The Checa Silurian Section, an Outstanding Fossil Site in the Molina-Alto Tajo UNESCO Global Geopark, Spain

Abstract

The Paleozoic succession in the Nevera inlier of the Molina-Alto Tajo UNESCO Global Geopark (Western Iberian Cordillera, NE Spain) includes an incomplete, richly fossiliferous Silurian succession, ca. 350‒400 m thick, at the locality of Checa, one of the geosites of international interest in the Paleozoic of Spain. The Checa section starts with quartzites (Los Puertos Formation: Rhuddanian to Aeronian) which rest unconformably on Late Ordovician glaciomarine diamictites (Orea Formation: Hirnantian) and are succeeded by graptolitic black shales (Bádenas Formation). The basal 60 m of the latter unit are of Telychian age and exhibit rich graptolite faunas of nine successive graptolite biozones and subzones, with more than 85 graptolite species identified of which four were new. Besides the scientific value of the fossil locality for paleontology and international correlation of the early Silurian, aspects of the promotion and preservation of its geological heritage have been enhanced by designation as a national and international geosite, as well as by the integration in a geo-trail for visitors to the park and the fencing of part of the fossil locality to avoid illegal digging and collecting.