SP Fig. 1. LA-ICP-MS U–Pb dating of Carboniferous ash layers in the Cantabrian Zone (N Spain): stratigraphic implications Merino-ToméOscar Gutiérrez-AlonsoGabriel VillaElisa Fernández-SuárezJavier Martín LlanezaJaime HofmannMandy 2017 SP Fig. 1. Synthetic stratigraphic section of the Baleas and Alba Formation in the Las Baleas section with the location of samples BA-1 and BA-2. Conodont zones of the Baleas Formation and the base of the Alba Formation according García-Alcalde (1985). Conodont zones of the Alba Formation according Sánz-López & Blanco-Ferrera (2012).