inclusions were performed as defined (by Goldstein and Reynolds (1994 on a Linkam THM600 stage. Results Igneous rocks in the Zafarghand area are dominated by the Eocene and post Eocene acidic-intermediate rocks that include dacite, rhyodacite and andesite associated with diorite, quartz diorite and microdiorite intrusions. The present investigations indicate that all rocks of the Zafarghand district exhibit a variety of alterations. Hydrothermal alterations include phyllic, potassic, silicification, and argillic with widespread propylitic. The mineralization consists of malachite, azurite, hematite, and goethite, rare amounts of magnetite, pyrite, and chalcopyrite. Numerical traditional statistical analysis techniques have been applied to interpret the geochemical data of the study area. These methods are aimed at

Geochemical patterns in soils of the karst region, Croatia

Science.gov (United States)

Prohic, E.; Hausberger, G.; Davis, J.C.

1997-01-01

Soil samples were collected at 420 locations in a 5-km grid pattern in the Istria and Gorski Kotar areas of Croatia, and on the Croatian islands of Cres, Rab and Krk, in order to relate geochemical variation in the soils to underlying differences in geology, bedrock lithology, soil type, environment and natural versus anthropogenic influences. Specific objectives included assessment of possible agricultural and industrial sources of contamination, especially from airborne effluent emitted by a local power plant. The study also tested the adequacy of a fixed-depth soil sampling procedure developed for meager karstic soils. Although 40 geochemical variables were analyzed, only 15 elements and 5 radionuclides are common to all the sample locations. These elements can be divided into three groups: (1) those of mostly anthropogenic origin -Pb, V, Cu and Cr; (2) those of mixed origin - radionuclides and Zn; and (3) those of mostly geogene origin -Ba, Sr, Ti, Al, Na, Ca, Mg, Fe, Mn, Ni and Co. Variation in Pb shows a strong correlation with the pattern of road traffic in Istria. The distributions of Ca, Na and Mg in the flysch basins of southern Istria and Slovenia are clearly distinguishable from the distributions of these elements in the surrounding carbonate terrains, a consequence of differences in bedrock permeability, type of drainage and pH. The spatial pattern of Cs from the Chernobyl nuclear power plant accident reflects almost exclusively the precipitation in Istria during the days immediately after the explosion. ?? 1997 Elsevier Science B.V.

Scientific fundamentals of the exploration and calculability of a waste repository. Project part III, sub-project 2: Validity and applicability of geochemical models

International Nuclear Information System (INIS)

Baumann, J.

1991-04-01

The thermodynamic computer models WATEQF, PHREEQE, EQ3NR/EQ6, and SOLMINEQ 88 have been verified for their applicability to describe geochemical processes in the system salt stock/cap rock/ground water, i.e. processes such as dissolution, sedimentation, exchange and redox reactions. To begin with, the hydrochemical data obtained by the hydrogeological survey at the Gorleben site have been evaluated to thus form a reference data base. Then, these data have been used to derive the essential conditions and benchmark data to establish a geochemical model. (HP) [de

A novel SNP analysis method to detect copy number alterations with an unbiased reference signal directly from tumor samples

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LaFramboise William A

2011-01-01

Full Text Available Abstract Background Genomic instability in cancer leads to abnormal genome copy number alterations (CNA as a mechanism underlying tumorigenesis. Using microarrays and other technologies, tumor CNA are detected by comparing tumor sample CN to normal reference sample CN. While advances in microarray technology have improved detection of copy number alterations, the increase in the number of measured signals, noise from array probes, variations in signal-to-noise ratio across batches and disparity across laboratories leads to significant limitations for the accurate identification of CNA regions when comparing tumor and normal samples. Methods To address these limitations, we designed a novel "Virtual Normal" algorithm (VN, which allowed for construction of an unbiased reference signal directly from test samples within an experiment using any publicly available normal reference set as a baseline thus eliminating the need for an in-lab normal reference set. Results The algorithm was tested using an optimal, paired tumor/normal data set as well as previously uncharacterized pediatric malignant gliomas for which a normal reference set was not available. Using Affymetrix 250K Sty microarrays, we demonstrated improved signal-to-noise ratio and detected significant copy number alterations using the VN algorithm that were validated by independent PCR analysis of the target CNA regions. Conclusions We developed and validated an algorithm to provide a virtual normal reference signal directly from tumor samples and minimize noise in the derivation of the raw CN signal. The algorithm reduces the variability of assays performed across different reagent and array batches, methods of sample preservation, multiple personnel, and among different laboratories. This approach may be valuable when matched normal samples are unavailable or the paired normal specimens have been subjected to variations in methods of preservation.

Geological and geochemical aspects of uranium deposits: a selected, annotated bibliography. [474 references

Energy Technology Data Exchange (ETDEWEB)

Thomas, J.M.; Garland, P.A.; White, M.B.; Daniel, E.W.

1980-09-01

This bibliography, a compilation of 474 references, is the fourth in a series compiled from the National Uranium Resource Evaluation (NURE) Bibliographic Data Base. This data base was created for the Grand Junction Office of the Department of Energy's National Uranium Resource Evaluation Project by the Ecological Sciences Information Center, Oak Ridge National Laboratory. The references in the bibliography are arranged by subject category: (1) geochemistry, (2) exploration, (3) mineralogy, (4) genesis of deposits, (5) geology of deposits, (6) uranium industry, (7) geology of potential uranium-bearing areas, and (8) reserves and resources. The references are indexed by author, geographic location, quadrangle name, geoformational feature, and keyword.

[Study on the method for the determination of trace boron, molybdenum, silver, tin and lead in geochemical samples by direct current arc full spectrum direct reading atomic emission spectroscopy (DC-Arc-AES)].

Science.gov (United States)

Hao, Zhi-hong; Yao, Jian-zhen; Tang, Rui-ling; Zhang, Xue-mei; Li, Wen-ge; Zhang, Qin

2015-02-01

The method for the determmation of trace boron, molybdenum, silver, tin and lead in geochemical samples by direct current are full spectrum direct reading atomic emission spectroscopy (DC-Arc-AES) was established. Direct current are full spectrum direct reading atomic emission spectrometer with a large area of solid-state detectors has functions of full spectrum direct reading and real-time background correction. The new electrodes and new buffer recipe were proposed in this paper, and have applied for national patent. Suitable analytical line pairs, back ground correcting points of elements and the internal standard method were selected, and Ge was used as internal standard. Multistage currents were selected in the research on current program, and each current set different holding time to ensure that each element has a good signal to noise ratio. Continuous rising current mode selected can effectively eliminate the splash of the sample. Argon as shielding gas can eliminate CN band generating and reduce spectral background, also plays a role in stabilizing the are, and argon flow 3.5 L x min(-1) was selected. Evaporation curve of each element was made, and it was concluded that the evaporation behavior of each element is consistent, and combined with the effects of different spectrographic times on the intensity and background, the spectrographic time of 35s was selected. In this paper, national standards substances were selected as a standard series, and the standard series includes different nature and different content of standard substances which meet the determination of trace boron, molybdenum, silver, tin and lead in geochemical samples. In the optimum experimental conditions, the detection limits for B, Mo, Ag, Sn and Pb are 1.1, 0.09, 0.01, 0.41, and 0.56 microg x g(-1) respectively, and the precisions (RSD, n=12) for B, Mo, Ag, Sn and Pb are 4.57%-7.63%, 5.14%-7.75%, 5.48%-12.30%, 3.97%-10.46%, and 4.26%-9.21% respectively. The analytical accuracy was

Geochemical prospecting for rare earth elements using termite mound materials

Science.gov (United States)

Horiuchi, Yu; Ohno, Tetsuji; Hoshino, Mihoko; Shin, Ki-Cheol; Murakami, Hiroyasu; Tsunematsu, Maiko; Watanabe, Yasushi

2014-12-01

The Blockspruit fluorite prospect, located in North West State of the Republic of South Africa, occurs within an actinolite rock zone that was emplaced into the Kenkelbos-type granite of Proterozoic age. There are a large number of termite mounds in the prospect. For geochemical prospecting for rare earth elements (REEs), in total, 200 samples of termite mound material were collected from actinolite rock and granite zones in the prospect. Geochemical analyses of these termite mound materials were conducted by two methods: portable X-ray fluorescence (XRF) spectrometry and inductively coupled plasma-mass spectrometry (ICP-MS). Comparison of the two methods broadly indicates positive correlations of REEs (La, Ce, Pr, Nd, and Y), in particular Y and La having a strong correlation. As the result of modal abundance analyses, the actinolite rock at surface mainly consists of ferro-actinolite (89.89 wt%) and includes xenotime (0.26 wt%) and monazite (0.21 wt%) grains as REE minerals. Termite mound materials from actinolite rock also contain xenotime (0.27 wt%) and monazite (0.41 wt%) grains. In addition, termite mound materials from the actinolite rock zone have high hematite and Fe silicate contents compared to those from granite zone. These relationships suggest that REE minerals in termite mound materials originate form actinolite rock. Geochemical anomaly maps of Y, La, and Fe concentrations drawn based on the result of the portable XRF analyses show that high concentrations of these elements trend from SW to NE which broadly correspond to occurrences of actinolite body. These results indicate that termite mounds are an effective tool for REE geochemical prospection in the study area for both light REEs and Y, but a more detailed survey is required to establish the distribution of the actinolite rock body.

Field-based tests of geochemical modeling codes usign New Zealand hydrothermal systems

International Nuclear Information System (INIS)

Bruton, C.J.; Glassley, W.E.; Bourcier, W.L.

1994-06-01

Hydrothermal systems in the Taupo Volcanic Zone, North Island, New Zealand are being used as field-based modeling exercises for the EQ3/6 geochemical modeling code package. Comparisons of the observed state and evolution of the hydrothermal systems with predictions of fluid-solid equilibria made using geochemical modeling codes will determine how the codes can be used to predict the chemical and mineralogical response of the environment to nuclear waste emplacement. Field-based exercises allow us to test the models on time scales unattainable in the laboratory. Preliminary predictions of mineral assemblages in equilibrium with fluids sampled from wells in the Wairakei and Kawerau geothermal field suggest that affinity-temperature diagrams must be used in conjunction with EQ6 to minimize the effect of uncertainties in thermodynamic and kinetic data on code predictions

Gender differences in a clinic-referred sample of Taiwanese attention-deficit/hyperactivity disorder children.

Science.gov (United States)

Yang, Pinchen; Jong, Yuh-Jyh; Chung, Li-Chen; Chen, Cheng-Sheng

2004-12-01

The purpose of this study was to examine gender differences within a clinic-referred sample of 6-11-year-old Taiwanese children with attention-deficit/hyperactivity disorder (ADHD)- combined subtype. The subjects were 21 girls with a diagnosis of ADHD from the 4th edition of the Diagnostic and Statistical Manual and 21 age-matched boys with ADHD. Comparisons were made of behavioral ratings, cognitive profiles, and vigilance/attention assessments between these two groups. The results found ADHD girls and ADHD boys to be statistically indistinguishable on nearly all measures except the subtests of block design (P = 0.016), the discrepancy between Performance Intelligence Quotient and Verbal Intelligence Quotient (P = 0.019), and the discrepancy between fluid and crystallized IQ (P = 0.041). In the study samples, ADHD girls and ADHD boys were strikingly similar on a wide range of measures. ADHD boys and girls in clinics may be expected to show more similarities than differences in treatment needs. However, these results should be interpreted with caution since data were only from clinic-referred samples.

Overview of the geochemical code MINTEQ: applications to performance assessment for low-level wastes

International Nuclear Information System (INIS)

Graham, M.J.; Peterson, S.R.

1985-09-01

The MINTEQ geochemical computer code, developed at Pacific Northwest Laboratory, integrates many of the capabilities of its two immediate predecessors, WATEQ3 and MINEQL. MINTEQ can be used to perform the calculations necessary to simulate (model) the contact of low-level waste solutions with heterogeneous sediments or the interaction of ground water with solidified low-level wastes. The code is capable of performing calculations of ion speciation/solubility, adsorption, oxidation-reduction, gas phase equilibria, and precipitation/dissolution of solid phases. Under the Special Waste Form Lysimeters-Arid program, the composition of effluents (leachates) from column and batch experiments, using laboratory-scale waste forms, will be used to develop a geochemical model of the interaction of ground water with commercial solidified low-level wastes. The wastes being evaluated include power reactor waste streams that have been solidified in cement, vinyl ester-styrene, and bitumen. The thermodynamic database for the code is being upgraded before the geochemical modeling is performed. Thermodynamic data for cobalt, antimony, cerium, and cesium solid phases and aqueous species are being added to the database. The need to add these data was identified from the characterization of the waste streams. The geochemical model developed from the laboratory data will then be applied to predict the release from a field-lysimeter facility that contains full-scale waste samples. The contaminant concentrations migrating from the wastes predicted using MINTEQ will be compared to the long-term lysimeter data. This comparison will constitute a partical field validation of the geochemical model. 28 refs

Application of Handheld Laser-Induced Breakdown Spectroscopy (LIBS) to Geochemical Analysis.

Science.gov (United States)

Connors, Brendan; Somers, Andrew; Day, David

2016-05-01

While laser-induced breakdown spectroscopy (LIBS) has been in use for decades, only within the last two years has technology progressed to the point of enabling true handheld, self-contained instruments. Several instruments are now commercially available with a range of capabilities and features. In this paper, the SciAps Z-500 handheld LIBS instrument functionality and sub-systems are reviewed. Several assayed geochemical sample sets, including igneous rocks and soils, are investigated. Calibration data are presented for multiple elements of interest along with examples of elemental mapping in heterogeneous samples. Sample preparation and the data collection method from multiple locations and data analysis are discussed. © The Author(s) 2016.

Geochemical Investigation of the Arbuckle-Simpson Aquifer, South-Central Oklahoma, 2004-06

Science.gov (United States)

Christenson, Scott; Hunt, Andrew G.; Parkhurst, David L.

2009-01-01

A geochemical reconnaissance investigation of the Arbuckle-Simpson aquifer in south-central Oklahoma was initiated in 2004 to characterize the ground-water quality at an aquifer scale, to describe the chemical evolution of ground water as it flows from recharge areas to discharge in wells and springs, and to determine the residence time of ground water in the aquifer. Thirty-six water samples were collected from 32 wells and springs distributed across the aquifer for chemical analysis of major ions, trace elements, isotopes of oxygen and hydrogen, dissolved gases, and age-dating tracers. In general, the waters from wells and springs in the Arbuckle-Simpson aquifer are chemically suitable for all regulated uses, such as public supplies. Dissolved solids concentrations are low, with a median of 347 milligrams per liter (mg/L). Two domestic wells produced water with nitrate concentrations that exceeded the U.S. Environmental Protection Agency's nitrate maximum contaminant level (MCL) of 10 mg/L. Samples from two wells in the confined part of the aquifer exceeded the secondary maximum contaminant level (SMCL) for chloride of 250 mg/L and the SMCL of 500 mg/L for dissolved solids. Water samples from these two wells are not representative of water samples from the other wells and springs completed in the unconfined part of the aquifer. No other water samples from the Arbuckle-Simpson geochemical reconnaissance exceeded MCLs or SMCLs, although not every chemical constituent for which the U.S. Environmental Protection Agency has established a MCL or SMCL was analyzed as part of the Arbuckle-Simpson geochemical investigation. The major ion chemistry of 34 of the 36 samples indicates the water is a calcium bicarbonate or calcium magnesium bicarbonate water type. Calcium bicarbonate water type is found in the western part of the aquifer, which is predominantly limestone. Calcium magnesium bicarbonate water is found in the eastern part of the aquifer, which is predominantly a

Geochemical wolframite fingerprinting - the likelihood ratio approach for laser ablation ICP-MS data.

Science.gov (United States)

Martyna, Agnieszka; Gäbler, Hans-Eike; Bahr, Andreas; Zadora, Grzegorz

2018-05-01

Wolframite has been specified as a 'conflict mineral' by a U.S. Government Act, which obliges companies that use these minerals to report their origin. Minerals originating from conflict regions in the Democratic Republic of the Congo shall be excluded from the market as their illegal mining, trading, and taxation are supposed to fuel ongoing violent conflicts. The German Federal Institute for Geosciences and Natural Resources (BGR) developed a geochemical fingerprinting method for wolframite based on laser ablation inductively coupled plasma-mass spectrometry. Concentrations of 46 elements in about 5300 wolframite grains from 64 mines were determined. The issue of verifying the declared origins of the wolframite samples may be framed as a forensic problem by considering two contrasting hypotheses: the examined sample and a sample collected from the declared mine originate from the same mine (H 1 ), and the two samples come from different mines (H 2 ). The solution is found using the likelihood ratio (LR) theory. On account of the multidimensionality, the lack of normal distribution of data within each sample, and the huge within-sample dispersion in relation to the dispersion between samples, the classic LR models had to be modified. Robust principal component analysis and linear discriminant analysis were used to characterize samples. The similarity of two samples was expressed by Kolmogorov-Smirnov distances, which were interpreted in view of H 1 and H 2 hypotheses within the LR framework. The performance of the models, controlled by the levels of incorrect responses and the empirical cross entropy, demonstrated that the proposed LR models are successful in verifying the authenticity of the wolframite samples. Graphical abstract Geochemical wolframite fingerprinting.

Phosphated minerals to be used as radioactive reference materials; Minerais fosfatados para serem utilizados como materiais de referencia radioativos

Energy Technology Data Exchange (ETDEWEB)

Braganca, M.J.C.S.; Tauhata, L. [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Lab. Nacional de Metrologia das Radiacoes Ionizantes (LNMRI); Clain, A.F. [Universidade Severino Sombra, Vassouras, RJ (Brazil); Moreira, I. [Pontificia Univ. Catolica do Rio de Janeiro (PUC/Rio), RJ (Brazil). Dept. de Quimica

2003-07-01

The production and the supplying of certified reference materials, or deliberated contaminated materials containing natural radionuclides for laboratories which analyses environmental samples are fundamentals for the correct measurements of their radioactive levels. This analysis quality represents a important step for the safeguards of the population health, and quality control of the imported and exported products, such as minerals, agricultural and raw materials. The phosphate rocks, containing significant concentrations of thorium, and used as raw material and fertilizers justified a study for better characterization and distinction to be used cas certified reference radioactive materials. Therefore, samples from the two carboanalytical-alkaline chimneys (Araxa and Catalao), and one from metasedimentar origin (Patos de Minas), distant 100 km from each other, were collected and chemical and cholecystographic characterized by optical emission, X-ray diffraction and fluorescence. The element concentrations were determined by neutron activation analysis, ICP-MS and ICP-AES. The results, after multivariate statistical analysis and study of correlations among elements, have shown geochemical similarities of the phosphates from Araxa and Catalao, and differences from Patos de Minas, despite of the geographic proximity. The concentration of thorium between 200 and 500 (mg/g) allows to use such minerals as reference materials.

Groundwater sampling in uranium reconnaissance

International Nuclear Information System (INIS)

Butz, T.R.

1977-03-01

The groundwater sampling program is based on the premise that ground water geochemistry reflects the chemical composition of, and geochemical processes active in the strata from which the sample is obtained. Pilot surveys have shown that wells are the best source of groundwater, although springs are sampled on occasion. The procedures followed in selecting a sampling site, the sampling itself, and the field measurements, as well as the site records made, are described

Geochemical characterization of fluoride in water, table salt, active sediment, rock and soil samples, and its possible relationship with the prevalence of enamel fluorosis in children in four municipalities of the department of Huila (Colombia).

Science.gov (United States)

Martignon, Stefania; Opazo-Gutiérrez, Mario Omar; Velásquez-Riaño, Möritz; Orjuela-Osorio, Iván Rodrigo; Avila, Viviana; Martinez-Mier, Esperanza Angeles; González-Carrera, María Clara; Ruiz-Carrizosa, Jaime Alberto; Silva-Hermida, Blanca Cecilia

2017-06-01

Fluoride is an element that affects teeth and bone formation in animals and humans. Though the use of systemic fluoride is an evidence-based caries preventive measure, excessive ingestion can impair tooth development, mainly the mineralization of tooth enamel, leading to a condition known as enamel fluorosis. In this study, we investigated the geochemical characterization of fluoride in water, table salt, active sediment, rock and soil samples in four endemic enamel fluorosis sentinel municipalities of the department of Huila, Colombia (Pitalito, Altamira, El Agrado and Rivera), and its possible relationship with the prevalence of enamel fluorosis in children. The concentration of fluoride in drinking water, table salt, active sediment, rock, and soil was evaluated by means of an ion selective electrode and the geochemical analyses were performed using X-ray fluorescence. Geochemical analysis revealed fluoride concentrations under 15 mg/kg in active sediment, rock and soil samples, not indicative of a significant delivery to the watersheds studied. The concentration of fluoride in table salt was found to be under the inferior limit (less than 180 μg/g) established by the Colombian regulations. Likewise, exposure doses for fluoride water intake did not exceed the recommended total dose for all ages from 6 months. Although the evidence does not point out at rocks, soils, fluoride-bearing minerals, fluoridated salt and water, the hypothesis of these elements as responsible of the current prevalence of enamel fluorosis cannot be discarded since, aqueducts might have undergone significant changes overtime.

Adjustment of geochemical background by robust multivariate statistics

Science.gov (United States)

Zhou, D.

1985-01-01

Conventional analyses of exploration geochemical data assume that the background is a constant or slowly changing value, equivalent to a plane or a smoothly curved surface. However, it is better to regard the geochemical background as a rugged surface, varying with changes in geology and environment. This rugged surface can be estimated from observed geological, geochemical and environmental properties by using multivariate statistics. A method of background adjustment was developed and applied to groundwater and stream sediment reconnaissance data collected from the Hot Springs Quadrangle, South Dakota, as part of the National Uranium Resource Evaluation (NURE) program. Source-rock lithology appears to be a dominant factor controlling the chemical composition of groundwater or stream sediments. The most efficacious adjustment procedure is to regress uranium concentration on selected geochemical and environmental variables for each lithologic unit, and then to delineate anomalies by a common threshold set as a multiple of the standard deviation of the combined residuals. Robust versions of regression and RQ-mode principal components analysis techniques were used rather than ordinary techniques to guard against distortion caused by outliers Anomalies delineated by this background adjustment procedure correspond with uranium prospects much better than do anomalies delineated by conventional procedures. The procedure should be applicable to geochemical exploration at different scales for other metals. ?? 1985.

Applications of inductively coupled plasma spectroscopy to geochemical reconnaissance for uranium exploration

International Nuclear Information System (INIS)

Cagle, G.W.; Butz, T.R.

1980-01-01

The analysis of large numbers of natural groundwater and stream sediment samples by Inductively Coupled Plasma (ICP) Spectroscopy has been applied to a geochemical reconnaissance program as part of the National Uranium Resource Evaluation Program. Approximately 25 elements have been determined in over 60,000 samples by ICP analysis. These data are combined with additional measurements obtained by atomic absorption, colorimetry, neutron activation, and fluorescence spectroscopy. Results are presented and interpreted in terms of the uranium favorability of areas in Texas where this survey has been completed

Geochemical evolution of groundwater in carbonate aquifers of southern Latium region, central Italy

Directory of Open Access Journals (Sweden)

Giuseppe Sappa

2013-03-01

Full Text Available Spring and well water samples, from carbonate aquifers of Latium region, have been characterized to determine the hydrochemical processes governing the evolution of the groundwater. Most of the spring samples, issuing from Lepini, Ausoni and Aurunci Mts., are characterized as alkaline earth HCO3 waters, however, some samples show a composition of Cl--SO4 -- alkaline earth waters. Groundwater samples from Pontina Plain shows three different hydrochemical facies: alkaline earth HCO3 type, Cl-- SO4 -- alkaline earth type and Cl--SO4 -- alkaline type waters. Geochemical modeling and saturation index computation of the sampled waters show an interaction with calcareous and calcareous-dolomitic lithologies. Most of the springs and wells was kinetically saturated with respect to calcite and dolomite, and all the samples were below the equilibrium state with gypsum. This indicates that the groundwater has capacity to dissolve the gypsum along the flow paths. The electrical conductivity and Cl- concentrations of the sampled waters show a positive trend with the decrease in the distance from the coast, highlighting seawater intrusion in the coastal area. According to hydrochemistry results and geochemical modeling, the dominant factors in controlling the hydrochemical characteristics of groundwater are: (i water rock interaction with calcareous and calcareous-dolomitic lithologies; (ii seawater intrusion in the coastal area; (iii dissolution and/or precipitation of carbonate and (i.e. dolomite and calcite evaporate minerals (gypsum determined by saturation indexes; (iv mineral weathering process; (the high Mg/Ca ratio due to the weathering of Mg-rich dolomite.

Monitoring active volcanoes: The geochemical approach

Directory of Open Access Journals (Sweden)

Takeshi Ohba

2011-06-01

Full Text Available

The geochemical surveillance of an active volcano aims to recognize possible signals that are related to changes in volcanic activity. Indeed, as a consequence of the magma rising inside the volcanic "plumbing system" and/or the refilling with new batches of magma, the dissolved volatiles in the magma are progressively released as a function of their relative solubilities. When approaching the surface, these fluids that are discharged during magma degassing can interact with shallow aquifers and/or can be released along the main volcano-tectonic structures. Under these conditions, the following main degassing processes represent strategic sites to be monitored.

The main purpose of this special volume is to collect papers that cover a wide range of topics in volcanic fluid geochemistry, which include geochemical characterization and geochemical monitoring of active volcanoes using different techniques and at different sites. Moreover, part of this volume has been dedicated to the new geochemistry tools.

Using geochemical indicators to distinguish high biogeochemical activity in floodplain soils and sediments

Energy Technology Data Exchange (ETDEWEB)

Kenwell, Amy [Hydrologic Sciences and Engineering Program, Colorado School of Mines, 1500 Illinois St., Golden, CO 80401 (United States); Navarre-Sitchler, Alexis, E-mail: asitchle@mines.edu [Hydrologic Sciences and Engineering Program, Colorado School of Mines, 1500 Illinois St., Golden, CO 80401 (United States); Prugue, Rodrigo [Hydrologic Sciences and Engineering Program, Colorado School of Mines, 1500 Illinois St., Golden, CO 80401 (United States); Spear, John R. [Department of Civil and Environmental Engineering, Colorado School of Mines, 1500 Illinois St., Golden, CO 80401 (United States); Hering, Amanda S. [Department of Applied Mathematics and Statistics, Colorado School of Mines, 1500 Illinois St., Golden, CO 80401 (United States); Maxwell, Reed M. [Hydrologic Sciences and Engineering Program, Colorado School of Mines, 1500 Illinois St., Golden, CO 80401 (United States); Carroll, Rosemary W.H. [Desert Research Institute, Division of Hydrologic Sciences, 2215 Raggio Parkway, Reno, NV 89512 (United States); Williams, Kenneth H. [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States)

2016-09-01

A better understanding of how microbial communities interact with their surroundings in physically and chemically heterogeneous subsurface environments will lead to improved quantification of biogeochemical reactions and associated nutrient cycling. This study develops a methodology to predict potential elevated rates of biogeochemical activity (microbial “hotspots”) in subsurface environments by correlating microbial DNA and aspects of the community structure with the spatial distribution of geochemical indicators in subsurface sediments. Multiple linear regression models of simulated precipitation leachate, HCl and hydroxylamine extractable iron and manganese, total organic carbon (TOC), and microbial community structure were used to identify sample characteristics indicative of biogeochemical hotspots within fluvially-derived aquifer sediments and overlying soils. The method has been applied to (a) alluvial materials collected at a former uranium mill site near Rifle, Colorado and (b) relatively undisturbed floodplain deposits (soils and sediments) collected along the East River near Crested Butte, Colorado. At Rifle, 16 alluvial samples were taken from 8 sediment cores, and at the East River, 46 soil/sediment samples were collected across and perpendicular to 3 active meanders and an oxbow meander. Regression models using TOC and TOC combined with extractable iron and manganese results were determined to be the best fitting statistical models of microbial DNA (via 16S rRNA gene analysis). Fitting these models to observations in both contaminated and natural floodplain deposits, and their associated alluvial aquifers, demonstrates the broad applicability of the geochemical indicator based approach. - Highlights: • Biogeochemical characterization of alluvial floodplain soils and sediments was performed to investigate parameters that may indicate microbial hot spot formation. • A correlation between geochemical parameters (total organic carbon and

Using geochemical indicators to distinguish high biogeochemical activity in floodplain soils and sediments

International Nuclear Information System (INIS)

Kenwell, Amy; Navarre-Sitchler, Alexis; Prugue, Rodrigo; Spear, John R.; Hering, Amanda S.; Maxwell, Reed M.; Carroll, Rosemary W.H.; Williams, Kenneth H.

2016-01-01

A better understanding of how microbial communities interact with their surroundings in physically and chemically heterogeneous subsurface environments will lead to improved quantification of biogeochemical reactions and associated nutrient cycling. This study develops a methodology to predict potential elevated rates of biogeochemical activity (microbial “hotspots”) in subsurface environments by correlating microbial DNA and aspects of the community structure with the spatial distribution of geochemical indicators in subsurface sediments. Multiple linear regression models of simulated precipitation leachate, HCl and hydroxylamine extractable iron and manganese, total organic carbon (TOC), and microbial community structure were used to identify sample characteristics indicative of biogeochemical hotspots within fluvially-derived aquifer sediments and overlying soils. The method has been applied to (a) alluvial materials collected at a former uranium mill site near Rifle, Colorado and (b) relatively undisturbed floodplain deposits (soils and sediments) collected along the East River near Crested Butte, Colorado. At Rifle, 16 alluvial samples were taken from 8 sediment cores, and at the East River, 46 soil/sediment samples were collected across and perpendicular to 3 active meanders and an oxbow meander. Regression models using TOC and TOC combined with extractable iron and manganese results were determined to be the best fitting statistical models of microbial DNA (via 16S rRNA gene analysis). Fitting these models to observations in both contaminated and natural floodplain deposits, and their associated alluvial aquifers, demonstrates the broad applicability of the geochemical indicator based approach. - Highlights: • Biogeochemical characterization of alluvial floodplain soils and sediments was performed to investigate parameters that may indicate microbial hot spot formation. • A correlation between geochemical parameters (total organic carbon and

Geochemical mapping of the Hyeonri, Bongpyeong, Yeongog and Doam sheets (1:50,000)

Energy Technology Data Exchange (ETDEWEB)

Lee, Jin Soo; Seo, Hyo Joon [Korea Institute of Geology Mining and Materials, Taejon (Korea, Republic of)

1997-12-01

A geochemical mapping was made on the four quadrangles of the Hyeonri, Bongpyeong, Yeongog and Doam Sheets (1:50,000) located in the northeastern part of South Korea. The area of about 2,500 Km{sup 2} is covered mostly the Precambrian metamorphic rocks and Jurassic granites, and partly by Permo-Triassic sedimentary and Cretaceous granites. Geochemical samples of stream sediment and natural surface water, totally 713 for each media, were systematically collected from in the primary and secondary order streams. The samples were chemically analysed for the trace elements by ICP, and anion elements of water samples were determined by IC. The pH. EC (electrical conductivity) Eh, DO (dissolved oxygen) and bicarbonate were measured in situ by digital portable equipment. Several deposits of gold, fluorite, molybdenite and iron deposits were weakly formed at or around the contact zone between metamorphic rocks and granites. The coal mines were actively operated until 1970`s in the southeastern part of the area. At present, none of them is operating owing to shortage of ore reserves and higher mining cost excepting a few non-metallic or construction stone mines. Geochemical anomalies were revealed out several areas deriving from mineralized factors or effected by some polluted evidences of human life. The anomalies of Pb, Zn, Co, Cr, Cd, etc for sulfide minerals were poorly confined around old prospects or calcareous formation of Chosun Supergroup. The conductivity of stream in the Odae national park is extremely high value to be expecting mineral deposit such as uranium or rare earth metals etc.. The anomalies with Cl, Na, Mg, NO{sub 3}, HCO{sub 3} near or along the expressway and main roads where the population, are densely, were identified to be polluted by human activities and stock-farming. (author). 36 refs., 11 tabs., 57 figs.

User's and reference guide to the INEL RML/analytical radiochemistry sample tracking database version 1.00

International Nuclear Information System (INIS)

Femec, D.A.

1995-09-01

This report discusses the sample tracking database in use at the Idaho National Engineering Laboratory (INEL) by the Radiation Measurements Laboratory (RML) and Analytical Radiochemistry. The database was designed in-house to meet the specific needs of the RML and Analytical Radiochemistry. The report consists of two parts, a user's guide and a reference guide. The user's guide presents some of the fundamentals needed by anyone who will be using the database via its user interface. The reference guide describes the design of both the database and the user interface. Briefly mentioned in the reference guide are the code-generating tools, CREATE-SCHEMA and BUILD-SCREEN, written to automatically generate code for the database and its user interface. The appendices contain the input files used by the these tools to create code for the sample tracking database. The output files generated by these tools are also included in the appendices

Martian Chemical and Isotopic Reference Standards in Earth-based Laboratories — An Invitation for Geochemical, Astrobiological, and Engineering Dialog on Considering a Weathered Chondrite for Mars Sample Return.

Science.gov (United States)

Ashley, J. W.; Tait, A. W.; Velbel, M. A.; Boston, P. J.; Carrier, B. L.; Cohen, B. A.; Schröder, C.; Bland, P.

2017-12-01

Exogenic rocks (meteorites) found on Mars 1) have unweathered counterparts on Earth; 2) weather differently than indigenous rocks; and 3) may be ideal habitats for putative microorganisms and subsequent biosignature preservation. These attributes show the potential of meteorites for addressing hypothesis-driven science. They raise the question of whether chondritic meteorites, of sufficient weathering intensity, might be considered as candidates for sample return in a potential future mission. Pursuant to this discussion are the following questions. A) Is there anything to be learned from the laboratory study of a martian chondrite that cannot be learned from indigenous materials; and if so, B) is the science value high enough to justify recovery? If both A and B answer affirmatively, then C) what are the engineering constraints for sample collection for Mars 2020 and potential follow-on missions; and finally D) what is the likelihood of finding a favorable sample? Observations relevant to these questions include: i) Since 2005, 24 candidate and confirmed meteorites have been identified on Mars at three rover landing sites, demonstrating their ubiquity and setting expectations for future finds. All have been heavily altered by a variety of physical and chemical processes. While the majority of these are irons (not suitable for recovery), several are weathered stony meteorites. ii) Exogenic reference materials provide the only chemical/isotope standards on Mars, permitting quantification of alteration rates if residence ages can be attained; and possibly enabling the removal of Late Amazonian weathering overprints from other returned samples. iii) Recent studies have established the habitability of chondritic meteorites with terrestrial microorganisms, recommending their consideration when exploring astrobiological questions. High reactivity, organic content, and permeability show stony meteorites to be more attractive for colonization and subsequent biosignature

Alligator Rivers Analogue project. Geochemical Data Bases

International Nuclear Information System (INIS)

Bennett, D.G.; Read, D.

1992-01-01

The Koongarra uranium deposit in the Northern Territory of Australia is being studied to evaluate the processes involved in the geochemical alteration of the ore body and the formation of the uranium dispersion fan. A broad range of research is being undertaken into the geochemistry and hydrology of the site with the aim of understanding the transport of radionuclides through the system. During the project a range of geochemical and hydrogeochemical models have been developed to account for measured data from the site and with which to predict site evolution. The majority of these models are based on the premise of thermodynamic chemical equilibrium and employ fundamental thermodynamic data to characterise the chemistry of the system. From the differences which exist between the thermodynamic data bases (Appendices I and II) it is possible to gain a view of the level of uncertainty associated with thermodynamic data in each set of calculations. This report gives a brief introduction to the geochemical processes underlying the models, and details the equations used to quantify the more common of these processes (e.g. aqueous speciation and mineral solubility). A description is given of the computer codes (EQ3/6, PHREEQE, MINTEQ) most commonly used during the project for geochemical modelling. Their key features are highlighted and comparisons made. It is concluded that the degree of uncertainty in geochemical modelling studies arising as a result of using one code rather than another is relatively insignificant when compared to that related to differences in the underlying data bases. 73 refs., 3 figs

Quality of determinations obtained from laboratory reference samples used in the calibration of X-ray electron probe microanalysis of silicate minerals

International Nuclear Information System (INIS)

Pavlova, Ludmila A.; Suvorova, Ludmila F.; Belozerova, Olga Yu.; Pavlov, Sergey M.

2003-01-01

Nine simple minerals and oxides, traditionally used as laboratory reference samples in the electron probe microanalysis (EPMA) of silicate minerals, have been quantitatively evaluated. Three separate series of data, comprising the average concentration, standard deviation, relative standard deviation, confidence interval and the z-score of data quality, were calculated for 21 control samples derived from calibrations obtained from three sets of reference samples: (1) simple minerals; (2) oxides; and (3) certified glass reference materials. No systematic difference was observed between the concentrations obtained from these three calibration sets when analyzed results were compared to certified compositions. The relative standard deviations obtained for each element were smaller than target values for all determinations. The z-score values for all elements determined fell within acceptable limits (-2< z<2) for concentrations ranging from 0.1 to 100%. These experiments show that the quality of data obtained from laboratory reference calibration samples is not inferior to that from certified reference glasses. The quality of results obtained corresponds to the 'applied geochemistry' type of analysis (category 2) as defined in the GeoPT proficiency testing program. Therefore, the laboratory reference samples can be used for calibrating EPMA techniques in the analysis of silicate minerals and for controlling the quality of results

Gamma Spectrometric Determination of U, Th, K and Some Geochemical Applications

International Nuclear Information System (INIS)

Dodona, A.; Tashko, A.

2001-01-01

The application of 'in situ' gamma-spectrometric method (''infinite'' environment), made possible the simultanious determination of U, Th and K. 4 channel gamma-spectrometric analyser with NaI(TI) scintilation counter crystal detector (103 cm 3 φ=50x50mm) was used to determin U, Th(more than 1-2 ppm) and K (more than 1%) in laboratory conditions. The detector was inserted into a lead camera and calibrated for measurement geometry with vessel of ''Marineli'' type of a 17o cm 3 volume. The study of main factors, which influence in the gamma spectrometric measurements, (the technical, physical, geometrical and time parameters) has been carried out. International standards of U, Th, K and internal monitoring standard samples are used for the calibration. External analytical control has been realized by other radiometric and chemical methods. The detection limits ( 1 ppm Th, 2ppm U and 1% K) and the relative errors (17-20% for 1-10 ppm U, Th and 10-15% for more than 10 ppm U, Th and more than 1% K) guarantee a quantitative analysis that may be used successfully in the geochemical studies. Some geochemical applications, based on the content of Th, U and Th/U ratio in rocks samples that we have we have analyzed with this method, are shown in this paper. U, Th and their ratio are used as trace elements to indicate the differences between the acidic magmatic rocks of Albania (Th/U ratio=2-6 and>10). The bimodal character of Th/U scattering in ignimbrides and monzonites (Korabi zone) shows that in addition to the ''normal'' rocks, there are also some ones enriched with Th, So, the differential analysis of Th, U, and K may be used as geochemical exploration criteria for the radioactive and non-radioactive mineralization, such as REE (Rare Earth Elements), phospghorites, bauxites, placers etc. (authors)

Coastal Aquifer Contamination and Geochemical Processes Evaluation in Tugela Catchment, South Africa—Geochemical and Statistical Approaches

Directory of Open Access Journals (Sweden)

Badana Ntanganedzeni

2018-05-01

Full Text Available Assessment of groundwater quality, contamination sources and geochemical processes in the coastal aquifer of Tugela Catchment, South Africa were carried out by the geochemical and statistical approach using major ion chemistry of 36 groundwater samples. Results suggest that the spatial distribution pattern of EC, TDS, Na, Mg, Cl and SO4 are homogenous and elevated concentrations are observed in the wells in the coastal region and few wells near the Tugela River. Wells located far from the coast are enriched by Ca, HCO3 and CO3. Durov diagrams, Gibbs plots, ionic ratios, chloro alkaline indices (CAI1 and CAI2 and correlation analysis imply that groundwater chemistry in the coastal aquifer of Tugela Catchment is regulated by the ion exchange, mineral dissolution, saline sources, and wastewater infiltration from domestic sewage; septic tank leakage and irrigation return flow. Principle component analysis also ensured the role of saline and anthropogenic sources and carbonates dissolution on water chemistry. Spatial distributions of factor score also justify the above predictions. Groundwater suitability assessment indicates that around 80% and 90% of wells exceeded the drinking water standards recommended by the WHO and South African drinking water standards (SAWQG, respectively. Based on SAR, RSC, PI, and MH classifications, most of the wells are suitable for irrigation in the study region. USSL classification suggests that groundwater is suitable for coarse-textured soils and salt-tolerant crops. The study recommends that a proper management plan is required to protect this coastal aquifer efficiently.

Application of the X-ray fluorescence analysis and X-ray diffraction in geochemical studies of the Pleistocene tills from Holy Cross Mountains

International Nuclear Information System (INIS)

Kubala-Kukuś, A.; Ludwikowska-Kedzia, M.; Banaś, D.; Braziewicz, J.; Majewska, U.; Pajek, M.; Wudarczyk-Moćko, J.

2013-01-01

X-ray fluorescence analysis methods (wavelength dispersive X-ray fluorescence analysis (WDXRF) and total reflection X-ray fluorescence (TXRF)) and X-ray powder diffraction (XRPD) have been applied in complementary geochemical studies of the Pleistocene till samples. The XRPD technique gave information about the mineral composition of the analyzed samples while the WDXRF and TXRF studies allowed the fast elemental analysis. The till samples were collected from different regions of Holy Cross Mountains (located in central Poland) which are still not unambiguously described in the context of the geochemical studies of the Quaternary sediments. The analysis was concentrated on the geochemical composition of the till samples both for materials occurring on the surface (characterized by continuous weathering processes) and for samples taken from core borehole. The overriding purpose of these studies is determination of the local lithotype of the tills and its lithologic and petrographic diagnostic properties, including the chemical composition of clay and minerals found in the clay. In the presented work the experimental sets up, sample preparation procedure and measurements programme will be discussed in details. Finally, the elemental and mineral compositions will be presented for studied different groups of the samples. - Highlights: • XRF analysis and X-ray diffraction used in studies of the till samples. • The till samples were collected from different regions of Holy Cross Mountains. • The analysis concentrates both on the samples from surface and from core borehole. • The purpose is determination of the local lithotype of the tills. • The experimental setup, sample preparation, measurements and results are discussed

An overview of the geochemical code MINTEQ: Applications to performance assessment for low-level wastes

International Nuclear Information System (INIS)

Peterson, S.R.; Opitz, B.E.; Graham, M.J.; Eary, L.E.

1987-03-01

The MINTEQ geochemical computer code, developed at the Pacific Northwest Laboratory (PNL), integrates many of the capabilities of its two immediate predecessors, MINEQL and WATEQ3. The MINTEQ code will be used in the Special Waste Form Lysimeters-Arid program to perform the calculations necessary to simulate (model) the contact of low-level waste solutions with heterogeneous sediments of the interaction of ground water with solidified low-level wastes. The code can calculate ion speciation/solubilitya, adsorption, oxidation-reduction, gas phase equilibria, and precipitation/dissolution of solid phases. Under the Special Waste Form Lysimeters-Arid program, the composition of effluents (leachates) from column and batch experiments, using laboratory-scale waste forms, will be used to develop a geochemical model of the interaction of ground water with commercial, solidified low-level wastes. The wastes being evaluated include power-reactor waste streams that have been solidified in cement, vinyl ester-styrene, and bitumen. The thermodynamic database for the code was upgraded preparatory to performing the geochemical modeling. Thermodynamic data for solid phases and aqueous species containing Sb, Ce, Cs, or Co were added to the MINTEQ database. The need to add these data was identified from the characterization of the waste streams. The geochemical model developed from the laboratory data will then be applied to predict the release from a field-lysimeter facility that contains full-scale waste samples. The contaminant concentrations migrating from the waste forms predicted using MINTEQ will be compared to the long-term lysimeter data. This comparison will constitute a partial field validation of the geochemical model

Assessment of geochemical and hydrologic conditions near Old Yuma Mine in Saguaro National Park, Arizona, 2014–17

Science.gov (United States)

Beisner, Kimberly R.; Gray, Floyd

2018-03-13

The Old Yuma Mine is an abandoned copper, lead, zinc, silver, and gold mine located within the boundaries of Saguaro National Park, Tucson Mountain District, Arizona. This study analyzed the geochemistry of sediments associated with the Old Yuma Mine and assessed hydrologic and geochemical conditions of groundwater to evaluate the area surrounding the Old Yuma Mine. The purpose of the study was to establish the geochemical signature of material associated with the Old Yuma Mine and to compare it with background material and groundwater in the area. Few groundwater samples exceeded the U.S. Environmental Protection Agency (EPA) drinking water standards. Concentrations of several elements were elevated in the waste rock and mine tailings compared with concentrations in sediments collected in background areas. A subset of 15 sediment samples was leached to simulate precipitation interacting with the solid material. Analysis of leachate samples compared to groundwater samples suggests that groundwater samples collected in this study are distinct from leachate samples associated with mining related material. Results suggest that at this time groundwater samples collected during this investigation are not influenced by elements leached from Old Yuma Mine materials.

Multivariate analysis of ATR-FTIR spectra for assessment of oil shale organic geochemical properties

Science.gov (United States)

Washburn, Kathryn E.; Birdwell, Justin E.

2013-01-01

In this study, attenuated total reflectance (ATR) Fourier transform infrared spectroscopy (FTIR) was coupled with partial least squares regression (PLSR) analysis to relate spectral data to parameters from total organic carbon (TOC) analysis and programmed pyrolysis to assess the feasibility of developing predictive models to estimate important organic geochemical parameters. The advantage of ATR-FTIR over traditional analytical methods is that source rocks can be analyzed in the laboratory or field in seconds, facilitating more rapid and thorough screening than would be possible using other tools. ATR-FTIR spectra, TOC concentrations and Rock–Eval parameters were measured for a set of oil shales from deposits around the world and several pyrolyzed oil shale samples. PLSR models were developed to predict the measured geochemical parameters from infrared spectra. Application of the resulting models to a set of test spectra excluded from the training set generated accurate predictions of TOC and most Rock–Eval parameters. The critical region of the infrared spectrum for assessing S1, S2, Hydrogen Index and TOC consisted of aliphatic organic moieties (2800–3000 cm−1) and the models generated a better correlation with measured values of TOC and S2 than did integrated aliphatic peak areas. The results suggest that combining ATR-FTIR with PLSR is a reliable approach for estimating useful geochemical parameters of oil shales that is faster and requires less sample preparation than current screening methods.

Analysis of the geochemical gradient created by surface-groundwater interactions within riverbanks of the East River in Crested Butte, Colorado

Science.gov (United States)

Lunzer, J.; Williams, K. H.; Malenda, H. F.; Nararne-Sitchler, A.

2016-12-01

An improved understanding of the geochemical gradient created by the mixing of surface and groundwater of a river system will have considerable impact on our understanding of microorganisms, organic cycling and biogeochemical processes within these zones. In this study, the geochemical gradient in the hyporheic zone is described using a variety of geochemical properties. A system of shallow groundwater wells were installed in a series of transects along a stream bank. Each transect consists of several wells that progress away from the river bank in a perpendicular fashion. From these wells, temperature, conductivity and pH of water samples were obtained via hand pumping or bailing. These data show a clear geochemical gradient that displays a distinct zone in the subsurface where the geochemical conditions change from surface water dominated to groundwater dominated. For this study, the East River near Crested Butte, Colorado has been selected as the river of interest due the river being a relatively undisturbed floodplain. Additionally, the specific section chosen on the East River displays relatively high sinuosity meaning that these meandering sections will produce hyporheic zones that are more laterally expansive than what would be expected on a river of lower sinuosity. This increase in lateral extension of the hyporheic zone will make depicting the subtle changes in the geochemical gradient much easier than that of a river system in which the hyporheic zone is not as laterally extensive. Data has been and will be continued to be collected at different river discharges to evaluate the geochemical gradient at differing rates. Overall, this characterization of the geochemical gradient along stream banks will produce results that will aid in the further use of geochemical methods to classify and understand hyporheic exchange zones and the potential expansion of these techniques to river systems of differing geologic and geographic conditions.

Comparison of analytical methods for the determination of histamine in reference canned fish samples

Science.gov (United States)

Jakšić, S.; Baloš, M. Ž.; Mihaljev, Ž.; Prodanov Radulović, J.; Nešić, K.

2017-09-01

Two screening methods for histamine in canned fish, an enzymatic test and a competitive direct enzyme-linked immunosorbent assay (CD-ELISA), were compared with the reversed-phase liquid chromatography (RP-HPLC) standard method. For enzymatic and CD-ELISA methods, determination was conducted according to producers’ manuals. For RP-HPLC, histamine was derivatized with dansyl-chloride, followed by RP-HPLC and diode array detection. Results of analysis of canned fish, supplied as reference samples for proficiency testing, showed good agreement when histamine was present at higher concentrations (above 100 mg kg-1). At a lower level (16.95 mg kg-1), the enzymatic test produced some higher results. Generally, analysis of four reference samples according to CD-ELISA and RP-HPLC showed good agreement for histamine determination (r=0.977 in concentration range 16.95-216 mg kg-1) The results show that the applied enzymatic test and CD-ELISA appeared to be suitable screening methods for the determination of histamine in canned fish.

An integrated geophysical and geochemical exploration of critical zone weathering on opposing montane hillslope

Science.gov (United States)

Singha, K.; Navarre-Sitchler, A.; Bandler, A.; Pommer, R. E.; Novitsky, C. G.; Holbrook, S.; Moore, J.

2017-12-01

Quantifying coupled geochemical and hydrological properties and processes that operate in the critical zone is key to predicting rock weathering and subsequent transmission and storage of water in the shallow subsurface. Geophysical data have the potential to elucidate geochemical and hydrologic processes across landscapes over large spatial scales that are difficult to achieve with point measurements alone. Here, we explore the connections between weathering and fracturing, as measured from integrated geochemical and geophysical borehole data and seismic velocities on north- and south-facing aspects within one watershed in the Boulder Creek Critical Zone Observatory. We drilled eight boreholes up to 13 m deep on north- and south-facing aspects within Upper Gordon Gulch, and surface seismic refraction data were collected near these wells to explore depths of regolith and bedrock, as well as anisotropic characteristics of the subsurface material due to fracturing. Optical televiewer data were collected in these wells to infer the dominant direction of fracturing and fracture density in the near surface to corroborate with the seismic data. Geochemical samples were collected from four of these wells and a series of shallow soil pits for bulk chemistry, clay fraction, and exchangeable cation concentrations to identify depths of chemically altered saprolite. Seismic data show that depth to unweathered bedrock, as defined by p-wave seismic velocity, is slightly thicker on the north-facing slopes. Geochemical data suggest that the depth to the base of saprolite ranges from 3-5 m, consistent with a p-wave velocity value of 1200 m/s. Based on magnitude and anisotropy of p-wave velocities together with optical televiewer data, regolith on north-facing slopes is thought to be more fractured than south-facing slopes, while geochemical data indicate that position on the landscape is another important characteristic in determining depths of weathering. We explore the importance

Stream-sediment geochemical prospecting for uranium in the Paleozoic of the Belgian Ardennes

International Nuclear Information System (INIS)

Martin, H.; Lefin, J.P.; Dejonghe, L.; Henry, J.

1983-01-01

Orientation studies showed that a positive geochemical response for uranium in the Belgium Ardennes could be obtained with bank sampling, which consists of collecting colluvium and alluvium on both sides of the rivers. This necessitates a large sampling density of about one sample per km 2 (10 205 samples from an area of 11 000 km 2 ). Anomalies (> 3 ppm) are found that fall into three main areas each in a different geological setting: (1) at the periphery of the Cambro-Silurian Massif of Stavelot; (2) within the transition beds between the Visean and Namurian; and (3) in the lower Devonian of the central Ardennes. (Auth.)

Geochemical fractionation of 210Pb in oxic estuarine sediments of Coatzacoalcos River, Gulf of Mexico

International Nuclear Information System (INIS)

Ontiveros-Cuadras, J.F.; Ruiz-Fernandez, A.C.; Perez-Bernal, L.H.; Sanchez-Cabeza, J.A.; Universitat Autonoma de Barcelona; Wee-Kwong, L.L.

2012-01-01

210 Pb activities were analyzed in surface sediments from the Coatzacoalcos River (Gulf of Mexico) to evaluate its distribution according to sediment grain size and in different geochemical compartments by using sequential extraction techniques. The geochemical fractionation experiments provided compatible results: by using the Tessier's method more than 90% of the 210 Pb activity in the samples was found the residual fraction (primary and secondary minerals) and the remaining ( 210 Pb content was found in comparative amounts in the reactive, the silicate, and the pyrite fractions (accounting together for >80%), and the rest was found in the residual fraction. The grain size fractionation analyses showed that the 210 Pb activities were mostly retained in the clay fraction, accounting up to 60-70% of the 210 Pb total activity in the sediment sample and therefore, it is concluded that the separation of the clay fraction can be useful to improve the analysis of low 210 Pb content sediments for dating purposes. (author)

Mineralization and geochemical studies in the Kalchouyeh occurrence, southwest of Naein

OpenAIRE

Hengameh Hosseini Dinani; Hashem Bagheri; Reza Shamsipour Dehkordi

2012-01-01

Kalchouyeh area in southwest of Naein is located in the Urumieh-Dokhtar volcano-plutonic belt. Mineralization occurred mainly as disseminations and veinlets hosted by trachy-andesite and pyroxene andesites. For mineralogy, alteration, fluid inclusion and geochemical studies, the two major mineralized zones: A (larger vein) from the north-northwest and B (smaller vein) from the east-southeast of the area were sampled. Alteration studies revealed that the main alteration assemblages are silicif...

Hydrogeochemical and stream sediment detailed geochemical survey for Edgemont, South Dakota; Wyoming

Energy Technology Data Exchange (ETDEWEB)

Butz, T.R.; Dean, N.E.; Bard, C.S.; Helgerson, R.N.; Grimes, J.G.; Pritz, P.M.

1980-05-31

Results of the Edgemont detailed geochemical survey are reported. Field and laboratory data are presented for 109 groundwater and 419 stream sediment samples. Statistical and areal distributions of uranium and possible uranium-related variables are given. A generalized geologic map of the survey area is provided, and pertinent geologic factors which may be of significance in evaluating the potential for uranium mineralization are briefly discussed. Groundwaters containing greater than or equal to 7.35 ppB uranium are present in scattered clusters throughout the area sampled. Most of these groundwaters are from wells drilled where the Inyan Kara Group is exposed at the surface. The exceptions are a group of samples in the northwestern part of the area sampled and south of the Dewey Terrace. These groundwaters are also produced from the Inyan Kara Group where it is overlain by the Graneros Group and alluvium. The high uranium groundwaters along and to the south of the terrace are characterized by high molybdenum, uranium/specific conductance, and uranium/sulfate values. Many of the groundwaters sampled along the outcrop of the Inyan Kara Group are near uranium mines. Groundwaters have high amounts of uranium and molybdenum. Samples taken downdip are sulfide waters with low values of uranium and high values of arsenic, molybdenum, selenium, and vanadium. Stream sediments containing greater than or equal to 5.50 ppM soluble uranium are concentrated in basins draining the Graneros and Inyan Kara Groups. These values are associated with high values for arsenic, selenium, and vanadium in samples from both groups. Anomalous values for these elements in the Graneros Group may be caused by bentonite beds contained in the rock units. As shown on the geochemical distribution plot, high uranium values that are located in the Inyan Kara Group are almost exclusively draining open-pit uranium mines.

Recent developments and evaluation of selected geochemical techniques applied to uranium exploration

International Nuclear Information System (INIS)

Wenrich-Verbeek, K.J.; Cadigan, R.A.; Felmlee, J.K.; Reimer, G.M.; Spirakis, C.S.

1976-01-01

Various geochemical techniques for uranium exploration are currently under study by the geochemical techniques team of the Branch of Uranium and Thorium Resources, US Geological Survey. Radium-226 and its parent uranium-238 occur in mineral spring water largely independently of the geochemistry of the solutions and thus are potential indicators of uranium in source rocks. Many radioactive springs, hot or cold, are believed to be related to hydrothermal systems which contain uranium at depth. Radium, when present in the water, is co-precipitated in iron and/or manganese oxides and hydroxides or in barium sulphate associated with calcium carbonate spring deposits. Studies of surface water samples have resulted in improved standardized sample treatment and collection procedures. Stream discharge has been shown to have a significant effect on uranium concentration, while conductivity shows promise as a ''pathfinder'' for uranium. Turbid samples behave differently and consequently must be treated with more caution than samples from clear streams. Both water and stream sediments should be sampled concurrently, as anomalous uranium concentrations may occur in only one of these media and would be overlooked if only one, the wrong one, were analysed. The fission-track technique has been applied to uranium determinations in the above water studies. The advantages of the designed sample collecting system are that only a small quantity, typically one drop, of water is required and sample manipulation is minimized, thereby reducing contamination risks. The fission-track analytical technique is effective at the uranium concentration levels commonly found in natural waters (5.0-0.01 μg/litre). Landsat data were used to detect alteration associated with uranium deposits. Altered areas were detected but were not uniquely defined. Nevertheless, computer processing of Landsat data did suggest a smaller size target for further evaluation and thus is useful as an exploration tool

Hydrogeochemical and stream sediment detailed geochemical survey for Edgemont, South Dakota; Wyoming

International Nuclear Information System (INIS)

Butz, T.R.; Dean, N.E.; Bard, C.S.; Helgerson, R.N.; Grimes, J.G.; Pritz, P.M.

1980-01-01

Results of the Edgemont detailed geochemical survey are reported. Field and laboratory data are presented for 109 groundwater and 419 stream sediment samples. Statistical and areal distributions of uranium and possible uranium-related variables are given. A generalized geologic map of the survey area is provided, and pertinent geologic factors which may be of significance in evaluating the potential for uranium mineralization are briefly discussed. Groundwaters containing greater than or equal to 7.35 ppB uranium are present in scattered clusters throughout the area sampled. Most of these groundwaters are from wells drilled where the Inyan Kara Group is exposed at the surface. The exceptions are a group of samples in the northwestern part of the area sampled and south of the Dewey Terrace. These groundwaters are also produced from the Inyan Kara Group where it is overlain by the Graneros Group and alluvium. The high uranium groundwaters along and to the south of the terrace are characterized by high molybdenum, uranium/specific conductance, and uranium/sulfate values. Many of the groundwaters sampled along the outcrop of the Inyan Kara Group are near uranium mines. Groundwaters have high amounts of uranium and molybdenum. Samples taken downdip are sulfide waters with low values of uranium and high values of arsenic, molybdenum, selenium, and vanadium. Stream sediments containing greater than or equal to 5.50 ppM soluble uranium are concentrated in basins draining the Graneros and Inyan Kara Groups. These values are associated with high values for arsenic, selenium, and vanadium in samples from both groups. Anomalous values for these elements in the Graneros Group may be caused by bentonite beds contained in the rock units. As shown on the geochemical distribution plot, high uranium values that are located in the Inyan Kara Group are almost exclusively draining open-pit uranium mines

Identification of a set of endogenous reference genes for miRNA expression studies in Parkinson's disease blood samples.

Science.gov (United States)

Serafin, Alice; Foco, Luisa; Blankenburg, Hagen; Picard, Anne; Zanigni, Stefano; Zanon, Alessandra; Pramstaller, Peter P; Hicks, Andrew A; Schwienbacher, Christine

2014-10-10

Research on microRNAs (miRNAs) is becoming an increasingly attractive field, as these small RNA molecules are involved in several physiological functions and diseases. To date, only few studies have assessed the expression of blood miRNAs related to Parkinson's disease (PD) using microarray and quantitative real-time PCR (qRT-PCR). Measuring miRNA expression involves normalization of qRT-PCR data using endogenous reference genes for calibration, but their choice remains a delicate problem with serious impact on the resulting expression levels. The aim of the present study was to evaluate the suitability of a set of commonly used small RNAs as normalizers and to identify which of these miRNAs might be considered reliable reference genes in qRT-PCR expression analyses on PD blood samples. Commonly used reference genes snoRNA RNU24, snRNA RNU6B, snoRNA Z30 and miR-103a-3p were selected from the literature. We then analyzed the effect of using these genes as reference, alone or in any possible combination, on the measured expression levels of the target genes miR-30b-5p and miR-29a-3p, which have been previously reported to be deregulated in PD blood samples. We identified RNU24 and Z30 as a reliable and stable pair of reference genes in PD blood samples.

X-Ray and Radiometrics in Geo-Ecological and Geochemical Mapping

Energy Technology Data Exchange (ETDEWEB)

Fedyanin, S. N. [Navoi Mining and Metallurgical Combinat (Uzbekistan)

2014-05-15

Monitoring of tailing pits of uranium ore conversion products and reserve supplies of low-grade ores stored in dumps is traditionally based on radiation environment on these sites and adjacent territories. The results of gamma-ray spectrometry of solid fractions and radon concentration measurement in liquid and gas phases of technogenic formations are used in radiation hazard evaluation. Radiometric testing practice of low-activity field formations in loose and lump masses shows that due to high emanating ability it is necessary to use dual-channel radiometer for ionizing radiation background record and compensation. Thus gamma-radiometry is not the direct method of uranium content determination and alfa- and beta-radiometry can be correctly used only for sample analysis in laboratory environment. Consequently, distant express testing with the help of X-ray radiometric (XRM) instruments (on calcium, iron, manganese, titanium, copper, arsenic, lead, strontium, selenium, molybdenum, uranium, etc.) is recommended for additional introduction in field observations of radio-ecological environment in mining and processing production tailing and dumps of low-grade ore reserve supplies. Thanks to preliminary areal schemes of geochemical zonality as per XRM data XRM application allows to use the sample limit, given for a wide range of laboratory analyses rationally. Sampling places and their number as well as kinds of laboratory analyses are chosen based on XRM data.It is rather effective to use laboratory variant of atomic absorptive analysis on mercury and stibium in gases (GA), generated in the process of grated samples calcination in muffle furnaces. During the presentation of the report In order to prove the effectiveness of XRM and GA presentation graphics with the results of areal mapping using the above methods and geochemical testing on the territories of Tashkent (Uzbekistan) and Chimkent (Kazakhstan) regions within the framework of the geological and ecological

Geochemical modeling of magmatic gas scrubbing

Directory of Open Access Journals (Sweden)

B. Gambardella

2005-06-01

Full Text Available The EQ3/6 software package, version 7.2 was successfully used to model scrubbing of magmatic gas by pure water at 0.1 MPa, in the liquid and liquid-plus-gas regions. Some post-calculations were necessary to account for gas separation effects. In these post-calculations, redox potential was considered to be fixed by precipitation of crystalline a-sulfur, a ubiquitous and precocious process. As geochemical modeling is constrained by conservation of enthalpy upon water-gas mixing, the enthalpies of the gas species of interest were reviewed, adopting as reference state the liquid phase at the triple point. Our results confirm that significant emissions of highly acidic gas species (SO2(g, HCl(g, and HF(g are prevented by scrubbing, until dry conditions are established, at least locally. Nevertheless important outgassing of HCl(g can take place from acid, HCl-rich brines. Moreover, these findings support the rule of thumb which is generally used to distinguish SO2-, HCl-, and HF-bearing magmatic gases from SO2-, HCl-, and HF-free hydrothermal gases.

Geochemical characteristics of oil sands fluid petroleum coke

International Nuclear Information System (INIS)

Nesbitt, Jake A.; Lindsay, Matthew B.J.; Chen, Ning

2017-01-01

The geochemical characteristics of fluid petroleum coke from the Athabasca Oil Sands Region (AOSR) of northern Alberta, Canada were investigated. Continuous core samples were collected to 8 m below surface at several locations (n = 12) from three coke deposits at an active oil sands mine. Bulk elemental analyses revealed the coke composition was dominated by C (84.2 ± 2.3 wt%) and S (6.99 ± 0.26 wt%). Silicon (9210 ± 3000 mg kg"−"1), Al (5980 ± 1200 mg kg"−"1), Fe (4760 ± 1200 mg kg"−"1), and Ti (1380 ± 430 mg kg"−"1) were present in lesser amounts. Vanadium (1280 ± 120 mg kg"−"1) and Ni (230 ± 80 mg kg"−"1) exhibited the highest concentrations among potentially-hazardous minor and trace elements. Sequential extractions revealed potential for release of these metals under field-relevant conditions. Synchrotron powder X-ray diffraction revealed the presence of Si and Ti oxides, organically-complexed V and hydrated Ni sulfate, and provided information about the asphaltenic carbon matrix. X-ray absorption near edge structure (XANES) spectroscopy at the V and Ni K-edges revealed that these metals were largely hosted in porphyrins and similar organic complexes throughout coke grains. Minor differences among measured V and Ni K-edge spectra were largely attributed to slight variations in local coordination of V(IV) and Ni(II) within these organic compounds. However, linear combination fits were improved by including reference spectra for inorganic phases with octahedrally-coordinated V(III) and Ni(II). Sulfur and Fe K-edge XANES confirmed that thiophenic coordination and pyritic-ilmenitic coordination are predominant, respectively. These results provide new information on the geochemical and mineralogical composition of oil sands fluid petroleum coke and improve understanding of potential controls on associated water chemistry. - Highlights: • Oil sands fluid petroleum coke contains wide range of major, minor and

Geochemical and physical drivers of microbial community structure in hot spring ecosystems

Science.gov (United States)

Havig, J. R.; Hamilton, T. L.; Boyd, E. S.; Meyer-Dombard, D. R.; Shock, E.

2012-12-01

Microbial communities in natural systems are typically characterized using samples collected from a single time point, thereby neglecting the temporal dynamics that characterize natural systems. The composition of these communities obtained from single point samples is then related to the geochemistry and physical parameters of the environment. Since most microbial life is adapted to a relatively narrow ecological niche (multiplicity of physical and chemical parameters that characterize a local habitat), these assessments provide only modest insight into the controls on community composition. Temporal variation in temperature or geochemical composition would be expected to add another dimension to the complexity of niche space available to support microbial diversity, with systems that experience greater variation supporting a greater biodiversity until a point where the variability is too extreme. . Hot springs often exhibit significant temporal variation, both in physical as well as chemical characteristics. This is a result of subsurface processes including boiling, phase separation, and differential mixing of liquid and vapor phase constituents. These characteristics of geothermal systems, which vary significantly over short periods of time, provide ideal natural laboratories for investigating how i) the extent of microbial community biodiversity and ii) the composition of those communities are shaped by temporal fluctuations in geochemistry. Geochemical and molecular samples were collected from 17 temporally variable hot springs across Yellowstone National Park, Wyoming. Temperature measurements using data-logging thermocouples, allowing accurate determination of temperature maximums, minimums, and ranges for each collection site, were collected in parallel, along with multiple geochemical characterizations as conditions varied. There were significant variations in temperature maxima (54.5 to 90.5°C), minima (12.5 to 82.5°C), and range (3.5 to 77.5°C) for

Sharp fronts within geochemical transport problems

International Nuclear Information System (INIS)

Grindrod, P.

1995-01-01

The authors consider some reactive geochemical transport problems in groundwater systems. When incoming fluid is in disequilibrium with the mineralogy sharp transition fronts may develop. They show that this is a generic property for a class of systems where the timescales associated with reaction and diffusion phenomena are much shorter than those associated with advective transport. Such multiple timescale problems are relevant to a variety of processes in natural systems: mathematically methods of singular perturbation theory reduce the dimension of the problems to be solved locally. Furthermore, they consider how spatial heterogeneous mineralogy can impact upon the propagation of sharp geochemical fronts. The authors developed an asymptotic approach in which they solve equations for the evolving geometry of the front and indicate how the non-smooth perturbations due to natural heterogeneity of the mineralogy on underlying ground water flow field are balanced against the smoothing effect of diffusion/dispersive processes. Fronts are curvature damped, and the results here indicate the generic nature of separate front propagation within both model (idealized) and natural (heterogeneous) geochemical systems

Magnetic and geochemical characterization of Andosols developed on basalts in the Massif Central, France

Science.gov (United States)

Grison, Hana; Petrovsky, Eduard; Stejskalova, Sarka; Kapicka, Ales

2015-05-01

Identification of Andosols is primarily based upon the content of their colloidal constituents—clay and metal-humus complexes—and on the determining of andic properties. This needs time and cost-consuming geochemical analyses. Our primary aim of this study is to describe the magnetic and geochemical properties of soils rich in iron oxides derived from strongly magnetic volcanic basement (in this case Andosols). Secondary aim is to explore links between magnetic and chemical parameters of andic soils with respect to genesis factors: parent material age, precipitation, and thickness of the soil profile. Six pedons of andic properties, developed on basaltic lavas, were analyzed down to parent rock by a set of magnetic and geochemical methods. Magnetic data of soil and rock samples reflect the type, concentration, and particle-size distribution of ferrimagnetic minerals. Geochemical data include soil reaction (pH in H2O), cation exchange capacity, organic carbon, and different forms of extractable iron and aluminum content. Our results suggest the following: (1) magnetic measurements of low-field mass-specific magnetic susceptibility can be a reliable indicator for estimating andic properties, and in combination with thermomagnetic curves may be suitable for discriminating between alu-andic and sil-andic subtypes. (2) In the studied Andosols, strong relationships were found between (a) magnetic grain-size parameters, precipitation, and exchangeable bases; (b) concentration of ferrimagnetic particles and degree of crystallization of free iron; and (c) parameters reflecting changes in magneto-mineralogy and soil genesis (parent material age + soil depth).

Significance of geochemical characterization to performance at Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Simmons, A.M.

1993-01-01

The U.S. concept for permanent disposal of high-level radioactive waste resembles those of other countries in that it relies upon burial in a deep geologic medium. This concept relies upon multiple barriers to retard transport of radionuclides to the accessible environment; those barriers consist of the waste form, waste container, engineered barrier system (including possible backfill) and retardant properties of the host rock. Because mobilization of radionuclides is fundamentally a geochemical problem, an understanding of past, present, and future geochemical processes is a requisite part of site characterization studies conducted by the U.S. Department of Energy at Yucca Mountain, Nevada. Geochemical information is needed for evaluating three favorable conditions (the rates of geochemical processes, conditions that promote precipitation or sorption of radionuclides or prohibit formation of colloids, and stable mineral assemblages) and four potentially adverse conditions of the site (groundwater conditions that could increase the chemical reactivity of the engineered barried system or reduce sorption, potential for gaseous radionuclide movement, and oxidizing groundwaters) for key issues of radionuclide release, groundwater quality, and stability of the geochemical environment. Preliminary results of long-term heating experiments indicate that although zeolites can be modified by long-term, low temperature reactions, their beneficial sorptive properties will not be adversely affected. Mineral reactions will be controlled by the aqueous activity of silica in groundwater with which the minerals are in contact. Geochemical barriers alone may satisfy release requirements to the accessible environment for many radionuclides; however, additional site specific geochemical and mineralogical data are needed to test existing and future radionuclide transport models

Lead Isotopes in Olivine-Phyric Shergottite Tissint: Implications for the Geochemical Evolution of the Shergottite Source Mantle

Science.gov (United States)

Moriwaki, R.; Usui, T.; Simon, J. I.; Jones, J. H.; Yokoyama, T.

2015-01-01

Geochemically-depleted shergottites are basaltic rocks derived from a martian mantle source reservoir. Geochemical evolution of the martian mantle has been investigated mainly based on the Rb-Sr, Sm-Nd, and Lu-Hf isotope systematics of the shergottites [1]. Although potentially informative, U-Th- Pb isotope systematics have been limited because of difficulties in interpreting the analyses of depleted meteorite samples that are more susceptible to the effects of near-surface processes and terrestrial contamination. This study conducts a 5-step sequential acid leaching experiment of the first witnessed fall of the geochemically-depleted olivinephyric shergottite Tissint to minimize the effect of low temperature distrubence. Trace element analyses of the Tissint acid residue (mostly pyroxene) indicate that Pb isotope compositions of the residue do not contain either a martian surface or terrestrial component, but represent the Tissint magma source [2]. The residue has relatively unradiogenic initial Pb isotopic compositions (e.g., 206Pb/204Pb = 10.8136) that fall within the Pb isotope space of other geochemically-depleted shergottites. An initial µ-value (238U/204Pb = 1.5) of Tissint at the time of crystallization (472 Ma [3]) is similar to a time-integrated mu- value (1.72 at 472 Ma) of the Tissint source mantle calculated based on the two-stage mantle evolution model [1]. On the other hand, the other geochemically-depleted shergottites (e.g., QUE 94201 [4]) have initial µ-values of their parental magmas distinctly lower than those of their modeled source mantle. These results suggest that only Tissint potentially reflects the geochemical signature of the shergottite mantle source that originated from cumulates of the martian magma ocean

Robust statistics and geochemical data analysis

International Nuclear Information System (INIS)

Di, Z.

1987-01-01

Advantages of robust procedures over ordinary least-squares procedures in geochemical data analysis is demonstrated using NURE data from the Hot Springs Quadrangle, South Dakota, USA. Robust principal components analysis with 5% multivariate trimming successfully guarded the analysis against perturbations by outliers and increased the number of interpretable factors. Regression with SINE estimates significantly increased the goodness-of-fit of the regression and improved the correspondence of delineated anomalies with known uranium prospects. Because of the ubiquitous existence of outliers in geochemical data, robust statistical procedures are suggested as routine procedures to replace ordinary least-squares procedures

Coupling of transport and geochemical models

International Nuclear Information System (INIS)

Noy, D.J.

1985-01-01

This contract stipulated separate pieces of work to consider mass transport in the far-field of a repository, and more detailed geochemical modelling of the groundwater in the near-field. It was envisaged that the far-field problem would be tackled by numerical solutions to the classical advection-diffusion equation obtained by the finite element method. For the near-field problem the feasibility of coupling existing geochemical equilibrium codes to the three dimensional groundwater flow codes was to be investigated. This report is divided into two sections with one part devoted to each aspect of this contract. (author)

Integrated geophysical-geochemical methods for archaeological prospecting

OpenAIRE

Persson, Kjell

2005-01-01

A great number of field measurements with different methods and instruments were conducted in attempts to develop a method for an optimal combination of various geochemical and geophysical methods in archaeological prospecting. The research presented in this thesis focuses on a study of how different anthropogenic changes in the ground can be detected by geochemical and geophysical mapping and how the results can be presented. A six-year pilot project, Svealand in Vendel and Viking periods (S...

Retention/sorption and geochemical modelling

Energy Technology Data Exchange (ETDEWEB)

Arcos, D.; Grandia, F.; Domenech, C. [Enviros Spain, S.L., Barcelona (Spain); SCK-CEN, Mol (Belgium); Sellin, P. [SKB - Swedish Nuclear Fuel and Waste Management, SE, Stockholm (Sweden); Hunter, F.M.I.; Bate, F.; Heath, T.G.; Hoch, A. [Serco Assurance, Oxfordshire (United Kingdom); Werme, L.O. [SKB - Svensk Karnbranslehantering AB, Stockholm (Sweden); Bruggeman, C.; Maes, I.A.; Breynaert, E.; Vancluysen, J. [Leuven Katholieke Univ., Lab. for Colloid Chemistry (Belgium); Montavon, G.; Guo, Z. [Ecole des Mines, 44 - Nantes (France); Riebe, B.; Bunnenberg, C.; Meleshyn, A. [Leibniz Univ. Hannover, Zentrum fur Strahlenschutz und Radiookologie, Hannover (Germany); Dultz, S. [Leibniz Univ. Hannover, Institut fur Bodenkunde, Hannover (Germany)

2007-07-01

This session gathers 4 articles dealing with: the long-term geochemical evolution of the near field of a KBS-3 HLNW repository: insights from reactive transport modelling (D. Arcos, F. Grandia, C. Domenech, P. Sellin); the investigation of iron transport into bentonite from anaerobically corroding steel: a geochemical modelling study (F.M.I. Hunter, F. Bate, T.G. Heath, A. Hoch, L.O. Werme); SeO{sub 3}{sup 2-} adsorption on conditioned Na-illite: XAS spectroscopy, kinetics, surface complexation model and influence of compaction (C. Bruggeman, A. Maes, G. Montavon, E. Breynaert, Z. Guo, J. Vancluysen); the influence of temperature and gamma-irradiation on the anion sorption capacity of modified bentonites (B. Riebe, C. Bunnenberg, A. Meleshyn, S. Dultz)

Development of Microanaytical Reference Materials for In-situ Anaysis at the U.S. Geological Survey

Science.gov (United States)

Wilson, S.

2006-05-01

With the increased use of microanalysis in geochemical investigations comes the need for a reliable and diversified supply of reference materials homogenous at the micrometer scale to assist analysts in element quantification. To meet these requirements, the U.S. Geological Survey (USGS) has undertaken a program to develop a series of reference materials which cover a range of sample types currently being investigated in our microanalytical laboratories. Initial efforts have focused on the development of natural basalt glasses (BCR- 2G, BHVO-2G, BIR-1G, TB-1G, NKT-1G) from a variety of geologic settings. In addition to these natural basalt materials a series of synthetic basalt glasses GSA-1G, GSC-1G, GSD-1G, GSE-1G have also been developed with 65 trace elements at 0, 3, 30, and 300, ppm respectively. The homogeneity of these materials and their use in international microanalytical proficiency studies will be presented. Application of this technology to the development of glass reference materials as part of a USGS/NASA collaborative studies on the development of Lunar Soil Simulant material will also be discussed.

Neutron activation analysis in reconnaissance geochemical survey of Northwestern Mindoro

International Nuclear Information System (INIS)

Santos, G. Jr.; Fernandez, L.G.

1987-01-01

Instrumental neutron activation analysis (NAA) technique was used to analyze stream sediments collected in Northwestern Mindoro. The concentration levels of 18 elements were determined. It was noted that NAA is suitable for the determination of rare earth, gold, arsenic and cobalt among others because of favorable high neutron cross sections. Samples collected in regional reconnaissance geochemical surveys could be analyzed usng NAA technique to complement other non-nuclear techniques, such as atomic absorption and X-ray fluorescence analysis. (Author). 11 figs.; 2 tabs.; 12 refs

Determination of element concentrations in biological reference materials by solid sampling and other analytical methods

International Nuclear Information System (INIS)

Schauenburg, H.; Weigert, P.

1992-01-01

Using solid sampling with graphite furnace atomic absorption spectrometry (GFAAS), values for cadmium, copper, lead and zinc in six biological reference materials were obtained from up to four laboratories participating in three collaborative studies. These results are compared with those obtained with other methods used in routine analysis from laboratories of official food control. Under certain conditions solid sampling with GFAAS seems to be suitable for routine analysis as well as conventional methods. (orig.)

Precision and Accuracy of k0-NAA Method for Analysis of Multi Elements in Reference Samples

International Nuclear Information System (INIS)

Sri-Wardani

2004-01-01

Accuracy and precision of k 0 -NAA method could determine in the analysis of multi elements contained in reference samples. The analyzed results of multi elements in SRM 1633b sample were obtained with optimum results in bias of 20% but it is in a good accuracy and precision. The analyzed results of As, Cd and Zn in CCQM-P29 rice flour sample were obtained with very good result in bias of 0.5 - 5.6%. (author)

Geochemical reconnaissance for uranium in the Palmyrides region of central Syria

International Nuclear Information System (INIS)

Jubeli, Y.M.

1990-01-01

An account is given of the application of multielement reconnaissance rock chemistry, coupled with ground scintillation γ-ray measurements, to the investigation of the dispersion patterns of uranium and other major and trace elements in the rocks of the arid Palmyrides region of central Syria. The region is underlain by 10 km of sediments that accumulated in an interplatform depression during the Mesozoic and Caenozoic. Uranium and associated elements were syngenetically incorporated into the Upper Cretaceous and Lower Palaeogene sediments - especially phosphorites, which are well represented in the region. The oxidizing environment of the region has facilitated the subsequent geochemical redistribution of uranium. In the investigation more than 400 lithogeochemical samples collected from an area of approximately 9000 km 2 were analysed for over 30 elements. The resulting data were interpreted with the aid of univariate and multivariate statistical methods and the areal distribution of uranium, its associated elements, multivariate geochemical functions and factor scores were mapped with the use of computer graphics. Anomalies of U are accompanied by concentrations of As, Se, V, Mo, Zn, Cd, Cu, Ni and P in various combinations. The highest U concentrations are found in the Upper Cretaceous, which contains a high proportion of phosphatic rocks; younger sediments contain progressively less U. Uranium anomalies close to faults, which have provided conduits for wider U migration, are superimposed on this pattern. Lithogeochemical methods thus define geochemical dispersion patterns with good contrast and delineate areas for further investigation. (author)

Geochemical controls on groundwater chemistry in shales

International Nuclear Information System (INIS)

Von Damm, K.L.

1989-01-01

The chemistry of groundwaters is one of the most important parameters in determining the mobility of species within a rock formation. A three pronged approach was used to determine the composition of, and geochemical controls, on groundwaters specifically within shale formations: (1) available data were collected from the literature, the US Geological Survey WATSTORE data base, and field sampling, (2) the geochemical modeling code EQ3/6 was used to simulate interaction of various shales and groundwaters, and (3) several types of shale were reacted with synthetic groundwaters in the laboratory. The comparison of model results to field and laboratory data provide a means of validating the models, as well as a means of deconvoluting complex field interactions. Results suggest that groundwaters in shales have a wide range in composition and are primarily of the Na-Cl-HCO 3 - type. The constancy of the Na:Cl (molar) ratio at 1:1 and the Ca:Mg ratio from 3:1 to 1:1 suggests the importance of halite and carbonates in controlling groundwater compositions. In agreement with the reaction path modeling, most of the groundwaters are neutral to slightly alkaline at low temperatures. Model and experimental results suggest that reaction (1) at elevated temperatures, or (2) in the presence of oxygen will lead to more acidic conditions. Some acetate was found to be produced in the experiments; depending on the constraints applied, large amounts of acetate were produced in the model results. 13 refs., 1 tab

Evaluation of botanical reference materials for the determination of vanadium in biological samples

International Nuclear Information System (INIS)

Heydorn, K.; Damsgaard, E.

1982-01-01

Three botanical reference materials prepared by the National Bureau of Standards have been studied by neutron activation analysis to evaluate their suitability with respect to the determination of vanadium in biological samples. Various decomposition methods were applied in connection with chemical or radiochemical separations, and results for vanadium were compared with those found by purely instrumental neutron activation analysis. Significantly lower results indicate losses or incomplete dissolution, which makes SRM 1575 Pine Needles and SRM 1573 Tomato Leaves less satisfactory than SRM 1570 Spinach. A reference value of 1.15 mg/kg of this material is recommended, based on results from 3 different methods. All three materials are preferable to SRM 1571 Orchard Leaves, while Bowen's Kale remains the material of choice because of its lower concentration. (author)

Geochemical behaviour of natural uranium-series nuclides in geological formation

International Nuclear Information System (INIS)

Yamakawa, Minoru

1991-01-01

Recent research and investigation show that the Tono uranium deposit and its natural uranium-series nuclides have been preserved, without any significant changes like re-migration or reconcentration, throughout geological events such as upheaval-submergence, marine transgression-regression, and faulting which can readily change geological, hydrogeological, and geochemical conditions. This situation might have come about as a result of being kept in a geometrical closure system, with reducing and milk alkalic geochemical conditions, from the hydrogeological and geochemical point of view. (author)

GANSEKI: JAMSTEC Deep Seafloor Rock Sample Database Emerging to the New Phase

Science.gov (United States)

Tomiyama, T.; Ichiyama, Y.; Horikawa, H.; Sato, Y.; Soma, S.; Hanafusa, Y.

2013-12-01

constraints on geochemical data and thumbnail browsing of sample and thin-section photos. 'MyList' function allows users to organize, compare and download the data of selected samples. To develop a close network among online databases, the new GANSEKI allows multiple URL entries for individual samples. Now the curatorial staffs are working for maintaining references to other JAMSTEC databases such as 'DARWIN [3]' and 'J-EDI [4]'.

Notes on the geochemical survey for uranium in Mindoro Island, Philippines

International Nuclear Information System (INIS)

Santos, G. Jr.; Fernandez, L.G.; Villamater, D.T.; Seguis, J.E.; Ibe, M.G.

1981-03-01

Geochemical reconnaisance using stream sediment and heavy-mineral concentrates panned from coarse alluvium has been carried out in Mindoro Island, one of the oldest and diverse geologic terrains in the Philippines. A total of 135 selected sampling points situated near accessible areas along the periphery of the island were sampled. The samples were collected at a density of one sample per 53 sq. km. A set minus 80 mesh stream sediment fraction and heavy-mineral concentrates was obtained from each sampling point. Mobile or extractable and total uranium were determined. A large uranium anomaly was delineated over the Carboniferous Mindoro Metamorphics as well as in areas underlain by Early Tertiary sedimentary formations. Another group of anomalies were outlined in the southern part of the island underlain by Jurassic Mansalay Formation and Early to Middle Tertiary sedimentary rocks with associated limestone and coal measures. (author)

Multielement geochemical reconnaissance for uranium in the Palmyrides region of central Syria

International Nuclear Information System (INIS)

Jubeli, Y.M.; Hale, M.

1988-01-01

Multielement reconnaissance geochemistry coupled with ground scintillation gamma ray measurements has been used to investigate the dispersion patterns of uranium and other major and trace elements in the arid Palmyrides region of central Syria. Over 500 geochemical samples of outcropping rock, wadi and playa sediments, overburden and groundwaters were taken over an area of approximately 9000 sq km. Most samples were analyzed for 25 major and trace elements by nebulization ICPAES; for As, Sb, Bi and Se by hydride generation and ICPAES; and for U, Th and La and other REE by neutron activation analysis. The resulting data were interpreted with the aid of univariate and multivariate statistical methods. The areal distributions of U, its associated elements, multivariate geochemical functions and factor scores were mapped using computer graphics. Results of the factor analysis indicate that the primary lithogeochemical dispersion patterns of uranium and associated elements are controlled by a combination of structural, lithological and environmental factors. Uranium and associated elements have subsequently been leached out of the phosphorite and other U enriched clayey limestones and carbonate rocks into the hydro- geologic regime. Redistribution of these elements is taking place along fracture zones and major faults. A degree of urnaium accumulation in a Neogene aquifer of the Ad-Daww basin is evident

Geochemical prospecting for thorium and uranium deposits

International Nuclear Information System (INIS)

Boyle, R.W.

1982-01-01

The basic purpose of this book is to present an analysis of the various geochemical methods applicable in the search for all types of thorium and uranium deposits. The general chemistry and geochemistry of thorium and uranium are briefly described in the opening chapter, and this is followed by a chapter on the deposits of the two elements with emphasis on their indicator (pathfinder) elements and on the primary and secondary dispersion characteristics of thorium and uranium in the vicinity of their deposits. The next seven chapters form the main part of the book and describe geochemical prospecting for thorium and uranium, stressing selection of areas in which to prospect, radiometric surveys, analytical geochemical surveys based on rocks (lithochemical surveys), unconsolidated materials (pedochemical surveys), natural waters and sediments (hydrochemical surveys), biological materials (biogeochemical surveys), gases (atmochemical surveys), and miscellaneous methods. A final brief chapter reviews radiometric and analytical methods for the detection and estimation of thorium and uranium. (Auth.)

The role of geochemical prospecting in phased uranium exploration. A case history

International Nuclear Information System (INIS)

Smith, A.Y.; Armour-Brown, A.; Olsen, H.; Lundberg, B.; Niesen, P.L.

1976-01-01

The commencement of a UNDP/IAEA uranium exploration project in Northern Greece in 1971 offered the opportunity to test and apply an exploration strategy based on a phased use of geochemical exploration methods. The paper reviews the exploration task, the strategy selected, and some results obtained. The project area (22000 km 2 ) was explored by car-borne survey, covering 15000 km of road and track. Concurrently, a stream sediment geochemical survey was begun which aimed at a nominal sample density of one sample per square kilometre. Samples were analysed for copper, lead, zinc, silver, cobalt, nickel, molybdenum, mercury and manganese, in addition to uranium. At each site, a general reading of radioactivity was made, and treated like another element analysis. The reconnaissance programme succeeded in delineating a number of important target areas, varying in size from a few to several hundred square kilometres with significant uranium potential. Follow-up and detailed surveys have been carried out over a number of these, including a sedimentary basin of continental deposits which have been found to contain occurrences of secondary uranium minerals, and two areas in which granitic bodies have been found to have fracture systems and secondary uranium mineralization of economic interest. In no case has sufficient work been yet done to prove economic deposits of uranium. The phased strategy used has, however, already been demonstrated to be effective in the environment of northern Greece. (author)

Geochemical evidence for diversity of dust sources in the southwestern United States

Science.gov (United States)

Reheis, M.C.; Budahn, J.R.; Lamothe, P.J.

2002-01-01

Several potential dust sources, including generic sources of sparsely vegetated alluvium, playa deposits, and anthropogenic emissions, as well as the area around Owens Lake, California, affect the composition of modern dust in the southwestern United States. A comparison of geochemical analyses of modern and old (a few thousand years) dust with samples of potential local sources suggests that dusts reflect four primary sources: (1) alluvial sediments (represented by Hf, K, Rb, Zr, and rare-earth elements, (2) playas, most of which produce calcareous dust (Sr, associated with Ca), (3) the area of Owens (dry) Lake, a human-induced playa (As, Ba, Li, Pb, Sb, and Sr), and (4) anthropogenic and/or volcanic emissions (As, Cr, Ni, and Sb). A comparison of dust and source samples with previous analyses shows that Owens (dry) Lake and mining wastes from the adjacent Cerro Gordo mining district are the primary sources of As, Ba, Li, and Pb in dusts from Owens Valley. Decreases in dust contents of As, Ba, and Sb with distance from Owens Valley suggest that dust from southern Owens Valley is being transported at least 400 km to the east. Samples of old dust that accumulated before European settlement are distinctly lower in As, Ba, and Sb abundances relative to modern dust, likely due to modern transport of dust from Owens Valley. Thus, southern Owens Valley appears to be an important, geochemically distinct, point source for regional dust in the southwestern United States. Copyright ?? 2002 Elsevier Science Ltd.

A reference sample for investigating the stability of the imaging system of x-ray computed tomography

International Nuclear Information System (INIS)

Sun, Wenjuan; Brown, Stephen; Flay, Nadia; McCarthy, Michael; McBride, John

2016-01-01

The use of x-ray computed tomography for dimensional measurements associated with engineering applications has flourished in recent years. However, error sources associated with the technology are not well understood. In this paper, a novel two-sphere reference sample has been developed and used to investigate the stability of the imaging system that consists of an x-ray tube and a detector. In contrast with other research work reported, this work considered relative positional variation along the x -, y - and z -axes. This sample is a significant improvement over the one sphere sample proposed previously, which can only be used to observe the stability of the imaging system along x - and y -axes. Temperature variations of different parts of the system have been monitored and the relationship between temperature variations and x-ray image stability has been studied. Other effects that may also influence the stability of the imaging system have been discussed. The proposed reference sample and testing method are transferable to other types of x-ray computed tomography systems, for example, systems with transmission targets and systems with sub-micrometre focal spots. (paper)

Geochemical engineering reference manual

Energy Technology Data Exchange (ETDEWEB)

Owen, L.B.; Michels, D.E.

1984-01-01

The following topics are included in this manual: physical and chemical properties of geothermal brine and steam, scale and solids control, processing spent brine for reinjection, control of noncondensable gas emissions, and goethermal mineral recovery. (MHR)

A comparison study on detection of key geochemical variables and factors through three different types of factor analysis

Science.gov (United States)

Hoseinzade, Zohre; Mokhtari, Ahmad Reza

2017-10-01

Large numbers of variables have been measured to explain different phenomena. Factor analysis has widely been used in order to reduce the dimension of datasets. Additionally, the technique has been employed to highlight underlying factors hidden in a complex system. As geochemical studies benefit from multivariate assays, application of this method is widespread in geochemistry. However, the conventional protocols in implementing factor analysis have some drawbacks in spite of their advantages. In the present study, a geochemical dataset including 804 soil samples collected from a mining area in central Iran in order to search for MVT type Pb-Zn deposits was considered to outline geochemical analysis through various fractal methods. Routine factor analysis, sequential factor analysis, and staged factor analysis were applied to the dataset after opening the data with (additive logratio) alr-transformation to extract mineralization factor in the dataset. A comparison between these methods indicated that sequential factor analysis has more clearly revealed MVT paragenesis elements in surface samples with nearly 50% variation in F1. In addition, staged factor analysis has given acceptable results while it is easy to practice. It could detect mineralization related elements while larger factor loadings are given to these elements resulting in better pronunciation of mineralization.

Lateritinga project: a geochemical orientation study for Amazon lateritic

International Nuclear Information System (INIS)

Costa, M.L. da

1990-01-01

The aim of this project is the development of systematic geochemical orientation survey in lateritic weathered terrain, like those form Amazon Region. The main selected targets (sheets) are: Turiacu, Cajuapara and Serra dos Carajas, with 690 samples collected (soils and lateritic rocks). For the Aurizona-Serra do Pirocaua target (Turiacu sheet), within the purpose of this work, 49 samples were collected in a 100x 200m regular grid. From all samples the fraction minor than 200 mesh was taken to analyses (by XRF, AA, OES, ICP and fire assay) for SiO sub(2), Fe sub(2) O sub(3), TiO sub(2), P sub(2) O sub(5), Sr, Ba, Y, Nb, Zr, Ga, Sc, Ni, Co, Cr, Cu, Mn, V, As, Bi, Pt, Pd, Th, Au and REE, as well for their mineralogy by XRD. The chemical results were submitted to statistical treatment with the Geoquant-software for IBM-compatible microcomputer. (author)

Identification of Reliable Reference Genes for Quantification of MicroRNAs in Serum Samples of Sulfur Mustard-Exposed Veterans.

Science.gov (United States)

Gharbi, Sedigheh; Shamsara, Mehdi; Khateri, Shahriar; Soroush, Mohammad Reza; Ghorbanmehr, Nassim; Tavallaei, Mahmood; Nourani, Mohammad Reza; Mowla, Seyed Javad

2015-01-01

In spite of accumulating information about pathological aspects of sulfur mustard (SM), the precise mechanism responsible for its effects is not well understood. Circulating microRNAs (miRNAs) are promising biomarkers for disease diagnosis and prognosis. Accurate normalization using appropriate reference genes, is a critical step in miRNA expression studies. In this study, we aimed to identify appropriate reference gene for microRNA quantification in serum samples of SM victims. In this case and control experimental study, using quantitative real-time polymerase chain reaction (qRT-PCR), we evaluated the suitability of a panel of small RNAs including SNORD38B, SNORD49A, U6, 5S rRNA, miR-423-3p, miR-191, miR-16 and miR-103 in sera of 28 SM-exposed veterans of Iran-Iraq war (1980-1988) and 15 matched control volunteers. Different statistical algorithms including geNorm, Normfinder, best-keeper and comparative delta-quantification cycle (Cq) method were employed to find the least variable reference gene. miR-423-3p was identified as the most stably expressed reference gene, and miR- 103 and miR-16 ranked after that. We demonstrate that non-miRNA reference genes have the least stabil- ity in serum samples and that some house-keeping miRNAs may be used as more reliable reference genes for miRNAs in serum. In addition, using the geometric mean of two reference genes could increase the reliability of the normalizers.

Geochemical surveys in the United States in relation to health

Energy Technology Data Exchange (ETDEWEB)

Tourtelot, H A

1979-12-11

Geochemical surveys in relation to health may be classified as having one, two or three dimensions. One-dimensional surveys examine relations between concentrations of elements such as Pb in soils and other media and burdens of the same elements in humans, at a given time. The spatial distributions of element concentrations are not investigated. The primary objective of two-dimensional surveys is to map the distributions of element concentrations, commonly according to stratified random sampling designs based on either conceptual landscape units or artificial sampling strata, but systematic sampling intervals have also been used. Political units have defined sample areas that coincide with the units used to accumulate epidemiological data. Element concentrations affected by point sources have also been mapped. Background values, location of natural or technological anomalies and the geographic scale of variation for several elements often are determined. Three-dimensional surveys result when two-dimensional surveys are repeated to detect environmental changes.

Geochemical baseline level and function and contamination of phosphorus in Liao River Watershed sediments of China.

Science.gov (United States)

Liu, Shaoqing; Wang, Jing; Lin, Chunye; He, Mengchang; Liu, Xitao

2013-10-15

The quantitative assessment of P contamination in sediments is a challenge due to sediment heterogeneity and the lacking of geochemical background or baseline levels. In this study, a procedure was proposed to determine the average P background level and P geochemical baseline level (GBL) and develop P geochemical baseline functions (GBF) for riverbed sediments of the Liao River Watershed (LRW). The LRW has two river systems - the Liao River System (LRS) and the Daliao River System (DRS). Eighty-eight samples were collected and analyzed for P, Al, Fe, Ca, organic matter, pH, and texture. The results show that Fe can be used as a better particle-size proxy to construct the GBF of P (P (mg/kg) = 39.98 + 166.19 × Fe (%), R(2) = 0.835, n = 66). The GBL of P was 675 mg/kg, while the average background level of P was 355 mg/kg. Noting that many large cities are located in the DRS watershed, most of the contaminated sites were located within the DRS and the riverbed sediments were more contaminated by P in the DRS watershed than in the LRS watershed. The geochemical background and baseline information of P are of great importance in managing P levels within the LRW. Copyright © 2013 Elsevier Ltd. All rights reserved.

Instrumental neutron activation analysis of rib bone samples and of bone reference materials

International Nuclear Information System (INIS)

Saiki, M.; Takata, M.K.; Kramarski, S.; Borelli, A.

2000-01-01

The instrumental neutron activation analysis method was used for the determination of trace elements in rib bone samples taken from autopsies of accident victims. The elements Br, Ca, Cl, Cr, Fe, Mg, Mn, Na, P, Sr, Rb and Zn were determined in cortical tissues by using short and long irradiations with thermal neutron flux of the IEA-R1m nuclear reactor. The reference materials NIST SRM 1400 Bone Ash and NIST SRM 1486 Bone Meal were also analyzed in order to evaluate the precision and the accuracy of the results. It was verified that lyophilization is the most convenient process for drying bone samples since it does not cause any element losses. Comparisons were made between the results obtained for rib samples and the literature values as well as between the results obtained for different ribs from a single individual and for bones from different individuals. (author)

Assessing fundamental motor skills in Belgian children aged 3-8 years highlights differences to US reference sample.

Science.gov (United States)

Bardid, Farid; Huyben, Floris; Lenoir, Matthieu; Seghers, Jan; De Martelaer, Kristine; Goodway, Jacqueline D; Deconinck, Frederik J A

2016-06-01

This study aimed to understand the fundamental motor skills (FMS) of Belgian children using the process-oriented Test of Gross Motor Development, Second Edition (TGMD-2) and to investigate the suitability of using the United States (USA) test norms in Belgium. FMS were assessed using the TGMD-2. Gender, age and motor performance were examined in 1614 Belgian children aged 3-8 years (52.1% boys) and compared with the US reference sample. More proficient FMS performance was found with increasing age, from 3 to 6 years for locomotor skills and 3 to 7 years for object control skills. Gender differences were observed in object control skills, with boys performing better than girls. In general, Belgian children had lower levels of motor competence than the US reference sample, specifically for object control skills. The score distribution of the Belgian sample was skewed, with 37.4% scoring below average and only 6.9% scoring above average. This study supported the usefulness of the TGMD-2 as a process-oriented instrument to measure gross motor development in early childhood in Belgium. However, it also demonstrated that caution is warranted when using the US reference norms. ©2016 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

Validation of endogenous reference genes for qRT-PCR analysis of human visceral adipose samples.

Science.gov (United States)

Mehta, Rohini; Birerdinc, Aybike; Hossain, Noreen; Afendy, Arian; Chandhoke, Vikas; Younossi, Zobair; Baranova, Ancha

2010-05-21

Given the epidemic proportions of obesity worldwide and the concurrent prevalence of metabolic syndrome, there is an urgent need for better understanding the underlying mechanisms of metabolic syndrome, in particular, the gene expression differences which may participate in obesity, insulin resistance and the associated series of chronic liver conditions. Real-time PCR (qRT-PCR) is the standard method for studying changes in relative gene expression in different tissues and experimental conditions. However, variations in amount of starting material, enzymatic efficiency and presence of inhibitors can lead to quantification errors. Hence the need for accurate data normalization is vital. Among several known strategies for data normalization, the use of reference genes as an internal control is the most common approach. Recent studies have shown that both obesity and presence of insulin resistance influence an expression of commonly used reference genes in omental fat. In this study we validated candidate reference genes suitable for qRT-PCR profiling experiments using visceral adipose samples from obese and lean individuals. Cross-validation of expression stability of eight selected reference genes using three popular algorithms, GeNorm, NormFinder and BestKeeper found ACTB and RPII as most stable reference genes. We recommend ACTB and RPII as stable reference genes most suitable for gene expression studies of human visceral adipose tissue. The use of these genes as a reference pair may further enhance the robustness of qRT-PCR in this model system.

Validation of endogenous reference genes for qRT-PCR analysis of human visceral adipose samples

Directory of Open Access Journals (Sweden)

Afendy Arian

2010-05-01

Full Text Available Abstract Background Given the epidemic proportions of obesity worldwide and the concurrent prevalence of metabolic syndrome, there is an urgent need for better understanding the underlying mechanisms of metabolic syndrome, in particular, the gene expression differences which may participate in obesity, insulin resistance and the associated series of chronic liver conditions. Real-time PCR (qRT-PCR is the standard method for studying changes in relative gene expression in different tissues and experimental conditions. However, variations in amount of starting material, enzymatic efficiency and presence of inhibitors can lead to quantification errors. Hence the need for accurate data normalization is vital. Among several known strategies for data normalization, the use of reference genes as an internal control is the most common approach. Recent studies have shown that both obesity and presence of insulin resistance influence an expression of commonly used reference genes in omental fat. In this study we validated candidate reference genes suitable for qRT-PCR profiling experiments using visceral adipose samples from obese and lean individuals. Results Cross-validation of expression stability of eight selected reference genes using three popular algorithms, GeNorm, NormFinder and BestKeeper found ACTB and RPII as most stable reference genes. Conclusions We recommend ACTB and RPII as stable reference genes most suitable for gene expression studies of human visceral adipose tissue. The use of these genes as a reference pair may further enhance the robustness of qRT-PCR in this model system.

Removal of iron interferences by solvent extraction for geochemical analysis by atomic-absorption spectrophotometry

Science.gov (United States)

Zhou, L.; Chao, T.T.; Sanzolone, R.F.

1985-01-01

Iron is a common interferent in the determination of many elements in geochemical samples. Two approaches for its removal have been taken. The first involves removal of iron by extraction with methyl isobutyl ketone (MIBK) from hydrochloric acid medium, leaving the analytes in the aqueous phase. The second consists of reduction of iron(III) to iron(II) by ascorbic acid to minimize its extraction into MIBK, so that the analytes may be isolated by extraction. Elements of interest can then be determined using the aqueous solution or the organic extract, as appropriate. Operating factors such as the concentration of hydrochloric acid, amounts of iron present, number of extractions, the presence or absence of a salting-out agent, and the optimum ratio of ascorbic acid to iron have been determined. These factors have general applications in geochemical analysis by atomic-absorption spectrophotometry. ?? 1985.

Uranium geochemical exploration in northwestern Luzon

International Nuclear Information System (INIS)

Santos, G. Jr.; Fernandez, L.; Ogena, M.; Tauli, G.

1980-01-01

A reconnaissance geochemical stream water and sediment survey which was conducted in northwestern Luzon was able to detect ten (10) uranium anomalous areas. These anomalous areas are located along a north-south trending zone of Miocene marine clastics and sedimentary rocks with tuffaceous sediment intercalations. In general, northwest Luzon has low radioactivity except for two anomalous areas which have 3 to 6 times background radioactivity. Radon anomalies occur in sparsely scattered locations. The anomalous zones appear to be related to major north-south faults and secondary northeast-southwest trending structures. Geochemical correlations between uranium and other elements such as copper, lead, zinc, manganese, silver, cobalt and nickel are generally very poor. (author)

Constraining Lateral Evolution of Magmatic Behavior in North Tanzania from Geophysical and Geochemical Analyses

Science.gov (United States)

Gautier, S.; Tiberi, C.; Parat, F.; Baudouin, C.

2016-12-01

In the framework of CRAFTI and CoLiBrEA experiments in 2013, we proceeded to both seismic and geochemical studies along an EW profile through the North Tanzania Divergence. The data were collected along a line starting at the Ngorongoro volcanic area, ending at Kitumbeine edifice and crossing the rift valley. Recent seismological studies show lateral and depth variations for both velocity and Vp/Vs ratio within this area, particularly a change of Moho depth between the western and central parts of the rift. These two zones also exhibit diverse geochemical signatures that involve different magma storage (depth of reservoir, magma volume) and ascent as well as higher partial melts content for the western part. We take advantage of the recent and precise 3D lithospheric velocity models and receiver functions in this area to compare the structure and nature of Ngorongoro area and rift valley. We first compute ray path and establish regional coherency maps between piercing points, Vp/Vs ratio and tomographic images. Second, those results are compared with the composition of magma at depth obtained from a petrophysical and geochemical analysis of lava samples. We will discuss those results in terms of magmatic processes, and how they interact with the rifting in a cratonic lithosphere.

Instrumenting caves to collect hydrologic and geochemical data: case study from James Cave, Virginia

Science.gov (United States)

Schreiber, Madeline E.; Schwartz, Benjamin F.; Orndorff, William; Doctor, Daniel H.; Eagle, Sarah D.; Gerst, Jonathan D.

2015-01-01

Karst aquifers are productive groundwater systems, supplying approximately 25 % of the world’s drinking water. Sustainable use of this critical water supply requires information about rates of recharge to karst aquifers. The overall goal of this project is to collect long-term, high-resolution hydrologic and geochemical datasets at James Cave, Virginia, to evaluate the quantity and quality of recharge to the karst system. To achieve this goal, the cave has been instrumented for continuous (10-min interval) measurement of the (1) temperature and rate of precipitation; (2) temperature, specific conductance, and rate of epikarst dripwater; (3) temperature of the cave air; and (4) temperature, conductivity, and discharge of the cave stream. Instrumentation has also been installed to collect both composite and grab samples of precipitation, soil water, the cave stream, and dripwater for geochemical analysis. This chapter provides detailed information about the instrumentation, data processing, and data management; shows examples of collected datasets; and discusses recommendations for other researchers interested in hydrologic and geochemical monitoring of cave systems. Results from the research, briefly described here and discussed in more detail in other publications, document a strong seasonality of the start of the recharge season, the extent of the recharge season, and the geochemistry of recharge.

Analytical Methodology for the Determination of Radium Isotopes in Environmental Samples

International Nuclear Information System (INIS)

2010-01-01

Reliable, comparable and 'fit for purpose' results are an essential requirement for any decision based on analytical measurements. For the analyst, the availability of tested and validated analytical procedures is an extremely important tool for production of such analytical measurements. For maximum utility, such procedures should be comprehensive, clearly formulated, and readily available to both the analyst and the customer for reference. Since 2004, the environment programme of the IAEA has included activities aimed at the development of a set of procedures for the determination of radionuclides in terrestrial environmental samples. Measurements of radium isotopes are important for radiological and environmental protection, geochemical and geochronological investigations, hydrology, etc. The suite of isotopes creates and stimulates continuing interest in the development of new methods for determination of radium in various media. In this publication, the four most routinely used analytical methods for radium determination in biological and environmental samples, i.e. alpha spectrometry, gamma spectrometry, liquid scintillation spectrometry and mass spectrometry, are reviewed

Uruguay mining inventory. Geochemical prospecting results of the Las Flores aerial map

International Nuclear Information System (INIS)

Zeegers, H.; Bonnefoy, D.; Garau, M.; Spangenberg, J.

1981-01-01

In the context of the Uruguay mining inventory, the aerial photography map Las Flores had been covered by a specific strategic which included geochemical prospecting elements. The surface covered has the 550 km2, and 1042 samples which they have been analized in Orleans France. 22 elements by plasma spectroscopy and gold by atomic absorption and for uranium laser spectroscopy . They have been evidenced the following anomalies: gold, Pb, Pb-Ba-Cu, Ba and Ni-Cr

Microbial iron cycling in acidic geothermal springs of Yellowstone National Park: Integrating molecular surveys, geochemical processes and isolation of novel Fe-active microorganisms

Directory of Open Access Journals (Sweden)

Mark A Kozubal

2012-03-01

Full Text Available Geochemical, molecular, and physiological analyses of microbial isolates were combined to study the geomicrobiology of acidic iron oxide mats in Yellowstone National Park (YNP. Nineteen sampling locations from 11 geothermal springs were studied ranging in temperature from 53 to 84 °C and pH 2.4 to 3.6. All iron-oxide mats exhibited high diversity of crenarchaeal sequences from the Sulfolobales, Thermoproteales, and Desulfurococcales. The predominant Sulfolobales sequences were highly similar to Metallosphaera yellowstonensis str. MK1, previously isolated from one of these sites. Other groups of archaea were consistently associated with different types of iron oxide mats, including undescribed members of the phyla Thaumarchaeota and Euryarchaeota. Bacterial sequences were dominated by relatives of Hydrogenobaculum spp. above 65-70 °C, but increased in diversity below 60 °C. Cultivation of relevant iron-oxidizing and iron-reducing microbial isolates included Sulfolobus str. MK3, Sulfobacillus str. MK2, Acidicaldus str. MK6, and a new candidate genus in the Sulfolobales referred to as Sulfolobales str. MK5. Strains MK3 and MK5 are capable of oxidizing ferrous iron autotrophically, while strain MK2 oxidizes iron mixotrophically. Similar rates of iron oxidation were observed for M. yellowstonensis str. MK1 and Sulfolobales str. MK5 cultures, and these rates are close to those measured in situ. Biomineralized phases of ferric iron varied among cultures and field sites, and included ferric oxyhydroxides, K-jarosite, goethite, hematite, and scorodite depending on geochemical conditions. Strains MK5 and MK6 are capable of reducing ferric iron under anaerobic conditions with complex carbon sources. The combination of geochemical and molecular data as well as physiological observations of isolates suggests that the community structure of acidic Fe mats is linked with Fe cycling across temperatures ranging from 53 to 88 oC.

Historical reconstruction of oil and gas spills during moderate and strong earthquakes and related geochemical surveys in Southern Apennines

Science.gov (United States)

Sciarra, Alessandra; Cantucci, Barbara; Ferrari, Graziano; Pizzino, Luca; Quattrocchi, Fedora

2016-04-01

The aim of this study is to contribute to the assessment of natural hazards in a seismically active area of southern Italy through the joint analysis of historical sources and fluid geochemistry. In particular, our studies have been focalized in the Val d'Agri basin, in the Apennines extensional belt, since it hosts the largest oilfield in onshore Europe and normal-fault systems with high seismogenic potential (up to M7). The work was organized into three main themes: 1) literature search aimed at identifying fluid emissions during previous moderate-strong earthquakes; 2) consultation of local and national archives to identify historic local place names correlated to natural fluids emissions; 3) geochemical sampling of groundwater and gas issuing at surface, identified on the basis of the bibliographic sources. A reasoned reading of written documents and available historical data was performed. Moreover, we reworked information reported in historical catalogues, referred to liquid and gas hydrocarbon leakages occurred during seismic events of the past (in a range of magnitude from 5 to 7) in the Southern Apennines (with a particular focus on the Val d'Agri). Special attention was given to the phenomena of geochemical emissions related to major historical earthquakes that took place in the area, most notably that of 16 December 1857 (M = 7). A careful analysis of the Robert Mallet's report, a complete work aimed at describing the social impact and the effects on the environment produced by this earthquake through illustrated maps and diagrams, included several hundred monoscopic and stereoscopic photographs, was done. From archival sources (at national and/or local administrations), "sensitive" sites to the onset of leakage of liquid and gaseous hydrocarbons in the past were identified. A soil-gas survey (22 gas concentrations and flux measurements) and 35 groundwater samplings were carried out in specific sites recognized through the above studies. From a

Organic geochemical investigation and coal-bed methane characteristics of the Guasare coals (Paso Diablo mine, western Venezuela)

Science.gov (United States)

Quintero, K.; Martinez, M.; Hackley, P.; Marquez, G.; Garban, G.; Esteves, I.; Escobar, M.

2011-01-01

The aim of this work was to carry out a geochemical study of channel samples collected from six coal beds in the Marcelina Formation (Zulia State, western Venezuela) and to determine experimentally the gas content of the coals from the Paso Diablo mine. Organic geochemical analyses by gas chromatography-mass spectrometry and isotopic analyses on-line in coalbed gas samples were performed. The results suggest that the Guasare coals were deposited in a continental environment under highly dysoxic and low salinity conditions. The non-detection of 18??(H)-oleanane does not preclude that the organic facies that gave rise to the coals were dominated by angiosperms. In addition, the presence of the sesquiterpenoid cadalene may indicate the subordinate contribution of gymnosperms (conifers) in the Paleocene Guasare mire. The average coalbed gas content obtained was 0.6 cm3/g. ??13C and D values indicate that thermogenic gas is prevalent in the studied coals. Copyright ?? Taylor & Francis Group, LLC.

Geochemical site-selection criteria for HLW repositories in Europe and North America

International Nuclear Information System (INIS)

Savage, David; Arthur, Randolph C.; Sasamoto, Hiroshi; Shibata, Masahiro; Yui, Mikazu

2000-01-01

Geochemical as well as socio-economic issues associated with the selection of potential sites to host a high-level nuclear waste repository have received considerable attention in repository programs in Europe (Belgium, Finland, France, Germany, Spain, Sweden, Switzerland and the U.K.) and North America (Canada and the United States). The objective of the present study is to summarize this international experience with particular emphasis on geochemical properties that factor into the adopted site-selection strategies. Results indicate that the geochemical properties of a site play a subordinate role, at best, to other geotechnical properties in the international site-selection approaches. In countries where geochemical properties are acknowledged in the site-selection approach, requirements are stated qualitatively and tend to focus on associated impacts on the stability of the engineered barrier system and on radionuclide transport. Site geochemical properties that are likely to control the long-term stability of geochemical conditions and radionuclide migration behavior are unspecified, however. This non-prescriptive approach may be reasonable for purposes of screening among potential sites, but a better understanding of site properties that are most important in controlling the long-term geochemical evolution of the site over a range of possible scenarios would enable the potential sites to be ranked in terms of their suitability to host a repository. (author)

Geochemical differentiation processes for arc magma of the Sengan volcanic cluster, Northeastern Japan, constrained from principal component analysis

Science.gov (United States)

Ueki, Kenta; Iwamori, Hikaru

2017-10-01

In this study, with a view of understanding the structure of high-dimensional geochemical data and discussing the chemical processes at work in the evolution of arc magmas, we employed principal component analysis (PCA) to evaluate the compositional variations of volcanic rocks from the Sengan volcanic cluster of the Northeastern Japan Arc. We analyzed the trace element compositions of various arc volcanic rocks, sampled from 17 different volcanoes in a volcanic cluster. The PCA results demonstrated that the first three principal components accounted for 86% of the geochemical variation in the magma of the Sengan region. Based on the relationships between the principal components and the major elements, the mass-balance relationships with respect to the contributions of minerals, the composition of plagioclase phenocrysts, geothermal gradient, and seismic velocity structure in the crust, the first, the second, and the third principal components appear to represent magma mixing, crystallizations of olivine/pyroxene, and crystallizations of plagioclase, respectively. These represented 59%, 20%, and 6%, respectively, of the variance in the entire compositional range, indicating that magma mixing accounted for the largest variance in the geochemical variation of the arc magma. Our result indicated that crustal processes dominate the geochemical variation of magma in the Sengan volcanic cluster.

Geochemical prospecting for Cu mineralization in an arid terrain-central Iran

Science.gov (United States)

Mokhtari, Ahmad Reza; Roshani Rodsari, Parisa; Fatehi, Moslem; Shahrestani, Shahed; Pournik, Peyman

2014-12-01

Geochemical sampling and data processing were implemented for prospecting Cu mineralization through catchment basin approach in central Iran, Yazd province, over drainage systems in order to determine areas of interest for the detailed exploration program. The target zone, inside an area called Kalout-e-Ashrafa in Yazd province-Iran, was characterized by the collection of 107 stream sediment samples. Catchment basin modeling was conducted based on digital elevation model (DEM) and geological map of the study area. Samples were studied by univariate and multivariate statistical techniques of exploratory data analysis, classical statistical analysis and cluster analysis. The results showed that only Cu had anomalous behavior and it did not exhibit a considerable correlation with other elements. Geochemical maps were prepared for Cu and anomalous zones and separated for potential copper mineralization. It was concluded that due to especial geomorphological and geographical characteristics (smooth topography, negligible annual precipitation and insufficient thickness of silicified Cu-bearing outcrops of the area), low concentrations of Cu would be expected for the delineation of promising zones in similar trains. Using cluster analysis showed that there was a strong correlation between Ag, Sr and S. Calcium and Pb present moderate correlation with Cu. Additionally, there was a strong correlation between Zn and Li, thereby indicating a meaningful correlation with Fe, P, Ti and Mg. Aluminum, Sc and V had a correlation with Be and K. Applying threshold value according to MAD (median absolute deviation) helped us to distinguish anomalous catchments more properly. Finally, there was a significant kind of conformity among anomalous catchment basins and silicified veins and veinlets (as validating index) at the central part of the area.

Granite-repository - geochemical environment

International Nuclear Information System (INIS)

1979-04-01

Some geochemical data of importance for a radioactive waste repository in hard rock are reviewed. The ground water composition at depth is assessed. The ground water chemistry in the vicinity of uranium ores is discussed. The redox system in Swedish bedrock is described. Influences of extreme climatic changes and of repository mining and construction are also evaluated

Geochemical signature of columbite-tantalite and radiometric survey of radioactive pegmatites in the region of Parelhas, Rio Grande do Norte, Brazil

International Nuclear Information System (INIS)

Moura, Jorge Costa de

2013-01-01

This thesis is the result of geochemical, structural and radiometric investigations on radioactive pegmatites of the Borborema Pegmatitic Province in Northeast Brazil. The studied area, located in the surroundings of the city of Parelhas in the region of the Serra da Borborema, is well known for its thousands of pegmatitic bodies exploited in primitive mines called 'garimpos'. The main goal was to find an efficient, cheap and routine inspection procedure to identify the origin of commercialized radioactive columbite-tantalite (coltan) ore. The Brazilian Nuclear Energy Agency (CNEN) controls uranium commerce and nuclear activity in Brazil. Without an effective method to characterize coltan ores from different localities it is impossible to control the trade. The here presented new method was developed by correlating structural features of these pegmatites with the geochemical behavior of their coltan samples. It was found that the variation of the ratio U/Th versus Nb 2 O 5 /Ta 2 O 5 provides geochemical signatures (analytical fingerprints) for the source location of such ore. A test of the new method with coltan samples of commercial batches from the Brazilian states Amapa and Rondonia also generated distinct geochemical signatures. A radiometric survey (CPS) was carried out in several mines and pegmatites to study the environmental impact of gamma radiation. It included in situ measurements of pegmatite walls, host rocks, soil, and accumulated water and revealed that gamma emitters are hardly solubilized and environmental gamma radiation therefore generally is not enhanced to a dangerous level. (author)

Petrographic and geochemical characteristics of the Cypress Creek salt core

International Nuclear Information System (INIS)

1983-07-01

Law Engineering Testing Company supervised the drilling of a corehole into the stock of Cypress Creek Dome, located in Perry County, Mississippi. A total of 170 ft of caprock and 501 ft of salt stock was recovered for physical examination and chemical analysis. This report describes the types of analyses performed and summarizes the data developed. The entire caprock and salt core were described and photographed prior to selection of samples for petrologic and geochemical analysis. Transmitted light techniques were used to determine gross structural and compositional variations in the core. The core lithologies are presented graphically, at a scale of 1 in. to 2 ft. In addition to the detailed field descriptions and photographs, petrologic studies performed on selected caprock and salt samples included: thin-section examination, scanning-electron microscope studies, energy-dispersion analysis, and x-ray-diffraction analysis. Geochemical analyses were performed to determine the average elemental composition of the salt core and amounts of methane and carbon dioxide gases contained within the salt grains. Except for two thin (3 and 6 ft thick) gypsum zones in the top 27 ft of the caprock, the core is predominantly anhydrite (generally 80%). Minor amounts of dolomite and calcite are also present. The salt core consists predominantly of crystalline halite, fine- to medium-grained (0.25 to 1 in.) with few megacrysts. Anhydrite occurs in the salt core as disseminated grains, ranging in length from <0.1 in. to 12 in. Discrete zones exist within the salt core, distinguished from one another primarily by the character of the anhydrite inclusions

Detailed geochemical survey for east-central Minnesota, geology and geochemistry of selected uranium targets

International Nuclear Information System (INIS)

Morey, G.B.; Lively, R.S.

1980-01-01

Results of a detailed geochemical survey of approximately 6820 km 2 in parts of Aitkin, Carlton, Kanabec, and Pine Counties, east-central Minnesota are reported. Geochemical data are presented for 883 groundwater samples and 200 bedrock samples. Although all of the groundwaters in the study area have similar major-element concentrations and therefore presumably a common ancestry, small differences in the minor-element concentrations serve to characterize various aquifers, both in the Quaternary deposits and in the bedrock. All of the aquifers locally yield waters having statistically anomalous concentrations of uranium or radon, but these anomalies are spatially coincident only in a few places and particularly in three geologic environments considered favorable for uranium mineralization. These include the following: (1) Thomson Formation near the unconformably overlying Fond du Lac Formation, (2) Hinckley Sandstone near a major fault system, and (3) Denham Formation near the unconformity with the McGrath Gneiss, particularly where these rocks are faulted and overlain by the Fond du Lac Formation. One additional uranium environment characterized by thin laminae of uraniferous apatite was located in the Thomson Formation during outcrop reconnaissance and sampling. The coincidence of this and other anomalously high uranium values in the bedrock with specific uranium and radon anomalies in the groundwater confirms the usefulness of the hydrogeochemical data to uranium exploration in this glaciated terrane

Geochemical anomalies from bottom ash in a road construction--comparison of the leaching potential between an ash road and the surroundings.

Science.gov (United States)

Lind, Bo B; Norrman, Jenny; Larsson, Lennart B; Ohlsson, Sten-Ake; Bristav, Henrik

2008-01-01

A study was performed between June 2001 and December 2004 with the primary objective of assessing long-term leaching from municipal solid waste incineration bottom ash in a test road construction in relation to a reference road made up of conventional materials and the natural geochemical conditions in the surroundings. The metal leaching from the test road and the reference road was compared with the natural weathering in the regional surroundings for three time scales: 16, 80 and 1000 years. The results show that Cu and Zn cause a geochemical anomaly from the test road compared with the surroundings. The leaching of Cu from the test road is initially high but will decline with time and will in the long term be exceeded by natural weathering. Zn on the other hand has low initial leaching, which will increase with time and will in the long term exceed that of the test road and the surroundings by a factor of 100-300. For the other metals studied, Al, Na, K and Mg, there is only very limited leaching over time and the potential accumulation will not exceed the background values in a 1000 years.

Expected Geochemical and Mineralogical Properties of Meteorites from Mercury: Inferences from Messenger Data

Science.gov (United States)

McCubbin, F. M.; McCoy, T. J.

2016-01-01

Meteorites from the Moon, Mars, and many types of asteroid bodies have been identified among our global inventory of meteorites, however samples of Mercury and Venus have not been identified. The absence of mercurian and venusian meteorites could be attributed to an inability to recognize them in our collections due to a paucity of geochemical information for Venus and Mercury. In the case of mercurian meteorites, this possibility is further supported by dynamical calculations that suggest mercurian meteorites should be present on Earth at a factor of 2-3 less than meteorites from Mars [1]. In the present study, we focus on the putative mineralogy of mercurian meteorites using data obtained from the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft, which has provided us with our first quantitative constraints on the geochemistry of planet Mercury. We have used the MESSENGER data to compile a list of mineralogical and geochemical characteristics that a meteorite from Mercury is likely to exhibit.

Validity of the WISC-IV Spanish for a clinically referred sample of Hispanic children.

Science.gov (United States)

San Miguel Montes, Liza E; Allen, Daniel N; Puente, Antonio E; Neblina, Cris

2010-06-01

The Wechsler Intelligence Scale for Children (WISC) is the most commonly used intelligence test for children. Five years ago, a Spanish version of the WISC-IV was published (WISC-IV Spanish; Wechsler, 2005), but a limited amount of published information is available regarding its utility when assessing clinical samples. The current study included 107 children who were Spanish speaking and of Puerto Rican descent that had been administered the WISC-IV Spanish. They were subdivided into a clinical sample of 35 children with diagnoses of various forms of brain dysfunction (primarily learning disability, attention-deficit/hyperactivity disorder, and epilepsy) and a comparison group made up of 72 normal children who were part of the WISC-IV Spanish version standardization sample. Comparisons between these groups and the standardization sample were performed for the WISC-IV Spanish index and subtest scores. Results indicated that the clinical sample performed worse than the comparison samples on the Working Memory and Processing Speed Indexes, although findings varied to some extent depending on whether the clinical group was compared with the normal comparison group or the standardization sample. These findings provide support for the criterion validity of the WISC-IV Spanish when it is used to assess a clinically referred sample with brain dysfunction.

The relation between geochemical characteristics and landslide in Hungtsaiping area, Nantou, Taiwan

Science.gov (United States)

Lin, P.; Tsai, L.

2009-12-01

Hungtsaiping is located at the south bank of the Yonglu stream, Chungliao Village of Nantou County, central Taiwan. Hungtsaiping landslide was triggered by the Chi-Chi earthquake (Mw=7.6) occurring on September 20, 1999 UTC near the town of Chi-Chi in Nantou County, central Taiwan. Coping with the geological and geomorphologic investigations, this study makes an attempt to find the relation between geochemical characteristics and landslide in Hungtsaiping area. Water samples were collected from spring waters, creeks, ponds, groundwater and the Yonglu stream once every month from May 2008 to May 2009. Oxygen and hydrogen stable isotopic, ionic concentrations, as well as electrical conductivity and pH value were analyzed. The results indicate that calcium and magnesium bicarbonate-rich water was found on the top and the middle part of the slope. On the other hand, sodium bicarbonate-rich water as well as exceptionally high sulfate concentration was found on the foot of the slope, the sulfate content decreased with increasing elevations until the middle part of slope. A conceptual model of flow process and water origin in Hungtsaiping landslide was established by summarizing the features of hydrogeochemical analyses and the profiles in this study. Keywords: landslide, geochemical characteristics, isotope, hydrochemistry. Fig. 1 The sampling locations of Hungtsaiping landslide. Fig. 2 Isogram: the concentration of sulfate in May 2008 in Hungtsaiping area.

Geochemical effects of CO2 sequestration in sandstones under simulated in situ conditions of deep saline aquifers

International Nuclear Information System (INIS)

Wigand, M.; Carey, J.W.; Schuett, H.; Spangenberg, E.; Erzinger, J.

2008-01-01

The geochemical effects of brine and supercritical CO 2 (SCCO 2 ) on reservoir rocks from deep (1500-2000 m) saline aquifers were examined via experimental simulation at in situ conditions. Dry sandstone samples were mounted in a triaxial cell and autoclave system, evacuated, and saturated with 1 M NaCl solution. The brine-rock system was allowed to react at 30 MPa confining pressure, 15 MPa pore fluid pressure, and 60 deg. C while SCCO 2 was injected at a pressure gradient of 1-2 MPa. The experiment was conducted for a period of 1496 h, during which fluids were periodically sampled and analyzed. The pH measured in partially degassed fluid samples at 25 deg. C decreased from a starting value of 7.0-4.3 (9 days) and finally 5.1 after saturation with SCCO 2 . Fluid analyses indicate that most of the major (e.g. Ca, Mg, Fe, Mn) and trace elements (e.g. Sr, Ba, Pb) of the sandstone increase in concentration during the reaction with brine and SCCO 2 . These results are supported by scanning electron microscopy which indicates dissolution of dolomite cement, K-feldspar, and albite. In addition to dissolution reactions the formation of montmorillonite was observed. By adjusting surface area and reaction rates of dissolution and precipitation, geochemical modeling of the experiments could reproduce long-term trends in solution chemistry and indicated limited rates of dissolution as the system remained strongly undersaturated with most minerals, including carbonates. The geochemical models could not account for decreases in concentration of some elements, changes in solution composition resulting from changes in imposed pressure gradient, and the observed Ca/Mg and Si/Al ratios in solution

Geochemical Distribution of Lead and Chromium in River Getsi-Kano

African Journals Online (AJOL)

Geochemical forms of lead (Pb) and Chromium (Cr) from the sediment of River Getsi Kano-Nigeria were determined using Atomic Absorption spectrometer for eighteen months. Apart from determination of the metals in water, geochemical forms of the metals were also evaluated into five fractions. Exchangeable, bound to ...

Analysis of marine sediment and lobster hepatopancreas reference materials by instrumental photon activation

International Nuclear Information System (INIS)

Landsberger, S.; Davidson, W.F.

1985-01-01

By use of instrumental photon activation analysis, twelve trace (As, Ba, Cr, Co, Mn, Ni, Pb, Sb, Sr, U, Zn, and Zr) and eight minor (C, Na, Mg, Co, K, Ca, Tl, and Fe) elements were determined in a certified marine sediment standard reference material as well as eight trace (Mn, Ni, Cu, Zn, As, Sr, Cd, and Pb) and four minor (Na, Mg, Cl, and Ca) elements in a certified marine tissue (lobster hepatopancreas) standard reference material. The precision and accuracy of the present results when compared to the accepted values clearly demonstrate the reliability of this nondestructive technique and its applicability to marine environmental or marine geochemical studies. 24 references, 4 figures, 3 tables

Geochemical study of evaporite and clay mineral-oxyhydroxide samples from the Waste Isolation Pilot Plant site

International Nuclear Information System (INIS)

Brookins, D.G.

1993-06-01

Samples of clay minerals, insoluble oxyhydroxides, and their host evaporites from the WIPP site have been studied for their major and minor elements abundances, x-ray diffraction characteristics, K-Ar ages, and Rb-Sr ages. This study was undertaken to determine their overall geochemical characteristics and to investigate possible interactions between evaporates and insoluble constituents. The evaporite host material is water-soluble, having Cl/Br ratios typical of marine evaporites, although the Br content is low. Insoluble material (usually a mixture of clay minerals and oxyhydroxide phases) yields very high Cl/Br ratios, possibly because of Cl from admixed halide minerals. This same material yields K/Rb and Th/U ratios in the normal range for shales; suggesting little, if any, effect of evaporite-induced remobilization of U, K, or Rb in the insoluble material. The rare-earth element (REE) data also show normal REE/chondrite (REE/CHON) distribution patterns, supporting the K/Rb and Th/U data. Clay minerals yield K-Ar dates in the range 365 to 390 Ma and a Rb-Sr isochron age of 428 ± 7 Ma. These ages are well in excess of the 220- to 230-Ma formational age of the evaporites, and confirm the detrital origin of the clays. The ages also show that any evaporite or clay mineral reactions that might have occurred at or near the time of sedimentation and diagenesis were not sufficient to reset the K-Ar and Rb-Sr systematics of the clay minerals. Further, x-ray data indicate a normal evaporitic assemblage of clay minerals and Fe-rich oxyhydroxide phases. The clay minerals and other insoluble material appear to be resistant to the destructive effects of their entrapment in the evaporites, which suggests that these insoluble materials would be good getters for any radionuclides (hypothetically) released from the storage of radioactive wastes in the area

Geochemical prospecting in Guiana

International Nuclear Information System (INIS)

Coulomb, R.

1957-01-01

During the last few years geochemical prospecting techniques have become common usage in the field of mineral deposit prospecting. The real scope of these methods lies in their use in the prospecting of large areas. The most promising use of the geochemistry and hydro-geochemistry of uranium is in heavily forested tropical territories, with few outcrops, where radiometry is strongly handicapped. (author) [fr

Direct determination of uranium in soil, rock, ore and biological samples by laser-induced fluorometry

International Nuclear Information System (INIS)

Li Qingzhen; Zhang Yanan

1993-03-01

A laser-induced fluorometric method with modified J-22 anti-interferent fluorescent reagent for directly determining the uranium in soil, rock, ore, geochemical, biological and other samples has been studied. The effects of external ions and dilution law of sample are examined in detail. A method for correcting inner effect is proposed. A mixed solution of 0.25% NaOH-10% J-22 is prepared which can be added to the sample cuvette for direct measurement without any pre-adjustment of acidity. Therefore, it is much simpler for operation and reduces the loss and contamination of uranium. By changing the laser fluorometer sensitivity (400 ∼ 200), up to 3000 ng uranium in the cuvette can be detected. Thus, both analytical accuracy and detectable range are improved. This method is simple, rapid, accurate and applicable to various uranium-bearing samples. The detection limit is better than 0.05 μgU/g. The relative standard deviation is ≤+-5% for the rock reference samples of 0.95, 84.8, 669 and 7240 μgU/g

Geochemical and geochronological constrains on the Chiang Khong volcanic rocks (northwestern Thailand) and its tectonic implications

Science.gov (United States)

Qian, Xin; Feng, Qinglai; Chonglakmani, Chongpan; Monjai, Denchok

2013-12-01

Volcanic rocks in northwestern Thailand exposed dominantly in the Chiang Khong area, are commonly considered to be genetically linked to the tectonic evolution of the Paleo-Tethyan Ocean. The volcanic rocks consist mainly of andesitic to rhyolitic rocks and are traditionally mapped as Permian-Triassic sequences. Our zircon U-Pb geochronological results show that two andesitic samples (TL-1-B and TL-31-B), are representative of the Doi Yao volcanic zone, and give a mean weighted age of 241.2±4.6 Ma and 241.7±2.9 Ma, respectively. The rhyolitic sample (TL-32-B1) from the Doi Khun Ta Khuan volcanic zone erupted at 238.3±3.8 Ma. Such ages indicate that Chiang Khong volcanic rocks erputed during the early Middle Triassic period. Seven samples from the Doi Yao and Doi Khun Ta Khuan zones exhibit an affinity to arc volcanics. Three rhyolitic samples from the Chiang Khong area have a geochemical affinity to both arc and syn-collisional volcanic rocks. The Chiang Khong arc volcanic rocks can be geochemically compared with those in the Lampang area in northern Thailand, also consistent with those in Jinghong area of southwestern Yunnan. This indicates that the Chiang Rai arc-volcanic zone might northwardly link to the Lancangjiang volcanic zone in southwestern China.

Geochemical processes of mercury in Wujiangdu and Dongfeng reservoirs, Guizhou, China

International Nuclear Information System (INIS)

Feng Xinbin; Jiang Hongmei; Qiu Guangle; Yan Haiyu; Li Guanghui; Li Zhonggen

2009-01-01

The geochemical processes of mercury in Dongfeng (DF) and Wujiangdu (WJD) reservoirs, which were constructed in 1992 and 1979, respectively in Wujiang River, which is the upper branch of Yangtze River were investigated. One sampling site was chosen upriver of 1 km from the dam for each reservoir. Three sampling campaigns were conducted at these sampling sites in December 2003, April 2004 and July 2004, respectively. The distributions of different mercury species in the water column, sediment, and sediment pore water were studied. We found that the sediment is the net source of both inorganic and MeHg to the water column for both reservoirs. The MeHg diffusion fluxes in WJD reservoir at all sampling campaigns were significantly higher than those in DF reservoir. Our study demonstrated that the high primary productivity in the reservoir produced elevated organic matter content that would favor the methylmercury production in sediment. - Surface sediment in the reservoirs is the active mercury methylating sites in the systems.

Collected radiochemical and geochemical procedures

Energy Technology Data Exchange (ETDEWEB)

Kleinberg, J [comp.

1990-05-01

This revision of LA-1721, 4th Ed., Collected Radiochemical Procedures, reflects the activities of two groups in the Isotope and Nuclear Chemistry Division of the Los Alamos National Laboratory: INC-11, Nuclear and radiochemistry; and INC-7, Isotope Geochemistry. The procedures fall into five categories: I. Separation of Radionuclides from Uranium, Fission-Product Solutions, and Nuclear Debris; II. Separation of Products from Irradiated Targets; III. Preparation of Samples for Mass Spectrometric Analysis; IV. Dissolution Procedures; and V. Geochemical Procedures. With one exception, the first category of procedures is ordered by the positions of the elements in the Periodic Table, with separate parts on the Representative Elements (the A groups); the d-Transition Elements (the B groups and the Transition Triads); and the Lanthanides (Rare Earths) and Actinides (the 4f- and 5f-Transition Elements). The members of Group IIIB-- scandium, yttrium, and lanthanum--are included with the lanthanides, elements they resemble closely in chemistry and with which they occur in nature. The procedures dealing with the isolation of products from irradiated targets are arranged by target element.

Geochemical behaviour of rare earths in Vitis vinifera grafted onto different rootstocks and growing on several soils

International Nuclear Information System (INIS)

Censi, P.; Saiano, F.; Pisciotta, A.; Tuzzolino, N.

2014-01-01

The geochemical behaviour of lanthanides and yttrium (Rare Earth Elements, REEs) has been investigated mainly in geological systems where these elements represent the best proxies of processes involving the occurrence of an interface between different media. This behaviour is assessed according to features recorded in sequences of REE concentrations along the REE series normalised with respect to a reference material. In this study, the geochemical behaviour of REE was investigated in different parts of Vitis vinifera specimens grown off-soil, on soils of different nature and grafted onto several rootstocks in order to evaluate effects induced by these changes. The results indicated that roots are the plant organs where REEs are preferentially concentrated, in particular elements from Sm to Ho (middle REE, MREE) whereas Eu enrichments occur in aerial parts. The geochemical behaviour of REE suggests that MREE enrichments in roots are due to preferential MREE interactions with biological membranes or to surface complexation with newly formed phosphates. Eu-positive anomalies suggest that Eu 3+ can form stable organic complexes in place of Ca 2+ in several biological processes in xylem fluids. The possibility that Eu mobility in these fluids can be enhanced by its reductive speciation as Eu 2+ cannot be ruled out. The assessment of the geochemical behaviour of REE according to the theory of the Tetrad Effect carried out confirms that REEs coming from soil are scavenged onto root tissues or mineral surfaces whereas their behaviour in aerial parts of V. vinifera is driven by dissolved complexation. - Highlights: • REE behaviour is driven by scavenging onto authigenic solids or membranes in roots. • REE behaviour is driven by dissolved complexation in aerial plant parts. • Positive Eu anomalies are a consequence of the REE translocation by xylem fluids. • Significant REE tetrad effects are observed in Vitis vinifera plants

Summary report on geochemical barrier special study

International Nuclear Information System (INIS)

1988-12-01

Long-term management of uranium mill tailings must provide assurance that soluble contaminants will not migrate beyond the Point of Compliance. Conventional management alternatives provide containment through the use of physical barriers which are designed to prevent migration of water through the tailings pile. An alternative is to geochemically modify the tailings to immobilize the contaminants. This investigation examined three potential geochemical modifiers to determine their ability to immobilize inorganic groundwater contaminants found in uranium mill tailings. These modifiers were hydrated lime (Ca(OH) 2 ), limestone (CaCO 3 ), and a sphaegnum peat moss. This investigation focused on both the geochemical interactions between the tailings and the modifiers, and the effects the modifiers had on the physical strength of the tailings. The geochemical investigations began with characterization of the tailings by X-ray diffraction and scanning electron microscopy. This was followed by batch leaching experiments in which various concentrations of each modifier were added to tailings in shaker flasks and allowed to come to equilibrium. Finally, column experiments were conducted to simulate flow through a tailings pile. The results show that all of the modifiers were at least moderately effective at immobilizing most of the groundwater contaminants of concern at uranium mill tailings sites. Hydrated lime was able to achieve 90 percent concentration reduction of arsenic, cadmium, selenium, uranium, and sulfate when added at a two percent concentration. Limestone was somewhat less effective and peat removed greater than 90 percent of arsenic, lead, uranium, and sulfate at a one percent concentration. The column tests showed that kinetic and/or mass transfer limitations are important and that sufficient time must be allowed for the immobilization reactions to occur

Identification and assembly of genomes and genetic elements in complex metagenomic samples without using reference genomes

DEFF Research Database (Denmark)

Nielsen, Henrik Bjørn; Almeida, Mathieu; Juncker, Agnieszka

2014-01-01

of microbial genomes without the need for reference sequences. We demonstrate the method on data from 396 human gut microbiome samples and identify 7,381 co-abundance gene groups (CAGs), including 741 metagenomic species (MGS). We use these to assemble 238 high-quality microbial genomes and identify...

New results for Palaeozoic volcanic phases in the Prague Basin – magnetic and geochemical studies of Lištice, Czech Republic

Directory of Open Access Journals (Sweden)

Tiiu Elbra

2015-02-01

Full Text Available Palaeo-, rock magnetic and geochemical studies were conducted on volcanic samples from the Lištice area to improve the knowledge of Palaeozoic volcanic evolution in the Prague Basin. The magnetic data display no significant differences between two studied localities, indicating one magnetizing event for both localities. Geochemical data suggest that Lištice basalt could have originated from deep melting of the garnet peridotite mantle source during the attenuation and rifting of the continental lithosphere connected with asthenospheric mantle upwelling. The dataset furthermore supports the evidence of syn- or post-intrusive fluid interactions and low-temperature stages of alteration. The Ti-magnetite within amygdales of the samples was found to be carrying the characteristic remanent magnetization and reflects probably the Permo-Carboniferous remagnetization of volcanic phases.

Proceedings of 2. Brazilian Geochemical Congress

International Nuclear Information System (INIS)

1989-01-01

Some works about geochemistry are presented, including themes about geochemical exploration, lithogeochemistry and isotope geochemistry, environmental geochemistry, analytical geochemistry, geochemistry of carbonatites and rare earth elements and organic geochemistry. (C.G.C.) [pt

Geochemical signature of columbite-tantalite and environmental impact of radioactive pegmatite mining in the Parelhas region, Rio Grande do Norte, Northeast Brazil

International Nuclear Information System (INIS)

Moura, Jorge Costa de; Cruz, Paulo R.; Pereira, Valmir; Ludka, Isabel P.; Mendes, Julio C.

2013-01-01

This article comprises geochemical, structural and radiometric investigations on radioactive pegmatites of the Borborema Pegmatitic Province in Northeast Brazil. The studied area is located in the surroundings of the city of Parelhas, in the geotectonic Province of Borborema. It is well known for its thousands of pegmatitic bodies exploited in primitive mines called garimpos. The main goal was to find an efficient, cheap and routine inspection procedure to identify the origin of commercialized radioactive columbite-tantalite (coltan) ore. The Brazilian Nuclear Energy Agency (CNEN) controls uranium commerce and nuclear activity in Brazil. Without an effective method to characterize coltan ores from different localities it is impossible to control the trade. The here presented new method was developed by correlating structural features of these pegmatites with the geochemical behavior of their coltan samples. It was found that the variation of U/Th vs. Nb 2 O 5 /Ta 2 O 5 provides geochemical signatures (analytical fingerprints) for the source location of such ore. The new method was tested with coltan samples of commercial batches from the Brazilian states of Amapa and Rondonia and also generated distinct geochemical signatures. A radiometric survey (CPS) to study the environmental impact of gamma radiation was also carried out in several mines and pegmatites. It included in situ measurements of pegmatite walls, enclosing rocks, soil, and accumulated water and revealed that gamma emitters are hardly solubilized and therefore environmental gamma radiation generally is not enhanced to a dangerous level. (author)

Geochemical prospecting for copper and nickel in the Wulgai and Tor Tangi areas southeast of Hindubagh, Quetta Division, Pakistan

Science.gov (United States)

Stanin, S. Anthony; Wahid, M.A.; Khan, Shamsher

1975-01-01

Showings of magnetite, copper, and possible nickel mineralization in the Hindubagh chromite mining district are near Wulgai and Tor Tangi. Several hundred samples of clastic material from dry streambeds in these areas were sieved for the minus-80-mesh fraction and analyzed for copper using 2, 2'-biquinoline and for nickel using alpha-furildioxime. The copper threshold is 75 ppm, and the nickel threshold is 400 ppm. A geochemical map has been prepared that shows nine areas of anomalously high copper and six areas of high nickel. The nickel anomalies may represent secondary dispersion patterns derived from the erosion of nickeliferous ultramafic rocks of the Hindubagh intrusive complex. Copper showings in and near four of the anomalous copper areas indicate that detailed geological investigation and detailed geochemical sampling of rocks, soil, and unconsolidated clastic material are required to determine the source of the anomalies.

Geochemical modelling. Pt.1, Pt.2

International Nuclear Information System (INIS)

Skytte Jensen, B.; Jensen, H.; Pearson, F.J.

1992-01-01

This work is carried out under cost-sharing contract with the European Atomic Energy Community in the framework of its fourth research programme on radioactive waste management and radioactive waste storage. This final report is subdivided into two parts. In the first part, JENSEN, a computer code for the computation of chemical equilibria in aqueous systems, describes the structure, function and use of a new geochemical computer program intended for PC's. The program, which is written in Turbo Pascal, version 4, is fundamentally similar to most other geochemical programs, but combines in one program several of the merits these programs have. The intention has been to make an advanced program, which also should be user friendly and fast, and to attain this several new algorithms have been developed and implemented. The program has a built-in database mainly based on the CHEMVAL compilation containing data for 395 soluble species and 149 minerals. The program can find equilibria in the presence of all or some of these soluble species, under conditions or fixed or floating pH and / or Redox potential. The program by itself eliminates a bad guess of a candidate for precipitation. In the present version, the program can identify which minerals and how much of them there will be formed when equilibrium is established. In the second part, LITTLE JOE, an expert system to support geochemical modelling, describes the construction of a minor expert system for use in the evaluation of analytical data for the composition of ground waters from limestone formation. Although the example given is rather limited in scope, the application of the expert system for the evaluation of the analytical data clearly demonstrates the mature expert knowledge imbedded in the system which is contrasted with the uncritical acceptance of analytical or theoretical data. With the overall neglect of ion-exchange and the formation of solid solutions in geochemical calculations, geochemistry is

Geochemical evaluation of marginal basins in the south of Bahia state, Brazil

International Nuclear Information System (INIS)

Gaglianone, P.C.; Trindade, L.A.F.; Nascimento, M.M. do

1987-01-01

Geochemical analyses were performed on more than 700 rock samples and 4 oil samples, from Mucuri, Cumuruxatiba and Jequitinhonha basins, offshore Bahia state, Brazil. The methods employed in this study includes the evaluation of organic carbon contents, Rock-Eval pyrolysis, vitrinite reflectance, carbon isotopes, assessment of oils and extrats by liquid and gas chromatography and gas chromatography - spectrometry. Three main source rock systems have been identified in offshore Bahia: the Mucuri shales from Rio da Serra and Aratu Stages lower Neocomian related to a lacustrine fresh water environment; the Jiquia shales (Upper Neocomian) deposited in a lacustrine saline water environment, and the Alagoas Shales related to an evaporitic environment of Aptian age. (author) [pt

Geochemical modelling of groundwater evolution using chemical equilibrium codes

International Nuclear Information System (INIS)

Pitkaenen, P.; Pirhonen, V.

1991-01-01

Geochemical equilibrium codes are a modern tool in studying interaction between groundwater and solid phases. The most common used programs and application subjects are shortly presented in this article. The main emphasis is laid on the approach method of using calculated results in evaluating groundwater evolution in hydrogeological system. At present in geochemical equilibrium modelling also kinetic as well as hydrologic constrains along a flow path are taken into consideration

Determination of geochemical characters of insterstitial waters of pleistocene Italian clay formations

International Nuclear Information System (INIS)

Fontanive, A.; Gragnani, R.; Mignuzzi, C.; Spat, G.

1985-01-01

The geochemical characters of clay formations and of their pore water are fundamental with regards to the mobility of the radionuclides as well as to the corrosion processes on enginered barriers. Experimental researches have been carried out in different types of clay, which represent Italian formations, for the characterization of pore water. A squeezer system, which reaches 1500 Kg/cm 2 in pressure, and an analytical micro-scale methodology, for the determination of dissolved constituents in pore water, were set up. The extracted pore water ranges from 60% to 85% in relation to consolidation state of clay. The chemical composition of the extracted fluid has been checked during the squeezing. During this step the observed variations were smaller than those between the different specimens of the same sample. The comparison between the results obtained by squeezing and by a multiple washing technique, using increasing water/sediment ratios, shows that the last one does not give reliable results on the chemical composition of pore water. This is due to the presence of easily weatherable minerals and to the exchange processes between the clayey minerals and the solution. Nevertheless both these techniques have supplied complementary information about geochemical processes in water-rock interaction. The salinity of pore water ranges from 0.45 g/l to 24.5 g/l and the chemism always shows a high content of calcium-magnesium sulfate, or sodium chloride or calcium-magnesium-sulfate with sodium chloride. The correlation between geochemical composition of pore water and mineralogical composition of clay is not significant

Behaviour of nature and technogenic radioisotopes in buried geochemical barriers

International Nuclear Information System (INIS)

Kuznetsov, V.A.; Onoshko, M.P.; Generalova, V.A.

1998-01-01

Behaviour of potassium 40, radium 226, thorium 232, strontium 90 and cesium 137 on geochemical barriers connected with buried soils and cut-off meander sediments of the Holocene age of the Sozh river valley are examined. Some sides of the barrier geochemical structure caused by syngeneic and epigenetic processes have been taken into consideration

Research on the hydrogeological and geochemical conditions at the coastal area and submarine formations

International Nuclear Information System (INIS)

Tokunaga, Tomochika; Taniguchi, Makoto; Goto, Junji

2003-05-01

One of the major concerns for the high-level radioactive waste disposal is the possibility of the radionuclides to reach biosphere by groundwater flow. Recent research results have shown that the fresh groundwater discharge from subsea formations are widespread phenomena, thus, it is necessary to evaluate the submarine groundwater discharge as possible pathways of contaminant discharge towards the biosphere. It is also important to unravel the groundwater flow and associated material transport at the coastal area and subsea formations. To better understand the groundwater flow processes and the submarine groundwater discharge, we have conducted the hydrological, hydrogeological, geochemical, and numerical modeling studies at the Kurobe alluvial fan and its offshore, Toyama Prefecture, Japan. In this report, the results of the following research activities are presented: 1) Development and application of a method to detect the locations of the submarine groundwater discharge. 2) Development and application of a method to collect uncontaminated groundwater samples from subsea formations. 3) Measurements of submarine groundwater discharge fluxes by automated seepage meter. 4) Hydrological and geochemical studies for groundwater flow at the coastal area. 5) Geochemical studies to understand sources of fresh submarine groundwater discharge. 6) Examination of groundwater flow and submarine groundwater discharge using methane concentration and carbon isotope ratio. 7) Numerical modeling studies for coastal groundwater flow system. (author)

Geochemical analysis of Minho Estuary sedimentary record and its contribution to palaeoenvironmental evolution

International Nuclear Information System (INIS)

Ivarez-Iglesias, P. A.

2009-01-01

Two sediment cores (∼30 m long) were retrieved at the mouth of the Minho Estuary to assess its palaeoenvironmental evolution for the last millennia. Samples were characterized by Energy-Dispersive X-Ray Fluorescence Spectrometry and Instrumental Neutron Activation Analysis, complemented by sedimentological analyses. Provenance of major and trace element contents (lithogenic or biogenic, continental or marine) is assessed. The influence of grain size effect on total element concentration is discussed. Most of the samples present a negative Eu anomaly. Sedimentological and geochemical parameters allow differentiating four geological units - fluvial, marine, estuarine and sand barrier - which reflects the temporal evolution of the Minho Estuary. (author)

LASL approach to uranium geochemical reconnaissance

Energy Technology Data Exchange (ETDEWEB)

Sharp, R.R. Jr.

1977-01-01

The US ERDA, as part of the NURE program, has initiated a nationwide Hydrogeochemical and Stream Sediment Reconnaissance (HSSR). The aims of the NURE program are to provide data on which to base more accurate estimates of US uranium reserves for long-range planning and to aid in meeting the nation's projected uranium demands into the next century. The HSSR objective is to complete, by 1980, a reconnaissance of the nation's surface waters, ground waters, and stream and lake sediments, to aid in assessment of uranium reserves and identification of areas of interest for exploration. Patterned after extensive uranium reconnaissance done in many other countries, the LASL project is comprised of the following five components: (1) organization and planning, which includes management, design, and execution; (2) field sampling, which includes orientation studies, generation of specifications, and contracting and inspection of field work; (3) sample receiving and analysis, which includes development of methods and hardware, quality assurance, and archival storage; (4) data handling and presentation, including verification, storage, output, and plotting; and (5) data evaluation and publication, which incorporates geochemical, geological, statistical, and empirical evaluation and report writing. The LASL approach to each component and the current status in each state are described.

LASL approach to uranium geochemical reconnaissance

International Nuclear Information System (INIS)

Sharp, R.R. Jr.

1977-01-01

The US ERDA, as part of the NURE program, has initiated a nationwide Hydrogeochemical and Stream Sediment Reconnaissance (HSSR). The aims of the NURE program are to provide data on which to base more accurate estimates of US uranium reserves for long-range planning and to aid in meeting the nation's projected uranium demands into the next century. The HSSR objective is to complete, by 1980, a reconnaissance of the nation's surface waters, ground waters, and stream and lake sediments, to aid in assessment of uranium reserves and identification of areas of interest for exploration. Patterned after extensive uranium reconnaissance done in many other countries, the LASL project is comprised of the following five components: (1) organization and planning, which includes management, design, and execution; (2) field sampling, which includes orientation studies, generation of specifications, and contracting and inspection of field work; (3) sample receiving and analysis, which includes development of methods and hardware, quality assurance, and archival storage; (4) data handling and presentation, including verification, storage, output, and plotting; and (5) data evaluation and publication, which incorporates geochemical, geological, statistical, and empirical evaluation and report writing. The LASL approach to each component and the current status in each state are described

An organic geochemical correlation study of some Drmno depresssion crude oils (southern part of the Pannonian Basin, Yugoslavia

Directory of Open Access Journals (Sweden)

D. VITOROVIC

2001-05-01

Full Text Available The results of an investigation of crude oils originating from the Sirakovo and Bradarac-Maljurevac localities (southern part of the Pannonian Basin are reported in this paper. The aim was to estimate the organic geochemical similarity of the crude oils from the Drmno (Kostolac depression oil fields. The nine selected samples originated from reservoir rocks of various depths. Reliable source and organic geochemical maturation parameters served as the basis for the correlation studies. The similar origin of the investigated Drmno depression crude oils was corroborated, characterized by a significant participation of terrestrial precursor biomass. They were shown to be of relatively low maturity and to have been formed during the earlier stages of the diagenet- ic-catagenetic sequence of processes leading to the formation of crude oils, most probably in source rocks ofTertiary age, corresponding to vitrinite reflectances between Ro = 0.70 % and Ro = 0.80 %. The crude oils from Bradarac-Maljurevac seemed to be somewhat less homogeneous with respect to organic geochemical parameters compared to Sirakovo crude oils.

A comparative proteomics method for multiple samples based on a 18O-reference strategy and a quantitation and identification-decoupled strategy.

Science.gov (United States)

Wang, Hongbin; Zhang, Yongqian; Gui, Shuqi; Zhang, Yong; Lu, Fuping; Deng, Yulin

2017-08-15

Comparisons across large numbers of samples are frequently necessary in quantitative proteomics. Many quantitative methods used in proteomics are based on stable isotope labeling, but most of these are only useful for comparing two samples. For up to eight samples, the iTRAQ labeling technique can be used. For greater numbers of samples, the label-free method has been used, but this method was criticized for low reproducibility and accuracy. An ingenious strategy has been introduced, comparing each sample against a 18 O-labeled reference sample that was created by pooling equal amounts of all samples. However, it is necessary to use proportion-known protein mixtures to investigate and evaluate this new strategy. Another problem for comparative proteomics of multiple samples is the poor coincidence and reproducibility in protein identification results across samples. In present study, a method combining 18 O-reference strategy and a quantitation and identification-decoupled strategy was investigated with proportion-known protein mixtures. The results obviously demonstrated that the 18 O-reference strategy had greater accuracy and reliability than other previously used comparison methods based on transferring comparison or label-free strategies. By the decoupling strategy, the quantification data acquired by LC-MS and the identification data acquired by LC-MS/MS are matched and correlated to identify differential expressed proteins, according to retention time and accurate mass. This strategy made protein identification possible for all samples using a single pooled sample, and therefore gave a good reproducibility in protein identification across multiple samples, and allowed for optimizing peptide identification separately so as to identify more proteins. Copyright © 2017 Elsevier B.V. All rights reserved.

GEOBASI: The geochemical Database of Tuscany Region (Italy

Directory of Open Access Journals (Sweden)

Brunella Raco

2015-03-01

Full Text Available In this study the new Regional Geochemical Database (RGDB, called GEOBASI, is presented and illustrated in the framework of a joint collaboration among the three Tuscan universities (Florence, Pisa and Siena, CNR-IGG (Institute of Geosciences and Earth Resources of Pisa, ARPAT (Regional Agency for the Environmental Protection, LAMMA (Environmental Modelling and Monitoring Laboratory for Sustainable Development Consortium and S.I.R.A. (Territorial and Environmental Informative System of Tuscany. The database has permitted the construction of a repository where the geochemical information (compositional and isotopic has been stored in a structured way so that it can be available for different groups of users (e.g. institutional, public and private companies. The information contained in the database can in fact be downloaded freely and queried to correlate geochemistry to other non compositional variables. The first phase of the project was aimed at promoting the use of the geochemical data already available from previous investigations through a powerful Web-GIS interface to implement the exploratory statistics graphical-numerical tools used to: 1 analyse the spatial variability of the investigated context, 2 highlight the geographic location of data pertaining to classes of values or single cases, 3 compare the results of different analytical methodologies applied to the determination of the same element and/or chemical species, 4 extract the geochemical data related to specific monitoring plans and/or geographical areas, and finally 5 recover information about data below the detection limit to understand their impact on the behaviour of the investigated variable. Developments of this project will be focused on the definition of rules and standardized methods in a way that external users could also interactively pursue the RGDB. Furthermore, a detailed investigation of the Scarlino-Follonica plain will permit the improvement and test of

Geochemical Anomalies in the Sediments of Lake Druksiai

International Nuclear Information System (INIS)

Kleinas, A.

1999-01-01

In order to evaluate the impact of Ignalina Nuclear Power Plant (NPP) on natural processes in Lake Druksiai and accumulation of pollutants, in 19931997, carrying on the state scientific program, the Marine Geochemistry Division of the Institute of Geography performed lithological geochemical mapping of lake bottom sediments on a scale of 1 .50 000. The results obtained enabled to distinguish zones of higher anthropogenous geochemical load, where geochemical anomalies of pollutants, including oil hydrocarbons and heavy metals, had been taken into account. Applying concentration coefficients for oil hydrocarbons and heavy metals (Cr, Cu, Ni, Pb, and Zn) and their natural background, the attempt was made to differentiate natural and technogenous components in the geochemical anomalies As expected, the finer sediments -aleurite-pelite mud - showed amounts of oil hydrocarbons and heavy metals being 12.1 times higher than in fine sand - the most coarse of the sediments studied Sediments with organic mater exceeding 20% contained 11.7 times more pollutants than those with organic matter below 1 .5%. Calculations of concentration coefficients (CC) showed no elements in no stations exceeded 10 - the sediments did not reach the category of high pollution However, in many sites, the coefficients exceeded values of 1-2, thus, showing sediments attributable to the categories of weakly polluted or just polluted. Mapping model done by GIS methods (by superimposing schemes of pollutant CCs distribution in the lake and summing them) for geochemical anomalies two derivative map-schemes were obtained for oil hydrocarbons and heavy metals. They showed that clean sediments cover just 24.75% (according to the pollutant background for soil types) and 12.35% (according to the organic matter background for its amount intervals) lake bottom area. Zones slightly polluted by an element at least cover 69.7 and 80.29% of lake area, correspondingly; whereas zones slightly polluted by all

Reconnaisance geochemical survey of heavy minerals in Northern Luzon, Philippines

International Nuclear Information System (INIS)

Santos, G. Jr.; Seguis, J.E.; Fernandez, L.G.

1983-07-01

A reconnaissance sampling was undertaken in northern Luzon to study the distribution of uranium as well as copper, lead, zinc, manganese, silver, cobalt and nickel in heavy minerals. The average background and threshold values of the elements were determined. Uranium content in the heavy mineral was low, in the order of 0.5-0.6 ppm U. Three uranium anomaly zones were delineated in Malanas Rever-Licuan area, Abra, Itogon, Benguet and Bambang, Nueva Viscaya, all within the Central Cordillera. The anomalous zones appeared to be related to copper-gold mineral areas. Geochemical correlations between uranium and the other elements were generally poor. (author)

Geochemical mapping using stream sediments in west-central Nigeria: Implications for environmental studies and mineral exploration in West Africa

International Nuclear Information System (INIS)

Lapworth, Dan J.; Knights, Katherine V.; Key, Roger M.; Johnson, Christopher C.; Ayoade, Emmanuel; Adekanmi, Michael A.; Arisekola, Tunde M.; Okunlola, Olugbenga A.; Backman, Birgitta; Eklund, Mikael; Everett, Paul A.; Lister, Robert T.; Ridgway, John; Watts, Michael J.; Kemp, Simon J.; Pitfield, Peter E.J.

2012-01-01

This paper provides an overview of regional geochemical mapping using stream sediments from central and south-western Nigeria. A total of 1569 stream sediment samples were collected and 54 major and trace elements determined by ICP-MS and Au, Pd and Pt by fire assay. Multivariate statistical techniques (e.g., correlation analysis and principal factor analysis) were used to explore the data, following appropriate data transformation, to understand the data structure, investigate underlying processes controlling spatial geochemical variability and identify element associations. Major geochemical variations are controlled by source geology and provenance, as well as chemical weathering and winnowing processes, more subtle variations are a result of land use and contamination from anthropogenic activity. This work has identified placer deposits of potential economic importance for Au, REE, Ta, Nb, U and Pt, as well as other primary metal deposits. Areas of higher As and Cr (>2 mg/kg and >70 mg/kg respectively) are associated with Mesozoic and younger coastal sediments in SW Nigeria. High stream sediment Zr concentrations (mean >0.2%), from proximal zircons derived from weathering of basement rocks, have important implications for sample preparation and subsequent analysis due to interferences. Associated heavy minerals enriched in high field strength elements, and notably rare earths, may also have important implications for understanding magmatic processes within the basement terrain of West Africa. This study provides important new background/baseline geochemical values for common geological domains in Nigeria (which extend across other parts of West Africa) for assessment of contamination from urban/industrial land use changes and mining activities. Regional stream sediment mapping is also able to provide important new information with applications across a number of sectors including agriculture, health, land use and planning.

Stream sediment detailed geochemical survey for Marysvale, Utah

International Nuclear Information System (INIS)

Butz, T.R.; Vreeland, J.L.; Bard, C.S.; Helgerson, R.N.; Grimes, J.G.; Pritz, P.M.

1980-01-01

Results of the Marysvale detailed geochemical survey are reported. Field and laboratory data are presented for 397 stream sediment samples and 160 radiometric readings. Statistical and areal distributions of uranium and possible uranium-related variables are displayed. A generalized geologic map of the area is provided, and pertinent geologic factors which may be of significance in evaluating the potential for uranium mineralization are briefly discussed. Stream sediments containing significant amounts of soluble uranium (greater than or equal to 16.93 ppM) occur in numerous areas, the most prevalent being in the western portion of the survey area, within and surrounding the Mount Belknap Caldera. Thorium, beryllium, cerium, manganese, molybdenum, niobium, potassium, yttrium, zinc, and zirconium occur in concentrations greater than or equal to 84th percentile in many sediment samples taken from within and surrounding the Mount Belknap Caldera. The uranium and related variables are associated with highly silicic intrusions and extrusions of the Mount Belknap Volcanics, as well as hydrothermal activity which has occurred in the Marysvale volcanic field

The geochemical environment of nuclear fuel waste disposal

International Nuclear Information System (INIS)

Gascoyne, M.

1995-01-01

The concept for disposal of Canada's nuclear fuel waste in a geologic environment on the Canadian Shield has recently been presented by Atomic Energy of Canada Limited (AECL) to governments, scientists, and the public, for review. An important part of this concept concerns the geochemical environment of a disposal vault and includes consideration of rock and groundwater compositions, geochemical interactions between rocks, groundwaters, and emplaced vault materials, and the influences and significance of anthropogenic and microbiological effects following closure of the vault. This paper summarizes the disposal concept and examines aspects of the geochemical environment. The presence of saline groundwaters and reducing conditions at proposed vault depths (500-1000 m) in the Canadian Shield has an important bearing on the stability of the used nuclear fuel, its container, and buffer and backfill materials. The potential for introduction of anthropogenic contaminants and microbes during site investigations and vault excavation, operation, and sealing is described with examples from AECL's research areas on the Shield and in their underground research laboratory in southeastern Manitoba. (author)

Well sediments: a medium for geochemical prospecting, an example from the Nisa region, Portugal

NARCIS (Netherlands)

Vriend, S.P.; Dekkers, M.J.; Janssen, M.A.; Commandeur, J.

1991-01-01

Vriend, S.P., Dekkers, M.J.. Janssen, M.A. and Commandeur, J., 1991. Well sediments: a medium for geochemical prospecting, an example from the Nisa region. Portugal. In: A.W. Rose and P.M. Taufen I Editors). Geochemical Exploration ! 989. J. Geochem. Expior., 4 ! : ! 5 I- 167. Tile potential of

Baseline and premining geochemical characterization of mined sites

Science.gov (United States)

Nordstrom, D. Kirk

2015-01-01

A rational goal for environmental restoration of new, active, or inactive mine sites would be ‘natural background’ or the environmental conditions that existed before any mining activities or other related anthropogenic activities. In a strictly technical sense, there is no such thing as natural background (or entirely non-anthropogenic) existing today because there is no part of the planet earth that has not had at least some chemical disturbance from anthropogenic activities. Hence, the terms ‘baseline’ and ‘pre-mining’ are preferred to describe these conditions. Baseline conditions are those that existed at the time of the characterization which could be pre-mining, during mining, or post-mining. Protocols for geochemically characterizing pre-mining conditions are not well-documented for sites already mined but there are two approaches that seem most direct and least ambiguous. One is characterization of analog sites along with judicious application of geochemical modeling. The other is reactive-transport modeling (based on careful synoptic sampling with tracer-injection) and subtracting inputs from known mining and mineral processing. Several examples of acidic drainage are described from around the world documenting the range of water compositions produced from pyrite oxidation in the absence of mining. These analog sites provide insight to the processes forming mineralized waters in areas untouched by mining. Natural analog water-chemistry data is compared with the higher metal concentrations, metal fluxes, and weathering rates found in mined areas in the few places where comparisons are possible. The differences are generally 1–3 orders of magnitude higher for acid mine drainage.

Determination and interpretation of environmental water samples contaminated by uranium mining activities

International Nuclear Information System (INIS)

Meinrath, G.; Volke, P.; Helling, C.; Merkel, B.J.; Dudel, E.G.

1999-01-01

Interpretation of environmental behavior of uranium is based on several steps of data analysis and statistical inference. First step is sampling and analyzing of uranium in field samples by routine laboratory methods. Such methods have to fulfill multiple requirements like robustness, efficiency, low detection limit and precision. A comparison of different approaches in assigning uncertainty to experimentally obtained analytical data shows that classical error estimation is not significantly inferior to more sophisticated modern techniques like inverse regression or orthogonal regression. A second step is the correlation of analytical data with current state of insight into environmental behavior of uranium. Such a correlation furthers the choice of adequate geochemical models and quality of geochemical data base for subsequent detailed analysis, e.g. by geochemical modeling. An appraisal of the individual steps in this complex analysis is given on the basis of statistical procedures for calibration and an E H -pH diagram of uranium for atmospheric conditions. (orig.)

Geochemical and Pb, Sr, and O isotopic study of the Tiva Canyon Tuff and Topopah Spring Tuff, Yucca Mountain, Nye County, Nevada

International Nuclear Information System (INIS)

Neymark, L.A.; Marshall, B.D.; Kwak, L.M.; Futa, Kiyoto; Mahan, S.A.

1995-01-01

Yucca Mountain is currently being studied as a potential site for an underground repository for high-level radioactive waste. One aspect of the site characterization studies is an evaluation o the resource potential at Yucca Mountain. Geochemical and isotopic signatures of past alteration of the welded tuffs that underlie Yucca Mountain provide a means of assessing the probability of hydrothermal ore deposits being present within Yucca Mountain. In this preliminary report, geochemical and isotopic measurements of altered Tiva Canyon Tuff and Topopah Spring Tuff collected from fault zones exposed on the east flank of Yucca Mountain and from one drill core are compared to their unaltered equivalents sampled both in outcrop and drill core. The geochemistry and isotopic compositions of unaltered Tiva Canyon Tuff and Topopah Spring Tuff (high-silica rhyolite portions) are fairly uniform; these data provide a good baseline for comparisons with the altered samples. Geochemical analyses indicate that the brecciated tuffs are characterized by addition of calcium carbonate and opaline silica; this resulted in additions of calcium and strontium,increases in oxygen-18 content, and some redistribution of trace elements. After leaching the samples to remove authigenic carbonate, no differences in strontium or lead isotope compositions between altered and unaltered sections were observed. These data show that although localized alteration of the tuffs has occurred and affected their geochemistry, there is no indication of additions of exotic components. The lack of evidence for exotic strontium and lead in the most severely altered tuff samples at Yucca Mountain strongly implies a similar lack of exotic base or precious metals

Validation of the WATEQ4 geochemical model for uranium

International Nuclear Information System (INIS)

Krupka, K.M.; Jenne, E.A.; Deutsch, W.J.

1983-09-01

As part of the Geochemical Modeling and Nuclide/Rock/Groundwater Interactions Studies Program, a study was conducted to partially validate the WATEQ4 aqueous speciation-solubility geochemical model for uranium. The solubility controls determined with the WATEQ4 geochemical model were in excellent agreement with those laboratory studies in which the solids schoepite [UO 2 (OH) 2 . H 2 O], UO 2 (OH) 2 , and rutherfordine ((UO 2 CO 3 ) were identified as actual solubility controls for uranium. The results of modeling solution analyses from laboratory studies of uranyl phosphate solids, however, identified possible errors in the characterization of solids in the original solubility experiments. As part of this study, significant deficiencies in the WATEQ4 thermodynamic data base for uranium solutes and solids were corrected. Revisions included recalculation of selected uranium reactions. Additionally, thermodynamic data for the hydroxyl complexes of U(VI), including anionic (VI) species, were evaluated (to the extent permitted by the available data). Vanadium reactions were also added to the thermodynamic data base because uranium-vanadium solids can exist in natural ground-water systems. This study is only a partial validation of the WATEQ4 geochemical model because the available laboratory solubility studies do not cover the range of solid phases, alkaline pH values, and concentrations of inorganic complexing ligands needed to evaluate the potential solubility of uranium in ground waters associated with various proposed nuclear waste repositories. Further validation of this or other geochemical models for uranium will require careful determinations of uraninite solubility over the pH range of 7 to 10 under highly reducing conditions and of uranyl hydroxide and phosphate solubilities over the pH range of 7 to 10 under oxygenated conditions

Variation of Geochemical Signatures and Correlation of Biomarkers in Icelandic Mars Analogue Environments

Science.gov (United States)

Gentry, D.; Amador, E. S.; Cable, M. L.; Cantrell, T.; Chaudry, N.; Cullen, T.; Duca, Z. A.; Jacobsen, M. B.; McCaig, H. C.; Murukesan, G.; Rennie, V.; Schwieterman, E. W.; Stevens, A. H.; Tan, G.; Yin, C.; Stockton, A.; Cullen, D.; Geppert, W.

2015-12-01

Exploration missions to Mars rely on rovers to perform deep analyses over small sampling areas; however, landing site selection is done using large-scale but low-resolution remote sensing data. Using Earth analogue environments to estimate the small-scale spatial and temporal distributions of key geochemical signatures and (for habitability studies) biomarkers helps ensure that the chosen sampling strategies meet mission science goals. We conducted two rounds of analogue expeditions to recent Icelandic lava fields. In July 2013, we tested correlation between three common biomarker assays: cell quantification via fluorescence microscopy, ATP quantification via bioluminescence, and quantitative PCR with universal primer sets. Sample sites were nested at four spatial scales (1 m, 10 m, 100 m, and > 1 km) and homogeneous at 'remote imaging' resolution (overall temperature, apparent moisture content, and regolith grain size). All spatial scales were highly diverse in ATP, bacterial 16S, and archaeal 16S DNA content; nearly half of sites were statistically different in ATP content at α = 0.05. Cell counts showed significant variation at the 10 m and 100 m scale; at the > 1 km scale, the mean counts were not distinguishable, but the median counts were, indicating differences in underlying distribution. Fungal 18S DNA content similarly varied at 1 m, 10 m, and 100 m scales only. Cell counts were not correlated with ATP or DNA content at any scale. ATP concentration and DNA content for all three primer sets were positively correlated. Bacterial DNA content was positively correlated with archaeal and fungal DNA content, though archaeal correlation was weak. Fungal and archaeal correlation was borderline. In July 2015, we repeated the sampling strategy, with the addition of a smaller-scale sampling grid of 10 cm and a third > 1 km location. This expedition also measured reflectance of the tephra cover and preserved mineral samples for future Raman spectroscopy in order to

Optimum sampling scheme for characterization of mine tailings

CSIR Research Space (South Africa)

Debba, Pravesh

2009-07-01

Full Text Available The paper describes a novice method for sampling geochemicals to characterize mine tailings. The author’s model the spatial relationships between a multi-element signature and, as covariates, abundance estimates of secondary iron-bearing minerals...

Solid phase speciation of arsenic by sequential extraction in standard reference materials and industrially contaminated soil samples

International Nuclear Information System (INIS)

Herreweghe, Samuel van; Swennen, Rudy; Vandecasteele, Carlo; Cappuyns, Valerie

2003-01-01

Leaching experiments, a mineralogical survey and larger samples are preferred when arsenic is present as discrete mineral phases. - Availability, mobility, (phyto)toxicity and potential risk of contaminants is strongly affected by the manner of appearance of elements, the so-called speciation. Operational fractionation methods like sequential extractions have been applied for a long time to determine the solid phase speciation of heavy metals since direct determination of specific chemical compounds can not always be easily achieved. The three-step sequential extraction scheme recommended by the BCR and two extraction schemes based on the phosphorus-like protocol proposed by Manful (1992, Occurrence and Ecochemical Behaviours of Arsenic in a Goldsmelter Impacted Area in Ghana, PhD dissertation, at the RUG) were applied to four standard reference materials (SRM) and to a batch of samples from industrially contaminated sites, heavily contaminated with arsenic and heavy metals. The SRM 2710 (Montana soil) was found to be the most useful reference material for metal (Mn, Cu, Zn, As, Cd and Pb) fractionation using the BCR sequential extraction procedure. Two sequential extraction schemes were developed and compared for arsenic with the aim to establish a better fractionation and recovery rate than the BCR-scheme for this element in the SRM samples. The major part of arsenic was released from the heavily contaminated samples after NaOH-extraction. Inferior extraction variability and recovery in the heavily contaminated samples compared to SRMs could be mainly contributed to subsample heterogeneity

Uruguay mining inventory. Geochemical prospecting results of the Las Flores aerial map[Study of Uranium geochemical prospection in Uruguay]; Inventario minero del Uruguay. Resultados de la prospeccion geoquimica del fotoplano Las Flores

Energy Technology Data Exchange (ETDEWEB)

Zeegers, H; Bonnefoy, D; Garau, M; Spangenberg, J

1981-07-01

In the context of the Uruguay mining inventory, the aerial photography map Las Flores had been covered by a specific strategic which included geochemical prospecting elements. The surface covered has the 550 km2, and 1042 samples which they have been analized in Orleans France. 22 elements by plasma spectroscopy and gold by atomic absorption and for uranium laser spectroscopy . They have been evidenced the following anomalies: gold, Pb, Pb-Ba-Cu, Ba and Ni-Cr.

An integrated geochemical, geophysical and mineralogical study of river sediments in alpine area and soil samples near steel plant, in Austria

Science.gov (United States)

Irfan, M. I.; Meisel, T.

2012-04-01

Concentration of nickel and chromium in any part of the ecosystem is important for environmental concerns in particular human health due to the reason that some species of them can cause health problem e.g. dermatitis and cancer. Sediment samples collected form a river Vordernberger Bach (Leoben, Austria) in an alpine region and soil samples collected in an area adjacent to steel production unit in same narrow valley were investigated. In previous studies a correlation between magnetic susceptibility values and concentration of nickel and chromium showed that a magnetic susceptibility meter can be used to point out the contaminated areas as in-situ device. The purpose of the whole study is to understand the real (point or diffuse, anthropogenic or geogenic) sources of contamination of soils, water and river sediments through heavy metal deposition. Unseparated, magnetic and non-magnetic fractions of soil samples were investigated for geochemical and mineralogical aspects with XRF, ICP-MS, EMPA, Multi-Functional Kappabridge (MFK1) and laser ablation coupled with ICP-MS. Mineralogical study of sediment samples for several sampling points with higher Ni and Cr content was performed. Sediment samples were sieved below 1.4 mm and then a concentrate of heavy minerals was prepared in the field through panning. Concentrated heavy minerals were then subjected for heavy liquid separation in the laboratory. Separated magnetic and non-magnetic fractions below 0.71/0.1 mm and density greater than 2.9 g/cm3 were selected for mineralogical investigation. The abundance of typical anthropogenic particles, e.g., spherical, tinder, roasted ores, iron and steel mill slag was observed under the microscope. Magnetite (mostly anthropogenic), maghemite, chromspinel, chromite (type I & II), (Ca,Al)-ferrite, wustite, apatite (anthropogenic), olivine mixed crystals, calcium silicate and spinel (anthropogenic) are found in magnetic fraction. Non-magnetic fractions contain hematite, siderite

Kriging - a challenge in geochemical mapping

Czech Academy of Sciences Publication Activity Database

Štojdl, J.; Matys Grygar, Tomáš; Elznicová, J.; Popelka, J.; Váchová, T.; Hošek, Michal

2017-01-01

Roč. 19, APR (2017) ISSN 1607-7962. [EGU General Assembly 2017. 23.04.2017-28.04.2017, Vienna] Institutional support: RVO:61388980 Keywords : kriging * geochemical mapping Subject RIV: DD - Geochemistry http://meetingorganizer.copernicus.org/EGU2017/EGU2017-3615.pdf

Geochemical signature of columbite-tantalite and environmental impact of radioactive pegmatite mining in the Parelhas region, Rio Grande do Norte, Northeast Brazil

Energy Technology Data Exchange (ETDEWEB)

Moura, Jorge Costa de; Cruz, Paulo R.; Pereira, Valmir, E-mail: jcmoura@cnen.gov.br, E-mail: pcruz@cnen.gov.br, E-mail: vpereira@cnen.gov.br [Comissao Nacional de Energia Nuclear (CNEN-RJ), Rio de Janeiro, RJ (Brazil); Ludka, Isabel P.; Mendes, Julio C., E-mail: ludka@geologia.ufrj.br, E-mail: julio@geologia.ufrj.br [Universidade Federal de Rio do Janeiro (CCMN/UFRJ), Rio de Janeiro, RJ (Brazil). Centro de Ciencias Matematicas e da Natureza. Dept. de Geologia

2013-07-01

This article comprises geochemical, structural and radiometric investigations on radioactive pegmatites of the Borborema Pegmatitic Province in Northeast Brazil. The studied area is located in the surroundings of the city of Parelhas, in the geotectonic Province of Borborema. It is well known for its thousands of pegmatitic bodies exploited in primitive mines called garimpos. The main goal was to find an efficient, cheap and routine inspection procedure to identify the origin of commercialized radioactive columbite-tantalite (coltan) ore. The Brazilian Nuclear Energy Agency (CNEN) controls uranium commerce and nuclear activity in Brazil. Without an effective method to characterize coltan ores from different localities it is impossible to control the trade. The here presented new method was developed by correlating structural features of these pegmatites with the geochemical behavior of their coltan samples. It was found that the variation of U/Th vs. Nb{sub 2}O{sub 5}/Ta{sub 2}O{sub 5} provides geochemical signatures (analytical fingerprints) for the source location of such ore. The new method was tested with coltan samples of commercial batches from the Brazilian states of Amapa and Rondonia and also generated distinct geochemical signatures. A radiometric survey (CPS) to study the environmental impact of gamma radiation was also carried out in several mines and pegmatites. It included in situ measurements of pegmatite walls, enclosing rocks, soil, and accumulated water and revealed that gamma emitters are hardly solubilized and therefore environmental gamma radiation generally is not enhanced to a dangerous level. (author)

Kinetic and thermodynamic modelling of geochemical effects of a nuclear waste storage in granitic environment

International Nuclear Information System (INIS)

Made, B.; Fritz, B.

1993-01-01

In the world, various experimental sites are selected to study the behavior of different types of source rocks under nuclear waste storage influence. The surrounding rock tested to receive the waste storage must be a stable geological formation. In France, four geological formations are preselected for the feasibility study of repository for spent nuclear fuel at long term: shale, salt, clay and granite. At present time, numerous studies are carried out in Europe (Germany, Belgium, Sweden, Switzerland, United-Kingdom...), in North America (U.S.A. and Canada) and in Japan. Water-rock interactions control the most of rock transformations near the surface of the earth. The rock forming minerals react with the aqueous solutions, the primary minerals dissolution releases ionic species in solution and secondary minerals precipitate if equilibrium or oversaturation is reached. The weathering processes (hydrothermal or not) are always very complicated thus, geochemical codes has been developed to simulate the water-rock interactions. The first generation of codes is based on purely thermodynamic laws without reference to the time dependence of chemical reactions and then the dissolution path calculation refer to the irreversible dissolution of reactants and reversible precipitation of products ([1] to [4]). The system evolution is followed according to the reaction progress ξ which has been introduced in chemical system by Gibbs. Since few years, the experimental studies on the kinetics of minerals dissolution have allowed to take into account of dissolution rates data for the major minerals (silicates, carbonates...). More recently, a new geochemical codes generation appears based on thermodynamic potential and kinetic laws ([5] to [8]). The system evolution is followed according to the reaction time. (authors). 8 figs., 4 tabs., 24 refs

Assessment Cu, Ni and Zn Pollution in the Surface Sediments in the Southern Peninsular Malaysia using Cluster Analysis, Ratios of Geochemical Nonresistant to Resistant Fractions, and Geochemical Indices

Directory of Open Access Journals (Sweden)

Yap. C. K.

2011-01-01

Full Text Available The intertidal sediment samples collected in May 2007 from 12 sampling sites in the southern part of Peninsular Malaysia, were determined for the total concentrations of Cu, Ni and Zn and their four geochemical fractions. The total concentrations (μg/g dry weight of Cu, Ni and Zn ranged from 9.48 to 115.82, 12.95 to 36.18 and 45.35 to 136.56, respectively. The ratios of nonresistant to resistant fractions based on geochemical analysis revealed that the Pantai Lido and Senibong had > 1.0, indicating > 50% of the total concentrations of Cu, Ni and Cu were contributed by anthropogenic sources. This is well complemented by the cluster analysis in which Pantai Lido and Senibong are clustered together based on the three metals clustering pattern. By using Fe as a normalizing element, Cu found at Pantai Lido and Senibong showed > 1.5 for the enrichment factor (EF, which indicated that the Cu was delivered from non-crustal materials or anthropogenic origins while all sampling sites showed Ni and Zn may be entirely from crustal materials. Based on the geoaccumulation index (Igeo (Müller, 1981, similar pattern was also found for Pantai Lido and Senibong in which again only Cu concentrations ranged from 1-2, indicating 'moderate pollution' (Igeo 1 < 2; Class 2.while other sites can be considered as 'unpolluted' (Igeo < 0; Class 0 by Cu, Ni and Zn. Ratios of NR/R exhibited better in the assessment of polluted sites while EF and Igeo should be revised according to Malaysian sedimentary characteristics. This study should prompt more biochemical and molecular studies on the intertidal molluscs from the Straits of Johore since the identified two sites are located in the Straits of Johore, especially the commercial mussel, Perna viridis.

Multi-edge X-ray absorption spectroscopy study of road dust samples from a traffic area of Venice using stoichiometric and environmental references

Science.gov (United States)

Valotto, Gabrio; Cattaruzza, Elti; Bardelli, Fabrizio

2017-02-01

The appropriate selection of representative pure compounds to be used as reference is a crucial step for successful analysis of X-ray absorption near edge spectroscopy (XANES) data, and it is often not a trivial task. This is particularly true when complex environmental matrices are investigated, being their elemental speciation a priori unknown. In this paper, an investigation on the speciation of Cu, Zn, and Sb based on the use of conventional (stoichiometric compounds) and non-conventional (environmental samples or relevant certified materials) references is explored. This method can be useful in when the effectiveness of XANES analysis is limited because of the difficulty in obtaining a set of references sufficiently representative of the investigated samples. Road dust samples collected along the bridge connecting Venice to the mainland were used to show the potentialities and the limits of this approach.

Status report on geochemical modelling

International Nuclear Information System (INIS)

Read, D.

1991-12-01

This report describes the findings of a review undertaken on behalf of the project management group of the programme 'Endlagersicherheit in der Nachbetriebsphase' based at GSF-IfT (Forschungszentrum fuer Umwelt und Gesundheit - Institut fuer Tieflagerung) to establish the current status of research into the simulation of geochemical processes relevant to radiological assessment. The review is intended to contribute to Stage 1 of a strategy formulated to enhance the use of geochemical models in Germany. Emphasis has been placed on processes deemed to be of greatest relevance to performance assessment for a HLW-repository in a salt dome principally, speciation-solubility in high salinity solutions, complexation by natural organics and generation-transport of colloids. For each of these and other topics covered, a summary is given of fundamental concepts, theoretical representations and their limitations, highlighting, where appropriate, the advantages and disadvantages of alternative approaches. The availability of data to quantify any given representation is addressed, taking into account the need for information at elevated temperatures and pressures. Mass transfer is considered in terms of aqueous, particulate and gas-mediated transport, respectively. (orig.) [de

Geochemical evidence for mixing of three components in martian orthopyroxenite ALH 84001. [Abstract only

Science.gov (United States)

Mittlefehldt, D. W.; Lindstrom, M. M.

1994-01-01

ALH 84001, a ferroan martian orthopyroxenite, originally consisted of three petrographically defined components: a cumulus assemblage of orthopyroxene + chromite, a trapped melt assemblage of orthopyroxene(?) + chromite + maskelynite + apatite + augite +/- pyrite, and a metasomatic assemblage of carbonate +/- pyrite. We present the results of Instrumental Neutron Activation Analysis (INAA) study of five bulk samples of ALH 84001, combined with Scanning Ion Mass Spectrometer (SIMS) data on the orthopyroxene, in order to attempt to set limits on the geochemical characteristics of the latter two components, and therefore on the petrogenesis of ALH 84001. The INAA data support the petrographic observations, suggesting that there are at least three components in ALH 84001. We will assume that each of the three geochemically required components can be equated with one of the petrographically observed components. Both trapped melt and metasomatic components in ALH 84001 have higher Na than orthopyroxene based on compositions of maskelynite, apatite, and carbonate. For the metasomatic component, we will assume its Na content is that of carbonate, while for a trapped melt component, we will use a typical Na content inferred for martian meteorite parent melts, approximately 1 wt% Na2O. Under these assumptions, we can set limits on the Light Rare Earth Elements/Heavy Rare Earth Elements (LREE/HREE) ratios of the components, and use this information to compare the petrogenesis of ALH 84001 with other martian meteorites. The above calculations assume that the bulk samples are representative of different portions of ALH 84001. We will also evaluate the possible heterogeneous distribution of mineral phases in the bulk samples as the cause of compositional heterogeneity in our samples.

Role of geochemical background at evaluation of investment attractiveness of recreational territories

Directory of Open Access Journals (Sweden)

Vdovina Ol'ga Konstantinovna

2014-09-01

Full Text Available The article shows the role of natural geochemical background when estimating investment attractiveness of recreational areas. It is noted, that geochemical background influence on people's sickness rate isn't considered now. Though it's understood, that even insignificant increase of geochemical background in relation to percentage abundance of Earth crest may lead to endemic diseases of people, animals and plants. An indicator of geochemical endemicity areas was proposed for assessing the impact of storage elements and of a lack of geological environment on human health. Thanks to this measure, and taking into account landscape features of the area, the authors allocated lands, dangerous and potentially dangerous in terms of endemicity. The importance of ratings was achieved by the use of those factors that could have a great influence on the cost of land development. This includes, first of all, the factors that affect population health, and economic and geographic factors that minimize the cost of the territory development and the factors that give rise to financial risks and risks of human losses. The main risk factors include: potential ecological and geochemical risk; high absolute heights, development and activity of dangerous geological processes and phenomena. Systemacity of researches was reached by using factors, that characterize the object from different aspects; readiness of area infrastructure to its exploration and possible risks. Objectivity was achieved by the use of figures obtained from the results of geochemical and engineering surveys with their metrological support.

Geochemical Influence on Microbial Diversity in the Warm, Salty, Stinking Spring, Utah, USA

Science.gov (United States)

Spear, J. R.

2012-12-01

Little is known of the geochemistry and microbiology in the Stinking Springs, a sulfidic, saline, warm spring northeast of the Great Salt Lake, Utah. The International Geobiology Course of 2012 investigated the geochemistry, lipid abundances, dissolved inorganic carbon (DIC) uptake rates and microbial diversity on different kinds of samples from a number of locations in the spring. The measured pH, temperature, salinity, and sulfide concentration along the 100 m flow path ranged from 6.64-7.77, 40-28° C, 2.9-2.2%, and 250 μM - negligible, respectively. Five sites were selected along the flow path and within each site microbial mats were sub-sampled according to their morphological characteristics; a range from floating to streamer-style in zones of higher flow rates to highly-layered mats in low- or sheet-flow zones. Geochemical characterization of the above plus metals, anions and cations were conducted at each site. Genomic DNA was extracted from each microbial sample / layer, and 16S rRNA genes were amplified and subjected to pyrosequencing. Fatty acids and pigments were extracted from the mat samples / layers and analyzed by liquid chromatography and mass spectrometry for lipid / pigment composition. Bicarbonate uptake rates for mat samples / layers were determined with 24 hour light and dark incubations of 13HCO3-spiked spring water. Microbial diversity varied by site and was generally high in all three domains of life with phototrophs, sulfur oxidizers, sulfate reducers, methanogens, and other bacteria / archaea identified by 16S rRNA gene sequence. Diatoms, identified by both microscopy and lipid analyses were found to increase in abundance with distance from the source. Methanogens were generally more abundant in deeper mat laminae and underlying sediments. Photoheterotrophs were found in all mat layers. Microbial diversity increased significantly with depth at most sites. In addition, two distinct microbial streamers were also identified and

Geochemical evidence for waning magmatism and polycyclic volcanism at Crater Flat, Nevada

International Nuclear Information System (INIS)

Perry, F.V.; Crowe, B.M.

1992-01-01

This paper reports that petrologic and geochemical studies of basaltic rocks in the Yucca Mountain region are currently focused on understanding the evolution of volcanism in the Crater Flat volcanic field and the mechanisms of polycyclic volcanic field and the mechanisms of polycyclic volcanism at the Lathrop Wells volcanic center, the youngest center in the Crater Flat volcanic field. Geochemical and petrologic data indicate that the magma chambers which supplied the volcanic centers at Crater Flat became situated at greater crustal depths as the field evolved. Deep magma chambers may be related to a waning magma flux that was unable to sustain upper crustal magma conduits and chambers. Geochemical data from the Lathrop Wells volcanic center indicate that eruptive units identified from field and geomorphic relationships are geochemically distinct. The geochemical variations cannot be explained by fractional crystallization of a single magma batch, indicating that several magma batches were involved in the formation of the Lathrop Wells center. Considering the low magma flux in the Yucca Mountain region in the Quaternary, the probability of several magma batches erupting essentially simultaneously at Lathrop Wells is considered remote

Spatial and Temporal Water Quality Dynamics in the Lake Maumelle Reservoir (Arkansas): Geochemical and Planktonic Variance in a Drinking Water Source

Science.gov (United States)

Carey, M. D.; Ruhl, L. S.

2017-12-01

The Lake Maumelle reservoir is Central Arkansas's main water supply. Maintaining a high standard of water quality is important to the over 400,000 residents of this area whom rely on this mesotrophic waterbody for drinking water. Lake Maumelle is also a scenic attraction for recreational boating and fishing. Past research has focused primarily on watershed management with land use/land cover modeling and quarterly water sampling of the 13.91mi2 reservoir. The surrounding land within the watershed is predominately densely forested, with timber farms and the Ouachita National Forest. This project identifies water quality changes spatially and temporally, which have not been as frequently observed, over a 6-month timespan. Water samples were collected vertically throughout the water column and horizontally throughout the lake following reservoir zonation. Parameters collected vertically for water quality profiles are temperature, dissolved oxygen, electrical conductivity, salinity, and pH. Soft sediment samples were collected and pore water was extracted by centrifuge. Cation and anion concentrations in the water samples were determined using ion chromatography, and trace element concentrations were determined using ICPMS. Planktonic abundances were determined using an inverted microscope and a 5ml counting chamber. Trace element, cation, and anion concentrations have been compared with planktonic abundance and location to determine microorganismal response to geochemical variance. During June 2017 sampling, parameters varied throughout the water column (temperature decreased 4 degrees Celsius and dissolved oxygen decreased from 98% to 30% from surface to bottom depths), revealing that the reservoir was becoming stratified. Collected plankton samples revealed the presence of copepod, daphnia, and dinoflagellate algae. Utricularia gibba was present in the littoral zone. Low electrical conductivity readings and high water clarity are consistent with the lake

Oak Ridge Geochemical Reconnaissance Program

International Nuclear Information System (INIS)

Arendt, J.W.

1977-03-01

The Oak Ridge reconnaissance program is responsible for the geochemical survey in a 12-state area covering Texas, Oklahoma, Kansas, Nebraska, South Dakota, North Dakota, Minnesota, Wisconsin, Michigan, Iowa, Indiana, and Illinois as part of the National Uranium Resource Evaluation Program. The program concept is outlined and the planning and organization of the program is discussed

The effects of sorting by aeolian processes on the geochemical characteristics of surface materials: a wind tunnel experiment

Science.gov (United States)

Wang, Xunming; Lang, Lili; Hua, Ting; Zhang, Caixia; Li, Hui

2018-03-01

The geochemical characteristics of aeolian and surface materials in potential source areas of dust are frequently employed in environmental reconstructions as proxies of past climate and as source tracers of aeolian sediments deposited in downwind areas. However, variations in the geochemical characteristics of these aeolian deposits that result from near-surface winds are currently poorly understood. In this study, we collected surface samples from the Ala Shan Plateau (a major potential dust source area in Central Asia) to determine the influence of aeolian processes on the geochemical characteristics of aeolian transported materials. Correlation analyses show that compared with surface materials, the elements in transported materials (e.g., Cu, As, Pb, Mn, Zn, Al, Ca, Fe, Ga, K, Mg, P, Rb, Co, Cr, Na, Nb, Si, and Zr) were subjected to significant sorting by aeolian processes, and the sorting also varied among different particle size fractions and elements. Variations in wind velocity were significantly correlated with the contents of Cr, Ga, Sr, Ca, Y, Nd, Zr, Nb, Ba, and Al, and with the Zr/Al, Zr/Rb, K/Ca, Sr/Ca, Rb/Sr, and Ca/Al ratios. Given the great variation in the geochemical characteristics of materials transported under different aeolian processes relative to those of the source materials, these results indicate that considerable uncertainty may be introduced to analyses by using surface materials to trace the potential source areas of aeolian deposits that accumulate in downwind areas.

Estimated ventricle size using Evans index: reference values from a population-based sample.

Science.gov (United States)

Jaraj, D; Rabiei, K; Marlow, T; Jensen, C; Skoog, I; Wikkelsø, C

2017-03-01

Evans index is an estimate of ventricular size used in the diagnosis of idiopathic normal-pressure hydrocephalus (iNPH). Values >0.3 are considered pathological and are required by guidelines for the diagnosis of iNPH. However, there are no previous epidemiological studies on Evans index, and normal values in adults are thus not precisely known. We examined a representative sample to obtain reference values and descriptive data on Evans index. A population-based sample (n = 1235) of men and women aged ≥70 years was examined. The sample comprised people living in private households and residential care, systematically selected from the Swedish population register. Neuropsychiatric examinations, including head computed tomography, were performed between 1986 and 2000. Evans index ranged from 0.11 to 0.46. The mean value in the total sample was 0.28 (SD, 0.04) and 20.6% (n = 255) had values >0.3. Among men aged ≥80 years, the mean value of Evans index was 0.3 (SD, 0.03). Individuals with dementia had a mean value of Evans index of 0.31 (SD, 0.05) and those with radiological signs of iNPH had a mean value of 0.36 (SD, 0.04). A substantial number of subjects had ventricular enlargement according to current criteria. Clinicians and researchers need to be aware of the range of values among older individuals. © 2017 EAN.

Development of thermodynamic databases for geochemical calculations

Energy Technology Data Exchange (ETDEWEB)

Arthur, R.C. [Monitor Scientific, L.L.C., Denver, Colorado (United States); Sasamoto, Hiroshi; Shibata, Masahiro; Yui, Mikazu [Japan Nuclear Cycle Development Inst., Tokai, Ibaraki (Japan); Neyama, Atsushi [Computer Software Development Corp., Tokyo (Japan)

1999-09-01

Two thermodynamic databases for geochemical calculations supporting research and development on geological disposal concepts for high level radioactive waste are described in this report. One, SPRONS.JNC, is compatible with thermodynamic relations comprising the SUPCRT model and software, which permits calculation of the standard molal and partial molal thermodynamic properties of minerals, gases, aqueous species and reactions from 1 to 5000 bars and 0 to 1000degC. This database includes standard molal Gibbs free energies and enthalpies of formation, standard molal entropies and volumes, and Maier-Kelly heat capacity coefficients at the reference pressure (1 bar) and temperature (25degC) for 195 minerals and 16 gases. It also includes standard partial molal Gibbs free energies and enthalpies of formation, standard partial molal entropies, and Helgeson, Kirkham and Flowers (HKF) equation-of-state coefficients at the reference pressure and temperature for 1147 inorganic and organic aqueous ions and complexes. SPRONS.JNC extends similar databases described elsewhere by incorporating new and revised data published in the peer-reviewed literature since 1991. The other database, PHREEQE.JNC, is compatible with the PHREEQE series of geochemical modeling codes. It includes equilibrium constants at 25degC and l bar for mineral-dissolution, gas-solubility, aqueous-association and oxidation-reduction reactions. Reaction enthalpies, or coefficients in an empirical log K(T) function, are also included in this database, which permits calculation of equilibrium constants between 0 and 100degC at 1 bar. All equilibrium constants, reaction enthalpies, and log K(T) coefficients in PHREEQE.JNC are calculated using SUPCRT and SPRONS.JNC, which ensures that these two databases are mutually consistent. They are also internally consistent insofar as all the data are compatible with basic thermodynamic definitions and functional relations in the SUPCRT model, and because primary

Development of thermodynamic databases for geochemical calculations

International Nuclear Information System (INIS)

Arthur, R.C.; Sasamoto, Hiroshi; Shibata, Masahiro; Yui, Mikazu; Neyama, Atsushi

1999-09-01

Two thermodynamic databases for geochemical calculations supporting research and development on geological disposal concepts for high level radioactive waste are described in this report. One, SPRONS.JNC, is compatible with thermodynamic relations comprising the SUPCRT model and software, which permits calculation of the standard molal and partial molal thermodynamic properties of minerals, gases, aqueous species and reactions from 1 to 5000 bars and 0 to 1000degC. This database includes standard molal Gibbs free energies and enthalpies of formation, standard molal entropies and volumes, and Maier-Kelly heat capacity coefficients at the reference pressure (1 bar) and temperature (25degC) for 195 minerals and 16 gases. It also includes standard partial molal Gibbs free energies and enthalpies of formation, standard partial molal entropies, and Helgeson, Kirkham and Flowers (HKF) equation-of-state coefficients at the reference pressure and temperature for 1147 inorganic and organic aqueous ions and complexes. SPRONS.JNC extends similar databases described elsewhere by incorporating new and revised data published in the peer-reviewed literature since 1991. The other database, PHREEQE.JNC, is compatible with the PHREEQE series of geochemical modeling codes. It includes equilibrium constants at 25degC and l bar for mineral-dissolution, gas-solubility, aqueous-association and oxidation-reduction reactions. Reaction enthalpies, or coefficients in an empirical log K(T) function, are also included in this database, which permits calculation of equilibrium constants between 0 and 100degC at 1 bar. All equilibrium constants, reaction enthalpies, and log K(T) coefficients in PHREEQE.JNC are calculated using SUPCRT and SPRONS.JNC, which ensures that these two databases are mutually consistent. They are also internally consistent insofar as all the data are compatible with basic thermodynamic definitions and functional relations in the SUPCRT model, and because primary

Petrographic and geochemical analyisis for determination of provenance of the Slovenj Gradec Miocene Basin fill (Western Central Paratethys)

Science.gov (United States)

Ivančič, Kristina; Trajanova, Mirka; Skaberne, Dragomir; Šmuc, Andrej

2017-04-01

The Slovenj Gradec Basin (SGB) is located in northern Slovenia between eastern margin of the Northern Karavanke and the western Pohorje Mts. Structurally, it belongs to Eastern Alps. It is filled with Miocene clastic sediments. Modal composition of sandstones was determined on thin sections by point-counter and presented with the QFL and QmFLt diagrams. Their geochemical composition was determined by classical method and by Inductively Coupled Plasma-Mass Spectrometry. Based on petrography, sedimentary fill of the SGB consists mostly of lithic grains and quartz, derived from metamorphic and carbonate rocks. Locally, fragments of granitoids occur. Binder consists of carbonate, subordinately quartz cement, and carbonate matrix. Recycled orogen (lithic and transitional recycled) provenance of the grains was determined. Geochemical composition shows that: - Sandstones from the SGB belong to the fields of shale, wacke, litharenite, arkose and subarkose (Pettijohn, 1972). - In the ternary diagram of weathering trends (cf. Nesbitt & Young 1984), the samples group near the CaO+Na2OAl2O3 conjunctive. Calculated minimum CIA (Fedo et al., 1995) is 40.06, indicating that the source rocks were not subjected to considerable weathering. - According to discriminant function (cf. Roser & Korsch, 1988) all samples from SGB originate from quartzose sedimentary rocks. - For determination of tectonic setting of source rocks (Verma & Armstrong-Altrin, 2013) the studied samples plot in the field of collision zone. - In the multidimensional discriminant function diagram for the discrimination of active and passive margin after Verma and Armstrong (2016), the samples plot into the field of passive margin. The data indicate that source rocks of the SGB sedimentary fill were derived from Eastern Alps and Southern Alps. It is suggested that SGB was detached from the Styrian and Mura-Zala Basins in the course of the Pohorje Mts. oblique transpressive uplift during the late Miocene to Pliocene

Top Soils Geochemical and Radioactivity Survey of Naples (Italy) Metropolitan.

Science.gov (United States)

Somma, R.; De Vivo, B.; Cicchella, D.

2001-05-01

The metropolitan area of Naples due to intense human activities is an emblematic area affected by various environmental pollution of soils and waters in addition to hydrogeological volcanic, seismic and bradyseismic hazards. The geology of the area is prevailing represented by volcanics erupted, from the Upper Pleistocene to Recent by Mt. Somma-Vesuvius on the east and the Campi Flegrei fields on the west. The morphology of the metropolitan area of Naples city can be subdivided in flat areas, constituted by reworked pyroclastic terrains, and by hills originated by the overlapping of different welded pyroclastic flows (i.e.: Campanian Ignimbrite and Neapoletan Yellow Tuff) intercalated with pyroclastic deposits of different origins (i.e.: Campi Flegrei, Mt. Somma-Vesuvius, Ischia) and ages. In order to compile a multi-element baseline geochemical and radioactivity mapping of the metropolitan area of the Napoli we have sampled for this study, in situ top soil and imported filling material (mainly soil, volcanic ash, pumice and scoriae). The sampling and radioactivity survey has been carried out on about 200 sampling sites covering an area of about 150 Km2, with a grid of 0.5 x 0.5 km in the urbanised downtown and 1 km x 1 km in the sub urban areas. In each site has been determined a radioactivity by a Scintrex GRS-500 at different emission spectra as total radioactivity (> 0.08 MeV and > 0.40 MeV), 238U (at 1.76 MeV mostly from 214Bi), 232Th (at 2.6 MeV mostly from 208Tl) and 40K (at 1.46 MeV mostly for 40K). The range of values of in situ soils are as follow for the in situ soils (Total radioactivity: 1327- 360 and 114- 47; 238U: 2.6- 1.3; 40K: 8.1- 3.1; 232U: 0.5- 0.1). Analyses of major, metallic elements and pH of each soil sample are in progress, while Pb isotopes compositions, for a selected number of samples, will be determined to discriminate the natural (geogenic) from the anthropogenic components in the soils by versus the anthropogenetic origin. The data

Manual for the sampling of uranium mine tailings

International Nuclear Information System (INIS)

Feenstra, S.; Reades, D.W.; Cherry, J.A.; Chambers, D.B.; Case, G.G.; Ibbotson, B.G.

1983-04-01

The purpose of this manual is to describe the requisite sampling procedures to provide a basis for the application of uniform high-quality standards to detailed geotechnical, hydrogeological, geochemical and air quality measurements at Canadian uranium tailings disposal sites. The report describes the objective and scope of a sampling program, the preliminary data collection, and the procedures for sampling of tailings solids, surface water and seepage, tailings porewater, and wind-blown dust and radon

Geochemical Fractionations and Mobility of Arsenic, Lead and Cadmium in Sediments of the Kanto Plain, Japan.

Science.gov (United States)

Hossain, Sushmita; Oguchi, Chiaki T.; Hachinohe, Shoichi; Ishiyama, Takashi; Hamamoto, Hideki

2014-05-01

Lowland alluvial and floodplain sediment play a major role in transferring heavy metals and other elements to groundwater through sediment water interaction in changing environmental conditions. However identification of geochemical forms of toxic elements such as arsenic (As), lead (Pb) and cadmium (Cd) requires risk assessment of sediment and subsequent groundwater pollution. A four steps sequential extraction procedure was applied to characterize the geochemical fractionations of As, Pb and Cd for 44 sediment samples including one peat sample from middle basin area of the Nakagawa river in the central Kanto plain. The studied sediment profile extended from the bottom of the river to 44 m depth; sediment samples were collected at 1m intervals from a bored core. The existing sedimentary facies in vertical profile are continental, transitional and marine. There are two aquifers in vertical profile; the upper aquifer (15-20m) contains fine to medium sand whereas medium to coarse sand and gravelly sand contain in lower aquifer (37-44m). The total As and Pb contents were measured by the X-Ray Fluorescence analysis which ranged from 4 to 23 mg/kg of As and 10 to 27 mg/kg of Pb in sediment profile. The three trace elements and major heavy metals were determined by ICP/MS and ICP/AES, and major ions were measured by an ion chromatograph. The marine sediment is mainly Ca-SO4 type. The Geochemical analysis showed the order of mobility trends to be As > Pb > Cd for all the steps. The geochemical fractionations order was determined to be Fe-Mn oxide bound > carbonate bound > ion exchangeable > water soluble for As and Pb whereas the order for Cd is carbonate bound > Fe-Mn oxide bound > ion exchangeable > water soluble. The mobility tendency of Pb and Cd showed high in fine silty sediment of marine environment than for those from continental and transitional environments. In the case of As, the potential mobility is very high (>60%) in the riverbed sediments and clayey silt

Maceral and geochemical characteristics of oil shale 2 from the Huangxian Basin, China

Energy Technology Data Exchange (ETDEWEB)

Sun, Yuzhuang; Lin, Mingyue; Li, Haimei; Zhang, Hongjian; Li, Shifeng; Jin, Kankun [Hebei Architectural Science and Technology Inst., Handan, Hebei (China)

2001-07-01

Five samples of Oil Shale 2 from the Huangxian Basin have been analysed by coal petrographic and geochemical methods in order to study its formation environment. Higher alginite ratios and hopanes in Oil Shale 2 indicate a lower plants and anoxic environment. Two ternary diagrams of 'facies diagnostic' macerals and biomarkers were used to interpret the depositional environments of organic matter in Oil Shale 2. In both diagrams, Oil Shale 2 plots in a lower plant zone, and was deposited in a deeper water environment. (Author)

Geochemical dispersion of Si, Al, Fe, Mn, Na, K, Cu and Zn elements in soils and their use for characterization areas geochemically homogeneous

International Nuclear Information System (INIS)

Silva, W.R.L. da.

1982-01-01

Variations in the chemical composition of soils are used to characterize sub-areas geochemically - homogenous. The application of this methodology in a tropical humid region of accentuated topography constitute the principal objective of the present research. Samples of red latosols (Horizon B) developed over granite, sandstone and basalt occurring in the Central Granite Region of the Serra dos Carajas, Para State, Brazil were analized for the elements Si, Al, Fe, Mn, Na, K, Cu e Zn, by atomic absorption spectrophotometry. Based on the criterion of similarity in the chemical composition (Cluster Analysis, Factor Analysis) the soils were separeted in to different groups. The geographical distribution of the different groups permit the establishment of a close relationship between the different parent lithologies and their corresponding soils. (author)

Petrological mineralogical and geochemical characterization of the granitoids and fracture fillings developed in Ratones Mines (Spain)

International Nuclear Information System (INIS)

Buil Gutierrez, B.

2002-01-01

The petrological, mineralogical and geochemical characterisation of the granitoids and fracture fillings developed in the Ratones Mine (Caceres, Spain) has been done in order to understand rock-water interaction processes which control water geochemical parameters. Special interest has been devoted to the analysis and interpretation of REE patterns in the solid phase (granitoids and fracture fillings) because they constitute geochemical tracers in water-rock interaction process. Moreover, REE are considered as actinide analogues. In order to characterise the solid phase (granitoids and fracture fillings) several investigation scales (system, outcrop, whole rock, mineral and geochemical components) have been considered and different types of samples have been analysed. These factors control the methodological approach used in this investigation. The analytical methods we have used in this investigation are microscope, qualitative and semi-quantitative methods (XRD, SEM,EDAX) and quantitative methods (ICP-MS, XRF, EM, LAM-IC-MS). The bulk of the granitoids located around the Ratones Mine Belongs to the alkaline feldspar granite-sienogranite lihotype and they show a peraluminous and subalkaline pattern. From the mineralogical point of view, they are composed by quartz, K-feldspar (Or>90%), showing sericitation, moscovitization and turmolinization altherations, alkaline plagioclase (An-=-3%), usually altered to sericite, saussirite and less frequently affected by moscovitization processes, Fe-Al biotite, frequently affected by chloritization processes and sometimes replaced by muscovite, and finally muscovite (>2% celadonite and <4% paragonite) both of primary and secondary origin. The differences observed between the different lithotypes are related with the modal proportion of the principal minerals,with the presence or absence of certain accessory minerals ( turmaline, cordierite), with specific textural patterns, grain size and also with the richness in specific

Geochemical evolution of highly alkaline and saline tank waste plumes during seepage through vadose zone sediments

International Nuclear Information System (INIS)

Wan, Jiamin; Tokunaga, Tetsu K.; Larsen, Joern T.; Serne, R. JEFFREY

2004-01-01

Leakage of highly saline and alkaline radioactive waste from storage tanks into underlying sediments is a serious environmental problem at the Hanford Site in Washington State. This study focuses on geochemical evolution of tank waste plumes resulting from interactions between the waste solution and sediment. A synthetic tank waste solution was infused into unsaturated Hanford sediment columns (0.2, 0.6, and 2 m) maintained at 70C to simulate the field contamination process. Spatially and temporally resolved geochemical profiles of the waste plume were obtained. Thorough OH neutralization (from an initial pH 14 down to 6.3) was observed. Three broad zones of pore solutions were identified to categorize the dominant geochemical reactions: the silicate dissolution zone (pH > 10), pH-neutralized zone (pH 10 to 6.5), and displaced native sediment pore water (pH 6.5 to 8). Elevated concentrations of Si, Fe, and K in plume fluids and their depleted concentrations in plume sediments reflected dissolution of primary minerals within the silicate dissolution zone. The very high Na concentrations in the waste solution resulted in rapid and complete cation exchange, reflected in high concentrations of Ca and Mg at the plume front. The plume-sediment profiles also showed deposition of hydrated solids and carbonates. Fair correspondence was obtained between these results and analyses of field borehole samples from a waste plume at the Hanford Site. Results of this study provide a well-defined framework for understanding waste plumes in the more complex field setting and for understanding geochemical factors controlling transport of contaminant species carried in waste solutions that leaked from single-shell storage tanks in the past

Magnetic and Geochemical Properties of Andic Soils from the Massif Central, France

Science.gov (United States)

Grison, H.; Petrovsky, E.; Dlouha, S.; Kapicka, A.

2014-12-01

Ferrimagnetic iron oxides are the key magnetic minerals responsible for enhancement of the magnetic susceptibility in soils. Soils with andic properties contain high amount of Fe-oxides, but only few attempts were made to characterize these soils using magnetic methods. Magnetic susceptibility is in particular suitable for its sensitivity and fast measurement; the presence of Fe-oxides can be easily identified directly in the field. The aim of our study is to describe main magnetic and geochemical properties of soils rich in Fe oxides derived from strongly magnetic volcanic basement. The studied sites are located at the basalt parent rock formed during Pleistocene, Pliocene and Miocene. Investigated soils are exposed to the mountainous climate with the perudic soil moisture regime and cryic temperature soil regime. Seven basalt soil profiles with typical andic properties were analyzed down to parent rock by a set of magnetic and geochemical methods. The magnetic susceptibility was measured in situ and in laboratory using the Bartington MS2D and AGICO MFK1. Its temperature dependence was measured in order to assess phase transformations of magnetic minerals using the KLY4. Magnetic data were completed by the hysteresis, IRM and DCD measurements using ADE EV9 VSM. Geochemical data include soil reaction (pH), organic carbon, cations exchange capacity, and extractable iron and aluminium in the soil extracted by a dithionite-citrate, acid-ammonium oxalate and a pyrophosphate solution. Scanning electron microscopy was done for top/sub-soil and rock samples. Geochemical soil properties reflecting iron oxide stability correlate well with mass-specific magnetic susceptibility. Well pronounced relationship was observed between magnetic grain size, precipitation and soil pH, second group is reflecting concentration of feri-magnetic particles and age of parent rock, and the third group reflects degree of weathering and the thermomagnetic indices expressing changes in magneto

Rare Earth Elements (La, Ce, Pr, Nd, and Sm from a Carbonatite Deposit: Mineralogical Characterization and Geochemical Behavior

Directory of Open Access Journals (Sweden)

Mohamed Edahbi

2018-02-01

Full Text Available Geochemical characterization including mineralogical measurements and kinetic testing was completed on samples from the Montviel carbonatite deposit, located in Quebec (Canada. Three main lithological units representing both waste and ore grades were sampled from drill core. A rare earth element (REE concentrate was produced through a combination of gravity and magnetic separation. All samples were characterized using different mineralogical techniques (i.e., quantitative evaluation of minerals by scanning electron microscopy (QEMSCAN, X-ray diffraction (XRD, and scanning electron microscopy with X-ray microanalysis (SEM-EDS in order to quantify modal mineralogy, liberation, REE deportment and composition of REE-bearing phases. The REE concentrate was then submitted for kinetic testing (weathering cell in order to investigate the REE leaching potential. The mineralogical results indicate that: (i the main REE-bearing minerals in all samples are burbankite, kukharenkoite-Ce, monazite, and apatite; (ii the samples are dominated by REE-free carbonates (i.e., calcite, ankerite, and siderite; and (iii LREE is more abundant than HREE. Grades of REE minerals, sulfides and oxides are richer in the concentrate than in the host lithologies. The geochemical test results show that low concentrations of light REE are leached under kinetic testing conditions (8.8–139.6 µg/L total light REE. These results are explained by a low reactivity of the REE-bearing carbonates in the kinetic testing conditions, low amounts of REE in solids, and by precipitation of secondary REE minerals.

Diffuse Volcanism at the Young End of the Walvis Ridge - Tristan - Gough Seamount Province: Geochemical Sampling and Constraints on Plume Dynamics

Science.gov (United States)

Class, C.; Koppers, A. A. P.; Sager, W. W.; Schnur, S.

2014-12-01

The Walvis Ridge-Tristan/Gough seamount province in the South Atlantic represents 130 Myr of continuous intra-plate volcanism that can be connected to the once conjunct Parana-Etendeka flood basalt province. With this it represents one of the few primary hotspots consistent with the thermal plume model. However, around 60 Ma, the morphological expression of the Walvis Ridge changed drastically from a robust 200 km wide aseismic ridge into a 400 km wide region of diffuse and diminished volcanism. As a result, this part of the plume trail has been described by two subtracks, one ending at Tristan da Cunha and another at Gough Island more than 400 km to the SSE. Where the Walvis Ridge forks into these two tracks there is a center prong. There is also the 39.5°S lineament of seamounts between, but oblique to, the two subtracks, which is parallel to the local fracture zone directions. All these features are at odds with the classical definition of a narrow hotspot track although Rohde et al. (2013) showed that the Tristan and Gough subtracks retain a distinct geochemical signature over 70 Myr and are consistent with a zoned, deep-seated plume. The first Sr-Nd-Hf-Pb isotopic and trace element analyses from the detailed dredge sampling cruise MV1203 show that samples from two prominent seamounts at the western end of the 39.5°S lineament have a Gough-type signature, which makes an upper mantle source for this lineament unlikely but rather indicates that the Gough-type source stretches some 200 km NNW from Gough. Tristan track seamount samples are comparable with published data, however, one new sample has a Gough-type composition suggesting leakage of this component into the Tristan-type plume zone. Seamounts on the middle prong of the Walvis Ridge fork have compositions intermediate to Gough and Tristan domains, suggesting mixing between sources or melts of the two domains. Thus, the Gough-component in the last 60 Myr of plume activity is volumetrically much more

Geochemical characterisation of Elbe river high flood sediments

Energy Technology Data Exchange (ETDEWEB)

Krueger, F. [UFZ - Umweltforschungszentrum Leipzig-Halle GmbH, Falkenberg (Germany). Sektion Boden-/Gewaesserforschung]|[UFZ - Umweltforschungszentrum Leipzig-Halle GmbH, Magdeburg (Germany). Sektion Gewaesserforschung; Rupp, H.; Meissner, R. [UFZ - Umweltforschungszentrum Leipzig-Halle GmbH, Falkenberg (Germany). Sektion Boden-/Gewaesserforschung; Lohse, M.; Buettner, O.; Friese, K. [UFZ - Umweltforschungszentrum Leipzig-Halle GmbH, Magdeburg (Germany). Sektion Gewaesserforschung; Miehlich, G. [Hamburg Univ. (Germany). Inst. fuer Bodenkunde

2001-07-01

Quality aims for land usage in flood plains have to be worked out in the Russian-German research project 'Effects of floods on the pollution of agricultural used flood plain soils of the Oka River and the Elbe River'. It is financed by the Germany Ministry of Education and Research (FKZ 02 WT 9617/0). Beside the characterisation of the present pollution of soils for the middle Elbe, it is necessary to prognosticate the current pollutant input. At the examination site nearby Wittenberge, Elbe River kilometers 435 and 440, natural deposited flood sediments were sampled by artificial lawn mats. By the geochemical characterisation it is possible to record the metal input into the flood plain and to win knowledge about the sedimentation process. The results of sediment investigation of the high flood in spring 1997 are presented. (orig.)

On adequacy of reference sample composition to metal oxide composition in spectral analysis by the method of sublimating additions

International Nuclear Information System (INIS)

Zakhariya, N.F.; Turulina, O.P.

1983-01-01

The problem on adequacy of zirconium dioxide reference samples to analysed samples is considered. The mechanism of impurities evaporation process in the presence of the sublimating addition for elements of different nature is studied and limiting it stages have been found. It is shown that kinetic probability of impurities transfer into the form of more high-volatile compounds depending on conditions of preparing zirconium dioxide samples may not coincide with the thermodynamic one. With this connected are systematic deviations of the analytical signal value for samples of different technological prehistory

DEPOSITIONAL ENVIRONMENT AND ORGANIC GEOCHEMICAL CHARACTERISTICS OF LOWER EOCENE BITUMINOUS ROCKS, IN THE KÜRNÜÇ/GÖYNÜK-BOLU AREA

Directory of Open Access Journals (Sweden)

Ali SARI

2016-12-01

Full Text Available In this study, dark gray and dark brown colored, organic-carbon rich bituminous rocks (bituminous marl and bituminous shale exposing around the Kürnüç area (Göynük, Bolu are investigated by means of or- ganic geochemical characteristics. In this respect, rock lithologies, depositional environments, rock source potential, kerogen and organic maturity types and hydrocarbon generation potentials of bituminous rocks were determined. For this reason, pyrolysis (Rock Eval–VI analysis, gas chromatography (GC and gas chromatography-mass spectrometer (GC-MS analyses were carried out. In addition, spore color index (SCI was determined with organic petrographic method and stable carbon analysis (δ13C of the samples were also conducted. Lithology of the studied samples is of clastic source and the depositional environ- ment is a lagoon with a partial connection to the sea. In bituminous rocks with excellent source rock potential TOC values are in the range of 2.52-8.38 wt % (average 6.08 wt %. With the exception of two samples (Type II kerogen type of all samples is Type I. According to pyrolysis, GC and GC-MS organic maturity results, all the samples are in immature stage. Organic geochemical data indicate that bituminous rocks have an excellent oil generation potential and there is no organic contamination.

Platinum stable isotope analysis of geological standard reference materials by double-spike MC-ICPMS.

Science.gov (United States)

Creech, J B; Baker, J A; Handler, M R; Bizzarro, M

2014-01-10

We report a method for the chemical purification of Pt from geological materials by ion-exchange chromatography for subsequent Pt stable isotope analysis by multiple-collector inductively coupled plasma mass spectrometry (MC-ICPMS) using a 196 Pt- 198 Pt double-spike to correct for instrumental mass bias. Double-spiking of samples was carried out prior to digestion and chemical separation to correct for any mass-dependent fractionation that may occur due to incomplete recovery of Pt. Samples were digested using a NiS fire assay method, which pre-concentrates Pt into a metallic bead that is readily dissolved in acid in preparation for anion-exchange chemistry. Pt was recovered from anion-exchange resin in concentrated HNO 3 acid after elution of matrix elements, including the other platinum group elements (PGE), in dilute HCl and HNO 3 acids. The separation method has been calibrated using a precious metal standard solution doped with a range of synthetic matrices and results in Pt yields of ≥90% with purity of ≥95%. Using this chemical separation technique, we have separated Pt from 11 international geological standard reference materials comprising of PGE ores, mantle rocks, igneous rocks and one sample from the Cretaceous-Paleogene boundary layer. Pt concentrations in these samples range from ca. 5 ng g -1 to 4 μg g -1 . This analytical method has been shown to have an external reproducibility on δ 198 Pt (permil difference in the 198 Pt/ 194 Pt ratio from the IRMM-010 standard) of ±0.040 (2 sd) on Pt solution standards (Creech et al., 2013, J. Anal. At. Spectrom. 28, 853-865). The reproducibility in natural samples is evaluated by processing multiple replicates of four standard reference materials, and is conservatively taken to be ca. ±0.088 (2 sd). Pt stable isotope data for the full set of reference materials have a range of δ 198 Pt values with offsets of up to 0.4‰ from the IRMM-010 standard, which are readily resolved with this technique. These

Geochemical methods for identification of formations being prospective for uranium

International Nuclear Information System (INIS)

Zhukova, A.M.; Komarova, N.I.; Spiridonov, A.A.; Shor, G.M.

1985-01-01

Geochemical methods of uranium content evaluation in metamorphic, ultrametamorphic and sedimentary formations are considered. At that, the following four factors are of the highest importance: 1) average uranium content-geochemical background; 2) character of uranium distribution; 3) forms of uranium presence; 4) the value of thorium-uranium ratio. A complex of radiogeochemical criteria, favourable for uranium presence is formulated: high average background content of total and '' mobile''uranium and high value of variation coefficient (80-100% and above); low (approximately one or lower) thorium-uranium ratio; sharp increase in uranium concentration in accessory minerals. Radiogeochemical peculiarities of metamorphic and ultrametamorphic formations prospective for uranium are enumerated. The peculiarities condition specificity of geochemical prospecting methods. Prospecting methods first of all must be directed at the evaluation of radioelement distribution parameters and specification of the forms of their presence

Synthesizing Earth's geochemical data for hydrogeochemical analysis

Science.gov (United States)

Brantley, S. L.; Kubicki, J.; Miller, D.; Richter, D.; Giles, L.; Mitra, P.

2007-12-01

For over 200 years, geochemical, microbiological, and chemical data have been collected to describe the evolution of the surface earth. Many of these measurements are data showing variations in time or in space. To forward predict hydrologic response to changing tectonic, climatic, or anthropogenic forcings requires synthesis of these data and utilization in hydrogeochemical models. Increasingly, scientists are attempting to synthesize such data in order to make predictions for new regions or for future time periods. However, to make such complex geochemical data accessible requires development of sophisticated cyberinfrastructures that both invite uploading as well as usage of data. Two such cyberinfrastructure (CI) initiatives are currently developing, one to invite and promote the use of environmental kinetics data (laboratory time course data) through ChemxSeer, and the other to invite and promote the use of spatially indexed geochemical data for the Earth's Critical Zone through CZEN.org. The vision of these CI initiatives is to provide cyber-enhanced portals that encourage domain scientists to upload their data before publication (in private cyberspace), and to make these data eventually publicly accessible (after an embargo period). If the CI can be made to provide services to the domain specialist - e.g. to provide data analysis services or data comparison services - we envision that scientists will upload data. In addition, the CI can promote the use and comparison of datasets across disciplines. For example, the CI can facilitate the use of spatially indexed geochemical data by scientists more accustomed to dealing with time-course data for hydrologic flow, and can provide user-friendly interfaces with CI established to facilitate the use of hydrologic data. Examples of the usage of synthesized data to predict soil development over the last 13ky and its effects on active hydrological flow boundaries in surficial systems will be discussed for i) a N

Geochemical and mineralogical study of selected weathered samples from Olkiluoto site

International Nuclear Information System (INIS)

Lindberg, A.

2009-02-01

Optical microscopy, chemical analyses and X-ray diffraction method were used to study the influence of weathering from 11 drill core samples from shallow depths (< 25 m). The samples, 4 to 22 cm in length were drilled from Olkiluoto study site, Eurajoki, and they represent the common rock types of local bedrock: mica gneiss, tonalitic and granodioritic gneiss. Two of the samples were macroscopically unweathered and 9 of them were remarkably altered. The alteration was shown as porosity, the abundance of chlorite instead of biotite and pink, unclear feldspars. Many samples also contained red-brown hematite and fractures, some of them coated with secondary minerals, even clay. Microscopically the most visible feature of weathering was the total alteration of plagioclase and cordierite to sericite. In many samples also biotite was richly altered to chlorite and opaque minerals. Microfractures were common and they were filled by hematite, kaolinite and fine-grained muscovite (sericite). Hematite was, in some cases, also largely replacing the weathered minerals, feldspars and cordierite. Chemical alteration was not clear, because the alteration of main minerals have produced secondary minerals with almost the same chemical composition without any reasonable depleting or enrichment of certain elements. X-ray diffraction determination of samples proved, that often plagioclase was replaced by mica and biotite by chlorite. In some cases the samples contained products of chemical weathering, kaolinite and smectite. (orig.)

Geochemical fingerprints and pebbles zircon geochronology

Indian Academy of Sciences (India)

Home; Journals; Journal of Earth System Science; Volume 125; Issue 7. Geochemical fingerprints and pebbles zircon geochronology: Implications for the provenance and tectonic setting of Lower Cretaceous sediments in the Zhucheng Basin (Jiaodong peninsula, North China). Jin-Long Ni Jun-Lai Liu Xiao-Ling Tang ...

Multielemental analysis of Korean geological reference samples by INAA, ICP-AES and ICP-MS

International Nuclear Information System (INIS)

Naoki Shirai; Hiroki Takahashi; Yuta Yokozuka; Mitsuru Ebihara; Meiramkhan Toktaganov; Shun Sekimoto

2015-01-01

Six Korean geological reference samples (KB-1, KGB-1, KT-1, KD-1, KG-1 and KG-2) prepared by Korea Institutes of Geoscience and Mineral Resources were analyzed by using INAA, ICP-AES and ICP-MS. Some elements could be determined by both INAA and non-INAA methods (ICP-AES and ICP-MS), and these data are consistent with each other. This study confirms that a combination of ICP-AES and ICP-MS is comparable to INAA in determining a wide range of major, minor and trace elements in geological materials. (author)

Geochemical, hydrological, and biological cycling of energy residual. Research plan

International Nuclear Information System (INIS)

Wobber, F.J.

1983-03-01

Proposed research goals and specific research areas designed to provide a base of fundamental scientific information so that the geochemical, hydrological, and biophysical mechanisms that contribute to the transport and long term fate of energy residuals in natural systems can be understood are described. Energy development and production have resulted in a need for advanced scientific information on the geochemical transformations, transport rates, and potential for bioaccumulation of contaminants in subsurface environments

Prescribing Patterns in a Psychiatrically Referred Sample of Youth With Autism Spectrum Disorder.

Science.gov (United States)

Shekunov, Julia; Wozniak, Janet; Conroy, Kristina; Pinsky, Elizabeth; Fitzgerald, Maura; de Leon, Melissa F; Belser, Abigail; Biederman, Joseph; Joshi, Gagan

The aim of this study was to examine the pattern of psychopharmacologic interventions in a psychiatrically referred sample of youth with autism spectrum disorder (ASD). This retrospective chart review aimed at collecting demographic and clinical information, including data on DSM-IV-TR criteria-based psychiatric disorders and related current medication treatment and response. Data were collected in December 2011. Clinicians identified the target disorder for each medication and any adverse events. Level of psychopathology and therapeutic response was assessed by the clinician-rated Clinical Global Impressions scale (CGI). Psychiatrically referred youth with ASD (n = 54) suffered from multiple psychopathologies (mean = 2.3) and had a marked level of morbidity (range of baseline CGI-Severity of Illness mean scores, 4.3-5.6). The most prevalent psychopathology was ADHD (83%), anxiety disorders (67%), bipolar spectrum disorder (43%), and mood disorder not otherwise specified (44%). The majority (80%) of the subjects received combination therapy (mean ± SD number of psychotropic medications = 3 ± 1.5). Forty percent of the participants responded on all treatment target symptoms (CGI-Improvement scale score ≤ 2), and an additional 10% experienced response versus nonresponse on a relatively greater number of target symptoms. Half of the subjects reported an adverse event, most commonly weight gain (28%) and sedation (12%), both from antipsychotic medication use. Psychiatrically referred youth with ASD suffer from multiple highly impairing psychiatric disorders that require combination pharmacotherapy. These findings highlight the need for further research to guide clinical decision-making and treatment. © Copyright 2017 Physicians Postgraduate Press, Inc.

Adaptive Multiscale Modeling of Geochemical Impacts on Fracture Evolution

Science.gov (United States)

Molins, S.; Trebotich, D.; Steefel, C. I.; Deng, H.

2016-12-01

Understanding fracture evolution is essential for many subsurface energy applications, including subsurface storage, shale gas production, fracking, CO2 sequestration, and geothermal energy extraction. Geochemical processes in particular play a significant role in the evolution of fractures through dissolution-driven widening, fines migration, and/or fracture sealing due to precipitation. One obstacle to understanding and exploiting geochemical fracture evolution is that it is a multiscale process. However, current geochemical modeling of fractures cannot capture this multi-scale nature of geochemical and mechanical impacts on fracture evolution, and is limited to either a continuum or pore-scale representation. Conventional continuum-scale models treat fractures as preferential flow paths, with their permeability evolving as a function (often, a cubic law) of the fracture aperture. This approach has the limitation that it oversimplifies flow within the fracture in its omission of pore scale effects while also assuming well-mixed conditions. More recently, pore-scale models along with advanced characterization techniques have allowed for accurate simulations of flow and reactive transport within the pore space (Molins et al., 2014, 2015). However, these models, even with high performance computing, are currently limited in their ability to treat tractable domain sizes (Steefel et al., 2013). Thus, there is a critical need to develop an adaptive modeling capability that can account for separate properties and processes, emergent and otherwise, in the fracture and the rock matrix at different spatial scales. Here we present an adaptive modeling capability that treats geochemical impacts on fracture evolution within a single multiscale framework. Model development makes use of the high performance simulation capability, Chombo-Crunch, leveraged by high resolution characterization and experiments. The modeling framework is based on the adaptive capability in Chombo

Determining origin of underground water in coal mines by means of natural isotopes and other geochemical parameters

Energy Technology Data Exchange (ETDEWEB)

Dolenec, T; Pezdic, J; Herlec, U; Kuscer, D; Mitrevski, G [Institut Josef Stefan, Ljubljana (Yugoslavia)

1989-07-01

Presents a preliminary report on origin of water in Slovenian brown coal mines. Water, coal and strata samples from the Hrastnik and Ojstro mines were analyzed for changes in chemical composition. Water samples were also analyzed for changes in isotopic composition and inorganic carbon and sulfur contents. Chemical, isotopic and geochemical techniques are described and results are presented with 21 diagrams. An attempt is made to explain the origin and age of water flowing from mine aquifers into mine rooms, and to explain the interdependence of surface and underground water flow. 10 refs.

Combination of geo- pedo- and technogenic magnetic and geochemical signals in soil profiles - Diversification and its interpretation: A new approach.

Science.gov (United States)

Szuszkiewicz, Marcin; Łukasik, Adam; Magiera, Tadeusz; Mendakiewicz, Maria

2016-07-01

Magnetic and geochemical parameters of soils are determined with respect to geology, pedogenesis and anthropopression. Depending on local conditions these factors affect magnetic and geochemical signals simultaneously or in various configurations. We examined four type of soils (Entic Podzol, Eutric Cambisol, Humic Cambisol and Dystric Cambisol) developed on various bedrock (the Tumlin Sandstone, basaltoid, amphibolite and serpentinite, respectively). Our primary aim was to characterize the origin and diversification of the magnetic and geochemical signal in soils in order to distinguish the most reliable methods for correct interpretation of measured parameters. Presented data include selected parameters, both magnetic (mass magnetic susceptibility - χ, frequency-dependent magnetic susceptibility - χfd and thermomagnetic susceptibility measurement - TSM), and geochemical (selected heavy metal contents: Co, Cr, Cu, Fe, Mn, Ni, Pb, Zn). Additionally, the enrichment factor (EF) and index of geoaccumulation (Igeo) were calculated. Our results suggest the following: (1) the χ/Fe ratio may be a reliable indicator for determining changes of magnetic signal origin in soil profiles; (2) magnetic and geochemical signals are simultaneously higher (the increment of χ and lead and zinc was noted) in topsoil horizons because of the deposition of technogenic magnetic particles (TMPs); (3) EF and Igeo evaluated for lead and zinc unambiguously showed anthropogenic influence in terms of increasing heavy metal contents in topsoil regardless of bedrock or soil type; (4) magnetic susceptibility measurements supported by TSM curves for soil samples of different genetic horizons are a helpful tool for interpreting the origin and nature of the mineral phases responsible for the changes of magnetic susceptibility values. Copyright © 2016 Elsevier Ltd. All rights reserved.

Acceptance of the 2014 Geochemical Society Distinguished Service Award by Carla Koretsky

Science.gov (United States)

Koretsky, Carla

2015-06-01

I am deeply touched to have received the Geochemical Society Distinguished Service Award. It was a great surprise when I received the notice that I had been chosen for the award. It has been a tremendous pleasure to work on behalf of student members of the Geochemical Society, Japanese Geochemical Society and the European Association of Geochemists to organize the student travel grants over the past few years. Certainly, this is not an effort that I undertook on my own. Many, many members of the GS, the JGS and the EAG generously donated their time and expertise to serve as reviewers for the many travel grant applicants we receive each year. Seth Davis, the GS Chief Operating Officer, spent countless hours helping to organize applications, the website, distribution of funds and many other aspects of the competition. Without Seth and the many expert reviewers, we could not run the travel grant program each year and provide this important financial support to allow more students to experience the Goldschmidt Conference. I also enjoyed my time as Geochemical News co-editor, and I should point out that GN during those years was ably co-edited by Johnson Haas. It has been a pleasure to see Elements take off, and GN evolve into a timely source of important announcements and information about cutting-edge science since I stepped down as co-editor. I feel very fortunate to work with so many outstanding colleagues in the global geochemical community, and I am a little embarrassed, and also very grateful, to have been selected for the Geochemical Society Distinguished Service Award. Thank you!

Geochemistry study of orientation made in the Uranio mission context[Geochemical prospection of Uranium in Uruguay]; Estudios geoquimicos de orientacion realizados en el marco de la mision Uranio

Energy Technology Data Exchange (ETDEWEB)

NONE

1982-07-01

The objective of the geochemical study or guidance study, is to select the three main parameters of strategic a geochemical prospection: place election for samples extraction, king of material to sample, the average density of sampling. Also throughout the tours, complementary studies can take place in order to improve the chosen techniques initially. Inspiring by results obtained by Alain Lambert to us by the end of 1981 in diverse tactics done in known indications, we have come to a preliminary study days 7 and 8 of January of 1982 in the South Long Hill region. During the campaign of strategic prospection, two complementary studies were realised: one in the region of Yerba Sola and another one in Paso Severino from the 6 to the 9 of October of 1982.

Statistical treatment of geochemical data and its application in the geologic mapping and in the definition of the geochemical anomalies in the Alvo 2-Corpo 4 -Provincia Mineral de Carajas

International Nuclear Information System (INIS)

Moura, C.A.V.

1982-01-01

It was given a statistical treatment for the geochemical data about soil in the are named Alvo2 - Corpo4- in the Provincia Mineral de Carajas, Para, Brazil, for application of the geological mapping and definition of geochemical anomalies. (A.B.) [pt

Chlorine isotopes potential as geo-chemical tracers

Digital Repository Service at National Institute of Oceanography (India)

Shirodkar, P.V.; Pradhan, U.K.; Banerjee, R.

The potential of chlorine isotopes as tracers of geo-chemical processes of earth and the oceans is highlighted based on systematic studies carried out in understanding the chlorine isotope fractionation mechanism, its constancy in seawater and its...

Is avoidant disorder part of the social phobia spectrum in a referred sample of Brazilian children and adolescents?

Directory of Open Access Journals (Sweden)

Denardin D.

2004-01-01

Full Text Available The diagnosis of avoidant disorder was deleted from the Diagnostic and Statistical Manual of Mental disorders - fourth edition (DSM-IV based on a `committee decision' suggesting that avoidant disorder is part of the social phobia spectrum. The objective of the present study was to examine the nature of this clinical association in a referred sample of Brazilian children and adolescents. We assessed a referred sample of 375 youths using semi-structured diagnostic interview methodology. Demographic (age at admission to the study and sex and clinical (level of impairment, age at onset of symptoms and pattern of comorbidity data were assessed in subsamples of children with avoidant disorder (N = 7, social phobia (N = 26, and comorbidity between both disorders (N = 24. Although a significant difference in the male/female ratio was detected among groups (P = 0.03, none of the other clinical variables differed significantly among subjects that presented each condition separately or in combination. Most of the children with avoidant disorder fulfilled criteria for social phobia. Thus, our findings support the validity of the conceptualization of avoidant disorder as part of the social phobia spectrum in a clinical sample.

Is avoidant disorder part of the social phobia spectrum in a referred sample of Brazilian children and adolescents?

Directory of Open Access Journals (Sweden)

D. Denardin

2004-06-01

Full Text Available The diagnosis of avoidant disorder was deleted from the Diagnostic and Statistical Manual of Mental disorders - fourth edition (DSM-IV based on a `committee decision' suggesting that avoidant disorder is part of the social phobia spectrum. The objective of the present study was to examine the nature of this clinical association in a referred sample of Brazilian children and adolescents. We assessed a referred sample of 375 youths using semi-structured diagnostic interview methodology. Demographic (age at admission to the study and sex and clinical (level of impairment, age at onset of symptoms and pattern of comorbidity data were assessed in subsamples of children with avoidant disorder (N = 7, social phobia (N = 26, and comorbidity between both disorders (N = 24. Although a significant difference in the male/female ratio was detected among groups (P = 0.03, none of the other clinical variables differed significantly among subjects that presented each condition separately or in combination. Most of the children with avoidant disorder fulfilled criteria for social phobia. Thus, our findings support the validity of the conceptualization of avoidant disorder as part of the social phobia spectrum in a clinical sample.

Structure of the Wechsler Intelligence Scale for Children-Fourth Edition among a National Sample of Referred Students

Science.gov (United States)

Watkins, Marley W.

2010-01-01

The structure of the Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV; D. Wechsler, 2003a) was analyzed via confirmatory factor analysis among a national sample of 355 students referred for psychoeducational evaluation by 93 school psychologists from 35 states. The structure of the WISC-IV core battery was best represented by four…

Geochemical and mineralogical characterization of the Eagle Ford Shale: Results from the USGS Gulf Coast #1 West Woodway core

Science.gov (United States)

Birdwell, Justin E.; Boehlke, Adam; Paxton, Stanley T.; Whidden, Katherine J.; Pearson, Ofori N.

2017-01-01

The Eagle Ford shale is a major continuous oil and gas resource play in southcentral Texas and a source for other oil accumulations in the East Texas Basin. As part of the U.S. Geological Survey’s (USGS) petroleum system assessment and research efforts, a coring program to obtain several immature, shallow cores from near the outcrop belt in central Texas has been undertaken. The first of these cores, USGS Gulf Coast #1 West Woodway, was collected near Waco, Texas, in September 2015 and has undergone extensive geochemical and mineralogical characterization using routine methods to ascertain variations in the lithologies and chemofacies present in the Eagle Ford at this locale. Approximately 270 ft of core was examined for this study, focusing on the Eagle Ford Group interval between the overlying Austin Chalk and underlying Buda Limestone (~20 ft of each). Based on previous work to identify the stratigraphy of the Eagle Ford Group in the Waco area and elsewhere (Liro et al., 1994; Robison, 1997; Ratcliffe et al., 2012; Boling and Dworkin, 2015; Fairbanks et al., 2016, and references therein), several lithological units were expected to be present, including the Pepper Shale (or Woodbine), the Lake Waco Formation (or Lower Eagle Ford, including the Bluebonnet, Cloice, and Bouldin or Flaggy Cloice members), and the South Bosque Member (Upper Eagle Ford). The results presented here indicate that there are three major chemofacies present in the cored interval, which are generally consistent with previous descriptions of the Eagle Ford Group in this area. The relatively high-resolution sampling (every two ft above the Buda, 432.8 ft depth, and below the Austin Chalk, 163.5 ft depth) provides great detail in terms of geochemical and mineralogical properties supplementing previous work on immature Eagle Ford Shale near the outcrop belt.

Revision of the SNPforID 34-plex forensic ancestry test: Assay enhancements, standard reference sample genotypes and extended population studies.

Science.gov (United States)

Fondevila, M; Phillips, C; Santos, C; Freire Aradas, A; Vallone, P M; Butler, J M; Lareu, M V; Carracedo, A

2013-01-01

A revision of an established 34 SNP forensic ancestry test has been made by swapping the under-performing rs727811 component SNP with the highly informative rs3827760 that shows a near-fixed East Asian specific allele. We collated SNP variability data for the revised SNP set in 66 reference populations from 1000 Genomes and HGDP-CEPH panels and used this as reference data to analyse four U.S. populations showing a range of admixture patterns. The U.S. Hispanics sample in particular displayed heterogeneous values of co-ancestry between European, Native American and African contributors, likely to reflect in part, the way this disparate group is defined using cultural as well as population genetic parameters. The genotyping of over 700 U.S. population samples also provided the opportunity to thoroughly gauge peak mobility variation and peak height ratios observed from routine use of the single base extension chemistry of the 34-plex test. Finally, the genotyping of the widely used DNA profiling Standard Reference Material samples plus other control DNAs completes the audit of the 34-plex assay to allow forensic practitioners to apply this test more readily in their own laboratories. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Geochemical character of Southern African Kimberlites: a new approach based on isotopic constraints

International Nuclear Information System (INIS)

Smith, C.B.; Gurney, J.J.; Ebrahim, N.

1985-01-01

Major and trace element compositions of southern African kimberlite samples previously analysed for isotopic compositions confirm that isotopically defined Group I (basaltic) and Group II (micaceous) variants have distinctive geochemical signatures. These signatures are generally consistent with geochemical variation in petrographically defined types. Stepwise discriminant function analysis is used to define the most important geochemical distinctions at the group level and to derive a procedure which successfully classifies a large number of unknowns based on chemical composition only. In comparison to Group I, Group II kimberlites have consistently higher abundances of SiO 2 , K 2 O, Pb, Rb, Ba and LREE, and lower abundances of TiO 2 and Nb. In conjunction with isotopic results, the distinctions in incompatible element contents in particular are believed to reflect broad differences in source rock character. Results are consistent with derivation of Group I kimberlites from asthenospheric-like sources similar to those from which oceanic island basalts are produced. In contrast, Group II kimberlites are inferred to originate from sources within ancient stabilized subcontinental lithosphere characterized by time-averaged incompatible element enrichment. Group I kimberlites can be further subdivided into two isotopically similar types to some degree correlative with tectonic environment. Compared to subgroup IA (on-craton), IB kimberlites have lower SiO 2 and higher CaO, FeO + Fe 2 O 3 and volatile contents in addition to somewhat greater TiO 2 , P 2 O 5 , Nb, Zr and Y abundances, and tend to occur outside the inferred boundaries of the Kaapvaal Craton though exceptions are present and new unpublished data suggest that this group may be relatively common on the craton

Geochemical nature of sub-ridge mantle and opening dynamics of the South China Sea

Science.gov (United States)

Zhang, Guo-Liang; Luo, Qing; Zhao, Jian; Jackson, Matthew G.; Guo, Li-Shuang; Zhong, Li-Feng

2018-05-01

The Indian-type mantle (i.e., above the north hemisphere reference line on the plot of 208Pb/204Pb vs. 206Pb/204Pb) has been considered as a "Southern Hemisphere" geochemical signature, whose origin remains enigmatic. The South China Sea is an extensional basin formed after rifting of the Euro-Asia continent in the Northern Hemisphere, however, the geochemical nature of the igneous crust remains unexplored. For the first time, IODP Expedition 349 has recovered seafloor basalts covered by the thick sediments in the Southwest sub-basin (Sites U1433 and U1434) and the East sub-basin (Site U1431). The Southwest sub-basin consists of enriched (E)-MORB type basalts, and the East sub-basin consists of both normal (N)-MORB-type and E-MORB-type basalts based on trace element compositions. The basalts of the two sub-basins are Indian-type MORBs based on Sr-Nd-Pb-Hf isotope compositions, and the Southwest sub-basin basalts show isotopic compositions (i.e., 206Pb/204Pb of 17.59-17.89) distinctly different from the East sub-basin (i.e., 206Pb/204Pb of 18.38-18.57), suggesting a sub-basin scale mantle compositional heterogeneity and different histories of mantle compositional evolution. Two different enriched mantle end-members (EM1 and EM2) are responsible for the genesis of the Indian-type mantle in the South China Sea. We have modeled the influences of Hainan mantle plume and lower continental crust based on Sr-Nd-Pb-Hf isotope compositions. The results indicate that the influence of Hainan plume can explain the elevated 206Pb/204Pb of the East sub-basin basalts, and the recycling of lower continental crust can explain the low 206Pb/204Pb of the Southwest sub-basin basalts. Based on the strong geochemical imprints of Hainan plume in the ridge magmatism, we propose that the Hainan plume might have promoted the opening of the South China Sea, during which the Hainan plume contributed enriched component to the sub-ridge mantle and caused thermal erosion and return of lower

Geochemical typification of kimberlite and related rocks of the North Anabar region, Yakutia

Science.gov (United States)

Kargin, A. V.; Golubeva, Yu. Yu.

2017-11-01

The results of geochemical typification of kimberlites and related rocks (alneites and carbonatites) of the North Anabar region are presented with consideration of the geochemical specification of their source and estimation of their potential for diamonds. The content of representative trace elements indicates the predominant contribution of an asthenospheric component (kimberlites and carbonatites) in their source, with a subordinate contribution of vein metasomatic formations containing Cr-diopside and ilmenite. A significant contribution of water-bearing potassium metasomatic parageneses is not recognized. According to the complex of geochemical data, the studied rocks are not industrially diamondiferous.

A Geochemical Mass-Balance Method for Base-Flow Separation, Upper Hillsborough River Watershed, West-Central Florida, 2003-2005 and 2009

Science.gov (United States)

Kish, G.R.; Stringer, C.E.; Stewart, M.T.; Rains, M.C.; Torres, A.E.

2010-01-01

Geochemical mass-balance (GMB) and conductivity mass-balance (CMB) methods for hydrograph separation were used to determine the contribution of base flow to total stormflow at two sites in the upper Hillsborough River watershed in west-central Florida from 2003-2005 and at one site in 2009. The chemical and isotopic composition of streamflow and precipitation was measured during selected local and frontal low- and high-intensity storm events and compared to the geochemical and isotopic composition of groundwater. Input for the GMB method included cation, anion, and stable isotope concentrations of surface water and groundwater, whereas input for the CMB method included continuous or point-sample measurement of specific conductance. The surface water is a calcium-bicarbonate type water, which closely resembles groundwater geochemically, indicating that much of the surface water in the upper Hillsborough River basin is derived from local groundwater discharge. This discharge into the Hillsborough River at State Road 39 and at Hillsborough River State Park becomes diluted by precipitation and runoff during the wet season, but retains the calcium-bicarbonate characteristics of Upper Floridan aquifer water. Field conditions limited the application of the GMB method to low-intensity storms but the CMB method was applied to both low-intensity and high-intensity storms. The average contribution of base flow to total discharge for all storms ranged from 31 to 100 percent, whereas the contribution of base flow to total discharge during peak discharge periods ranged from less than 10 percent to 100 percent. Although calcium, magnesium, and silica were consistent markers of Upper Floridan aquifer chemistry, their use in calculating base flow by the GMB method was limited because the frequency of point data collected in this study was not sufficient to capture the complete hydrograph from pre-event base-flow to post-event base-flow concentrations. In this study, pre-event water

Concerning initial and secondary character of radionuclide distribution in elementary landscape geochemical systems

Science.gov (United States)

Korobova, Elena; Romanov, Sergey

2017-04-01

study confirms that Cs-137 as a label helps to trace processes and patterns of chemical elements' migration on the level of ELGS that are numerously reproduced elsewhere in natural systems. The study is aimed at and believed to provide solution for a number of important problems related to generation and evolution of soil structure, spatial redistribution of fertilizers and pesticides, other important processes of matter redistribution on the level of local LGS. References Korobova E.M., Korovaykov P.A., 1990. Landscape and geochemical approach to drawing up a soil distribution profile for Chernobyl radionuclides in distant areas //Seminar "Comparative assessment of the environmental impact of radionuclides released during three major nuclear accidents: Kyshtum, Windscale, Chernobyl". V. 1. Luxembourg, 309-327. Linnik V.G., 2008. Landscape differentiation of technogenic radionuclides: geoinformation systems and models. Thesis. Moscow: Moscow State University, 42 p. Romanov S.L., 1989. Principles of formation of radionuclide dispersion and concentration fields // Abstracts of the All-Union Conference "Principles and methods of landscape geochemical studies of radionuclide migration". Moscow: Vernadsky Institute, p. 46. Shcheglov A.I., Tsvetnova O.B., KlyashtorinA.L., 2001. Biogeochemical migration of technogenic radionuclides in forest ecosystems. Moscow: Nauka, 235 p.

High-precision isotopic characterization of USGS reference materials by TIMS and MC-ICP-MS

Science.gov (United States)

Weis, Dominique; Kieffer, Bruno; Maerschalk, Claude; Barling, Jane; de Jong, Jeroen; Williams, Gwen A.; Hanano, Diane; Pretorius, Wilma; Mattielli, Nadine; Scoates, James S.; Goolaerts, Arnaud; Friedman, Richard M.; Mahoney, J. Brian

2006-08-01

The Pacific Centre for Isotopic and Geochemical Research (PCIGR) at the University of British Columbia has undertaken a systematic analysis of the isotopic (Sr, Nd, and Pb) compositions and concentrations of a broad compositional range of U.S. Geological Survey (USGS) reference materials, including basalt (BCR-1, 2; BHVO-1, 2), andesite (AGV-1, 2), rhyolite (RGM-1, 2), syenite (STM-1, 2), granodiorite (GSP-2), and granite (G-2, 3). USGS rock reference materials are geochemically well characterized, but there is neither a systematic methodology nor a database for radiogenic isotopic compositions, even for the widely used BCR-1. This investigation represents the first comprehensive, systematic analysis of the isotopic composition and concentration of USGS reference materials and provides an important database for the isotopic community. In addition, the range of equipment at the PCIGR, including a Nu Instruments Plasma MC-ICP-MS, a Thermo Finnigan Triton TIMS, and a Thermo Finnigan Element2 HR-ICP-MS, permits an assessment and comparison of the precision and accuracy of isotopic analyses determined by both the TIMS and MC-ICP-MS methods (e.g., Nd isotopic compositions). For each of the reference materials, 5 to 10 complete replicate analyses provide coherent isotopic results, all with external precision below 30 ppm (2 SD) for Sr and Nd isotopic compositions (27 and 24 ppm for TIMS and MC-ICP-MS, respectively). Our results also show that the first- and second-generation USGS reference materials have homogeneous Sr and Nd isotopic compositions. Nd isotopic compositions by MC-ICP-MS and TIMS agree to within 15 ppm for all reference materials. Interlaboratory MC-ICP-MS comparisons show excellent agreement for Pb isotopic compositions; however, the reproducibility is not as good as for Sr and Nd. A careful, sequential leaching experiment of three first- and second-generation reference materials (BCR, BHVO, AGV) indicates that the heterogeneity in Pb isotopic compositions

NEW GEOCHEMICAL DATA OF BASALTS IN THE TSOROIDOG AREA, CENTRAL MONGOLIA

Directory of Open Access Journals (Sweden)

T. Oyunchimeg

2017-01-01

Full Text Available At present, geochemical data are widely used for reconstructing geodynamic settings, especially, volcanic rocks of mafic composition, i.e., basalts, because they are widespread in many orogenic belts and are indicative of different geodynamic environments. In general, we propose the reconstruction of the tectonic settings of basalts according to their relationships with associated ocean plate stratigraphy (OPS sediments, their petrogenesis and their geochemical features.

Application of radio-geochemical exploration to investigation on geo-ecological environment

International Nuclear Information System (INIS)

Ye Qingsen

2000-01-01

Taking investigation on radon hazards and natural radioactivity as examples, the author expounds the prospects of the application of radio-geochemical exploration to the investigation on geo-ecological environment. It is especially emphasized that the methods of radio-geochemical exploration can not be only widely applied in the field of traditional radio-geological prospecting but also play an important role in the investigation on geo-ecological environment

A comparison of geochemical exploration techniques and sample media within accretionary continental margins: an example from the Pacific Border Ranges, Southern Alaska, U.S.A.

Science.gov (United States)

Sutley, S.J.; Goldfarb, R.J.; O'Leary, R. M.; Tripp, R.B.

1990-01-01

The Pacific Border Ranges of the southern Alaskan Cordillera are composed of a number of allochthonous tectonostratigraphic terranes. Within these terranes are widespread volcanogenic, massive sulfide deposits in and adjacent to portions of accreted ophiolite complexes, bands and disseminations of chromite in accreted island-arc ultramafic rocks, and epigenetic, gold-bearing quartz veins in metamorphosed turbidite sequences. A geochemical pilot study was undertaken to determine the most efficient exploration strategy for locating these types of mineral deposits within the Pacific Border Ranges and other typical convergent continental margin environments. High-density sediment sampling was carried out in first- and second-order stream channels surrounding typical gold, chromite and massive sulfide occurrences. At each site, a stream-sediment and a panned-concentrate sample were collected. In the laboratory, the stream sediments were sieved into coarse-sand, fine- to medium-sand, and silt- to clay-size fractions prior to analysis. One split of the panned concentrates was retained for analysis; a second split was further concentrated by gravity separation in heavy liquids and then divided into magnetic, weakly magnetic and nonmagnetic fractions for analysis. A number of different techniques including atomic absorption spectrometry, inductively coupled plasma atomic emission spectrometry and semi-quantitative emission spectrography were used to analyze the various sample media. Comparison of the various types of sample media shows that in this tectonic environment it is most efficient to include a silt- to clay-size sediment fraction and a panned-concentrate sample. Even with the relatively low detection limits for many elements by plasma spectrometry and atomic absorption spectrometry, anomalies reflecting the presence of gold veins could not be identified in any of the stream-sediment fractions. Unseparated panned-concentrate samples should be analyzed by emission

Testing the homogeneity of candidate reference materials by solid sampling - AAS and INAA

International Nuclear Information System (INIS)

Rossbach, M.; Grobecker, K.-H.

2002-01-01

The necessity to quantify a natural material's homogeneity with respect to its elemental distribution prior to chemical analysis of a given aliquot is emphasised. Available instruments and methods to obtain the relevant information are described. Additionally the calculation of element specific, relative homogeneity factors, H E , and of a minimum sample mass M 5% to achieve 5% precision on a 95% confidence level is given. Especially, in the production and certification of Certified Reference Materials (CRMs) this characteristic information should be determined in order to provide the user with additional inherent properties of the CRM to enable more economical use of the expensive material and to evaluate further systematic bias of the applied analytical technique. (author)

Ionizing radiation and radionuclides in the environment: sources, origin, geochemical processes and health risks

International Nuclear Information System (INIS)

Dangic, A.

1995-01-01

Ionizing radiation related to the radioactivity and radionuclides appears to be ones of most dangerous environmental risks to the human health. The paper considers appearance and importance of radionuclides, both natural (cosmogenic and Earth's) and anthropogenic, mode of their entering into and movement through the environment. Most risk to the population are radionuclides related to the geological-geochemical systems - in Serbia, high concentrations of radionuclides related to these sources were indicated at a number of localities. Movement of radionuclides through the environment is regulated by the geochemical processes i.e. the geochemical cycles of the elements. For the discovering of radionuclides in the nature, the assessment of the health risks to the population and the related protection are necessary multilayer geochemical studies. (author)

Geochemical and isotopic features of geothermal fluids around the Sea of Marmara, NW Turkey

Science.gov (United States)

Italiano, Francesco; Woith, Heiko; Seyis, Cemil; Pizzino, Luca; Sciarra, Alessandra

2016-04-01

Earthquake processes provoke modifications of the crust affecting the fluid regime with changes in water level in wells, in temperature and/or chemical composition of groundwaters, in the flow-rate of gas discharges and in their chemical and isotopic composition. In the frame of MARsite (MARsite has received funding from the European Union's Seventh Programme for research, technological development and demonstration under grant agreement No 308417) the relationship between fluids and seismogenesis has been approached collecting geochemical data of local significance and evaluating them in geochemical interpretative models of fluids circulation and interactions as well as defining their behaviour over a seismic-prone area. During three fluid sampling campaigns in 2013, 2014, and 2015 a suite of 120 gas samples were collected from 72 thermal and mineral water springs/wells in the wider Marmara region along the Northern and Southern branches of the North Anatolian Fault Zone (NAFZ). Bubbling gases were collected if available, in all other cases the gas phase was extracted from water samples collected on that purpose. Gas samples were analyzed for the main chemical composition as well as their isotopic composition (He and C). The results highlight that the vented gases are a binary mixture of two end-members having nitrogen and carbon dioxide as main components. The geochemical features of the gas phase are the result of several processes that have modified their pristine composition. Atmospheric and deep-originated volatiles mix at variable extents and interact with cold and hot groundwaters. CO2 is normally the main gas species. But it's concentration may decrease due to gas-water interactions (GWI) increasing the relative concentration of N2 and other less soluble gases. A high CO2 content indicates minor interactions. Thus, the easier and faster the pathways are from the deep layers toward the Earth's surface, the lower are the interactions. The volatiles keep

Geochemical Investigation of Clay Minerals in Marte, Borno State, Nigeria

Directory of Open Access Journals (Sweden)

F. D. Adams

2017-10-01

Full Text Available Clay deposit collected from various locations in Marte (Northern Borno, were studied to determine their physical and chemical characteristics in order to evaluate their suitability for industrial uses. Major and trace element analyses were carried out on clay samples using Inductively Couple Plasma-Optical Emission Spectrometry (ICP-OES and X- Ray Fluorescence (XRF. The result of the chemical analysis of the ten (10 samples collected showed significant amounts of SiO2 and Al2O3. Silica content ranges from 51.48 to 62.44 % while alumina varies from 12.49 to 19.00 %. The calcium oxide ranges from 1.17 to 3.39 %, Na2O ranges from 1.1 to 8.61 %, K2O from 1.54 to 3.66 %, MgO varies from 0.04 to0.14 %, Fe2O3 varies from 0.3 to 2.7 % and MnO ranges from 0.01 to 1.03 %. The result showed that the clays are mainly smectite with quartz and felspar as the main non-clay minerals. Generally, the geochemical results of the samples do not meet the standard for industrial utilization when compared to the Industrial specifications. However, for industrial utilization, some of the clay samples may be used after necessary beneficiations.

Improved Geothermometry Through Multivariate Reaction-path Modeling and Evaluation of Geomicrobiological Influences on Geochemical Temperature Indicators: Final Report

Energy Technology Data Exchange (ETDEWEB)

Mattson, Earl [Idaho National Lab. (INL), Idaho Falls, ID (United States); Smith, Robert [Idaho National Lab. (INL), Idaho Falls, ID (United States); Fujita, Yoshiko [Idaho National Lab. (INL), Idaho Falls, ID (United States); McLing, Travis [Idaho National Lab. (INL), Idaho Falls, ID (United States); Neupane, Ghanashyam [Idaho National Lab. (INL), Idaho Falls, ID (United States); Palmer, Carl [Idaho National Lab. (INL), Idaho Falls, ID (United States); Reed, David [Idaho National Lab. (INL), Idaho Falls, ID (United States); Thompson, Vicki [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2015-03-01

The project was aimed at demonstrating that the geothermometric predictions can be improved through the application of multi-element reaction path modeling that accounts for lithologic and tectonic settings, while also accounting for biological influences on geochemical temperature indicators. The limited utilization of chemical signatures by individual traditional geothermometer in the development of reservoir temperature estimates may have been constraining their reliability for evaluation of potential geothermal resources. This project, however, was intended to build a geothermometry tool which can integrate multi-component reaction path modeling with process-optimization capability that can be applied to dilute, low-temperature water samples to consistently predict reservoir temperature within ±30 °C. The project was also intended to evaluate the extent to which microbiological processes can modulate the geochemical signals in some thermal waters and influence the geothermometric predictions.

Geophysical and geochemical techniques for exploration of hydrocarbons and minerals

International Nuclear Information System (INIS)

Sittig, M.

1980-01-01

The detailed descriptive information in this book is based on 389 US patents that deal with geophysical and geochemical techniques useful for the exploration of hydrocarbons and minerals. Where it was necessary to round out the complete technological picture, a few paragraphs from cited government reports have been included. These techniques are used in prospecting for oil, coal, oil shale, tar sand and minerals. The patents are grouped under the following chapters: geochemical prospecting; geobiological prospecting; geophysical exploration; magnetic geophysical prospecting; gravitational geophysical prospecting; electrical geophysical prospecting; nuclear geophysical prospecting; seismic geophysical prospecting; and exploratory well drilling. This book serves a double purpose in that it supplies detailed technical information and can be used as a guide to the US patent literature in this field. By indicating all the information that is significant, and eliminating legal jargon and juristic phraseology, this book presents an advanced, industrially oriented review of modern methods of geophysical and geochemical exploration techniques

Determination of premining geochemical background and delineation of extent of sediment contamination in Blue Creek downstream from Midnite Mine, Stevens County, Washington

Science.gov (United States)

Church, Stan E.; Kirschner, Frederick E.; Choate, LaDonna M.; Lamothe, Paul J.; Budahn, James R.; Brown, Zoe Ann

2008-01-01

Geochemical and radionuclide studies of sediment recovered from eight core sites in the Blue Creek flood plain and Blue Creek delta downstream in Lake Roosevelt provided a stratigraphic geochemical record of the contamination from uranium mining at the Midnite Mine. Sediment recovered from cores in a wetland immediately downstream from the mine site as well as from sediment catchments in Blue Creek and from cores in the delta in Blue Creek cove provided sufficient data to determine the premining geochemical background for the Midnite Mine tributary drainage. These data provide a geochemical background that includes material eroded from the Midnite Mine site prior to mine development. Premining geochemical background for the Blue Creek basin has also been determined using stream-sediment samples from parts of the Blue Creek, Oyachen Creek, and Sand Creek drainage basins not immediately impacted by mining. Sediment geochemistry showed that premining uranium concentrations in the Midnite Mine tributary immediately downstream of the mine site were strongly elevated relative to the crustal abundance of uranium (2.3 ppm). Cesium-137 (137Cs) data and public records of production at the Midnite Mine site provided age control to document timelines in the sediment from the core immediately downstream from the mine site. Mining at the Midnite Mine site on the Spokane Indian Reservation between 1956 and 1981 resulted in production of more than 10 million pounds of U3O8. Contamination of the sediment by uranium during the mining period is documented from the Midnite Mine along a small tributary to the confluence of Blue Creek, in Blue Creek, and into the Blue Creek delta. During the period of active mining (1956?1981), enrichment of base metals in the sediment of Blue Creek delta was elevated by as much as 4 times the concentration of those same metals prior to mining. Cadmium concentrations were elevated by a factor of 10 and uranium by factors of 16 to 55 times premining

Sampling and chemical analysis of groundwaters from the exploratory boreholes

International Nuclear Information System (INIS)

Wittwer, C.

1986-10-01

As a part of the Nagra geological investigation programme in northern Switzerland, numerous water samples were taken in the Boettstein, Weiach, Riniken, Schafisheim, Kaisten and Leuggern boreholes to obtain information on the chemistry and residence times of deep groundwaters. This report contains a compilation of hydrochemical data, comments on the individual water sampling actions and an evaluation of sample quality with respect to admixing of drilling fluids. The samples were taken from separate test intervals in the sediments and the crystalline rock. After removal of various types of drilling fluids such as mud as well as fresh water or deionised water during a cleaning phase, the samples were taken at the surface or at depth using pressure vessels. The tracers added to the drilling fluids (uranine, m-TFMBA) as well as the tritium content were used for a quantiative estimation of the content of drilling fluid in the samples (contamination). With a view fo further geochemical modelling, the samples were assessed with reference to the effect of contamination on the results of the chemical analyses. A total of 68 water samples were taken from 53 different intervals: - 27 samples had problem-free cleaning phases and were taken with negligible contamination. - 23 samples were taken under difficult conditions. Problems with hydraulic communication around packers, uncertain origin, inaccuracy as to extent of contamination, presence of cement, possible traces of salt from drilling fluid etc. meant that the analyses could only be used with extreme caution or after additional data-processing. - The analysis results from 18 samples will be disregarded due to significant drilling fluid content or because more reliable data are available for the same test interval. (author)

Missing citations due to exact reference matching: Analysis of a random sample from WoS. Are publications from peripheral countries disadvantaged?

Energy Technology Data Exchange (ETDEWEB)

Donner, P.

2016-07-01

Citation counts of scientific research contributions are one fundamental data in scientometrics. Accuracy and completeness of citation links are therefore crucial data quality issues (Moed, 2005, Ch. 13). However, despite the known flaws of reference matching algorithms, usually no attempts are made to incorporate uncertainty about citation counts into indicators. This study is a step towards that goal. Particular attention is paid to the question whether publications from countries not using basic Latin script are differently affected by missed citations. The proprietary reference matching procedure of Web of Science (WoS) is based on (near) exact agreement of cited reference data (normalized during processing) to the target papers bibliographical data. Consequently, the procedure has near-optimal precision but incomplete recall - it is known to miss some slightly inaccurate reference links (Olensky, 2015). However, there has been no attempt so far to estimate the rate of missed citations by a principled method for a random sample. For this study a simple random sample of WoS source papers was drawn and it was attempted to find all reference strings of WoS indexed documents that refer to them, in particular inexact matches. The objective is to give a statistical estimate of the proportion of missed citations and to describe the relationship of the number of found citations to the number of missed citations, i.e. the conditional error distribution. The empirical error distribution is statistically analyzed and modelled. (Author)

Re-evaluation and extension of the scope of elements in US Geological Survey Standard Reference Water Samples

Science.gov (United States)

Peart, D.B.; Antweiler, Ronald C.; Taylor, Howard E.; Roth, D.A.; Brinton, T.I.

1998-01-01

More than 100 US Geological Survey (USGS) Standard Reference Water Samples (SRWSs) were analyzed for numerous trace constituents, including Al, As, B, Ba, Be, Bi, Br, Cd, Cr, Co, Cu, I, Fe, Pb, Li, Mn, Mo, Ni, Rb, Sb, Se, Sr, Te, Tl, U, V, Zn and major elements (Ca, Mg, Na, SiO2, SO4, Cl) by inductively coupled plasma mass spectrometry and inductively coupled plasma atomic emission spectrometry. In addition, 15 USGS SRWSs and National Institute of Standards and Technology (NIST) standard reference material (SRM) 1641b were analyzed for mercury using cold vapor atomic fluorescence spectrometry. Also USGS SRWS Hg-7 was analyzed using isotope dilution-inductively coupled plasma mass spectrometry. The results were compared with the reported certified values of the following standard reference materials: NIST SRM 1643a, 1643b, 1643c and 1643d and National Research Council of Canada Riverine Water Reference Materials for Trace Metals SLRS-1, SLRS-2 and SLRS-3. New concentration values for trace and major elements in the SRWSs, traceable to the certified standards, are reported. Additional concentration values are reported for elements that were neither previously published for the SRWSs nor traceable to the certified reference materials. Robust statistical procedures were used that were insensitive to outliers. These data can be used for quality assurance/quality control purposes in analytical laboratories.

Sample summary report for KOR1 pressure tube sample

International Nuclear Information System (INIS)

Lee, Hee Jong; Nam, Min Woo; Choi, Young Ha

2006-01-01

This summary report includes basically the following: - The FLAW CHARACTERIZATION TABLE of KOR1 sample and supporting documentation. - The CROSS REFERENCE TABLES for each investigator, which is the SAMPLE INSPECTION TABLE that cross reference to the FLAW CHARACTERIZATION TABLE. - Each Sample Inspection Report as Appendices

Late Cambrian magmatic arc activity in peri-Gondwana: geochemical evidence from the Basal Allochthonous Units of NW Iberia

Energy Technology Data Exchange (ETDEWEB)

Andonaegui, P.; Abati, J.; Díez-Fernández, R.

2017-07-01

The North African section of the Gondwana margin was the site of voluminous, arc-related magmatism during the Late Neoproterozoic (Avalonian–Cadomian orogen). The lower (and older) metasedimentary sequence that constitutes the Basal Units of the Allochthonous Complexes of NW Iberia was deposited in that setting. In these units, sedimentation was followed by the intrusion of tonalites and granodiorites in the late Cambrian (ca. 493–489Ma). In the Late Paleozoic, the collision of Gondwana and Laurussia (Variscan orogeny) deformed and metamorphosed the whole ensemble. New whole rock geochemical analysis performed in seven samples of metatonalites and fourteen samples of metagranodiorites are characterized by: i) slight enrichment in incompatible elements (Rb, Ba, Th, U), ii) negative anomalies in Nb, Ta, P, and Ti, and iii) negative anomalies in Eu. These chemical features are in agreement with a subduction-related setting for the genesis of both types of magma, which is also supported by chemical discrimination using tectonic setting diagrams. Positive anomalies of Pb suggest a crustal component. The new geochemical data reveal that the convergent orogen that ruled the paleogeography of the Gondwana periphery during the Neoproterozoic (Cadomian orogen) remained active bey.

Landscape and bio- geochemical strategy for monitoring transformation and reclamation of the soil mining sites

Science.gov (United States)

Korobova, Elena

2010-05-01

Sites of active or abandoned mining represent areas of considerable technogenic impact and need scientifically ground organization of their monitoring and reclamation. The strategy of monitoring and reclamation depends on the scale and character of the physical, chemical and biological consequences of the disturbances. The geochemical studies for monitoring and rehabilitation of the career-dump complexes should methodically account of formation of the particular new landforms and the changes in circulation of the remobilized elements of the soil cover. However, the general strategy should account of both the initial and transformed landscape geochemical structure of the area with due regard to the natural and new content of chemical elements in the environmental components. For example the tailings and waste rocks present new geochemical fields with specifically different concentration of chemical elements that cause formation of new geochemical barriers and landscapes. The way of colonization of the newly formed landscapes depends upon the new geochemical features of the technogenic environment and the adaptive ability of local and intrusive flora. The newly formed biogeochemical anomalies need organization of permanent monitoring not only within the anomaly itself but also of its impact zones. Spatial landscape geochemical monitoring combined with bio-geochemical criteria of threshold concentrations seems to be a helpful tool for decision making on reclamation and operation of the soil mining sites to provide a long-term ecologically sustainable development of the impact zone as a whole.

Version 4. 00 of the MINTEQ geochemical code

Energy Technology Data Exchange (ETDEWEB)

Eary, L.E.; Jenne, E.A.

1992-09-01

The MINTEQ code is a thermodynamic model that can be used to calculate solution equilibria for geochemical applications. Included in the MINTEQ code are formulations for ionic speciation, ion exchange, adsorption, solubility, redox, gas-phase equilibria, and the dissolution of finite amounts of specified solids. Since the initial development of the MINTEQ geochemical code, a number of undocumented versions of the source code and data files have come into use at the Pacific Northwest Laboratory (PNL). This report documents these changes, describes source code modifications made for the Aquifer Thermal Energy Storage (ATES) program, and provides comprehensive listings of the data files. A version number of 4.00 has been assigned to the MINTEQ source code and the individual data files described in this report.

Version 4.00 of the MINTEQ geochemical code

Energy Technology Data Exchange (ETDEWEB)

Eary, L.E.; Jenne, E.A.

1992-09-01

The MINTEQ code is a thermodynamic model that can be used to calculate solution equilibria for geochemical applications. Included in the MINTEQ code are formulations for ionic speciation, ion exchange, adsorption, solubility, redox, gas-phase equilibria, and the dissolution of finite amounts of specified solids. Since the initial development of the MINTEQ geochemical code, a number of undocumented versions of the source code and data files have come into use at the Pacific Northwest Laboratory (PNL). This report documents these changes, describes source code modifications made for the Aquifer Thermal Energy Storage (ATES) program, and provides comprehensive listings of the data files. A version number of 4.00 has been assigned to the MINTEQ source code and the individual data files described in this report.

Surface geochemical data evaluation and integration with geophysical observations for hydrocarbon prospecting, Tapti graben, Deccan Syneclise, India

OpenAIRE

Satish Kumar, T.; Dayal, A.M.; Sudarshan, V.

2014-01-01

The Deccan Syneclise is considered to have significant hydrocarbon potential. However, significant hydrocarbon discoveries, particularly for Mesozoic sequences, have not been established through conventional exploration due to the thick basalt cover over Mesozoic sedimentary rocks. In this study, near-surface geochemical data are used to understand the petroleum system and also investigate type of source for hydrocarbons generation of the study area. Soil samples were collected from favorable...

Geochemical processes controlling water salinization in an irrigated basin in Spain: Identification of natural and anthropogenic influence

Energy Technology Data Exchange (ETDEWEB)

Merchán, D., E-mail: d.merchan@igme.es [Geological Survey of Spain — IGME, C/Manuel Lasala 44 9B, 50006 Zaragoza (Spain); Auqué, L.F.; Acero, P.; Gimeno, M.J. [University of Zaragoza — Department of Earth Sciences (Geochemical Modelling Group), C/Pedro Cerbuna 12, 50009 Zaragoza (Spain); Causapé, J. [Geological Survey of Spain — IGME, C/Manuel Lasala 44 9B, 50006 Zaragoza (Spain)

2015-01-01

Salinization of water bodies represents a significant risk in water systems. The salinization of waters in a small irrigated hydrological basin is studied herein through an integrated hydrogeochemical study including multivariate statistical analyses and geochemical modeling. The study zone has two well differentiated geologic materials: (i) Quaternary sediments of low salinity and high permeability and (ii) Tertiary sediments of high salinity and very low permeability. In this work, soil samples were collected and leaching experiments conducted on them in the laboratory. In addition, water samples were collected from precipitation, irrigation, groundwater, spring and surface waters. The waters show an increase in salinity from precipitation and irrigation water to ground- and, finally, surface water. The enrichment in salinity is related to the dissolution of soluble mineral present mainly in the Tertiary materials. Cation exchange, precipitation of calcite and, probably, incongruent dissolution of dolomite, have been inferred from the hydrochemical data set. Multivariate statistical analysis provided information about the structure of the data, differentiating the group of surface waters from the groundwaters and the salinization from the nitrate pollution processes. The available information was included in geochemical models in which hypothesis of consistency and thermodynamic feasibility were checked. The assessment of the collected information pointed to a natural control on salinization processes in the Lerma Basin with minimal influence of anthropogenic factors. - Highlights: • Salinization in Lerma Basin was controlled by the dissolution of soluble salts. • Water salinization and nitrate pollution were found to be independent processes. • High NO{sub 3}, fresh groundwater evolved to lower NO{sub 3}, higher salinity surface water. • Inverse and direct geochemical modeling confirmed the hypotheses. • Salinization was a natural ongoing process

National Geochemical Survey Locations and Results for Iowa

Data.gov (United States)

Iowa State University GIS Support and Research Facility — The United States Geological Survey (USGS), in collaboration with other state and federal agencies, industry, and academia, is conducting a National Geochemical...

[Reference citation].

Science.gov (United States)

Brkić, Silvija

2013-01-01

Scientific and professional papers represent the information basis for scientific research and professional work. References important for the paper should be cited within the text, and listed at the end of the paper. This paper deals with different styles of reference citation. Special emphasis was placed on the Vancouver Style for reference citation in biomedical journals established by the International Committee of Medical Journal Editors. It includes original samples for citing various types of articles, both printed and electronic, as well as recommendations related to reference citation in accordance with the methodology and ethics of scientific research and guidelines for preparing manuscripts for publication.

Calibrating NIST SRM 683 as A New International Reference Standard for Zn Isotopes

Science.gov (United States)

Yang, Y.; Zhang, X.; Yu, H.; Huang, F.

2017-12-01

Zinc isotopes have been widely applied in the cosmochemical, geochemical, and environmental studies (Moynier et al. 2017). Obtaining precise Zn isotopic data for inter-laboratory comparison is a prerequisite to these applications. Currently, the JMC3-0749L is the primary reference standard for Zn isotopes (Albarède 2004), but it is not commercially available now. Thus, it is necessary to calibrate a new international primary reference standard for Zn isotopic analysis. Chen et al. (2016) showed that NIST SRM 683 (a pure Zn metal nugget of 140 grams) has a δ66ZnJMC of 0.12‰, which is falling within the range of natural Zn isotopic compositions, and it may a good candidate for the next generation of international reference standard (Chen et al. 2016). In order to further examine whether NIST SRM 683 has a homogeneous Zn isotopic composition, we measured more NIST SRM 683 by double-spike methods using MC-ICPMS (Conway et al. 2013). The metal nuggets of NIST SRM 683 were intensively sampled by micro-drilling. Zinc isotope analyses for two nuggets show that they have δ66Zn of 0.14 ± 0.02‰ (2SD, N = 32) and 0.13 ± 0.02‰ (2SD, N = 33), respectively. These values are similar to those of two Zn metal nuggets (0.11 ± 0.02‰ vs. 0.12 ± 0.02‰) reported previously by Chen et al. (2016). We fully dissolved one nugget, producing pure Zn solution with identical Zn isotopic composition with the drilling samples. All results strongly support that NIST SRM 683 is homogeneous in Zn isotopic compositions which could be an ideal candidate for the next reference for Zn isotopes. Tests on more metal nuggets will be performed in a few months for further confirming the Zn isotope compositions and homogeneity. Reference: Albarède et al., 2004. 'The stable isotope geochemistry of copper and zinc', Reviews in Mineralogy and Geochemistry, 55: 409-27. Chen et al., 2016. 'Zinc Isotopic Compositions of NIST SRM 683 and Whole-Rock Reference Materials', Geostandards and

A review of single-sample-based models and other approaches for radiocarbon dating of dissolved inorganic carbon in groundwater

Science.gov (United States)

Han, L. F; Plummer, Niel

2016-01-01

Numerous methods have been proposed to estimate the pre-nuclear-detonation 14C content of dissolved inorganic carbon (DIC) recharged to groundwater that has been corrected/adjusted for geochemical processes in the absence of radioactive decay (14C0) - a quantity that is essential for estimation of radiocarbon age of DIC in groundwater. The models/approaches most commonly used are grouped as follows: (1) single-sample-based models, (2) a statistical approach based on the observed (curved) relationship between 14C and δ13C data for the aquifer, and (3) the geochemical mass-balance approach that constructs adjustment models accounting for all the geochemical reactions known to occur along a groundwater flow path. This review discusses first the geochemical processes behind each of the single-sample-based models, followed by discussions of the statistical approach and the geochemical mass-balance approach. Finally, the applications, advantages and limitations of the three groups of models/approaches are discussed.The single-sample-based models constitute the prevailing use of 14C data in hydrogeology and hydrological studies. This is in part because the models are applied to an individual water sample to estimate the 14C age, therefore the measurement data are easily available. These models have been shown to provide realistic radiocarbon ages in many studies. However, they usually are limited to simple carbonate aquifers and selection of model may have significant effects on 14C0 often resulting in a wide range of estimates of 14C ages.Of the single-sample-based models, four are recommended for the estimation of 14C0 of DIC in groundwater: Pearson's model, (Ingerson and Pearson, 1964; Pearson and White, 1967), Han & Plummer's model (Han and Plummer, 2013), the IAEA model (Gonfiantini, 1972; Salem et al., 1980), and Oeschger's model (Geyh, 2000). These four models include all processes considered in single-sample-based models, and can be used in different ranges of

Development of geophysical and geochemical data processing software based on component GIS

International Nuclear Information System (INIS)

Ke Dan; Yu Xiang; Wu Qubo; Han Shaoyang; Li Xi

2013-01-01

Based on component GIS and mixed programming techniques, a software which combines the basic GIS functions, conventional and unconventional data process methods for the regional geophysical and geochemical data together, is designed and developed. The software has many advantages, such as friendly interface, easy to use and utility functions and provides a useful platform for regional geophysical and geochemical data processing. (authors)

Geochemical prospect ion results of Mariscala aerial photo

International Nuclear Information System (INIS)

Filippini, J.

1989-01-01

This report shows the geochemical prospect ion results carried out within the framework of the metalical mining prospect ion in Mariscala aerial photo. Lavalleja district belong to the Mining inventory programme of Uruguay.

Geochemical methodology for gold prospect ion in Uruguay

International Nuclear Information System (INIS)

Spangenber, J.

1987-01-01

This work is about the history of gold prospection in Uruguay. In this study there are considered the geochemical aspects, the gold performance, the applicability to mining prospection and the gold prospection aluvionar

Novel geochemical techniques integrated in exploration for uranium deposits at depth

International Nuclear Information System (INIS)

Kyser, K.

2014-01-01

Mineral deposits are in fact geochemical anomalies, and as such their detection and assessment of their impact on the environment should be facilitated using geochemical techniques. Although geochemistry has been used directly in the discovery of uranium deposits and more indirectly in shaping deposit models, the novel applications of geochemistry and integration with other data can be more effective in formulating exploration and remediation strategies. Recent research on the use of geochemistry in detecting uranium deposits at depth include: (1) more effective integration of geochemical with geophysical data to refine targets, (2) revealing element distributions in and around deposits to adequately assess the total chemical environment associated with the deposit, (3) the use of element tracing using elemental concentrations and isotopic compositions in the near surface environment to detect specific components that have migrated to the surface from uranium deposits at depth, (4) understand the effects of both macro- and micro-environments on element mobility across the geosphere-biosphere interface to enhance exploration using select media for uranium at depth. Geophysical data used in exploration can identify areas of conductors where redox contrasts may host mineralization, structures that act to focus fluids during formation of the deposits and act as conduits for element migration to the surface, and contrasts in geology that are required for the deposits. However, precision of these data is greatly diminished with depth, but geochemical data from drill core or surface media can enhance target identification when integrated with geophysical data. Geochemical orientation surveys over known unconformity-related deposits at depth clearly identify mineralization 900m deep. Drill core near the deposit, clay-size fractions separated from soil horizons and vegetation over and far from the deposit record element migration from the deposit as radiogenic He, Rn and Pb

Geological and Geochemical Criteria for the Estimation of the Area of The Lesser Hinggan for the Endogenous Gold Mineralization (The Far East, Russia)

Science.gov (United States)

Yurchenko, Yuriy

2015-04-01

The Area of the Lesser Hinggan in the middle of the XIX century has been known as one of the Gold areas of the Far East. Exploration of gold in different years were engaged by P.K. Yavorovskiy (1904), E.E. Anert (1928), G.V. Itsikson (1961), V.A. Buryak (1999, 2002, 2003), A.M. Zhirnov (1998, 2000, 2008), L.V. Eyrish (1960, 1964, 1995, 1999, 2002, 2008) and many others. But despite the abundance of factual materials in the problem of the gold metallogeny of the Lesser Hinggan are more aspects that still have not received a answer. Among them is the key issue about indigenous sources of the gold. First for the Lesser Hinggan area, structural-geochemical zoning at 1:200 000 scale was carried out based on the results of the precise analyses of over 2,600 soil and sediment stream samples. Three anomalous geochemical zones and nine anomalous geochemical clusters in their contours specialized for gold mineralization were revealed. Regional clarkes (fersms) for 19 chemical elements were calculated. Geological formations geochemically specialized for gold and their role in endogenous ore-forming processes were defined. Geochemical criteria for endogenous gold mineralization and its ore-formational affiliation were defined as well. Thus, from the geological and geochemical data, are the following signs of the gold mineralization of the Lesser Hinggan: 1. Some geological formations are geochemical specialized by the gold (carbon ("black") schists and ferruginous quartzite Vendian-Cambrian Hinggan series). They're considered as a source of the gold, involved in younger epigenetic processes of mobilization and redistribution of this element; 2. Contrasting geochemical anomalies of the gold and elements satellites in the secondary halos and stream sediments displayed in the contours of the geological formations of a wide age range - terrigenous-carbonate rocks of the Hinggan series, the Paleozoic granitoid massives, the Cretaceous volcanic fields ; 3. Samples of the native gold

Geochemical correlations between uranium and other components in U-bearing formations of Ogcheon belt

International Nuclear Information System (INIS)

Lee, M.S.; Chon, H.T.

1980-01-01

Some components in uranium-bearing formations which consist mainly of black shale, slate and low grade coal-bearing formation of Ogcheon Belt were processed statistically in order to find out the geochemical correlations with uranium. Geochemical enrichment of uranium, vanadium and molybdenum in low grade coal-bearing formations and surrounding rocks is remarkable in the studied area. Geochemical correlation coefficient of uranium and molybdenum in the rocks displays about 0.6 and that of uranium and fixed carbon about 0.4. Uranium and vanadium in uranium-bearing low grade coals denote very high correlation with fixed carbon, which is considered to be responsible for enrichment of metallic elements, especially molybdenum. Close geochemical correlation of uranium-molybdenum couple in the rocks can be applied as a competent exploration guide to low grade uranium deposits of this area. (author)

Role of soil geochemical and microbiological components on selenium behaviour in oxic and anoxic conditions

International Nuclear Information System (INIS)

Darcheville, O.

2008-09-01

Selenium (Se) is naturally present in the environment. Se is essential for living organisms at trace concentrations, but it becomes rapidly toxic with their increases. The 79 Se radioactive isotopes of Se, is found in nuclear wastes that may be buried in deep geological formations. In soil, Se exists in many forms and its mobility is affected by the redox potential and microbial activity. Very few studies have focused on Se behaviour at trace concentration. We have tried to distinguish the major abiotic geochemical and microbiological processes involved in the fate of trace selenite (Se(IV)) in a soil. The study was based on batch incubation in oxic or anoxic conditions of slurry suspension artificially contaminated with Se (IV) to 0.4 mg Se.kg -1 dry soil. The incubation involved sterilized and non-sterile soil samples with or without organic amendment to stimulate microbial activities. For each incubation, we followed the distribution of Se between solid, liquid and gaseous phases as well as the geochemical evolution of the solution, the composition of the atmosphere gas bottles and the soil microflora. The results showed that Se was relatively few mobile in the soil studied. Geochemical processes played a major role in controlling the Se mobility. Over time, some abiotic transformations in the solid phase contributed to increase the Se immobilisation. The microbiological processes contributed to this increase in the solid phase. Moreover, in oxic as in anoxic conditions, some microbial processes were responsible, to a lesser extent, for a dispersion of Se in the atmosphere by the production of volatile compounds. (author)

Geochemical interpretation of Kings Mountain, North Carolina, orientation area

International Nuclear Information System (INIS)

Price, V.; Ferguson, R.B.

1977-01-01

An orientation study has been made of uranium occurrences in the area of Kings Mountain, North Carolina. This is one of the orientation studies of known uranium occurrences that are being conducted in several geologic provinces and under various climatic (weathering) conditions to provide the technical basis for design and interpretation of NURE geochemical reconnaissance programs. The Kings Mountain area was chosen for study primarily because of the reported presence of high-uranium monazite. This 750-mi 2 area is in the deeply weathered southern Appalachian Piedmont and spans portions of the Inner Piedmont, Kings Mountain, and Charlotte geologic belts. Uranium concentration maps for ground and surface water samples clearly outline the outcrop area of the Cherryville Quartz Monzonite with highs up to 10 ppb uranium near the reported uraninite. Several surface water samples appear to be anomalous because of trace industrial contamination. Uranium concentration maps for -100 to +200 mesh stream sediments indicate the area of monazite abundance. Several samples with >100 ppM uranium content appear to be high in uranium-rich resistate minerals. When the uranium content of sediment samples is ratioed to the sum of Hf, Dy, and Th, the anomaly pattern shifts to coincide with uranium highs in ground and surface water samples. False anomalies from concentrations of monazite (Ce,ThPO 4 ), xenotime (Y,DyPO 4 ), and zircon (Zr,HfSiO 4 ) in stream sediment samples can thus be eliminated. Residual anomalies should be related to unusual uranium enrichment of these common minerals or to the presence of an uncommon uranium-rich mineral. Tantalum, beryllium, and tin in stream sediments correspond to high concentrations of uranium in stream and ground water but not to uranium in sediments. In an initial reconnaissance, several media should be sampled, and it is essential to correct uranium in sediments for the sample mineralogy

Evaluation and prediction of oil biodegradation: a novel approach integrating geochemical and basin modeling techniques in offshore Brazil

Energy Technology Data Exchange (ETDEWEB)

Baudino, Roger [YPF S.A. (Argentina); Santos, Glauce Figueiredo dos; Losilla, Carlos; Cabrera, Ricardo; Loncarich, Ariel; Gavarrino, Alejandro [RepsolYPF do Brasil, Sao Paulo, SP (Brazil)

2008-07-01

Oil fields accounting for a large portion of the world reserves are severely affected by biological degradation. In Brazil, giant fields of the Campos Basin are producing biodegraded oils with widely variable fluid characteristics (10 to 40 deg API) and no apparent logical distribution nor predictability. Modern geochemical techniques allow defining the level of biodegradation. When original (non-degraded) oil samples and other with varying degradation level are available it might be possible to define a distribution trend and to relate it to present day geological factors such as temperature and reservoir geometry. However, other critical factors must be taken into account. But most of all, it is fundamental to have a vision in time of their evolution. This can only be achieved through 3D Basin Models coupled with modern visualization tools. The multi-disciplinary work-flow described here integrates three-dimensional numerical simulations with modern geochemical analyses. (author)

Reference Materials for Trace Element Microanalysis of Carbonates by SIMS and other Mass Spectrometric Techniques

Science.gov (United States)

Layne, G. D.

2009-12-01

Today, many areas of geochemical research utilize microanalytical determinations of trace elements in carbonate minerals. In particular, there has been an explosion in the application of Secondary Ion Mass Spectrometry (SIMS) to studies of marine biomineralization. SIMS provides highly precise determinations of Mg and Sr at the concentration levels normally encountered in corals, mollusks or fish otoliths. It is also a highly effective means for determining a wide range of other trace elements at ppm levels (e.g., Na, Fe, Mn, Ba, REE, Pb, Th, and U) in a variety of naturally occurring calcite and aragonite matrices - and so is potentially valuable in studies of diagenesis, hydrothermal fluids and carbonatitic magmas. For SIMS, modest time per spot (often sputtered ion yields of most elements with the major element composition of the sample matrix, accuracy of SIMS depends intimately on matrix-matched solid reference materials. Despite its rapidly increasing use for trace element analyses of carbonates, there remains a dearth of certified reference materials suitable for calibrating SIMS. The pressed powders used by some analysts to calibrate LA-ICP-MS do not perform well for SIMS - they are not perfectly dense or homogeneous to the desired level at the micron scale of sampling. Further, they often prove incompatible with the sample high vacuum compatibility requirement for stable SIMS analysis (10-8 to 10-9 torr). Some naturally occurring calcite has apparent utility as a reference material. For example, equigranular calcite from some zones of carbonatite intrusions (sovites) and recrystallized calcites from highly metamorphosed metallic ore deposits. Most calcite marbles, though possibly appropriate as Sr standards, show substantial inhomogeneity in Mg, Mn and Ba. Some hydrothermal “Iceland Spar” calcite may prove useful as a reference for extremely low concentrations of Mg, Sr and Ba. The best carbonatitic calcites currently in use appear homogeneous to

Evaluation of disposal site geochemical performance using a containment factor

International Nuclear Information System (INIS)

Lerman, A.; Domenico, P.A.; Bartlett, J.W.

1988-01-01

The containment factor is a measure of retention by geologic setting of wastes released from a repository. The factor is alternatively defined either in terms of several measurable hydrological and geochemical parameters, or in terms of amounts of waste components that may be released to the geologic setting and, subsequently, to the environment. Containment factors for individual waste components in a given geologic setting are functions of groundwater to rock volume ratios, sorption or exchange characteristics of the rocks, and containment time to groundwater travel time ratios. For high-level radioactive wastes, containment factors based on the NRC and EPA limit values for cumulative releases from waste and to the environment provide a measure of the geochemical performance of the geologic setting in tuff, basalt, and salt. The containment factor values for individual nuclides from high-level wastes indicate that for some of the nuclides containment may be achieved by groundwater travel time along. For other nuclides, additional performance functions need to be allocated to geochemical retention by such processes as sorption, ion-exchange or precipitation

Experiments on geochemical prospecting for uranium in arid country; Essais de prospection geochimique de l'uranium en pays aride

Energy Technology Data Exchange (ETDEWEB)

Grimbert, A; Obellianne, J M [Commissariat a l' Energie Atomique, Centre d' Etudes Nucleaires de Fontenay-aux-Roses, 92 (France)

1962-07-01

The necessity for preliminary inquiries before applying routine geochemical prospecting techniques to the exploration of a new region is shown. Under conditions presumed to be unfavorable for geochemical prospecting as found in Nigeria along the banks of the Air, a preliminary examination showed that sampling of the stabilized superficial deposits at a depth of 15 cm made it possible to detect the presence of U-containing mineralizations hidden under about 20 meters of sterile sandy deposits. To confirm this result, a boring located on a U-containing geochemical anomaly in a paleosol, encountered a mineralized formation at a depth of 28 meters. (authors) [French] Les auteurs montrent la necessite des enquetes preliminaires avant toute application en routine des techniques geochimiques de prospection, lorsque l'on aborde une region nouvelle. Dans les conditions, a priori defavorables pour la prospection geochimique, que l'on trouve au Niger, en bordure de l'Air, une enquete preliminaire a etabli que l'echantillonnage des depots superficiels stabilises, a 15 centimetres de profondeur, permettait de deceler la presence de mineralisations uraniferes cachees sous une vingtaine de metres de sediments greseux steriles. Pour verifier ce resultat, un sondage implante sur une anomalie geochimique uranifere au sein d'un paleosol, a rencontre une formation mineralisee a 28 metres de profondeur. (auteurs)

Environmental and geochemical assessment of surface sediments on irshansk ilmenite deposit area

Directory of Open Access Journals (Sweden)

Наталия Олеговна Крюченко

2015-03-01

Full Text Available It is revealed the problem of pollution of surface sediments of Irshansk ilmenite deposit area of various chemical elements hazard class (Mn, V, Ba, Ni, Co, Cr, Mo, Cu, Pb, Zn. It is determined its average content in surface sediments of various functional areas (forest and agricultural land, flood deposits, reclaimed land, calculated geochemical criteria, so given ecological and geochemical assessment of area

[Errors in Peruvian medical journals references].

Science.gov (United States)

Huamaní, Charles; Pacheco-Romero, José

2009-01-01

References are fundamental in our studies; an adequate selection is asimportant as an adequate description. To determine the number of errors in a sample of references found in Peruvian medical journals. We reviewed 515 scientific papers references selected by systematic randomized sampling and corroborated reference information with the original document or its citation in Pubmed, LILACS or SciELO-Peru. We found errors in 47,6% (245) of the references, identifying 372 types of errors; the most frequent were errors in presentation style (120), authorship (100) and title (100), mainly due to spelling mistakes (91). References error percentage was high, varied and multiple. We suggest systematic revision of references in the editorial process as well as to extend the discussion on this theme. references, periodicals, research, bibliometrics.

Analysis of cement solidified product and ash samples and preparation of a reference material

International Nuclear Information System (INIS)

Ishimori, Ken-ichiro; Haraga, Tomoko; Shimada, Asako; Kameo, Yutaka; Takahashi, Kuniaki

2010-08-01

Simple and rapid analytical methods for radionuclides in low-level radioactive waste have been developed by the present authors. The methods were applied to simulated solidified products and actual metal wastes to confirm their usefulness. The results were summarized as analytical guide lines. In the present work, cement solidified product and ash waste were analyzed followed by the analytical guide lines and subjects were picked up and solved for the application of the analytical guide lines to these wastes. Pulverization and homogenization method for ash waste was improved to prevent a contamination since the radioactivity concentrations of the ash samples were relatively high. Pre-treatment method was altered for the cement solidified product and ash samples taking account for their high concentration of Ca. Newly, an analytical method was also developed to measure 129 I with a dynamic reaction cell inductively coupled plasma mass spectrometer. In the analytical test based on the improved guide lines, gamma-ray emitting nuclides, 60 Co and 137 Cs, were measured to estimate the radioactivity of the other alpha and beta-ray emitting nuclides. The radionuclides assumed detectable, 3 H, 14 C, 36 Cl, 63 Ni, 90 Sr, and alpha-ray emitting nuclides, were analyzed with the improved analytical guide lines and their applicability for cement solidified product and ash samples were confirmed. Additionally a cement solidified product sample was evaluated in terms of the homogeneity and the radioactivity concentrations in order to prepare a reference material for radiochemical analysis. (author)

[Geochemical characteristics of radon and mercury in soil gas in Lhasa, Tibet, China].

Science.gov (United States)

Zhou, Xiao-Cheng; Du, Jian-Guo; Wang, Chuan-Yuan; Cao, Zhong-Quan; Yi, Li; Liu, Lei

2007-03-01

The geochemical characteristics of radon and mercury in soil gas in Lhasa and vicinity are investigated based on the measurements of Rn and Hg concentrations, and environmental quality for Rn and Hg in soil gas was evaluated by means of the index of geoaccumulation. The data of Rn and Hg of 1 579 sampling site indicate that the values of environmental-geochemical background of Rn and Hg are 7 634.9 Bq/m3, 41.5 ng/m3 with standard deviations of 2.7 Bq/m3, 2.2 ng/m3, respectively. The environmental quality for Rn in soil gas is better in the west and east parts of studied area, but becomes moderate pollution (level III) in the north part of the central area. Rn is derived from radioactive elements in granitic sediments in the intermountain basin and granite base, which are the major sources of pollution. The environmental quality for Hg in soil gas becomes gradually polluted from the suburban to the center of urban, and the highest pollution reaches level IV. The background of Hg in soil gas is mainly controlled by compositions of sediments, but the Hg pollution caused by human waste and religionary use of mercury.

Organic geochemical characterization of potential hydrocarbon source rocks in the upper Benue Trough

International Nuclear Information System (INIS)

Obaje, N. G.; Pearson, M. J.; Suh, C. E.; Dada, S. S.

1999-01-01

The Upper Benue Trough of Nigeria is the northeastern most portion of the Benue rift structure that extends from the northern limit of the Niger Delta in the south to the southern limit of the Chad basin int he northeast. this portion of the trough is made up of two arms: the Gongola Arm and the Yola Arm. Stratigraphic sequence in the Gongola Arm comprises the continental Albian Bima Sandstone, the transitional Cenomanian Yolde Formation and the marine Turonian - Santonian Gongila, Pindiga, and Fika Formations. Overlying these are the continental Campane - Maastrichtian Gombe Sandstone and the Tertiary Kerri - Kerri Formation. In the Yola Arm, the Turonian - Santonian sequence is replaced by the equally marine Dukul, Jessu, Sekuliye Formations, Numanha Shale, and the Lamja Sandstone. Organic geochemical studies have been carried on outcrop sample form the Gongila, Pindiga, Dukul Formations, the Fika shale and the shaly units of the Gombe Sandstone, with the aim of assessing their source rock potential. Gas Chromatography (GC), Gas Chromatography - Mass Spectrometry (C - MS), and Rock Eval Pyrolysis were the major organic geochemical tools employed. Biomaker hydrocarbon signatures obtained from the GC - MS and the Rock Eval Pyrolysis results indicate that all he formations studied, except the Dukul formation, are immature and are all lean in organic matter

Geochemical surface exploration between Bueckeberge Hills and Rehburg Anticline (Lower Saxony Basin, Germany)

Energy Technology Data Exchange (ETDEWEB)

Berner, U. [Bundesanstalt fuer Geowissenschaften und Rohstoffe, Hannover (Germany); Marquardt, D. [Rijksuniversiteit Utrecht (Netherlands)

2013-01-15

The Lower Saxony Basin (LSB) of northwestern Germany is since long a target in hydrocarbon-related research in which the organic-rich Wealden sediments, known to contain good to excellent source rocks, play an important role. We demonstrate that cost effective surface exploration and geochemical research provide significant insight into the petroleum geology of an area of interest. Our research concentrates on a sub-basin in the eastern part of the LSB and aims at assessing the petroleum geology, hydrocarbon potential, depositional environment and tectonics of the Stadthagen syncline using surface samples of Wealden outcrops and evaluating these subsequently with geochemical methods (XRF, total sulfur, total organic carbon, Rock-Eval pyrolysis) and physical property data. The depositional environment in the research area varied significantly throughout the Lower Cretaceous (oxic to anoxic) due to paleoclimate changes and tectonically induced marine ingressions. Microbial sulfate reduction related to the marine ingressions reduced organic matter quality in the basin significantly, supporting the strong vertical variability in hydrocarbon potential of the sediments. Thermal maturity data suggests a complex tectonic history for the Stadthagen syncline. Thermal maturities (oil to wet gas window) combined with a multi-heat flow scenario result in estimated burial and subsequent uplift in the region of more than 2500 m. (orig.)

Geochemical modeling of the nuclear-waste repository system. A status report

International Nuclear Information System (INIS)

Deutsch, W.J.

1980-12-01

The primary objective of the geochemical modeling task is to develop an understanding of the waste-repository geochemical system and provide a valuable tool for estimating future states of that system. There currently exists a variety of computer codes which can be used in geochemical modeling studies. Some available codes contain the framework for simulating a natural chemical system and estimating, within limits, the response of that system to environmental changes. By data-base enhancement and code development, this modeling technique can be even more usefully applied to a nuclear-waste repository. In particular, thermodynamic data on elements not presently in the data base but identified as being of particular hazard in the waste-repository system, need to be incorporated into the code to estimate the near-field as well as the far-field reactions during a hypothetical breach. A reaction-path-simulation code, which estimates the products of specific rock/water reactions, has been tested using basalt and ground water. Results show that the mass-transfer capabilities of the code will be useful in chemical-evolution studies and scenario analyses. The purpose of this report is to explain the status of geochemical modeling as it currently applies to the chemical system of a hypothetical nuclear-waste repository in basalt and to present the plan proposed for further developmet and application

Geothermal investigations with isotope and geochemical techniques in Latin America

International Nuclear Information System (INIS)

1992-03-01

The IAEA Co-ordinated Research Programme (CRP) for Latin America on the Use of Isotope and Geochemical Techniques in Geothermal Exploration started in 1984. The first activity carried out was a Seminar on isotope and geochemical techniques in geothermal exploration, which took place in June 1984 in Morelia, Mexico. During the seminar, which was attended by representatives of the institutions which later took part in the programme, the objectives, main research lines, and geothermal fields to be studied during the CRP were discussed. The first research contracts were awarded towards the end of 1984. The field work started in 1985 and continued through 1990. During the implementation of the CRP a considerable number of geothermal fields were studied in the nine participating countries. The investigations carried out were geochemically quite comprehensive in most cases, but in some others they were still in a reconnaissance stage when the CRP ended: the latter studies are not reported in these proceedings, but the data obtained are in principle available from the relevant national institutions. While investigations with conventional geochemical techniques had already started in several fields before 1985, isotope methods were applied for the first time in all cases during this CRP. Due to the remoteness and high elevation of many of the fields studied and the adverse meteorological conditions during long periods of the year, the investigations could not proceed rapidly: this is the main reason for the unusually long duration of the CRP, which could be concluded only after more than five years after its inception

Use of natural geochemical tracers to improve reservoir simulation models

Energy Technology Data Exchange (ETDEWEB)

Huseby, O.; Chatzichristos, C.; Sagen, J.; Muller, J.; Kleven, R.; Bennett, B.; Larter, S.; Stubos, A.K.; Adler, P.M.

2005-01-01

This article introduces a methodology for integrating geochemical data in reservoir simulations to improve hydrocarbon reservoir models. The method exploits routine measurements of naturally existing inorganic ion concentration in hydrocarbon reservoir production wells, and uses the ions as non-partitioning water tracers. The methodology is demonstrated on a North Sea field case, using the field's reservoir model, together with geochemical information (SO{sub 4}{sup 2}, Mg{sup 2+} K{sup +}, Ba{sup 2+}, Sr{sup 2+}, Ca{sup 2+}, Cl{sup -} concentrations) from the field's producers. From the data-set we show that some of the ions behave almost as ideal sea-water tracers, i.e. without sorption to the matrix, ion-exchange with the matrix or scale-formation with other ions in the formation water. Moreover, the dataset shows that ion concentrations in pure formation-water vary according to formation. This information can be used to allocate produced water to specific water-producing zones in commingled production. Based on an evaluation of the applicability of the available data, one inorganic component, SO{sub 4}{sup 2}, is used as a natural seawater tracer. Introducing SO{sub 4}{sup 2} as a natural tracer in a tracer simulation has revealed a potential for improvements of the reservoir model. By tracking the injected seawater it was possible to identify underestimated fault lengths in the reservoir model. The demonstration confirms that geochemical data are valuable additional information for reservoir characterization, and shows that integration of geochemical data into reservoir simulation procedures can improve reservoir simulation models. (author)

Certified reference materials and reference methods for nuclear safeguards and security.

Science.gov (United States)

Jakopič, R; Sturm, M; Kraiem, M; Richter, S; Aregbe, Y

2013-11-01

Confidence in comparability and reliability of measurement results in nuclear material and environmental sample analysis are established via certified reference materials (CRMs), reference measurements, and inter-laboratory comparisons (ILCs). Increased needs for quality control tools in proliferation resistance, environmental sample analysis, development of measurement capabilities over the years and progress in modern analytical techniques are the main reasons for the development of new reference materials and reference methods for nuclear safeguards and security. The Institute for Reference Materials and Measurements (IRMM) prepares and certifices large quantities of the so-called "large-sized dried" (LSD) spikes for accurate measurement of the uranium and plutonium content in dissolved nuclear fuel solutions by isotope dilution mass spectrometry (IDMS) and also develops particle reference materials applied for the detection of nuclear signatures in environmental samples. IRMM is currently replacing some of its exhausted stocks of CRMs with new ones whose specifications are up-to-date and tailored for the demands of modern analytical techniques. Some of the existing materials will be re-measured to improve the uncertainties associated with their certified values, and to enable laboratories to reduce their combined measurement uncertainty. Safeguards involve the quantitative verification by independent measurements so that no nuclear material is diverted from its intended peaceful use. Safeguards authorities pay particular attention to plutonium and the uranium isotope (235)U, indicating the so-called 'enrichment', in nuclear material and in environmental samples. In addition to the verification of the major ratios, n((235)U)/n((238)U) and n((240)Pu)/n((239)Pu), the minor ratios of the less abundant uranium and plutonium isotopes contain valuable information about the origin and the 'history' of material used for commercial or possibly clandestine purposes, and

CLSI-based transference of the CALIPER database of pediatric reference intervals from Abbott to Beckman, Ortho, Roche and Siemens Clinical Chemistry Assays: direct validation using reference samples from the CALIPER cohort.

Science.gov (United States)

Estey, Mathew P; Cohen, Ashley H; Colantonio, David A; Chan, Man Khun; Marvasti, Tina Binesh; Randell, Edward; Delvin, Edgard; Cousineau, Jocelyne; Grey, Vijaylaxmi; Greenway, Donald; Meng, Qing H; Jung, Benjamin; Bhuiyan, Jalaluddin; Seccombe, David; Adeli, Khosrow

2013-09-01

The CALIPER program recently established a comprehensive database of age- and sex-stratified pediatric reference intervals for 40 biochemical markers. However, this database was only directly applicable for Abbott ARCHITECT assays. We therefore sought to expand the scope of this database to biochemical assays from other major manufacturers, allowing for a much wider application of the CALIPER database. Based on CLSI C28-A3 and EP9-A2 guidelines, CALIPER reference intervals were transferred (using specific statistical criteria) to assays performed on four other commonly used clinical chemistry platforms including Beckman Coulter DxC800, Ortho Vitros 5600, Roche Cobas 6000, and Siemens Vista 1500. The resulting reference intervals were subjected to a thorough validation using 100 reference specimens (healthy community children and adolescents) from the CALIPER bio-bank, and all testing centers participated in an external quality assessment (EQA) evaluation. In general, the transferred pediatric reference intervals were similar to those established in our previous study. However, assay-specific differences in reference limits were observed for many analytes, and in some instances were considerable. The results of the EQA evaluation generally mimicked the similarities and differences in reference limits among the five manufacturers' assays. In addition, the majority of transferred reference intervals were validated through the analysis of CALIPER reference samples. This study greatly extends the utility of the CALIPER reference interval database which is now directly applicable for assays performed on five major analytical platforms in clinical use, and should permit the worldwide application of CALIPER pediatric reference intervals. Copyright © 2013 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Geochemical features and effects on deep-seated fluids during the May-June 2012 southern Po Valley seismic sequence

Directory of Open Access Journals (Sweden)

Francesco Italiano

2012-10-01

Full Text Available A periodic sampling of the groundwaters and dissolved and free gases in selected deep wells located in the area affected by the May-June 2012 southern Po Valley seismic sequence has provided insight into seismogenic-induced changes of the local aquifer systems. The results obtained show progressive changes in the fluid geochemistry, allowing it to be established that deep-seated fluids were mobilized during the seismic sequence and reached surface layers along faults and fractures, which generated significant geochemical anomalies. The May-June 2012 seismic swarm (mainshock on May 29, 2012, M 5.8; 7 shocks M >5, about 200 events 3 > M > 5 induced several modifications in the circulating fluids. This study reports the preliminary results obtained for the geochemical features of the waters and gases collected over the epicentral area from boreholes drilled at different depths, thus intercepting water and gases with different origins and circulation. The aim of the investigations was to improve our knowledge of the fluids circulating over the seismic area (e.g. origin, provenance, interactions, mixing of different components, temporal changes. This was achieved by collecting samples from both shallow and deep-drilled boreholes, and then, after the selection of the relevant sites, we looked for temporal changes with mid-to-long-term monitoring activity following a constant sampling rate. This allowed us to gain better insight into the relationships between the fluid circulation and the faulting activity. The sampling sites are listed in Table 1, along with the analytical results of the gas phase. […

Estimation of Supraglacial Dust and Debris Geochemical Composition via Satellite Reflectance and Emissivity

Science.gov (United States)

Casey, Kimberly Ann; Kaab, Andreas

2012-01-01

We demonstrate spectral estimation of supraglacial dust, debris, ash and tephra geochemical composition from glaciers and ice fields in Iceland, Nepal, New Zealand and Switzerland. Surface glacier material was collected and analyzed via X-ray fluorescence spectroscopy (XRF) and X-ray diffraction (XRD) for geochemical composition and mineralogy. In situ data was used as ground truth for comparison with satellite derived geochemical results. Supraglacial debris spectral response patterns and emissivity-derived silica weight percent are presented. Qualitative spectral response patterns agreed well with XRF elemental abundances. Quantitative emissivity estimates of supraglacial SiO2 in continental areas were 67% (Switzerland) and 68% (Nepal), while volcanic supraglacial SiO2 averages were 58% (Iceland) and 56% (New Zealand), yielding general agreement. Ablation season supraglacial temperature variation due to differing dust and debris type and coverage was also investigated, with surface debris temperatures ranging from 5.9 to 26.6 C in the study regions. Applications of the supraglacial geochemical reflective and emissive characterization methods include glacier areal extent mapping, debris source identification, glacier kinematics and glacier energy balance considerations.

Estimation of Supraglacial Dust and Debris Geochemical Composition via Satellite Reflectance and Emissivity

Directory of Open Access Journals (Sweden)

Kimberly Casey

2012-09-01

Full Text Available We demonstrate spectral estimation of supraglacial dust, debris, ash and tephra geochemical composition from glaciers and ice fields in Iceland, Nepal, New Zealand and Switzerland. Surface glacier material was collected and analyzed via X-ray fluorescence spectroscopy (XRF and X-ray diffraction (XRD for geochemical composition and mineralogy. In situ data was used as ground truth for comparison with satellite derived geochemical results. Supraglacial debris spectral response patterns and emissivity-derived silica weight percent are presented. Qualitative spectral response patterns agreed well with XRF elemental abundances. Quantitative emissivity estimates of supraglacial SiO2 in continental areas were 67% (Switzerland and 68% (Nepal, while volcanic supraglacial SiO2 averages were 58% (Iceland and 56% (New Zealand, yielding general agreement. Ablation season supraglacial temperature variation due to differing dust and debris type and coverage was also investigated, with surface debris temperatures ranging from 5.9 to 26.6 C in the study regions. Applications of the supraglacial geochemical reflective and emissive characterization methods include glacier areal extent mapping, debris source identification, glacier kinematics and glacier energy balance considerations.