La sucesión paleozoica en el sinforme de la Sierra de San Pedro (provincias de Cáceres y Badajoz, SO de España)

Abstract

The Sierra of San Pedro forms a Paleozoic synform, located in the southern part of the Central Iberian zone (Iberian Massif). The thickness of the Paleozoic sequence in the synform can be evaluated at 2,800-3,000 m. Its base is in general formed by a 5-40 m thick quartzite unit, equivalent to the Armorican Quartzite (Arenig), resting unconformable on the Precambrian. However, a discontinuous conglomerate level, attributed to the basal Arenig, can locally be found underlying the quartzite. Above the quartzite, the sequence is essentially compound of an alternation of predominantly quartzite, sandstone and slate units. This alternation allows the sequence to be subdivided into several distinct lithological units. Towards the top, carbonate and volcanic levels are found, interlayered in the predominantly terrigenous sequence. Most of the lithostratigraphical units have provided fairly abundant faunas and could therefore be dated. The paleontological evidence shows that the sequence is continuous from the Lower Ordovician to the Lower Carboniferous, with the exception of a probable hiatus comprising the Middle Devonian. Upper Carboniferous conglomerates and sandstones also occur in the area.