Características texturales y variaciones morfológicas de los estromatolitos lacustres del Mioceno de la Sierra de Alcubierre (Cuenca del Ebro)Interpretación sedimentológica preliminar
- L. Martín Bello 1
- C. Arenas Abad 1
- A.M. Alonso Zarza 2
- G. Pardo Tirapu 1
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1
Universidad de Zaragoza
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2
Universidad Complutense de Madrid
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ISSN: 1576-5172
Année de publication: 2016
Titre de la publication: IX CONGRESO GEOLÓGICO DE ESPAÑA
Número: 16
Pages: 637-640
Type: Article
D'autres publications dans: Geotemas (Madrid)
Résumé
The Miocene lacustrine record of the central Ebro Basin (Spain) encompasses abundant stromatolites, in particular in the Sierra de Alcubierre. The stromatolites are associated with laminated limestones (locally dolostones), with lenticular and wavy stratification, hummocky-cross stratification and horizontal lamination. Both facies represent a shallow saline lake context with carbonate deposition. In the type-facies sequence (deepening-shallowing cycle), the stromatolites occur both at the base of deposits that represent the beginning of a deepening process and through deposits that represent a shallowing process. In both settings, different morphological types of stromatolites are present: thin planar beds (mm to 10 cm thick), bioherms and biostromes (up to 30 cm thick). The laminae are smooth; alternating porous and dense laminae, single and composite; however, the textural pattern is neither simple or single. Bioherms and biostromes developed in deeper conditions and longer fair-weather periods than the planar stromatolites.