Depósitos periglaciares da depressão de Tapeus (vertente NW da Serra do Rabaçal – Maciço de Sicó; Portugal central) – análise sedimentar e morfo‐estrutural

Abstract

This study aims to present calcareous conglomerate deposits, which have been taken as perigacial deposits related with slope evolution during Pleistocene cold periods. The studied deposits are located in a small tectonic depression near Tapeus. The outcrops show two main units: i) one at the bottom showing calcareous conglomerate with clast imbrication and planar structures that could indicate a northwestward palaeoflow; ii) at the top we can observe a red poligenic sandy silt deposit interbeded with small conglomeratic lenses composed by poorly sorted angular gravel elements of limestone. These are sedimentary and stratigraphic characteristics of typical deposits associated with the evolution of a slope under periglacial conditions. The preservation of the deposit is due to its location in a small depression (graben), which results from activity related with the tectonic evolution of the Sicó Massif. This also justifies the restrict geographic distribution of this deposits since they are confined to the small depression.