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Registros recuperados: 41
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A influência da mineralogia na evolução micromorfológica do colapso em saprólito e latossolo. Infoteca-e
CARDOSO, F. B. da F.; MARTINS, E. de S.; CARVALHO, J. C. de..
Resumo: Este trabalho mostra a aplicação de técnicas modernas de micromorfologia e mineralogia no desenvolvimento de um modelo evolutivo do colapso em solos tropicais profundamento intemperizados. Abstract: This work exibition the application of modern techniques of micromorphology and mineralogy in the development of an evolutionary model of the collapse in deeply weathering tropical soils.
Tipo: Boletim de Pesquisa e Desenvolvimento (INFOTECA-E) Palavras-chave: ECOSOL170; Mineralogia; Solo; Micromorfologia; Geoquímica; Colapso; Cerrado; Análise do solo; Mineralogy; Soil; Micromorphology; Geochemistry; Collapse; Soil testing.
Ano: 2002 URL: http://www.infoteca.cnptia.embrapa.br/handle/doc/567945
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Age, geochemical characteristics and petrogenesis of Cenozoic intraplate alkaline volcanic rocks in the Bafang region, West Cameroon ArchiMer
Ngongang, Nicaise Blaise Tchuimegnie; Kamgang, Pierre; Chazot, Gilles; Agranier, Arnaud; Bellon, Herve; Nonnotte, Philippe.
The origin of the volcanism in the Cameroon Volcanic Line and the nature of its mantle sources are still highly controversial. We present major and trace element compositions as well as Sr-Nd-Pb-Hf isotopic results on mafic and intermediate lavas from the Bafang area in the central part of the Cameroon Volcanic Line. The lavas range from basanites and basalts to hawaiites and mugearites with an alkaline affinity and were emplaced between 10 and 6 Ma ago. The evolution from basalts and basanites to more differentiated rocks involved fractionation of olivine, clinopyroxene and Fe-Ti oxides, but the isotopic compositions show that crustal contamination processes affected some magmas during their ascent in the crust. Basalts and basanites originated from a...
Tipo: Text Palavras-chave: Cameroon Volcanic Line; Geochemistry; Magmatism; Mantle source.
Ano: 2015 URL: https://archimer.ifremer.fr/doc/00221/33255/32158.pdf
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Background and Reference Values of Metals in Soils from Paraíba State, Brazil Rev. Bras. Ciênc. Solo
Almeida Júnior,Agenor Bezerra de; Nascimento,Clístenes Williams Araújo do; Biondi,Caroline Miranda; Souza,Adailson Pereira de; Barros,Felipe Martins do Rêgo.
ABSTRACT Soil contamination by heavy metals threatens ecosystems and human health. Environmental monitoring bodies need reference values for these contaminants to assess the impacts of anthropogenic activities on soil contamination. Quality reference values (QRVs) reflect the natural concentrations of heavy metals in soils without anthropic interference and must be regionally established. The aim of this study was to determine the natural concentrations and quality reference values for the metals Ag, Ba, Cd, Co, Cu, Cr, Mo, Ni, Pb, Sb and Zn in soils of Paraíba state, Brazil. Soil samples were collected from 94 locations across the state in areas of native vegetation or with minimal anthropic interference. The quality reference values (QRVs) were (mg...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Geochemistry; Soil pollution; Micronutrients; Trace elements.
Ano: 2016 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832016000100509
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Caractérisation physique et géochimique d'hydrates de gaz d'environnements géologiques différents. Apport des techniques de Diffraction X Synchrotron et de Spectroscopie Raman. Contribution à l'étude de leur origine, formation et stabilité sur les marges ArchiMer
Bourry, Christophe.
Clathrate hydrates are inclusion compounds consisting of an ice-like network of water cages surrounding occluded guest molecules. They occur beneath the oceans and in polar regions, where low temperature and high pressure conditions prevail. Natural gas hydrates, mainly composed of methane occur worldwide and may contain huge natural gas amount, but they can also play an important role in continental slope stability or climate change, due to the potentially enormous "greenhouse" feedback effect of methane. The knowledge of their occurrence in the natural environment, their physical, chemical or thermodynamical properties is essential to prevent geohazards, to anticipate their role in climate change or to develop technologies to take advantage of this...
Tipo: Text Palavras-chave: X Ray synchrotron diffraction; Raman spectroscopy; Geochemistry; Gas hydrate; Eau interstitielle; Diffraction X synchrotron; Spectroscopie Raman; Géochimie; Hydrate de gaz.
Ano: 2008 URL: http://archimer.ifremer.fr/doc/2008/these-6236.pdf
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Características oceanográficas y geoquímicas del Golfo de Guayaquil durante noviembre de 1994 OceanDocs
Cuadra, T. de la; Chalén, X.; Pérez, P.; Macías, P.; Ortega, D.; Ormaza, F..
Las masas de agua encontradas a partir de las variables de estado, indican una contribución muy pobre de Agua Subtropical Superficial (ASTS), mientras que las mayores contribuciones fueron de Agua Tropical Superficial (ATS). Parámetros como la temperatura y la salinidad determinaron un calentamiento del océano, tanto a nivel superficial como subsuperficial, lo cual sería una consecuencia de los procesos de redistribución de calor del océano.Esta dinámica ocasionaría anomalías del orden de los 30 metros para el caso de la profundidad de la termoclima y 2°C para el caso de la TSM. En el plancton se registraron valores mayores a 5000 larvas de peces/10 m2. La menor cantidad (260 larvas/10 m2) se registró hacia el norte del Golfo, observándose al mismo tiempo...
Tipo: Journal Contribution Palavras-chave: Oceanographic data; Geochemistry; Salinity data; Plankton; Organic matter; Plankton; Organic matter; Geochemistry; Http://aims.fao.org/aos/agrovoc/c_5950; Http://aims.fao.org/aos/agrovoc/c_5387; Http://aims.fao.org/aos/agrovoc/c_24848.
Ano: 1994 URL: http://hdl.handle.net/1834/3080
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Caracterização física e aspectos geoquímicos de dois solos da Península Keller, Ilha Rei George, Antártica Marítima. Infoteca-e
ALBUQUERQUE FILHO, M. R.; SCHAEFER, C. E. G. R.; SIMAS, F. B. N.; PEREIRA, V. V.; GUERRA, M. B. B..
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Tipo: Fôlder / Folheto / Cartilha (INFOTECA-E) Palavras-chave: Mineralogia; Solo; Geoquímica; Análise do solo; Mineralogy; Soil; Geochemistry; Soil testing.
URL: http://www.infoteca.cnptia.embrapa.br/handle/doc/569491
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Climatic evolution of the central equatorial Pacific since the Last Glacial Maximum ArchiMer
Seo, Inah; Lee, Yuri; Lee, Yong Il; Yoo, Chan Min; Hyeong, Kiseong.
This paper investigates paleoceanographic changes at a central equatorial Pacific site (6 degrees 40N, 177 degrees 28W) since the last glacial maximum using planktic foraminifera assemblages, together with the oxygen isotope (O-18) and Mg/Ca compositions of three species (Globigerinoides sacculifer, Pulleniatina obliquiloculata, and Globorotalia tumida) that dwell in the mixed layer, upper thermocline, and lower thermocline, respectively. While the Mg/Ca-derived temperatures of the mixed layer and lower thermocline varied within a narrow range from 18 ka onward, the upper thermocline temperature increased by as much as 3 degrees C during the last deglaciation (18-12 ka) with a simultaneous decrease of O-18. These changes are best explained by an enhanced...
Tipo: Text Palavras-chave: Planktic foraminifera; Geochemistry; Micropaleontology; Paleoceanography; Intertropical Convergence Zone; Last deglaciation.
Ano: 2016 URL: https://archimer.ifremer.fr/doc/00496/60721/65271.pdf
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Comportement chimique et geochimique des elements a l'état de traces dans l''estuaire de la Seine: Une synthese des resultats ArchiMer
Guegueniat, P.
Five topics are developed in this synthesis: (1) multi elements analysis in geochemistry; (2) iron geochemical behavior; (3) complexing properties of waters; (4) copper behavior in estuarine waters; (5) impact of sediment dynamics on dissolved metals concentration.
Tipo: Text Palavras-chave: Geographical distribution; Radiochemistry; Brackishwater pollution; Sediment dynamics; Dissolved chemicals; Heavy metals; Geochemistry; Physicochemical properties; Trace elements.
Ano: 1985 URL: http://archimer.ifremer.fr/doc/1985/acte-1290.pdf
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Determination of rare earth elements in geological samples using the agilent SVDV ICP-OES. Repositório Alice
AMARAL, C. D. B. do; MACHADO, R. C.; BARROS, J. A. V. de A.; VIRGILIO, A.; SCHIAVO, D.; NOGUEIRA, A. R. de A.; NOBREGA, J. de A..
2016
Tipo: Artigo em anais de congresso (ALICE) Palavras-chave: Geochemistry; Mineral.
Ano: 2016 URL: http://www.alice.cnptia.embrapa.br/handle/doc/1051472
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Diffusion induced Li isotopic fractionation during the cooling of magmatic rocks: The case of pyroxene phenocrysts from nakhlite meteorites ArchiMer
Beck, Pierre; Chaussidon, M; Barrat, J.a.; Gillet, Ph.; Bohn, Marcel.
Ion-microprobe was used to measure Li abundances and isotopic compositions in pyroxenes from three Martian meteorites belonging to the nakhlite family. The profiles performed across augite crystals from Northwest Africa 817 show a large isotopic zoning from crystal cores (delta Li-7 similar to 0 parts per thousand) to rims (delta Li-7 similar to +20 parts per thousand) while Li abundances are almost constant (similar to 9.2 mu g/g). Unlike NWA 817, the pyroxene studied in the Miller Range 03346 nakhlite shows a zoning in Li abundance, with concentrations increasing from similar to 2.5 mu g/g in the core to similar to 9 mu g/ g in the rim. The augite rim (delta Li-7 = +7 parts per thousand) is slightly enriched in Li-7 with regard to the core (delta Li-7 =...
Tipo: Text Palavras-chave: Magma; Pyroxene; Lithium; Geochemistry; Mars planet; Isotopic composition.
Ano: 2006 URL: http://archimer.ifremer.fr/doc/2006/publication-1955.pdf
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Estudio geoquímico de los sedimentos en el Canal de Jambelí OceanDocs
Jácome de Solórzano, M.; Llanos de Bonilla, L..
Se presenta las características geoquímicas del Canal de Jambelí en base al análisis de 41 muestras de sedimentos del fondo marino, obtenidas durante marzo y junio de 1986 (Fig.1). Se identifica la presencia de dos dominios de sedimentación, el uno de tipo fluvial y el otro marino; así mismo una posible tendencia de avance del sedimento fluvial sobre el sedimento marítimo. Se establece además que la concentración de los constituyentes orgánicos se encuentran dentro de rangos normales y guarda relación con la textura del sedimento.
Tipo: Journal Contribution Palavras-chave: Geochemistry; Sediments; Geochemistry; Http://aims.fao.org/aos/agrovoc/c_24848.
Ano: 1987 URL: http://hdl.handle.net/1834/2131
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Evaluación geoquímica en la fase sedimentaria de ecosistemas costeros del Estado de Sonora, México OceanDocs
Villalba, A.I.; Ortega Romero, P.; De la O Villanueva, M..
Se elaboró este trabajo en los cuerpos lagunares Guásimas, Algodones y Lobos y contribuir, de esta forma, al conocimiento geológico marino de los sistemas costeros del litoral de Sonora.
Tipo: Journal Contribution Palavras-chave: Evaluation; Geochemistry; Sediments; Coastal lagoons; Evaluation; Geochemistry; Coastal lagoons; Http://aims.fao.org/aos/agrovoc/c_2736; Http://aims.fao.org/aos/agrovoc/c_24848; Http://aims.fao.org/aos/agrovoc/c_1697.
Ano: 1989 URL: http://hdl.handle.net/1834/2159
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From intracratonic extension to mature spreading in back arc basins: Examples from the Okinawa, Lau, North Fiji basins ArchiMer
Auzende, Jean-marie; Boespflug, Xavier; Bougault, Henri; Dosso, Laure; Foucher, Jean-paul; Joron, Jean-louis; Ruellan, Etienne; Sibuet, Jean-claude.
Three cruises (POP 1, SEAPSO 3 and SEAPSO 4) carried out during the "Tour du Monde" of the R.V. Jean Charcot allow us to obtain new structural and geochemical data for the Okinawa, North Fiji and Lau basins. Taken together, the structural and geochemical data illustrate a difference in evolution stages of these sites. The less evolved stage is represented by the Okinawa basin, where accretion is evidenced only by volcanic intrusion into a thinned continental crust. The most evolved stage is illustrated in the North Fiji basin, where the present-day accretion can be directly compm·ed to the East Pacific Ridge. The Lau basin displays an intem1ediate stage with a complex system of accretionary ridges. This difference in the evolution stage is translated in...
Tipo: Text Palavras-chave: Ouest Pacifique; Bassins arriere arc; Structure; Accretion; Geochimie; West Pacific; Back arc basins; Structure; Accretion; Geochemistry.
Ano: 1990 URL: http://archimer.ifremer.fr/doc/00119/23058/20893.pdf
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Geochemistry and δ11 B evolution of tourmaline from tourmalinite as a record of oceanic crust in the Tonian Ibaré ophiolite, southern Brasiliano Orogen Anais da ABC (AABC)
ARENA,KARINE DA ROSA; HARTMANN,LÉO AFRANEO; LANA,CRISTIANO DE CARVALHO; QUEIROGA,GLÁUCIA NASCIMENTO; CASTRO,MARCO PAULO DE.
Abstract The isotopic and geochemical evolution of tourmaline constrain the processes of paleo-oceanic lithosphere in ophiolites. The Brasiliano Orogen is a major structure of South America and requires characterization for the understanding of Gondwana supercontinent evolution. We made a pioneering investigation of tourmaline from a tourmalinite in the Ibaré ophiolite by integrating field work with chemical analyses of tourmaline by electron microprobe (EPMA) and δ11B determinations via laser ablation inductively coupled plasma mass spectrometer (LA-ICP-MS). Remarkably massive tourmalinite (>90 vol.% tourmaline, some chlorite) enclosed in serpentinite has homogeneous dravite in chemical and isotopic composition (δ11B = +3.5 to +5.2‰). These results...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Boron isotopes; Geochemistry; Ibaré ophiolite; Tourmalinite; Southern Brasiliano Orogen.
Ano: 2020 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652020000100603
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Geochemistry of brazilian soils: present situation. Repositório Alice
PEREZ, D. V.; MANZATTO, C. V.; ALCÂNTARA, S. de; WASSERMAN, M. A. V..
2010
Tipo: Capítulo em livro científico (ALICE) Palavras-chave: Geochemistry.
Ano: 2010 URL: http://www.alice.cnptia.embrapa.br/handle/doc/919688
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Geology, petrography and geochemistry of the A-type granites from the Morro Redondo Complex (PR-SC), southern Brazil, Graciosa Province Anais da ABC (AABC)
VILALVA,FREDERICO C.J.; VLACH,SILVIO R.F..
The Morro Redondo Complex is one of the most important occurrences of the Graciosa A-type Province, southern Brazil. It consists of the Papanduva and Quiriri granitic plutons and a contemporaneous bimodal volcanic association. The Papanduva Pluton includes massive and deformed peralkaline alkali-feldspar granites with Na-Ca and Na-amphiboles and clinopyroxenes. The deformed types are the most evolved rocks in the province and carry rare ‘agpaitic’ minerals, some being described for the first time in granites from Brazil. The larger Quiriri Pluton comprises massive, slightly peraluminous, biotite syeno- and monzogranites with rare Ca-amphibole. Biotite compositions are relatively homogeneous, whereas sodic amphiboles and clinopyroxenes show increasing Na...
Tipo: Info:eu-repo/semantics/article Palavras-chave: A-type granites; Geochemistry; Petrography; Graciosa Province; Mineralogy; Morro Redondo Complex.
Ano: 2014 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652014000100085
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Holocene history of a lake filling and vegetation dynamics of the Serra Sul dos Carajás, southeast Amazonia Anais da ABC (AABC)
GUIMARÃES,JOSÉ T.F.; SAHOO,PRAFULLA K.; SOUZA-FILHO,PEDRO W.M.; FIGUEIREDO,MARIANA M.J. COSTA DE; REIS,LUIZA S.; SILVA,MARCIO S. DA; RODRIGUES,TARCÍSIO M..
ABSTRACT Down-core changes in sedimentary facies, elemental geochemistry, pollen, spore, δ13C, δ15N and radiocarbon records from a filled lake, named R4, of the Serra Sul dos Carajás were used to study the relationship between the paleomorphological and paleoecological processes and their significance for Holocene paleoclimatology of the southeast Amazonia. The sediment deposition of the R4 lake started around 9500 cal yr BP. Increase of detrital components from 9500 to 7000 cal yr BP suggests high weathering of surrounding catchment rocks and soils, and deposition into the lake basin under mudflows. At that time, montane savanna and forest formation were already established suggesting predominance of wet climate. However, from 7000 to 3000 cal yr BP, a...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Amazon Forest; Canga vegetation; Palynology; Carbon and nitrogen isotopes; Geochemistry.
Ano: 2019 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652019000400502
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Hydrologie, sédimentaire et géochimie de l'oued Tinja (Tunisie septentrionale OceanDocs
Ben Gharali, A.; Ouakad, M.; Gueddari, M..
L'oued Tinja relie la garaet Ichkeul à la lagune de Bizerte laquelle communique avec la mer Méditerranée par un long goulet. Les eaux de cet oued dépendent à la fois des apports saisonniers des eaux marine et douce et présente de ce fait, des salinités très fluctuantes. L'important réseau hydrographique associé au plan d'eau de l'Ichkeul (avec un bassin versant très important d'environ 2080 km2) est sujet à de nombreux aménagements hydrauliques, notamment la construction de barrages de retenues d'eau douce. Ces derniers sont susceptibles de perturber les caractéristiques hydrologiques, sédimentologiques et géochimiques du système laguno-lacustre (lagune de Bizerte et garaet Ichkeul) et d'entamer par voie de conséquence sa diversité et sa richesse...
Tipo: Journal Contribution Palavras-chave: Environmental impact; Geochemistry; Hydrology; Quality; Sediment analysis; Species diversity.
Ano: 2008 URL: http://hdl.handle.net/1834/4270
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Hydrologie, sédimentologie et géochimie de l'oued tinja (Tunisie septentrionale) OceanDocs
Ben Garali, A.; Ouakad, M.; Gueddari, M..
L'oued Tinja relie la garaet Ichkeul à la lagune de Bizerte laquelle communique avec la mer Méditerranée par un long goulet. Les eaux de cet oued dépendent à la fois des apports saisonniers des eaux marine et douce et présente de ce fait, des salinités très fluctuantes. L'important réseau hydrographique associé au plan d'eau de l'Ichkeul (avec un bassin versant très important d'environ 2080 km2) est sujet à de nombreux aménagements hydrauliques, notamment la construction de barrages de retenues d'eau douce. Ces derniers sont susceptibles de perturber les caractéristiques hydrologiques, sédimentologiques et géochimiques du système laguno-lacustre (lagune de Bizerte et garaet Ichkeul) et d'entamer par voie de conséquence sa diversité et sa richesse...
Tipo: Journal Contribution Palavras-chave: Marine sciences; Quality; Species diversity; Geochemistry; Environmental impact; Hydrology; Freshwater lagoons; Sediment analysis.
Ano: 2008 URL: http://hdl.handle.net/1834/4248
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Iron oxides and quality of organic matter in sugarcane harvesting systems Rev. Bras. Ciênc. Solo
Barbieri,Diogo Mazza; Marques Júnior,José; Siqueira,Diego Silva; Teixeira,Daniel De Bortoli; Panosso,Alan Rodrigo; Pereira,Gener Tadeu; La Scala Junior,Newton.
Improvements in working conditions, sustainable production, and competitiveness have led to substantial changes in sugarcane harvesting systems. Such changes have altered a number of soil properties, including iron oxides and organic matter, as well as some chemical properties, such as the maximum P adsorption capacity of the soil. The aim of this study was to characterize the relationship between iron oxides and the quality of organic matter in sugarcane harvesting systems. For that purpose, two 1 ha plots in mechanically and manually harvested fields were used to obtain soil samples from the 0.00-0.25 m soil layer at 126 different points. The mineralogical, chemical, and physical results were subjected to descriptive statistical analyses, such as the...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Degree of humification; Geochemistry; Soil management; Sustainable agriculture.
Ano: 2014 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832014000400010
Registros recuperados: 41
Primeira ... 123 ... Última
 

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