Pereira D. e Azevêdo T.

3ª Reunião do Quaternário Ibérico, 1993. Coimbra.

Resumo
Belonging to the same morphological context, the tectonic depressions associated with the Bragança-Vilariça-Manteigas accident present significant differences in the sedimentological characteristics of the deposits they enclose. Even though part of those differences are undoubtedly related to lithologic variations of the basement rocks, which include granites and mafic and ultramafic rocks of the Bragança and Morais massifs, others are due to modifications of the morphoclimatic conditions. The sedimentary structures, quartz morphometry and quartz, granite and schist frequency, light and heavy minerals, clay fraction mineralogy and grain-size distributions, allow to distinguish materials of distinct origins. The comparison of these deposits with others not situated in the depressions and their geomorphologic relations leads to the hypothesis of the existence of material deposited in different periods of the Cenozoic, namely in the Quaternary. In particular, a comparison is made between the characteristics of the Quaternary deposits of the Vilariça valley and those situated in the regions of Sortes (South of Bragança) and Podence (North of Macedo de Cavaleiros).