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| Vilhena,Maria do Perpetuo Socorro Progene; Costa,Marcondes Lima da; Berrêdo,José Francisco; Paiva,Rosildo Santos; Almeida,Pryscila Denise. |
| Phytoplankton is important bioindicator of chemical and biological modifications of natural ecosystems. The objective of this study was to determine the total chemical composition of the phytoplankton of the Pará and Mocajuba estuaries on the eastern coast of the Amazon region in the Brazilian state of Pará. The chemical composition of the surface water, bottom sediments (total sample and bioavailable fraction), and the phytoplankton were determined by inductively coupled plasma optical emission spectrometry. Phytoplankton contained high concentrations of Ca, P, Mn, Fe, Zn, Al, Ba, and Pb. The phytoplankton of the Mocajuba estuary is rich in Fe (2,967-84,750 µg g-1), while those from the Pará is rich in Al (1,216-15,389 µgg-1), probably reflecting... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Sediments; Trace metals; Plankton; Surface water. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0044-59672014000400012 |
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| Costa,Marcondes Lima da; Kern,Dirse Clara; Pinto,Alice Helena Eleotério; Souza,Jorge Raimundo da Trindade. |
| This paper carried out a chemical investigation of archaeological ceramic artifacts found in archaeological sites with Black Earth (ABE) in the Lower Amazon Region at Cachoeira-Porteira, State of Pará, Brazil. The ceramic artifacts, mostly of daily use, belong to Konduri culture (from 900 to 400 years BP). They are constituted of SiO2, Al2O3, Fe2O3, Na2O and P2O5; SiO2 and Al2O3 together add up to 80 % and indicate influence of acid rocks, transformed into clay minerals basically kaolinite. The relative high contents of P2O5 (2.37 % in average) come out as (Al,Fe)-phosphate, an uncommon fact in primitive red ceramics, but found in some roman and egyptian archaeological sites. The contents of the trace elements are similar or below the Earth's crust... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Terra preta; Black earth; Lower Amazon; Soil; Chemistry; Phosphorus; Geochemical Evolution. |
| Ano: 2004 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0044-59672004000300004 |
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| 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 |
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