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dc.contributor.authorCardoso Nery, Jose Reinaldo
dc.contributor.authorBonotto, Daniel Marcos [UNESP]
dc.identifier.citationJournal of Environmental Radioactivity. Oxford: Elsevier B.V., v. 102, n. 4, p. 348-362, 2011.
dc.description.abstractActivity profiles of excess Pb-210 determined in three sediment cores from Amazon River mouth, Macapa city, Brazil, provided the evaluation of sedimentation rates, contributing to a better knowledge of the hydrological conditions in the site that is the capital of Amapa State and is drained by the waters of the huge Amazon River. Chemical data were also determined in the sediments, allowing identify signatures coupled to anthropogenic inputs held in the past in Amapa State. Significant direct relationships between LOI (loss on ignition) and organic matter were found for all sediments profiles. Silica was found to be inversely related to organic matter in the three profiles: its decrease accompanied an increase on the specific surface of the sediments. This relationship was confirmed by a great number of inverse significant correlations among silica and oxides Na2O, K2O, CaO, MgO, Al2O3, P2O5, Fe2O3 and MnO. It was possible to identify the role of organic matter on adsorption of several oxides in the core sediments profiles. Apparent sediment mass accumulation rates corresponding to values between 450 and 2510 mg cm(-2) yr(-1) were obtained, and are compatible with the results of others studies. The Pb-210 activities in one sampling point suggested the occurrence of anthropogenic inputs related to the initial period of the mining activities conducted in Serra do Navio, Amapa State, for the commercialization of Mn ores. This was reinforced by the abrupt fluctuations in chemical data obtained for the sediments and composition of the interstitial waters occurring there. The Atlantic hurricane activity also appeared to affect the sedimentation rates in the area, as two different values were recorded in each profile. (C) 2011 Elsevier Ltd. All rights reserved.en
dc.description.sponsorshipConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
dc.publisherElsevier B.V.
dc.relation.ispartofJournal of Environmental Radioactivity
dc.sourceWeb of Science
dc.subjectSedimentation ratesen
dc.subjectPhysical weatheringen
dc.subjectPb-210-chronological methoden
dc.subjectAmazon River mouthen
dc.subjectAnthropogenic influencesen
dc.titlePb-210 and composition data of near-surface sediments and interstitial waters evidencing anthropogenic inputs in Amazon River mouth, Macapa, Brazilen
dcterms.rightsHolderElsevier B.V.
dc.contributor.institutionUniversidade Estadual Paulista (UNESP)
dc.contributor.institutionUniversidade Federal do Amapá (UNIFAP)
dc.description.affiliationUniv Estadual Paulista UNESP, Dept Petrol & Metalogenia, BR-13506900 São Paulo, Brazil
dc.description.affiliationUniv Fed Amapa UNIFAP, BR-68902280 Macapa, Amapa, Brazil
dc.description.affiliationUnespUniv Estadual Paulista UNESP, Dept Petrol & Metalogenia, BR-13506900 São Paulo, Brazil
dc.rights.accessRightsAcesso restrito
unesp.campusUniversidade Estadual Paulista (UNESP), Instituto de Geociências e Ciências Exatas, Rio Claropt
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