A zona costeira do Norte de Portugal : unidade e diversidade : o caso particular da região do Porto = Northern portuguese coastal zone : unity and diversity : the particular case of the Porto region

Abstract

The coastline of Northwest Portugal has a remarkable homogeneity when viewed on a small-scale map. It has a very consistent orientation towards NNW-SSE, along 122 km, from the latitude of Espinho, south of the city of Porto, up to the border with Galicia, at the mouth of the Minho River, and beyond this point up Baiona in Galicia. In addition to its straight appearance, another important feature of the coastal area of Portugal is the existence of the designated littoral platform, which develops as a fl attened surface, adjacent to the shoreline and usually separated from the interior reliefs by an abrupt alignment. One can consider several well-diff erentiated sectors within this stretch of about 100km long. The diff erentiation is related to the extension of the littoral platform and its altimetry. The study of deposits covering the littoral platform, quite detailed in the area surrounding the mouth of the Douro River, where these deposits are very representative and well exposed, seems to corroborate the hypothesis of tectonic movements during the late Cenozoic. Thus, both the topographic development and the detailed study of the deposits suggests the existence of compartments with diff erent tectonic movements along faults inherited from tardi-Hercynian times, which may continue to work during the Quaternary.