Linking Palaeozoic palaeogeography of the Betic Cordillera to the Variscan Iberian Massif: new insight through the first conodonts of the Nevado-Filábride Complex

摘要

Graphite-rich metamorphic limestones included within low-grade black schists of the lowest Nevado-Filabride tectonic unit in the Sierra de Baza (Bodurria Unit) provided the first conodonts found in this complex (Declinognathodus bernesgae, D. inaequalis. D. cf. praenoduliferus, and Idioprioniodus sp.). This demonstrates the early Bashkirian age of the sedimentary protoliths, and their deposition in open marine anoxic environments of a continental margin that opened towards the E and that was related to the Palaeotethys. This breakthrough offers strong support for the hypothesis that the lower Nevado-Filabride units show stratigraphic and palaeogeographic affinities with the external domains of the Iberian Massif (Palentian Domain of the Cantabrian Zone in particular). Consequently, this part of the Betic Internal Zones must be related to the basement of the South-Iberian Palaeomargin and excluded from the Alboran Domain tectonostratigraphic terrane.