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dc.contributor.authorFurquim, Sheila Aparecida Correia [UNIFESP]
dc.contributor.authorBarbiero, Laurent
dc.contributor.authorGraham, Robert C.
dc.contributor.authorQueiroz Neto, Jose Pereira de
dc.contributor.authorFerreira, Rosely Pacheco Dias
dc.contributor.authorFurian, Sonia
dc.identifier.citationGeoderma. Amsterdam: Elsevier B.V., v. 158, n. 3-4, p. 331-342, 2010.
dc.description.abstractThe mineralogy and origin of micas were investigated in incipient soils surrounding a modem alkaline-saline lake of Nhecolandia, a sub-region of Pantanal wetland. Soils were sampled along a toposequence and analyzed by XRD, TEM-EDS, and ICP-MS. the studied micas, mainly concentrated in a green horizon, are dioctahedral, strongly associated with Fe3+ and Al, and interstratified with smectite layers. Classification of individual crystals shows that glauconite and Fe-illite are the dominant micas, but one crystal of illite was recognized. Si-rich amorphous materials are associated with small crystallites in the mica-enriched horizon. A recent study shows that water samples from the studied lake and the surrounding water table have high pH, negative Eh, temperatures up to 40 C. high concentration of K. and low concentration of Si(OH)(4). Experimental studies of micas synthesis reported in the literature show that similar water conditions allow for dioctahedral mica crystallization from initial precipitation of amorphous hydroxides. Therefore, water characteristics combined with presence of Si-rich amorphous materials in the mica-enriched horizon suggest that the micas of the study area are neoformed. the alternated origin of illite, glauconite, and Fe-illite mixed-layer minerals probably occurs due to seasonal variations of pH. temperature, and chemical composition of waters in microenvironments, since the changes at this scale are possibly faster and more extreme. (C) 2010 Elsevier B.V. All rights reserved.en
dc.description.sponsorshipCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
dc.description.sponsorshipFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
dc.description.sponsorshipINSU-EC2CO (Ecosphere Continentale et Cotiere)
dc.publisherElsevier B.V.
dc.rightsAcesso restrito
dc.subjectChemical precipitationen
dc.subjectFerric illiteen
dc.subjectMica-smectite interstratificationen
dc.subjectSaline lakeen
dc.titleNeoformation of micas in soils surrounding an alkaline-saline lake of Pantanal wetland, Brazilen
dc.contributor.institutionUniversidade de São Paulo (USP)
dc.contributor.institutionUniv Toulouse
dc.contributor.institutionUniv Calif Riverside
dc.contributor.institutionUniversidade Federal de São Paulo (UNIFESP)
dc.description.affiliationUniv São Paulo, Dept Geog, Lab Pedol, São Paulo, Brazil
dc.description.affiliationUniv Toulouse, UPS SVT OMP, LMTG, F-31062 Toulouse, France
dc.description.affiliationLMTG, CNRS, UMR5563, F-31400 Toulouse, France
dc.description.affiliationLMTG, IRD, F-31400 Toulouse, France
dc.description.affiliationUniv Calif Riverside, Soil & Water Sci Program, Dept Environm Sci, Riverside, CA 92521 USA
dc.description.affiliationUnifespUNIFESP, ICAQF
dc.description.sponsorshipIDCAPES: 412/03
dc.description.sponsorshipIDFAPESP: 08/09086-7
dc.description.sponsorshipIDFAPESP: 09/53524-1
dc.description.sourceWeb of Science

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