El sílex de tipo “Urbasa”. Caracterización petrológica y geoquímica de un marcador litológico en yacimientos arqueológicos del Suroeste europeo durante el Pleistoceno superior y Holoceno inicial

The �Urbasa� flint, which occurs intercalated within shallow-water limestones of Thanetian (upper Paleocene) age was one of the best and most used flint sources during the Prehistoric times in the Basque-Cantabrian area. Two of the main outcrops/quarries where the �Urbasa� flint was exploited are located in the Urbasa ridge (W Navarra). The analysis of the compositional texture, mineralogy and geochemical features has revealed that the �Urbasa� flint is highly pure and of fine-grained texture, but with high contents of moganite, traces of organic matter and, less frequently, carbonates and clay.