The Silurian Section of the Valle Syncline (Sierra Norte de Sevilla UNESCO Global Geopark, Spain) as an International Standard for Graptolite Biostratigraphy

The Paleozoic succession of the Sierra Norte de Sevilla UNESCO Global Geopark (Ossa Morena Zone of the Iberian Massif, SW Spain) includes a nearly complete Silurian succession, ca. 150 m thick, deposited in an outer shelf setting. In the core part of the Valle syncline, the El Pintado-1 section exhibits a condensed graptolite-rich Silurian black-shale facies ranging from the base of the Rhuddanian to the upper Ludfordian. Most of the standard graptolite biozones of the Silurian System have been identified in the section. The preliminary record of Llandovery graptolites in the lower part of the succession comprises more than 200 species, 19 of them new. The El Pintado-1 geosite is of enormous value for the world’s palaeontological heritage, reinforced by the future placement here of the GSSP for the base of the Telychian Stage. The fragility of the site and its scientific importance mean that the section is not open to visitors to the Geopark, and its difficult accessibility also adds some protection, favoring its conservation beyond the regional legislative framework.