@prefix pubblicazioni: . @prefix unitaDiPersonaleInterno: . @prefix prodotto: . unitaDiPersonaleInterno:MATRICOLA6636 pubblicazioni:autoreCNRDi prodotto:ID34810 . @prefix prodottidellaricerca: . @prefix istituto: . istituto:CDS055 prodottidellaricerca:prodotto prodotto:ID34810 . @prefix modulo: . modulo:ID3974 prodottidellaricerca:prodotto prodotto:ID34810 . @prefix rdf: . prodotto:ID34810 rdf:type prodotto:TIPO1101 . @prefix retescientifica: . prodotto:ID34810 rdf:type retescientifica:ProdottoDellaRicerca . @prefix rdfs: . prodotto:ID34810 rdfs:label "Interstratified kaolinite-smectite: Nature of the layers and mechanism of smectite kaolinization (Articolo in rivista)"@en . @prefix xsd: . prodotto:ID34810 pubblicazioni:anno "2006-01-01T00:00:00+01:00"^^xsd:gYear . @prefix skos: . prodotto:ID34810 skos:altLabel "
Dudek T, Cuadros J, Fiore S. (2006)
Interstratified kaolinite-smectite: Nature of the layers and mechanism of smectite kaolinization
"^^rdf:HTML ; pubblicazioni:autori "Dudek T, Cuadros J, Fiore S."^^xsd:string ; pubblicazioni:paginaInizio "159"^^xsd:string ; pubblicazioni:paginaFine "170"^^xsd:string ; pubblicazioni:numeroVolume "91"^^xsd:string ; skos:note "ISI Web of Science (WOS)"^^xsd:string ; pubblicazioni:titolo "Interstratified kaolinite-smectite: Nature of the layers and mechanism of smectite kaolinization"^^xsd:string ; prodottidellaricerca:abstract "This study aims to contribute to a better understanding of the nature and evolution mechanism of interstratified clay minerals. We examined the <2 mu m or <0.2 pm size fraction of interstratified kaolinite-smectite (K-S) formed by hydrothermal and hydrogenic alteration of volcanogenic material from a Tortonian clay deposit (Almeria, Spain), a weathered Eocene volcanic ash (Yucatan, Mexico), and a weathered Jurassic bentonite (Northamptonshire, England). The methods used were X-ray diffraction analysis (XRD) of random and oriented preparations, thermogravimetry, chemical analysis, and Si-29 MAS nuclear magnetic resonance. The proportions of kaolinite and smectite in K-S (%K) were determined by fitting the XRD patterns of ethylene-glycol-saturated samples with patterns calculated with the NEWMOD computer program. The obtained range of compositions is 0-85%K. A comparison of the results from the various techniques showed non-linear relationships, indicating that the layers in K-S are complex and hybrid in nature. The smectite-to-kaolinite reaction is a solid-state transformation proceeding through formation of kaolinite-like patches within the smectite layers. The process consists of several non-simultaneous stages: (1) removal of parts of the tetrahedral sheet, resulting in formation of kaolinite-like patches; (2) layer collapse to similar to 7 angstrom where the kaolinite-like patches are sufficiently large; (3) Al for Mg substitution in the octahedral sheet, simultaneous or slightly delayed with respect to layer collapse, causing a layer-charge decrease and loss of interlayer cations; (4) Si for Al replacement in the tetrahedral sheet and further loss of interlayer cations. Iron remains in the kaolinite or is lost at the latest stages of the process." ; prodottidellaricerca:prodottoDi istituto:CDS055 , modulo:ID3974 ; pubblicazioni:autoreCNR unitaDiPersonaleInterno:MATRICOLA6636 . @prefix parolechiave: . prodotto:ID34810 parolechiave:insiemeDiParoleChiave . parolechiave:insiemeDiParoleChiaveDi prodotto:ID34810 .