Accedi

Bibliografie tematiche / Geochemical background

Letteratura scientifica selezionata sul tema "Geochemical background"

Autore: Grafiati

Pubblicato: 8 giugno 2024

Cita una fonte nei formati APA, MLA, Chicago, Harvard e in molti altri stili

Scegli il tipo di fonte:

Consulta la lista di attuali articoli, libri, tesi, atti di convegni e altre fonti scientifiche attinenti al tema "Geochemical background".

Accanto a ogni fonte nell'elenco di riferimenti c'è un pulsante "Aggiungi alla bibliografia". Premilo e genereremo automaticamente la citazione bibliografica dell'opera scelta nello stile citazionale di cui hai bisogno: APA, MLA, Harvard, Chicago, Vancouver ecc.

Puoi anche scaricare il testo completo della pubblicazione scientifica nel formato .pdf e leggere online l'abstract (il sommario) dell'opera se è presente nei metadati.

Indice

Articoli di riviste
Tesi
Libri
Capitoli di libri
Atti di convegni
Rapporti di organizzazioni

Articoli di riviste sul tema "Geochemical background":

1

Gałuszka, Agnieszka, e Zdzisław Migaszewski. "Geochemical background - an environmental perspective". Mineralogia 42, n. 1 (1 gennaio 2011): 7–17. http://dx.doi.org/10.2478/v10002-011-0002-y.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

Geochemical background - an environmental perspectiveThis article presents the concept of geochemical background from an environmental perspective. The idea of establishing the typical concentrations of elements in various environmental compartments, proposed by exploratory geochemists almost 50 years ago was important for the detection of anomalous element concentrations, thus providing a basic tool in the search for new mineral deposits. At present, the knowledge of the geochemical background of hazardous elements is essential for: defining pollution, identifying the source of contamination, and for establishing reliable environmental quality criteria for soils, sediments and surface waters. The article presents geochemical methods of evaluation of anthropogenic influence on the environment and discusses the problem of defining and understanding the term "geochemical background" and related terms in environmental sciences. It also briefly presents methods of geochemical background evaluation based on the results of environmental sample analyses. It stresses the role of geochemical background in our understanding of environmental pollution and pollution prevention.

2

Cembranel, Adir S., Silvio C. Sampaio, Marcelo B. Remor, Jackeline T. Gotardo e Pábolla M. Dalla Rosa. "GEOCHEMICAL BACKGROUND IN AN OXISOL". Engenharia Agrícola 37, n. 3 (giugno 2017): 565–73. http://dx.doi.org/10.1590/1809-4430-eng.agric.v37n3p565-573/2017.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

3

Reimann, Clemens, e Robert G. Garrett. "Geochemical background—concept and reality". Science of The Total Environment 350, n. 1-3 (novembre 2005): 12–27. http://dx.doi.org/10.1016/j.scitotenv.2005.01.047.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

4

Matschullat, J., R. Ottenstein e C. Reimann. "Geochemical background - can we calculate it?" Environmental Geology 39, n. 9 (14 luglio 2000): 990–1000. http://dx.doi.org/10.1007/s002549900084.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

5

Matschullat, Jörg, Silke Höfle, Juscimar da Silva, Jaime Mello, Germano Melo, Alexander Pleßow e Clemens Reimann. "A soil geochemical background for northeastern Brazil". Geochemistry: Exploration, Environment, Analysis 12, n. 3 (agosto 2012): 197–209. http://dx.doi.org/10.1144/1467-7873/10-ra-046.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

6

Garrett, Robert G., Gerald C. Lalor, John Preston e M. K. Vutchkov. "Variation in geochemical background levels for Jamaican soils". Geochemistry: Exploration, Environment, Analysis 8, n. 2 (23 aprile 2008): 149–56. http://dx.doi.org/10.1144/1467-7873/07-158.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

7

Zhou, Di. "Adjustment of geochemical background by robust multivariate statistics". Journal of Geochemical Exploration 24, n. 2 (novembre 1985): 207–22. http://dx.doi.org/10.1016/0375-6742(85)90046-9.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

8

Vodianitsky, Yu, N. Kosareva e A. Savichev. "LANTANIDES (Y, La, Ce, Pr, Nd, Sm) AND ACTINIDS (Th, U) IN SOILS OF THE HIBINO-LOVOZERO PROVINCE". Dokuchaev Soil Bulletin, n. 65 (30 giugno 2010): 75–86. http://dx.doi.org/10.19047/0136-1694-2010-65-75-86.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

In the Khibinsko-Lovozero district of the Kola Peninsula, the territory is divided into three geochemically different areas. In the background area near Umbozero, both mineral and peated samples contain all rare metals below clark: lanthanides and actinides are leaching heavily from acidic podzolic soils. В in the area of weak geochemical anomaly (near Lovozero), all lanthanides are inherited from the loparite-containing rock, and all actinides - Th: their content is 1.3-5.4 times higher than the clark value. In the zone of a strong geochemical anomaly (on the northern shore of Seidozero and on theThe concentration of lanthanides and actinides is even higher: 4-9 times higher than the clark value. There is an impact of a biological barrier that prevents excessive accumulation of of heavy metals in the mosses of a geochemical anomaly.

9

Zinkutė, Rimantė, Ričardas Taraškevičius, Margarita Jankauskaitė, Vaidotas Kazakauskas e Žilvinas Stankevičius. "Influence of site-classification approach on geochemical background values". Open Chemistry 18, n. 1 (11 dicembre 2020): 1391–411. http://dx.doi.org/10.1515/chem-2020-0177.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

AbstractThis study of peri-urban minerogenic topsoil on glacigenic or post-glacial deposits shows the influence of the site-classification approach on the differentiated median background (DMB) values of major elements and the potentially harmful elements (PHEs) Ba, Cr, Cu, Mn, Ni, Pb and Zn. Composite samples from forests and meadows were taken in 25 sites, each of which had five sub-sites. A fraction of <2 mm was used to determine the organic matter by loss on ignition (LOI), grain size by laser diffraction and the elemental contents by X-ray fluorescence. The following five site-classification approaches are compared: geochemical (G), using relative median contents of Al, K, Ti; textural (T), according to mean percentages of clay-sized fraction (CLF) and silt fraction (SIF); lithological (L), based on soil parent material texture from the soil database; soil type (S), presented in the soil database; and parent material (P), generalising the underlying Quaternary deposits. Sites were classified into four level groups in which the DMB values were estimated after eliminating anomalies. The average ranks of three scores according to SIF, CLF, LOI, Al, K, Ti, Fe, Mg, Ca and S in the respective groups revealed the highest value for the G approach. It better eliminates the CLF and SIF influences on the median assessment indices of PHEs in sites.

10

Nakić, Zoran, Kristijan Posavec e Andrea Bačani. "A Visual Basic Spreadsheet Macro for Geochemical Background Analysis". Ground Water 45, n. 5 (settembre 2007): 642–47. http://dx.doi.org/10.1111/j.1745-6584.2007.00325.x.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Più fonti

Tesi sul tema "Geochemical background":

1

Dalla, Libera Nico. "The Natural Background Level problem: A Hydro-geochemical study on the natural occurrence of Arsenic located in the Veneto region (NE Italy)". Doctoral thesis, Università degli studi di Padova, 2019. http://hdl.handle.net/11577/3424675.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

Excess of arsenic in groundwater is a worldwide problem threatening the health of the millions of people directly exposed to Arsenic-rich water intake. The problem is particularly acute in naturally occurring unconsolidated aquifers where Arsenic-rich groundwater is an easily accessible resource of drinking water, such arsenic in India, Bangladesh and Vietnam. In Italy, arsenic is found in aquifers from north to south and it is associated to different geological settings (i.e. volcanic areas and alluvial plains). The shallow aquifer of Venetian Alluvial Plain (VAP) is notoriously affected by arsenic contamination, characterized by a patchy distribution with variable extensions and concentrations. With concentrations exceeding the WHO limit of 10 μg/L, this metal poses a risk for locals, arsenic the aquifer is exploited for agricultural purposes. Although empirical evidences exist about the relationship between arsenic occurrence and other factors, several aspects regarding the physical and geochemical processes controlling arsenic in the VAP aquifers remain unclear. In this line, the present study aims to elucidate both the geochemical processes fostering arsenic mobility and their correlation with the subsurface heterogeneity, in order to improve the knowledge about arsenic-controlling processes and use them arsenic aid for the environmental management. To this end, we focused in detail on an agricultural zone nearby the Venice lagoon, affected by arsenic contamination (called “Western Agricultural Areas”, WAA). The available data, collected by several hydrogeological surveys, show a spatial and temporal variability of arsenic concentration, which can be associated to a variety of hydro-geochemical processes such arsenic redox variations, sorption or reductive dissolution of Arsenic-rich iron oxy-hydroxides. In order to point out the consistency and the importance of these processes, we structured the study in two main phases: 1) evaluation of geochemical processes by means of a PHREEQC batch-like reactive model and 2) creation of a 3D reactive transport model based on previous results. The former allows us for testing whether the supposed geochemical processes are able to fit the geochemical conditions of the study system, identifying the main actors for arsenic mobility. The latter couples the obtained reactive processes with a 3D flow model, in order to evaluate the spatial and temporal distribution of dissolved arsenic as function of the subsurface heterogeneity. The results highlighted a strong effect of oxy-reductive potential on arsenic mobility, and it seems to be strictly correlated to organic matter degradation. The uprising of reduced condition, then, affects other mechanism such arsenic reductive dissolution of iron hydroxides, ion exchange and sorption processes, causing arsenic mobilization. Moreover, this study shaded light on the existence of oxygen ingress arsenic function of local water recharge events, which seems to be responsible of space/time redox variation. The 3D reactive transport model showed a strong dependence between the aforementioned processes and subsurface heterogeneity. The material distribution, indeed, plays an import role affecting the arising of the main chemical reactions.

2

Barbosa, Ariadna Cristina Gomes. "Caracterização geoquímica marinha e avaliação do impacto das atividades antrópicas e de exploração de petróleo sobre os sedimentos da plataforma continental do estado de Sergipe e sul do estado do Alagoas". Universidade Federal de Sergipe, 2010. https://ri.ufs.br/handle/riufs/6068.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

The environmental impact caused by oil, sewage, industrial, mining, leaching of soil and urban surfaces in the Brazilian coast has generated effluents mixed, with the metal trace a specific problem because they are deposited in marine sediments and present toxicity at the same time, persistence and bioaccumulation. Sediments act as operating compartment corded an essential role in the redistribution of marine biota, because that guard the historical record of contamination of water body. Oil exploration extends to offshore environment, occupying a prominent position in the energy matrix, responsible for most of the national supply. The oil and gas activities may include a significant source of pollution of the planet. The aim of this study was to observe the sediment profiles of the continental shelf off Sergipe and Alagoas southern state, checking for a variation of the concentration of trace metals according to depth. Three cores (PCM-9 (A), PCM-9 (B), Est.2 (A)) were performed to obtain a vertical profile of sediment samples obtained at various depths. In this study, drew up the metals Co, Cr, Fe, Li, Mn, Ni, Pb, Zn, Al and Cu total and partial, were determined by atomic absorption spectrometric (AAS). In the extraction part, the result of the recovery was above 90%, ranging from 92% to 111.1%. In the extraction result of the total recovery ranged from 77.6 to 99%. These values were obtained in the studied parameters, indicating good accuracy of the methodology. The values of RSD are below 10%, expressing the accuracy of methodology. Showed that the concentration distribution of trace metals in sediment profiles vary with depth. Colors in PCM-9 (A), PCM-9 (B), increased concentrations of metals and the core Est.2 (A) decreased gradually from base to surface. The iron was approved as a geochemical normalizer better. The values of the calculated enrichment factor shown to be low, considering the low enriched, except Pb, Co, Mn and Al that have moderate values. The geochemical background values were estimated in three different procedures, which can generate unrealistic characterizations of the state of pollution. The values of trace metals are below the sediment quality guidelines, which leads to the adverse effect on aquatic biota is unlikely.
O impacto ambiental causado por óleo, esgotamento sanitário, industrial,mineração, lixiviação de solos e superfícies urbanas, na costa brasileira temgerado efluentes variados, sendo os metais traço um problema particular,pois se depositam nos sedimentos marinho e apresentam ao mesmo tempo toxicidade, persistência e bioacumulação. Os sedimentos funcionam comocompartimento operacional que exerce papel essencial na redistribuição àbiota marinha, visto que guardam registro histórico da contaminação decorpo d água. A exploração de petróleo se estende ao ambiente offshore, ocupando uma posição de destaque na matriz energética, responsável pela maior parte do suprimento nacional. As atividades petrolíferas podem consistir uma fonte poluidora significativa do planeta. O objetivo desse estudo foi observar os perfis sedimentares da plataforma continental de Sergipe e sul de estado de Alagoas, verificando se há uma variação da concentração dos metais traço de acordo com a profundidade. Três cores (PCM-9(A), PCM-9(B), Est.2(A)) foram realizadas para obter um perfil vertical do sedimento, obtendo amostras a várias profundidades. Nesse estudo, extraiu-se os metais Co, Cr, Fe, Li, Mn, Ni, Pb, Zn, Al e Cu totais e parciais e foram determinados através da espectrometria de absorção atômica. Na extração parcial, o resultado da recuperação foi acima de 90 %, variam de 92% a 111,1%. Já na extração total o resultado da recuperação variou de 77,6 a 99%. Esses valores foram obtidos nos elementos estudados, indicando boa exatidão da metodologia. Os valores do desvio padrão relativo estão abaixo de 10%, expressando a precisão da metodologia. Mostrou-se que a distribuição da concentração dos metais traço nos perfis sedimentares variam com a profundidade. Nos cores PCM- 9(A), PCM-9 (B), as concentrações dos metais aumentaram e no core Est.2 (A) diminuiu gradativamente da base até a superfície. O ferro foi aprovado como melhor normalizador geoquímico. Os valores do fator de enriquecimento calculado mostraram-se baixos, considerando-se pouco enriquecida, exceto o Pb, Co, Mn e Al que apresentam valores moderados. Os valores de background geoquímico estimado foram diferentes nos três procedimentos utilizados. Os valores dos metais traços estão abaixo dos valores guia de qualidade dos sedimentos, o que leva o efeito adverso a biota aquática ser pouco provável.

3

Metzner, Ines. "Zur Geochemie ausgewählter Bodenformen im Erzgebirge und Vogtland". Doctoral thesis, Technische Universitaet Bergakademie Freiberg Universitaetsbibliothek "Georgius Agricola", 2011. http://nbn-resolving.de/urn:nbn:de:bsz:105-qucosa-64364.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

Die geochemischen Verhältnisse der Böden des Erzgebirge und Vogtlandes werden auf der Grundlage der komplexen geochemischen Analyse von ausgewählten, flächenrepräsentativen Bodenprofilen auf Hauptgesteinen des Untersuchungegebietes charakterisiert. Die Wirkungsweisen vorhandener Einflussfaktoren (Gesteinschemismus, Bodengenese, Bodennutzung) werden untersucht und bewertet. Die Untersuchungen stellen eine Grundlage für die Ableitung von geologisch bedingten regionalen Hintergrundbelastungen dar
A characterization of the soil geochemistry of the Erzgebirge and Vogtland Regions (Saxony) is provided on the basis of the investigation of characteristic soil profiles on major bedrock types of the area. Different factors of influence (rock geochemistry, soil formation, land utilization) are investigated and evaluated. The investigation provides essential information for the development of regional background concentrations

4

Sauvaget, Baptiste. "Constitution de référentiels géochimiques locaux pour les sols et proches sous-sols urbains : de la base de données à l'interprétation géostatistique". Thesis, Paris Sciences et Lettres (ComUE), 2019. http://www.theses.fr/2019PSLEM014/document.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

Les grands réaménagements urbains génèrent d’importants volumes de terres excavées, dont la valorisation est désormais possible si elles sont compatibles avec le fond pédo-géochimique du site receveur. Afin de faciliter cette valorisation, cette thèse s’intéresse à des méthodologies de traitement de données acquises à d'autres fins que la détermination du fond pédo-géochimique, afin de fournir un référentiel de qualité géochimique des sols urbains à l'échelle d'un quartier ou d'une ville. Les premiers tests montrent les limites des calculs statistiques, usuellement utilisés avec des données dédiées au fond pédo-géochimique du fait de leur sensibilité à la limite de quantification, à la loi de distribution ou encore au pourcentage d'anomalie. Le découpage du territoire en entités géographiques cohérentes à partir de la nature des sols et sous-sols et des pressions anthropiques (actuelles ou passées) permet la constitution de différents niveaux de fond suivant la qualité géochimique des sols, mais une des difficultés concerne le renseignement de l'ensemble des entités. La classification statistique des échantillons, même spatialisée, n'apporte, actuellement pas de résultats exploitables pour la gestion des terres excavées. Enfin, le filtrage géostatistique via un modèle linéaire de corégionalisation présente une alternative solide pour le filtrage des anomalies et l'estimation du fond à l'échelle d'un quartier
Large urban redevelopments generate large volumes of excavated soils whose reusability is now possible if they are compatible with the pedo-geochemical background of the receiving site. In order to facilitate this valorization, this thesis focuses on processing methodologies on data acquired for other purposes than the determination of the pedo-geochemical background, in order to provide a geochemical quality reference system for urban soils at the scale of one neighborhood or city. The first tests show the limits of the statistical stresholds, usually used with data dedicated to the pedo-geochemical background because of their sensitivity to the limit of quantification, to the distribution law or to the percentage of anomaly. The segmentation of the territory into coherent geographical entities based on the nature of the soil and subsoil and the anthropogenic pressures (current or past) allows the constitution of different geochemical background levels according to the geochemical quality of the soils, but one of the difficulties concerns the information of all entities. The statistical classification of the samples, even if spatialized, does not currently provide usable results for the management of the excavated earth. Lastly, geostatistical filtering via a linear model of coregionalisation provides a solid alternative for anomaly filtering and background estimation at a neighborhood scale

5

Sauvaget, Baptiste. "Constitution de référentiels géochimiques locaux pour les sols et proches sous-sols urbains : de la base de données à l'interprétation géostatistique". Electronic Thesis or Diss., Paris Sciences et Lettres (ComUE), 2019. http://www.theses.fr/2019PSLEM014.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

Les grands réaménagements urbains génèrent d’importants volumes de terres excavées, dont la valorisation est désormais possible si elles sont compatibles avec le fond pédo-géochimique du site receveur. Afin de faciliter cette valorisation, cette thèse s’intéresse à des méthodologies de traitement de données acquises à d'autres fins que la détermination du fond pédo-géochimique, afin de fournir un référentiel de qualité géochimique des sols urbains à l'échelle d'un quartier ou d'une ville. Les premiers tests montrent les limites des calculs statistiques, usuellement utilisés avec des données dédiées au fond pédo-géochimique du fait de leur sensibilité à la limite de quantification, à la loi de distribution ou encore au pourcentage d'anomalie. Le découpage du territoire en entités géographiques cohérentes à partir de la nature des sols et sous-sols et des pressions anthropiques (actuelles ou passées) permet la constitution de différents niveaux de fond suivant la qualité géochimique des sols, mais une des difficultés concerne le renseignement de l'ensemble des entités. La classification statistique des échantillons, même spatialisée, n'apporte, actuellement pas de résultats exploitables pour la gestion des terres excavées. Enfin, le filtrage géostatistique via un modèle linéaire de corégionalisation présente une alternative solide pour le filtrage des anomalies et l'estimation du fond à l'échelle d'un quartier
Large urban redevelopments generate large volumes of excavated soils whose reusability is now possible if they are compatible with the pedo-geochemical background of the receiving site. In order to facilitate this valorization, this thesis focuses on processing methodologies on data acquired for other purposes than the determination of the pedo-geochemical background, in order to provide a geochemical quality reference system for urban soils at the scale of one neighborhood or city. The first tests show the limits of the statistical stresholds, usually used with data dedicated to the pedo-geochemical background because of their sensitivity to the limit of quantification, to the distribution law or to the percentage of anomaly. The segmentation of the territory into coherent geographical entities based on the nature of the soil and subsoil and the anthropogenic pressures (current or past) allows the constitution of different geochemical background levels according to the geochemical quality of the soils, but one of the difficulties concerns the information of all entities. The statistical classification of the samples, even if spatialized, does not currently provide usable results for the management of the excavated earth. Lastly, geostatistical filtering via a linear model of coregionalisation provides a solid alternative for anomaly filtering and background estimation at a neighborhood scale

6

Metzner, Ines. "Zur Geochemie ausgewählter Bodenformen im Erzgebirge und Vogtland". Doctoral thesis, 1991. https://tubaf.qucosa.de/id/qucosa%3A22746.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

Die geochemischen Verhältnisse der Böden des Erzgebirge und Vogtlandes werden auf der Grundlage der komplexen geochemischen Analyse von ausgewählten, flächenrepräsentativen Bodenprofilen auf Hauptgesteinen des Untersuchungegebietes charakterisiert. Die Wirkungsweisen vorhandener Einflussfaktoren (Gesteinschemismus, Bodengenese, Bodennutzung) werden untersucht und bewertet. Die Untersuchungen stellen eine Grundlage für die Ableitung von geologisch bedingten regionalen Hintergrundbelastungen dar.
A characterization of the soil geochemistry of the Erzgebirge and Vogtland Regions (Saxony) is provided on the basis of the investigation of characteristic soil profiles on major bedrock types of the area. Different factors of influence (rock geochemistry, soil formation, land utilization) are investigated and evaluated. The investigation provides essential information for the development of regional background concentrations.

Libri sul tema "Geochemical background":

1

Survey, United States Geological. Conterminous United States Mineral Assessment Program: Background Information to Accompany Folio of Geologic, Geophysical, Geochemical, Mineral-Occurrence, Mineral Resources Potential and Mineral: Production. S.l: s.n, 1986.

Cerca il testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

2

1924-, Harrison Jack Edward, Montana Bureau of Mines and Geology. e Geological Survey (U.S.), a cura di. The Conterminous United States Mineral Assessment Program: Background information to accompany folio of geologic, geochemical, geophysical, remote sensing, and mineral resource maps of the Wallace 1ʻ́. [Reston, Va.?]: Dept. of the Interior, U.S. Geological Survey, 1986.

Cerca il testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

3

1924-, Harrison Jack Edward, Montana Bureau of Mines and Geology. e Geological Survey (U.S.), a cura di. The Conterminous United States Mineral Assessment Program: Background information to accompany folio of geologic, geochemical, geophysical, remote sensing, and mineral resource maps of the Wallace 1. [Reston, Va.?]: Dept. of the Interior, U.S. Geological Survey, 1986.

Cerca il testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

4

A, John David, e Conterminous United States Mineral Assessment Program., a cura di. The Conterminous United States Mineral Appraisal Program: Background information to accompany folio of geologic, geochemical, geophysical, and mineral resources maps of the Tonopah 1⁰ by 2⁰ quadrangle, Nevada. Washington: U.S. G.P.O., 1991.

Cerca il testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

5

E, Elliott James, e Conterminous United States Mineral Assessment Program., a cura di. The Conterminous United States Mineral Assessment Program: Background information to accompany folio of geologic, geochemical remote sensing, and mineral resources maps of the Butte 1⁰ x 2⁰ quadrangle, Montana. Washington: U.S. G.P.O., 1993.

Cerca il testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

6

E, Elliott James, e United States Geological Survey, a cura di. The Conterminous United States Mineral Assessment Program: Background information to accompany folio of geologic, geochemical remote sensing, and mineral resources maps of the Butte 10 x 20 quadrangle, Montana. Washington: U.S. G.P.O., 1993.

Cerca il testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

7

Floyd, Gray, e Conterminous United States Mineral Assessment Program., a cura di. The Conterminous United States Mineral Assessment Program: Background information to accompany folio of geologic, geochemical, geophysical, and mineral resource maps of the Ajo and Lukeville 1⁰ by 2⁰ quadrangles, Arizona. Washington: U.S. G.P.O., 1992.

Cerca il testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

8

1924-, Harrison Jack Edward, Conterminous United States Mineral Assessment Program., Montana Bureau of Mines and Geology. e Geological Survey (U.S.), a cura di. The Conterminous United States Mineral Assessment Program: Background information to accompany folio of geologic, geochemical, geophysical, remote sensing, and mineral resource maps of the Wallace 1⁰ x 2⁰ quadrangle, Montana and Idaho. [Reston, Va?]: U.S. Geological Survey, 1986.

Cerca il testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

9

1922-, Gair Jacob Eugene, e Conterminous United States Mineral Assessment Program., a cura di. The Conterminous United States Mineral Assessment Program: Background information to accompany folio of geologic, geophysical, geochemical, mineral-occurrence, mineral-resource potential, mineral-production maps of the Charlotte 1⁰ x 2⁰ quadrangle, North Carolina and South Carolina. Denver, CO: Dept. of the Interior, U.S. Geological Survey, 1986.

Cerca il testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

10

Tossell, John A., e David J. Vaughan. Theoretical Geochemistry. Oxford University Press, 1992. http://dx.doi.org/10.1093/oso/9780195044034.001.0001.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

This work is based on the observation that further major advances in geochemistry, particularly in understanding the rules that govern the ways in which elements come together to form minerals and rocks, will require the application of the theories of quantum mechanics. The book therefore outlines this theoretical background and discusses the models used to describe bonding in geochemical systems. It is the first book to describe and critically review the application of quantum mechanical theories to minerals and geochemical systems. The book consolidates valuable findings from chemistry and materials science as well as mineralogy and geochemistry, and the presentation has relevance to professionals in a wide range of disciplines. Experimental techniques are surveyed, but the emphasis is on applying theoretical tools to various groups of minerals: the oxides, silicates, carbonates, borates, and sulfides. Other topics dealt with in depth include structure, stereochemistry, bond strengths and stabilities of minerals, various physical properties, and the overall geochemical distribution of the elements.

Capitoli di libri sul tema "Geochemical background":

1

Kempe, Stephan, Ingo Bauer e Stefan Glaser. "Hypogene Caves in Germany, Geological and Geochemical Background". In Hypogene Karst Regions and Caves of the World, 329–47. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-53348-3_21.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

2

Burnard, Pete, Laurent Zimmermann e Yuji Sano. "The Noble Gases as Geochemical Tracers: History and Background". In Advances in Isotope Geochemistry, 1–15. Berlin, Heidelberg: Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-28836-4_1.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

3

Spiridon, Andrei, Paulo Sá Caetano, Graça Brito, André Sanches e Ricardo Manuel. "Geochemical Background in Heavy Metals on Basaltic Soils from the Lisbon Volcanic Complex". In Advances in Geoengineering, Geotechnologies, and Geoenvironment for Earth Systems and Sustainable Georesources Management, 247–52. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-25986-9_41.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

4

Droit, Julie, Mohamed El Fadili e Marion Messager. "Assessment of the chemical quality of sediments in the maritime port of Reunion. Concentrations in trace metals and natural geochemical backgrounds." In Ninth International Symposium “Monitoring of Mediterranean Coastal Areas: Problems and Measurement Techniques”, 456–60. Florence: Firenze University Press, 2022. http://dx.doi.org/10.36253/979-12-215-0030-1.41.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

The analyzes carried out in the marine sediments sampled in the port and coastal areas of Reunion show, for certain metallic trace elements, significant variations in their contents and regular overruns of the regulatory thresholds for the management of dredged sediments. Several studies show that the volcanic nature of Reunion Island is the cause of high concentrations of metals in the soil. The objective of this study is to define, whether the observed exceedances of the management thresholds for dredged sediments are due to the geology of the island or to contributions of anthropogenic origin.

5

"Thermodynamic Background". In Environmental Applications of Geochemical Modeling, 32–73. Cambridge University Press, 2002. http://dx.doi.org/10.1017/cbo9780511606274.004.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

6

Zhang, Yunfeng, Qiang Jia, Houli Shi, Jitao Wang, Jianjun Shen e Qing Cao. "Geochemical Distribution of Soil Metals: A Case Study in Binzhou". In Advances in Transdisciplinary Engineering. IOS Press, 2022. http://dx.doi.org/10.3233/atde220988.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

In order to determine the geochemical distribution of metals in the survey area, we investigated and analyzed soil samples according to the regulations of land quality and soil contamination. We analyzed the geochemical properties of the soil, like topsoil and deep soil, at the Binzhou Economic and Technological Development Zone. The background values and distributions of various soil indicator elements were identified within the survey area. The geochemical distribution of various elements was also determined in the soil, and the land quality and contaminants in the soil were assessed. We found that the topsoil in the survey area was free of the risk of contaminants.

7

Cohen, Andrew S. "Geochemical Archives in Lake Deposits". In Paleolimnology. Oxford University Press, 2003. http://dx.doi.org/10.1093/oso/9780195133530.003.0013.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

As we saw in chapter 4, the isotopic, elemental, or molecular constituents of a lake and its sediments reflect both external chemical inputs and the lake’s internal biogeochemical cycles. Lake sediment geochemistry is the product of interactions between these external inputs from watershed geology, groundwater, vegetation, and the airshed, and internal lake processes. Both external and internal inputs are heavily influenced by climate, and for the past few thousand years, human activities. With careful consideration of the various information filters affecting their records, geochemists can greatly broaden the scope of questions that can be addressed using paleolimnology. It is of critical importance when interpreting chemical data, that it be placed in the context of other sedimentological or paleontological archives. With modern, automated techniques, it is possible to amass large amounts of geochemical data in a relatively short time, data that can be compiled into deceptively ‘‘simple’’ geochemical profiles. Perhaps more than any other types of indicator, geochemical profiles are often interpreted as standalone records, without reference to petrographical, or even gross lithofacies information. Although it is tempting to read chemical stratigraphies as a direct record of inputs from a watershed or airshed, the signals are blurred by the whole host of messy, internal processes that we have already encountered in the hydroclimate filter: lag and residence time effects, reworking, particle and redox focusing, organismal uptake, and bioturbation. Lake deposits integrate local changes in source conditions, background sedimentation rates, and geochemical focusing processes (Engstrom and Swain, 1986). As a result, different locations within a lake may provide different geochemical histories, and interpretations of an integrated lake history must take into account these internal variations and their probable causes. This is always harder to do with paleolake deposits, where the original basin morphometry and hydrology is obscure. In this chapter we will also consider postdepositional information filters that affect geochemical archives, in particular bioturbation and diagenesis. Because many geochemical components of interest to paleolimnologists are bound to fine-grained particles, they can be readily mixed by bioturbation.

8

Oliveira, Helder de, Diego Vendramini e Jefferson Mortatti. "Geochemical aspects of heavy metal fractionation in eucalyptus soils". In GLOBAL HEALTH TRENDS AND PERSPECTIVES IN HEALTH SCIENCES. Seven Editora, 2023. http://dx.doi.org/10.56238/globalhealthprespesc-033.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

Aspects of heavy metals fractionation (Cu, Cr and Co) in main eucalyptus cultivated soils were investigated after total extraction by alkaline fusion and selective sequential extractions. The study aimed to identify the major geochemical fractions and phases involved in metal complexation. Possible pollution classes were investigated through index of geo-accumulation (Igeo), considering the local natural background level. Among the main soils, Typic Hapludox showed the highest concentrations of these metals. However, there was no contamination according to the calculated Igeo. The selective sequential extractions showed that, for most analyzed soil, there was a predominance of these metals in the residual phase (> 80%), compared to the bioavailable fraction, and in this case, an association with the geochemical phase of Fe oxides. Cultural treatments, performed in this region during the eucalyptus cultivation, did not have residual effects in terms of heavy metals in soils.

9

A. Akinyemi, Segun, Olajide F. Adebayo, Henry Y. Madukwe, Adeyinka O. Aturamu e Olusola A. OlaOlorun. "Mineralogy and Geochemistry of Shales of Mamu Formation in Nigeria: Effects of Deposition, Source Rock, and Tectonic Background". In Geochemistry and Mineral Resources. IntechOpen, 2022. http://dx.doi.org/10.5772/intechopen.102454.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

Study of lithofacies identification, geochemical characterization of shales is vital to the provenance, paleoweathering, and tectonic setting reconstruction. The combination of morphological analysis, bulk chemical analysis and in-situ multi-element analysis was used to investigate the provenance, source area weathering, and depositional setting of outcropped Maastrichtian shale sequence of the Mamu Formation, Anambra Basin in Nigeria. Ten representative shale samples were examined by scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS). Geochemical analysis was performed by X-ray fluorescence (XRF) Spectroscopy and Laser Ablation-Induced Coupled Plasma Mass Spectrometry (LA-ICPMS) techniques. The structural and morphological development of kaolinite in the outcropped shale samples of Mamu Formation is due to mechanical disintegration during transportation and re-deposition. Major oxides such as SiO2, Al2O3 and Fe2O3 constitute greater than 86% of the bulk composition. The weathering indices suggest highly weathered source materials. The plot of Cr versus Ni indicated the studied samples are Late Archean shale. Binary plots of trace elements suggest derivation from acidic or felsic sources rather than intermediate or basic source rocks. Ternary plot of Na2O + K2O, SiO2/10 and CaO + MgO indicated multiple sources such as felsic igneous rocks or recycled residues of quartz-rich. Tectonic discrimination diagram depict a typical Passive Margin field.

10

Maslov, A. V., N. V. Politova, N. V. Kozina, A. B. Kuznetzov, M. D. Kravchishina, A. N. Novigatsky, V. P. Shevchenko e T. N. Alexeeva. "Rare and trace elements in modern bottom sediments of the Barents sea. Nd, Pb and Sr isotopic composition". In THE BARENTS SEA SYSTEM, 444–72. Shirshov Institute of Oceanology Publishing House, 2021. http://dx.doi.org/10.29006/978-5-6045110-0-8/(32).

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

The article presents a brief lithological description of the modern bottom sediments of the Barents Sea, selected in the 67th voyage of the R/V “Akademik Mstislav Keldysh” at the polygons: 1) “Pechora Sea”; 2) “Western slope of Kaninskoe shoal”; 3) “Central Barents Sea (Shtokman area)”; 4) “Russkaya Gavan’ fjord”; 5) “Medvezhinsky Trench”; 6) in the area to the south of Spitsbergen; 7) “Kola meridian”; 8) “Spitsbergen – Franz Josef Land archipelago”; 9) “Cambridge Strait”. The distribution of Cr, Ni, Cu, Zn, Cd, and Pb in samples of bottom sediments (pelitic, aleurite-pelitic and sandy-aleuritic-pelitic ooze) is compared with the background concentrations and contents of these elements in the Post-Archean Average Shale (PAAS). The data obtained are consistent with the notion that the distribution of heavy metals and other elements in the bottom sediments is controlled primarily by the global geochemical background. The relationship of the Sc, V, Cr, Ni, Y, Zr, Nb, Mo, Hf, Th, U and rare-earth elements concentrations with content of fine pelite (< 0.001 mm) fraction and organic carbon (Corg) is considered. It was found that most of these elements are characterized by a moderate positive correlation with the amount of fine pelite fraction in samples. By the magnitude of the correlation coefficient with the Corg content, all elements are attributed into three groups: (1) with moderate positive correlation, (2) weak positive correlation, (3) practically not pronounced correlation. The distribution in the bottom sediments of the Barents Sea of the element-indicators of the source rocks composition (Sc, Th, Co, Cr, La and Sm), as well as of rare earths, make it possible to consider that the majority of bottom sediments is mature in geochemical terms material, the sources of which were rocks of the Kola Peninsula and Spitsbergen (?). The bottom sediments of the Cambridge Strait are represented by geochemically less mature material, which, apparently, entered the sea as a result of erosion of the Franz Josef Land archipelago rocks. The established isotopic characteristics (εNd, 207Pb/206Pb and 87Sr/86Sr) of 17 samples of surface sediments suggest that the main contribution to the formation of bottom deposits of the central regions of the Barents Sea is made by rocks of the mainland part located in the influence zone of the North Cape Current. Archipelagos and islands (Franz Josef Land, Novaya Zemlya, etc.) that frame the Barents Sea supply a relatively small amount of clastic material that is carried by Arctic currents. The values of εNd and 87Sr/86Sr in the surface sediments of the central part of the Barents Sea and in the ice-rafted sediments carried by the Transpolar Drift showed a significant difference. This suggests that the contribution of such material to the formation of surface sediments of the Barents Sea is relatively small

Atti di convegni sul tema "Geochemical background":

1

Lazareva, I., S. Shnyukov, A. Andreiev, A. Aleksieienko, V. Zagorodnii e V. Morozenko. "Precision Analysis Of Geochemical Background Level During Industrial Geochemical Anomalies Monitoring". In 12th International Conference on Monitoring of Geological Processes and Ecological Condition of the Environment. Netherlands: EAGE Publications BV, 2018. http://dx.doi.org/10.3997/2214-4609.201803164.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

2

Boguslavsky, Anatoly, Vladimir Androkhanov, Igor Gossen e Olga Saeva. "THE GEOCHEMICAL BACKGROUND OF TECHNOSOL FORMED ON THE COAL MINING SPOILS". In 20th International Multidisciplinary Scientific GeoConference Proceedings SGEM 2020. STEF92 Technology, 2020. http://dx.doi.org/10.5593/sgem2020/3.1/s13.076.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

3

Kasatenkova, Maria, Maria Kasatenkova, Nicolay Kasimov, Nicolay Kasimov, Mihail Lychagin e Mihail Lychagin. "CHANGES IN BACKGROUND CONCENTRATIONS OF METALS IN THE SEDIMENTS OF MARSH-LAGOON LANDSCAPES OF THE WESTERN CASPIAN". In Managing risks to coastal regions and communities in a changing world. Academus Publishing, 2017. http://dx.doi.org/10.31519/conferencearticle_5b1b937de4b5c6.59040974.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

The last 1978-1995 transgression of the Caspian Sea caused the development of marsh-lagoon system along the Western Caspian seashore. Due to salt marshes are very vulnerable to sea-level fluctuations, complex and dynamic system, they may be considered as a regional model of rapid environmental transformation. Changing conditions of migration in the soils of marsh-lagoon landscapes during the sea-level rise influenced on the migration of elements of variable valency, primarily Fe and Mn, but also Zn, Cu, Pb, Ni, Co, leading to their mobilization in slightly alkaline and neutral reducing conditions and subsequent deposition on the geochemical barriers. That led to the emergence of landscape-geochemical anomalies of Fe and heavy metals in the soils of salt marshes with a characteristic time of formation of any persistent anomalies during 5-10 years.

4

Kasatenkova, Maria, Maria Kasatenkova, Nicolay Kasimov, Nicolay Kasimov, Mihail Lychagin e Mihail Lychagin. "CHANGES IN BACKGROUND CONCENTRATIONS OF METALS IN THE SEDIMENTS OF MARSH-LAGOON LANDSCAPES OF THE WESTERN CASPIAN". In Managing risks to coastal regions and communities in a changing world. Academus Publishing, 2017. http://dx.doi.org/10.21610/conferencearticle_58b4315901d72.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

The last 1978-1995 transgression of the Caspian Sea caused the development of marsh-lagoon system along the Western Caspian seashore. Due to salt marshes are very vulnerable to sea-level fluctuations, complex and dynamic system, they may be considered as a regional model of rapid environmental transformation. Changing conditions of migration in the soils of marsh-lagoon landscapes during the sea-level rise influenced on the migration of elements of variable valency, primarily Fe and Mn, but also Zn, Cu, Pb, Ni, Co, leading to their mobilization in slightly alkaline and neutral reducing conditions and subsequent deposition on the geochemical barriers. That led to the emergence of landscape-geochemical anomalies of Fe and heavy metals in the soils of salt marshes with a characteristic time of formation of any persistent anomalies during 5-10 years.

5

de Lima, E. Santos, e A. de Souza Moraes. "Trace metals geochemical background in soil in the Suape Port and Industrial Complex, Pernambuco Brazil". In SUSTAINABLE CITY 2014. Southampton, UK: WIT Press, 2014. http://dx.doi.org/10.2495/sc141462.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

6

Shipaeva, M. S., D. K. Nurgaliev, V. A. Sudakov, A. A. Shakirov, B. G. Ganiev e A. A. Lutfullin. "Flow Profile Evaluation in Producer Wells by Geochemical Studies of Oil and Water and Analysis of Anomalies Associated with Deep Fault Zones". In ADIPEC. SPE, 2023. http://dx.doi.org/10.2118/216170-ms.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

Abstract A major problem in the mature oil fields is the accompanying water production and oil production from different layers. Geochemical signals from different formations and sources can be used for identification flow profile. The study of geochemistry by area allows to establish the migration paths and movement of fluids inside the reservoir. This article focuses on the geochemical composition and isotopic geochemistry of brines and oils, as well as the metal content and the use of fingerprinting for oils (biomarker analysis). It allows to determine: the modes of development of reserves in different parts of the field, the distribution of liquid flows. The main tasks are: identification of geochemical anomalous zones and wells, analysis of the water source in return wells, analysis of communication between geochemical data and cumulative oil recovery. The first step involves selecting candidate wells for sampling. Then reservoir fluid samples are taken, and their unique composition is measured through high-precision mass spectrometric studies (ICP-MS), revealing the content of components to billions of fractions. The "oil fingerprinting" method (GC-MS) is used to identify biomarkers in oil composition and conditions of their origin. Using the developed automated algorithm allows identifying the distinctive characteristics of each reservoir and each phase - water and oil. Graphs and maps are plotted based on the distribution of the identified geoindicators. Geochemical survey was carried out by samples of wellhead samples of more than 100 wells, working for carbonate and terrigenous reservoirs. Area maps of changes in the geochemical background of the field have been constructed. The data of the fluid's geochemical composition from the development objects gave the determining of the inflow profile of each phase in the section of the perforated layers and allowed to compare it with the available geophysical field surveys. The identified difference of oils by the coefficient 2nC29/C28+C30 indicates different stages of hydrocarbons inflow into the traps. In the Devonian system the bright anomalies in the geochemical composition of water and oil were discovered, which are associated with faults and wells with record oil production for the last 50 years, where the actual cumulative production exceeds the volume of the originally estimated recoverable oil. Received data was used in the adaptation of the reservoir simulation model.

7

Bondu, Raphaël, Pauline Humez, Wolfram Kloppmann, Maria O. Naumenko-Dèzes e Bernhard Mayer. "Estimating geochemical background values for naturally-occurring constituents in groundwater - A case study of fluoride in Alberta groundwater". In Goldschmidt2021. France: European Association of Geochemistry, 2021. http://dx.doi.org/10.7185/gold2021.7201.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

8

Rafikova, Yuliya, Jalil Suyundukov, Yu Seregina, Irina Semenova, Reseda Khasanova, M. Suyundukova e Gulnaz Ilbulova. "ASSESSMENT OF THE DEGREE OF SOIL DEGRADATION IN THE ZONE OF INFLUENCE OF MINING ENTERPRISES". In Land Degradation and Desertification: Problems of Sustainable Land Management and Adaptation. LLC MAKS Press, 2020. http://dx.doi.org/10.29003/m1679.978-5-317-06490-7/74-78.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

The results of studying the processes of physical and chemical degradation of soils in mining territories are presented. The main categories of urban soils are: undegraded natural, medium-degraded anthropogenic-surface-transformed, and highly degraded anthropogenic-deep-transformed. The results of studies of the processes of physical degradation of soils on changes in morphological characteristics and physical properties of soils are presented. The imposition of industrial pollution of mining territories with heavy metals on the natural increased geochemical background leads to chemical degradation of soils, the formation of zones with different degrees of pollution, depending on the type of functional use of land.

9

Amorosi, Alessandro, e Irene Sammartino. "Background values of potentially harmful metals from surface sediments of the Po Plain (Italy): A combined sedimentological and geochemical approach". In 2nd Annual International Conference on Geological & Earth Sciences (GEOS 2013). Global Science and Technology Forum Pte Ltd, 2013. http://dx.doi.org/10.5176/2251-3353_geos13.28.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

10

Lima, Gustavo Filemon Costa, Jussara Da Silva Diniz Lima, Joyce Castro de Menezes Duarte, Vinícius Gonçalves Ferreira, Carlos Alberto De Carvalho Filho, Ana Cecília Dufilho, Rubens Martins Moreira e Renato Ribeiro Ciminelli. "Pre-Operational Environmental Baseline in a Tight Gas Reservoir: Hydrochemical Assessment and GeoChemical Background of Surface Water in São Francisco Basin (Brazil)". In SPE Argentina Exploration and Production of Unconventional Resources Symposium. SPE, 2023. http://dx.doi.org/10.2118/212421-ms.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

Abstract The definition of a predominant geogenic source of ions and its respective background ranges are powerful tools for detecting contaminations coming from the unconventional gas industry at earlier stages. Reference data to compare pre- vs post-drilling may enforce the planning, monitoring, and management in favor of unconventional production sustainability in the long-term. In 2022, the Brazilian Government launched a pilot project named "Transparent well" for public consultation, intending to foment its incipient unconventional hydrocarbon industry. In this context, this study presents preliminary results to compound an environmental baseline to structure reference data about water resources in a pre-drilling scenario. Then, a characterization of surface water and a geochemical background proposal of Indaiá and Borrachudo basins, two potential tight gas plays inside the São Francisco Basin, was performed to understand hydrochemical processes and susceptibilities previously the unconventional industry development. Two sampling campaigns collecting 13 samples each were made to characterize the study area in two different scenarios. Chemical analysis was performed using an Inductively Coupled Plasma - Mass Spectrometry. To settle a hydrochemical background and its respective environmental thresholds, the ±2 Median Absolute Deviation method was applied. Piper and Chadha's diagrams were used to define water-type and the major cations/anions dynamics in the environment. Piper diagram shows three distinct predominant water-type in the study area, Group 1 (Ca-Mg-HCO3-type); Group 2(Na-K-Ca-HCO3-type); and Group 3 (Ca-Na-HCO3-type). Groups 1 and 2 reflect a geological control in the hydrochemistry due to an interaction between the surface water and interlayered strata of Carbonates and Siltstones from the Bambuí Group whereas Group 3 suggest a seasonal influences in water chemistry. Background values and Upper/Lower environmental thresholds for nineteen elements in two different seasons were also proposed for the study area. Reference data to compare pre- vs post-drilling may enforce the planning, monitoring, and management in favor of unconventional production sustainability in the long-term. Environmental baselines focused on water resources may be a key to the responsible development of the incipient unconventional gas industry in Brazil.

Rapporti di organizzazioni sul tema "Geochemical background":

1

Garrett, R. G. Geochemical background. Natural Resources Canada/ESS/Scientific and Technical Publishing Services, 2011. http://dx.doi.org/10.4095/287946.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

2

Marsac, Kara. Modeling Background Radiation Using Geochemical Data. Office of Scientific and Technical Information (OSTI), maggio 2015. http://dx.doi.org/10.2172/1241522.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

3

Rencz, A. N., R. G. Garrett, S. W. Adcock e G. F. Bonham-Carter. Geochemical background in soil and till. Natural Resources Canada/ESS/Scientific and Technical Publishing Services, 2006. http://dx.doi.org/10.4095/222148.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

4

Garrett, R. G., e E. C. Grunsky. Geochemical background - what it is and how it varies. Natural Resources Canada/ESS/Scientific and Technical Publishing Services, 2011. http://dx.doi.org/10.4095/287965.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

5

Grunsky, E. C., A. N. Rencz e S. W. Adcock. Geochemical background in soil and till - an evaluation of additional elements from geochemical surveys of soils and tills: addendum to GSC Open File 5084. Natural Resources Canada/ESS/Scientific and Technical Publishing Services, 2012. http://dx.doi.org/10.4095/291919.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

6

Rencz, A. N., R. G. Garrett, I. M. Kettles, E. C. Grunsky e R J McNeil. Using soil geochemical data to estimate the range of background element concentrations for ecological and human-health risk assessments. Natural Resources Canada/ESS/Scientific and Technical Publishing Services, 2011. http://dx.doi.org/10.4095/288746.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

7

Rencz, A. N., R. G. Garrett, E. C. Grunsky, I. M. Kettles, R A Klassen e R. J. McNeil. Recommendations and guidelines for acquiring and analyzing soil geochemical data to estimate the range of background concentrations for risk assessments. Natural Resources Canada/ESS/Scientific and Technical Publishing Services, 2011. http://dx.doi.org/10.4095/287952.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

8

Grunsky, E. C., P. W. B. Friske e R. McNeil. A re-evaluation of lake sediment geochemistry from the Bancroft region of Ontario; recognizing geochemical background and sources of uranium and REE mineralization. Natural Resources Canada/ESS/Scientific and Technical Publishing Services, 2014. http://dx.doi.org/10.4095/294924.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

9

de Caritat, Patrice, Brent McInnes e Stephen Rowins. Towards a heavy mineral map of the Australian continent: a feasibility study. Geoscience Australia, 2020. http://dx.doi.org/10.11636/record.2020.031.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

Heavy minerals (HMs) are minerals with a specific gravity greater than 2.9 g/cm3. They are commonly highly resistant to physical and chemical weathering, and therefore persist in sediments as lasting indicators of the (former) presence of the rocks they formed in. The presence/absence of certain HMs, their associations with other HMs, their concentration levels, and the geochemical patterns they form in maps or 3D models can be indicative of geological processes that contributed to their formation. Furthermore trace element and isotopic analyses of HMs have been used to vector to mineralisation or constrain timing of geological processes. The positive role of HMs in mineral exploration is well established in other countries, but comparatively little understood in Australia. Here we present the results of a pilot project that was designed to establish, test and assess a workflow to produce a HM map (or atlas of maps) and dataset for Australia. This would represent a critical step in the ability to detect anomalous HM patterns as it would establish the background HM characteristics (i.e., unrelated to mineralisation). Further the extremely rich dataset produced would be a valuable input into any future machine learning/big data-based prospectivity analysis. The pilot project consisted in selecting ten sites from the National Geochemical Survey of Australia (NGSA) and separating and analysing the HM contents from the 75-430 µm grain-size fraction of the top (0-10 cm depth) sediment samples. A workflow was established and tested based on the density separation of the HM-rich phase by combining a shake table and the use of dense liquids. The automated mineralogy quantification was performed on a TESCAN® Integrated Mineral Analyser (TIMA) that identified and mapped thousands of grains in a matter of minutes for each sample. The results indicated that: (1) the NGSA samples are appropriate for HM analysis; (2) over 40 HMs were effectively identified and quantified using TIMA automated quantitative mineralogy; (3) the resultant HMs’ mineralogy is consistent with the samples’ bulk geochemistry and regional geological setting; and (4) the HM makeup of the NGSA samples varied across the country, as shown by the mineral mounts and preliminary maps. Based on these observations, HM mapping of the continent using NGSA samples will likely result in coherent and interpretable geological patterns relating to bedrock lithology, metamorphic grade, degree of alteration and mineralisation. It could assist in geological investigations especially where outcrop is minimal, challenging to correctly attribute due to extensive weathering, or simply difficult to access. It is believed that a continental-scale HM atlas for Australia could assist in derisking mineral exploration and lead to investment, e.g., via tenement uptake, exploration, discovery and ultimately exploitation. As some HMs are hosts for technology critical elements such as rare earth elements, their systematic and internally consistent quantification and mapping could lead to resource discovery essential for a more sustainable, lower-carbon economy.

10

Bourdeau, J. E., e R. D. Dyer. Regional-scale lake-sediment sampling and analytical protocols with examples from the Geological Survey of Canada. Natural Resources Canada/CMSS/Information Management, 2023. http://dx.doi.org/10.4095/331911.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

Abstract (sommario):

Regional-scale lake sediment surveys have been successfully used since the 1970s as a means for reconnaissance geochemical exploration. Lake sediment sampling is typically performed in areas with a lack of streams and an overabundance of small-sized (=5 km across) lakes. Lake sediments are known to have major, minor and trace element concentrations that reflect the local geology. Overall, lake sediment surveys are planned and conducted following four distinct stages: 1) background research, 2) orientation survey, 3) regional survey, and 4) detailed survey. At the Geological Survey of Canada, samples are usually collected from a helicopter with floats. Sample density ranges from 1 sample per 6 - 13 km2. Samples are collected from the centre of the lake using a gravity torpedo sampler which corresponds to a hollow-pipe, butterfly bottom-valved sampler attached by a rope to the helicopter. Collected sediment samples are then placed in labelled bags and left to air dry. Detailed field notes and additional samples (field duplicates), for the purpose of an adequate quality assurance and quality control program, are also taken. Samples are then milled and sent to analytical laboratories for element determination. Commonly used analytical methods include: X-ray fluorescence (XRF), atomic absorption spectroscopy (AAS), inductively coupled plasma-atomic emission spectrometry (ICP-AES) and -mass spectrometry (ICP-MS), instrumental neutron activation analysis (INAA), and/or determination of volatile compounds and organic carbon using Loss on Ignition (LOI). Analytical data is first evaluated for quality (contamination, accuracy and precision). Numerous options for the analysis of lake sediment data exist, ranging from simple basic element concentration maps and statistical graphical displays together with summary statistics, to employing multivariate methodologies, and, more recently, using machine learning algorithms. By adopting the set of guidelines and examples presented in this manual, scientific researchers, exploration geologists, geochemists and citizen scientists will be able to directly compare lake sediment datasets from anywhere in Canada.