U-Pb depositional age for the upper Barrios Formation (Armorican Quartzite facies) in the Cantabrian zone of Iberia: Implications for stratigraphic correlation and paleogeography

Magmatic evolution in the N-Gondwana margin related to the opening of the Rheic Ocean—evidence from the Upper Parautochthon of the Galicia-Trás-os-Montes Zone and from the Central Iberian Zone (NW Iberian Massif)

“…The interaction between (at least) two tectonic plates is considered the most plausible rifting trigger (Nance et al 2010), but plume activity can also be accounted for (e.g., Díez Fernández et al 2012a). Although the onset of continental rifting may differ in age from one part of the margin to the other, the opening and subsequent widening of the Rheic Ocean is thought to have occurred before the Upper Ordovician (Cocks and Torsvik 2002;Fortey and Cocks 2003), with the Armorican Quartzite facies (c. 477 Ma; Gutiérrez- Alonso et al 2007) representing the establishment of an stable platform in the early stages of the riftdrift process (Gutiérrez-Marco et al 2002). Yet, the U-Pb ages presented in this paper confirm that the igneous activity in the autochthonous and parautochthonous domains of the margin exposed today in NW Iberia lasted at least until the Upper Ordovician, in similarity to what is described in NE Iberia (e.g., Castiñeiras et al 2010;Navidad et al 2010;Casas et al 2011;Liesa et al 2011;Martínez et al 2011), in the Armorican Massif (e.g., Ballèvre et al 2002), in the French Massif Central (Roger et al 2004;Faure et al 2010;Melleton et al 2010) and in the Mediterranean realm (e.g., Trombetta et al 2004;Helbing and Tiepolo 2005;Oggiano et al 2010;Gaggero et al 2012).…”

The birth of the Rheic Ocean — Early Palaeozoic subsidence patterns and subsequent tectonic plate scenarios

“…Fig. 4) indicate the Ordovician rifting event in this zone (Gutiérrez-Marco and Bernárdez, 2003;Gutiérrez-Alonso et al, 2007). Contemporaneously, in the subsidence patterns of the Saxothuringian and the Barrandian areas (Fig.…”

SHRIMP U–Pb geochronological constraints on the timing of the intra-Alcudian (Cadomian) angular unconformity in the Central Iberian Zone (Iberian Massif, Spain)

“…On the contrary, the absolute dating is a more troublesome task. In some cases, the relative dating can be improved by radiometric ages of interbedded volcanic layers close to an unconformity (e.g., Gutiérrez-Alonso et al 2007). More rarely, datable minerals incorporated in the unconformable surface constrain the age of uplift/emersion (e.g., volcanic zircons in bauxite layers, Wang et al 2010).…”