Estratigrafía y estructura de la lámina tectónica del Para-autóctono y de su autóctono en el área de Chantada (Galicia, NO de España)

Abstract

Reviewing the geology of the variscan basement in the region between the Ordenes Complex and the Verin Syncline (Eastern Galicia) allows to establish more accurately the geometry of tectonic sheets below the allochthonous complexes in NW Iberia (the Paraautochthonous Sheet) and its autochthon (the Central-Iberian Zone). The emplacement of these units took place during the development of the Variscan Orogen as a consequence of the collision between Gondwana and Laurentia. In this work we present a geological map of the lower boundary of the Para-autochthonous Sheet in the study area and we establish a correlation of the rock sequence in the autochthonous with a comparable and better known stratigraphic sequence in the Ollo de Sapo Antiform within the Central-Iberian Zone. We suggest that the rocks previously named as the Santabaia Group correspond in fact to the Serie de los Cabos with the only difference that they include a volcano-sedimentary succession similar to the Ollo de Sapo Formation. The structural analysis of the geological map in the study area and its surrounding regions also allows to recognize the trace of several significant variscan shear zones.