Remarkable ichnological sites in the Armorican Quartzite (Lower Ordovician) from the Almadén- Porzuna areas (Central Iberian Zone, Spain)

Trabajo presentado en el 4th International Congress on Ichnology - ICHNIA 2016: Ichnology for the 21st century: (Palaeo) Biological Traces towards Sustainable Development, celebrado en Idanha-a-Nova (Portugal), del 6 al 9 de mayo de 2016Uppermost Armorican Quartzite strata in the synclines of Almadén and Porzuna comprise thick-bedded sandstones with an outstanding ichnofossil record. A locality near Ermita de San Blas (Agudo, Ciudad Real) exposed a large top surface of a quartzite bed yielding numerous Cruziana furcifera and weathered “Catenichnus” isp. in a concave epirelief preservation. The second locality lies 1km southwest of Ermita La Cruz de Mayo, near Porzuna, also in the province of Ciudad Real. The Skolithos and Cruziana ichnofacies alternate in successive thick sandstone beds. The first one stands out by the “pipe-rock” concentrations of Skolithos that vertically grades in large concentrations of wide Daedalus visible in cross-sections. The Cruziana ichnofacies is represented by large exposures showing circling behaviour of cruzianids, preserved as concave epireliefs. These outcrops were erroneously interpreted by locals and cultural officers as archeological rather than paleontological sites. The existence of these large ichnological surfaces may contribute in the future to allow a detailed study on the behaviour of trace markers in the shallow epicratonic South Gondwana shelf.This research is a contribution to the projects CGL2012-39471 of the Spanish MINECO, IGCP-591 (IUGSUNESCO).Peer reviewe