Aportaciones al estudio micromorfológico de costras calizas: el papel de la porosidad en dos perfiles del interior de la Península Ibérica.
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Universidad de Salamanca
info
ISSN: 0214-2708
Année de publication: 2011
Volumen: 24
Número: 3-4
Pages: 215-226
Type: Article
D'autres publications dans: Revista de la Sociedad Geológica de España
Résumé
The porosity of Ca-carbonate accumulations located at the upper parts of two profiles developed on lithologies poor in Ca has been studied by means of SEM with EDXRA, polarized light microscope, water and adsorption-desorption nitrogen techniques, and the mercury porosimeter. At the macroscopic scale, carbonate replaces parent minerals, including quartz, preserving the parent structures in both profiles. At the microscopic level new minerals of fibrous aspect are generated, while inherited clays are replaced by small crystals of rombohedric and prismatic shapes which show different stages of growing. At the nano scale the porosity of ca. 40Å looks dominant, but some small structures of the clay accumulations seem to be preserved. The aging and hardening (lithification) of these carbonate concentrations leads to a decrease of the general porosity.