“…The detrital zircons age spectra also show regional differences, although ca. 550-650 Ma grains are most abundant in most of the basin and in the lower allochthon in the NW corner of Iberia, and the zircons are often abraded, which indicates long-distance transport (Gutiérrez-Alonso et al, 2003;Pereira et al, 2012;Talavera et al, 2012;Diez-Fernández et al, 2012). Commonly, a small number of b 580 Ma and 0.9-1.2 Ma zircons are also present, but they form a prominent cluster only in the Narcea antiform (Section 4.1).…”