La estructura de la Zona Centroibérica en la región de Los Pedroches (Macizo Ibérico meridional)

Abstract

This paper describes the structure of a part of the southern Central Iberian Zone (Iberian Massif) as the result of the superposition of pre-Variscan and Variscan deformations. The pre-Variscan deformations originated three unconformities: Cadomian, intra-Alcudian and Sardic unconformities. Regarding the Variscan deformations, two tectonic units have been recognized: an autochthonous one and a para-autochthonous one. They are separated by a Middle Carboniferous thrust with top-to-the-NE sense of movement. The Variscan structure of the autochthonous unit, described in previous papers, is characterized by km-scale pre-Carboniferous NE-verging recumbent folds. We present here the structure of the southern part of the para-autochthonous unit, where NW-SE trending upright or slightly vergent folds of Westphalian age are the dominant structure. The large Carboniferous outcrop of Los Pedroches region has been classically considered as a syncline, but we show the existence of a large anticline along this outcrop, where Los Pedroches Batholith intruded. Subsequent deformations gave way to locally developed structures, including: new upright folds coaxial with respect to the previous ones, crenulations associated with the emplacement of Los Pedroches Batholith, and late vertical faults. Al1 these Middle and Late Carboniferous structures are interpreted as being related to a transpressional event following a transtensional tectonic regime that prevailed in the southwestern Iberian Massif during the Early Carboniferous.