Provenance analysis of the Paleozoic sequences of the northern Gondwana margin in NW Iberia: Passive margin to Variscan collision and orocline development

摘要: Abstract The Cantabrian Zone of NW Iberia preserves a voluminous, almost continuous, sedimentary sequence that ranges from Neoproterozoic to Early Permian in age. Its tectonic setting is controversial and recent hypotheses include (i) passive margin deposition along the northern Gondwana or (ii) an active continental (iii) drifting ribbon continent. In this paper we present detrital zircon U–Pb laser ablation age data 13 samples taken rocks ranging Silurian depositional obtained results, together with previously published ages Ediacaran–Ordovician strata, allow comprehensive analysis changing provenance through time. Collectively, these indicate portion was part at least Ordovician Late Devonian times. Zircon populations all show strong similarities Sahara Craton zircons found Libya, suggesting occupied paleoposition close those regions present-day Africa during time interval. Changes are attributed onset collision between Laurussia. Additionally, Middle Carboniferous record consistent recycling older sequences exhumation igneous formed before Variscan orogeny. Late-Devonian yield reflect topographic changes produced orogeny development lithospheric scale oroclinal buckling.