New data on the lithostratigraphy of Beiras Group (Schist Greywacke Complex) in the region of Góis-Arganil-Pampilhosa da Serra (Central Portugal)

Abstract

[Abstract] In the course of geological surveys conducted in the region of Góis (Central Portugal) a new unit was recognized at the top of Boque-Serpins Formation, characterized by the presence of levels of quartzites interlayered with shales, now called by Colmeal Formation. Its formal characterization is now presented and their regional geological implications are discussed in the context of the Neoproterozoic metasedimentary sequence of Beiras Group (Dúrico-Beirão Supergroup or “Schist –Greywacke Complex”). The geological surveys in progress confirm that the sequence, from the base to the top, of the Caneiro, Boque-Serpins and Colmeal Formations, feature the same structural and deformation pattern, common to the three units. It is noted that these units, defined in sector south of Coimbra – Lousã - Góis, have wide regional cartographic representation, as they have already been mapped and recognizable from Arganil until Sertã, to the south. To the west, they shall extend to the limit with Ossa-Morena Zone metasediments established by Porto-Tomar dextral wrench fault.