|
|
|
| Registros recuperados: 52 | |
|
| |
|
|
| 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 |
| |
|
| |
|
|
| 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 |
| |
|
|
| 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 |
| |
|
|
| HABERLE,S. G.; SZEICZ,J. M.; BENNETT,K. D.. |
| Palynological and geochemical analysis of late Holocene lake sediments and dendrochronological analysis of Pilgerodendron in a volcanically active region of southern Chile reveal the long-term impact of a series of tephra fall events and tectonic activity on lake sedimentation and local vegetation. An upper 0,75 m core overlaps with a 4,35 m long Livingstone piston core to give a 4,60 m long sediment record, extending back to 4800 yr BP. Geochemical data shows the shift from allogenic dominance to authigenic and biogenic dominance as waterlogged soils developed within the catchment. This is presumed to have occurred under the influence of continued addition of nutrients to the catchment from tephra deposition and the associated high sedimentation rates.... |
| Tipo: Journal article |
Palavras-chave: Hudson Volcano; Tephra; Pollen; Geochemistry; Dendrochronology. |
| Ano: 2000 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2000000400010 |
| |
|
|
| HARTMANN,LÉO A.; ANTUNES,LUCAS M.; ROSENSTENGEL,LEONARDO M.. |
| The Entre Rios mining district produces a large volume of amethyst geodes in underground mines and is part of the world class deposits in the Paraná volcanic province of South America. Two producing basalt flows are numbered 4 and 5 in the lava stratigraphy. A total of seven basalt flows and one rhyodacite flow are present in the district. At the base of the stratigraphy, beginning at the Chapecó river bed, two basalt flows are Esmeralda, low-Ti type. The third flow in the sequence is a rhyodacite, Chapecó type, Guarapuava subtype. Above the rhyodacite flow, four basalt flows are Pitanga, high-Ti type including the two mineralized flows; only the topmost basalt in the stratigraphy is a Paranapanema, intermediate-Ti type. Each individual flow is uniquely... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Amethyst geode; Entre Rios mining district; Paraná volcanic province; Geochemistry; Gamma-spectrometry. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652014000100187 |
| |
|
| |
|
|
| TRAVERSA,GIANBOSCO; GOMES,CELSO B.; BROTZU,PIERO; BURAGLINI,NICOLETTA; MORBIDELLI,LUCIO; PRINCIPATO,MARIA SPERANZA; RONCA,SARA; RUBERTI,EXCELSO. |
| The Araxá complex (16 km²) comprises carbonatites forming a central core and a complex network of concentric and radial dykes as well as small veins; additionally, it includes mica-rich rocks, phoscorites and lamprophyres. Fenites also occur and are represented by Proterozoic quartzites and schists of the Araxá Group. The petrographic study of 130 borehole samples indicates that the complex is basically made up by two rock-types, carbonatites and mica-rich rocks, and subordinately by a third unit of hybrid composition. Carbonatites range chemically in composition, the most abundant type being magnesiocarbonatites. Dolomite and calcite correspond to the chief constituents, but other carbonate phases, including the Ce-group RE minerals, are also recognized.... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Alkaline rocks; Carbonatites; Geochemistry. |
| Ano: 2001 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652001000100008 |
| |
|
| |
|
|
| 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 |
| |
|
| |
| Registros recuperados: 52 | |
|
|
|
