Pb-210 and compositional data of sediments from Rondonian lakes, Madeira River basin, Brazil

dc.contributorUniversidade Estadual Paulista (Unesp)
dc.contributorFundação Universidade Federal de Rondônia (UNIR)
dc.creatorBonotto, Daniel Marcos [UNESP]
dc.creatorVergotti, Marcelo
dc.date2015-10-21T20:18:19Z
dc.date2015-10-21T20:18:19Z
dc.date2015-05-01
dc.date.accessioned2023-09-12T06:47:57Z
dc.date.available2023-09-12T06:47:57Z
dc.identifierhttp://www.sciencedirect.com/science/article/pii/S0969804315000408
dc.identifierApplied Radiation And Isotopes. Oxford: Pergamon-elsevier Science Ltd, v. 99, p. 5-19, 2015.
dc.identifier0969-8043
dc.identifierhttp://hdl.handle.net/11449/129067
dc.identifier10.1016/j.apradiso.2015.02.002
dc.identifierWOS:000353853100002
dc.identifier7430102726026121
dc.identifier.urihttps://repositorioslatinoamericanos.uchile.cl/handle/2250/8778408
dc.descriptionGold exploration has been intensive in Brazilian Amazon over the last 40 years, where the use of mercury as an amalgam has caused abnormal Hg concentrations in water bodies. Special attention has been directed to Madeira River due to fact it is a major tributary of Amazon River and that since 1986, gold exploration has been officially permitted along a 350 km sector of the river. The Pb-210 method has been used to date sediments taken from nine lakes situated in Madeira River basin, Rondonia State, and to verify where anthropogenic Hg might exist due to gold exploitation in Madeira River. Activity profiles of excess Pb-210 determined in the sediment cores provided a means to evaluate the sedimentation rates using a Constant Flux: Constant Sedimentation (CF:CS) and Constant Rate of Supply (CRS) of unsupported/excess Pb-210 models. A significant relationship was found between the CF:CS sedimentation rates and the mean values of the CRS sedimentation rates (Pearson correlation coefficient r=0.59). Chemical data were also determined in the sediments for identifying possible relationships with Hg occurring in the area. Significant values were found in statistical correlation tests realized among the Hg, major oxides and Total Organic Carbon (TOC) content in the sediments. The TOC increased in the sediment cores accompanied by a loss on ignition (LOI) increment, whereas silica decreased following a specific surface area raising associated to the TOC increase. The CRS model always provided ages within the permitted range of the 210Pb-method in the studied lakes, whereas the CF:CS model predicted two values above 140 years.
dc.descriptionConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
dc.descriptionUniversidade Estadual Paulista, Departamento de Petrologia e Metalogenia, Instituto de Geociências e Ciências Exatas de Rio Claro
dc.format5-19
dc.languageeng
dc.publisherElsevier B.V.
dc.relationApplied Radiation And Isotopes
dc.relation1.123
dc.relation0,528
dc.rightsAcesso restrito
dc.sourceWeb of Science
dc.subjectPb-210-chronological method
dc.subjectSedimentation rates
dc.subjectCF:CS model
dc.subjectCRS model
dc.subjectMadeira river basin
dc.titlePb-210 and compositional data of sediments from Rondonian lakes, Madeira River basin, Brazil
dc.typeArtigo


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