Geochemistry and Biomarker Analysis of the Bentonites from Esquivias (Toledo, Spain)

[EN]The Tajo Basin is one of the richest in Mg-clays known around the world. Mg-bentonites, kwon as pink clays and green clays, alter in the Intermediate Unit of the Miocene sediments. In this work, a new approach to the genesis of these bentonites is performed by studying for the first time the bio...

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Detalles Bibliográficos
Autores: García Rivas, Javier, Suárez Barrios, María Mercedes, Torres, Trinidad, Sánchez-Palencia, Yolanda, García Romero, Emilia, Ortiz, José
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2018
País:España
Institución:Universidad de Salamanca (USAL)
Repositorio:GREDOS. Repositorio Institucional de la Universidad de Salamanca
OAI Identifier:oai:gredos.usal.es:10366/146681
Acceso en línea:http://hdl.handle.net/10366/146681
Access Level:acceso abierto
Palabra clave:Authigenic clays
Bentonite
Biomarker analysis
Geochemistry
Saponite
2506 Geología
Descripción
Sumario:[EN]The Tajo Basin is one of the richest in Mg-clays known around the world. Mg-bentonites, kwon as pink clays and green clays, alter in the Intermediate Unit of the Miocene sediments. In this work, a new approach to the genesis of these bentonites is performed by studying for the first time the biomarkers present in these clays in relation to the mineralogy and geochemistry, as well as using discriminatory criteria between green and pink clays. Samples were collected at a quarry of Mg-bentonites, in the proximities of Esquivias (Toledo, Spain). Mineralogical characterization and semi-quantification (X-ray diffraction (XRD)) allowed a well-defined classification according to the mineralogical content of the samples to be established, differentiating four associations. Geochemical analyses are clearly linked to the mineralogy and provide criteria to differentiate the genesis of the materials studied. In this regard, green clays are interpreted as having a more detrital character than pink clays, which present a more authigenic character.