|
|
|
Registros recuperados: 34 | |
|
|
Achab, M.; El hatimi, I.; El moumni, B.. |
Dans le but d’évaluer le degré de contamination chimique et/ou organique des sédiments superficiels le long des émissaires continentaux, des échantillons de sédiments de surface ont été prélevés et analysés le long des oueds Souani et Mghogha et au niveau de la canalisation majeure de la ville de Tanger débouchant sur la baie située sur la marge méditerranéenne marocaine. La dynamique sédimentaire dans les oueds montre exceptionnellement une évolution amont–aval granocroissante en relation avec l’activité anthropique (remblaiement des bassins versants par les matériaux de construction tels que les briques, ciments, verres, etc.). La matière organique est présente à des teneurs relativement élevées en corrélation positive avec la sédimentation fine. L’azote... |
Tipo: Journal Contribution |
Palavras-chave: Sedimentology; Mineralogy; Pollution; Geochemical surveys; Bay dynamics. |
Ano: 2002 |
URL: http://hdl.handle.net/1834/199 |
| |
|
|
Brahim, M.; Ben Amor, R.; Gueddari, M.. |
The results of the grain size and mineralogical analysis of the surface sediments of the Gulf of Gabes, taken with Various depths between the coast Sfax-Zarzis and the isobaths -100 m, allow to identify the origin of these sediments and to specify the factors and the phenomena, which are involved in their transport and their deposit. The mineralogical study resulted in high lighting a clear relation between the recent sedimentary stock of the gulf of Gabès and the bordering geological formations. The sediments study showed that the detritus materials are of continental origin and the sediments coming from the coastal erosion are subjected to a dynamics, which is controlled, primarily by the action of the currents (current coastal and currents tide and by... |
Tipo: Journal Contribution |
Palavras-chave: Grain size; Sediment analysis; Sediment chemistry; Sediments; Mineralogy. |
Ano: 2003 |
URL: http://hdl.handle.net/1834/1118 |
| |
|
| |
|
| |
|
| |
|
|
Vieira,Montesquieu da S.; Oliveira,Fábio H. T. de; Santos,Hemmannuella C.; Medeiros,Jailma dos S. de. |
ABSTRACT The state of Paraíba, Brazil, has soils from well- to poorly-developed, in which potassium (K) is found in different levels, forms and, consequently, with varying availability to plants. The objective of this study was to evaluate the contribution of non-exchangeable K forms to corn plants in 12 soils from Paraíba state, along four successive cycles. The experimental design was completely randomized block with three replicates and the 24 treatments consisted of the combination between two K levels (0 and 100 mg dm-3) and 12 soils. Before and after each cycle, subsamples of 0.2 dm3 were collected in each pot for the determination of non-exchangeable K (Kne), exchangeable K (Ke) and soluble K (Ks). For each cycle, dry matter production, dry matter... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Northeastern soils; Mineralogy; K forms; K availability. |
Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662016000100009 |
| |
|
| |
|
| |
|
|
Guimarães,José Tasso Felix; Cohen,Marcelo Cancela Lisboa; França,Marlon Carlos; Silva,Any Kelly Terra da; Rodrigues,Suyanne Flavia Santos. |
Based on sedimentological and geochemical data, this work relates spectrophotometric measurements with sediment composition and its application in palaeoecological studies of Amazon wetlands. The CIELAB values are directly related to mineralogical and chemical composition, mostly involving quartz, iron oxyhydroxides and sulfides (e.g. pyrite), and total organic carbon. Total organic carbon contents between 0.4-1%, 1-2%, 3-5% and 15-40% were related to L* (lightness) data of 27, 26-15, 7-10 and 7 or less, respectively. The CIELAB values of a deposit in Marabá, Pará, were proportional to variations in quartz and total organic carbon contents, but changes in zones of similar color, mainly in the +a* (red) and +b* (yellow) values of deposits in Calçoene, Amapá... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Sedimentology; Amazon region; Munsell color systems; Mineralogy; Chemical composition. |
Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0044-59672013000300009 |
| |
|
|
Costa,Marcondes Lima da; Kern,Dirse Clara; Pinto,Alice Helena Eleotério; Souza,Jorge Raimundo da Trindade. |
Several archaeological black earth (ABE) sites occur in the Amazon region. They contain fragments of ceramic artifacts, which are very important for the archaeological purpose. In order to improve the archaeological study in the region we carried out a detailed mineralogical and chemical study of the fragments of ceramic artifacts found in the two ABE sites of Cachoeira-Porteira, in the Lower Amazon Region. Their ceramics comprise the following tempers: cauixi, cariapé, sand, sand +feldspars, crushed ceramic and so on and are composed of quartz, clay equivalent material (mainly burned kaolinite), feldspars, hematite, goethite, maghemite, phosphates, anatase, and minerals of Mn and Ba. Cauixi and cariapé, siliceous organic compounds, were found too. The... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Terra Preta; Black Earth; Archaeological ceramic fragment; Lower Amazon; Phosphates; Mineralogy. |
Ano: 2004 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0044-59672004000200004 |
| |
|
| |
|
| |
|
|
Centurion,José Frederico; Beutler,Amauri Nelson; Souza,Zigomar Menezes de. |
The objective of this study was to assess the physical attributes of a kaolinitic oxisol, medium texture (Haplustox) and an oxidic oxisol, clayey (Eutrustox) under different usage systems, localized in the region of Jaboticabal, SP, Brazil. The usage systems were sugarcane, cotton and forest. Parameters such as soil bulk density, total porosity, macro and microporosity at the depths of 0.0-0.1; 0.1-0.2; 0.2-0.3, and 0.3-0.4 m were evaluated. Haplustox showed greater bulk density and smaller total porosity, macro and microporosity. The usage increased the bulk density in 0.0-0.3 m depth, with greater effects on the kaolinitic oxisol, mainly in 0.1-0.2 m depth in the areas cultivated with sugarcane. |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Sugarcane; Cotton; Forest; Mineralogy; Porosity; Bulk density. |
Ano: 2004 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132004000500007 |
| |
|
| |
Registros recuperados: 34 | |
|
|
|