Combined dating of goethites and kaolinites from ferruginous duricrusts. Deciphering the Late Neogene erosion history of Central Amazonia

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dc.contributor.authorAllard, Thierry
dc.contributor.authorGautheron, Cécile
dc.contributor.authorBressan Riffel, Silvana
dc.contributor.authorBalan, Etienne
dc.contributor.authorSoares, Bruna Fernandes
dc.contributor.authorPinna-Jamme, Rosella
dc.contributor.authorDerycke, Alexis
dc.contributor.authorMorin, Guillaume
dc.contributor.authorBueno, Guilherme Taitson
dc.contributor.authordo Nascimento, Nadia [UNESP]
dc.contributor.institutionUniversité Pierre et Marie Curie
dc.contributor.institutionUniversité Paris-Saclay
dc.contributor.institutionFederal University of Rio Grande do Sul
dc.contributor.institutionPontifícia Universidade Católica de Minas Gerais - Pós Graduação de Geografia
dc.contributor.institutionFederal University of Goias
dc.contributor.institutionUniversidade Estadual Paulista (Unesp)
dc.date.accessioned2018-12-11T16:51:46Z
dc.date.available2018-12-11T16:51:46Z
dc.date.issued2018-02-20
dc.description.abstractThis study focuses on the dating of millimetric pisoliths from ferruginous duricrusts located in central Amazonia (Brazil), by coupling detailed mineralogy and two relevant dating methods: (i) (U-Th)/He analysis of goethites by mass spectrometry; (ii) analysis of radiation-induced defects of kaolinites embedded in duricrusts by electron paramagnetic resonance spectroscopy (EPR). Three samples collected at different elevations in the landscape were selected. The goethite corrected ages range from 1.1–15.2 Ma and consistently increase with elevation. EPR was performed on kaolinites after several cycles of a deferration procedure. Considering extreme geochemical scenarii, the ages of kaolinites are 1.7–7.1 Ma for a closed system and 4.0–16.7 Ma for an open system with 100% Rn loss. Ages of goethites and kaolinites are close, in the limit of the uncertainty of the methods. They show important periods of duricrust formation at Middle Miocene and at Late Miocene/Pliocene. Data allow the estimation of lowering rates between 3 and 8 m/Ma, in agreement with independent data available in the literature for the central Amazonia region or even for erosion of other cratons in the world. The two dating methods can be compared on common duricrust samples. By revealing single or multi-step weathering/erosion episodes related to relictual paleosurfaces, they also bring promising contributions to an advanced knowledge of ancient and complex lateritic geosystems.en
dc.description.affiliationIMPMC UMR CNRS 7590 Université Pierre et Marie Curie, 4 place Jussieu
dc.description.affiliationGEOPS Université Paris-Sud 11 CNRS Université Paris-Saclay, Rue du Belvédère, Bât. 504
dc.description.affiliationUFRGS Federal University of Rio Grande do Sul, Av. Bento Gonçalves, 9500, Institute of Geosciences
dc.description.affiliationPontifícia Universidade Católica de Minas Gerais - Pós Graduação de Geografia, Av. Itaú, 505 - Prédio Emaús - Dom Cabral
dc.description.affiliationUFG IESA Federal University of Goias, Av. Esperança, s/n
dc.description.affiliationUNESP State University of São Paulo, Av. 24 A, 15, Bela Vista
dc.description.affiliationUnespUNESP State University of São Paulo, Av. 24 A, 15, Bela Vista
dc.format.extent136-150
dc.identifierhttp://dx.doi.org/10.1016/j.chemgeo.2018.01.004
dc.identifier.citationChemical Geology, v. 479, p. 136-150.
dc.identifier.doi10.1016/j.chemgeo.2018.01.004
dc.identifier.file2-s2.0-85041602816.pdf
dc.identifier.issn0009-2541
dc.identifier.scopus2-s2.0-85041602816
dc.identifier.urihttp://hdl.handle.net/11449/170632
dc.language.isoeng
dc.relation.ispartofChemical Geology
dc.relation.ispartofsjr1,755
dc.rights.accessRightsAcesso aberto
dc.sourceScopus
dc.subjectAmazonia
dc.subjectDating
dc.subjectDuricrust
dc.subjectGoethite (U-Th)/He
dc.subjectKaolinite EPR
dc.subjectLaterite
dc.titleCombined dating of goethites and kaolinites from ferruginous duricrusts. Deciphering the Late Neogene erosion history of Central Amazoniaen
dc.typeArtigo

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