Interacting lithogenesis and pressure-solution deformation in conglomerates: example from the Aliaga basin (Iberian Chain)
- Autores: José Luis Simón Gómez, Josep Gisbert Aguilar, Óscar Buj Fandos
- Localización: Geogaceta, ISSN 0213-683X, Nº. 53, 2013, págs. 41-44
- Idioma: inglés
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Resumen
In conglomerates made of soluble components,much deformation uses to be accommodated by pressure solution. This mechanism can result in strong volume reduction, as well as in lithological (textural and compositional) changes owing to selective dissolution of rock components, and development of anisotropic fabrics. We study an example of Cenozoic conglomerates deformed by Alpine compression in the Aliaga basin (Iberian Chain). Active pressure-solution was favoured by (i) high solubility of limestone pebbles in relation to matrix silicic grains, (ii) probable low strain rate, (iii) presence of early cementation. Low relative mobility between matrix grains prevents them from free-flowing around pebbles; instead, the ensemble matrix-cement behaved as a rigid flow unit, its interface with a soluble pebble becoming a single stylolitic surface. Solution lineations tend to be consistently parallel to each other and parallel to the maximum shortening/compression axis, which results in net volume reduction.
