Pamplona J. & Ribeiro A.

Presented in the 1ª Conferência Anual do Grupo de Geologia Estrutural e Tectónica, Lisboa, 1995

Abstract
The studied sector is at NNW of Viana do Castelo, between Praia do Norte (Viana do Castelo) and Carreço. All the sector is localized at littoral (beach zone and intertidal zone), with a tipical geomorphology of flat sandy littoral, with some outcropts.
The lithologies of this sector belongs to the Autochthonous of CIZ (Central Iberian Zone). They are characterized by the presence of chiastolite schistes with some iron oxides levels and garnet andalusite nodular schistes, that probably represent the Valongo's Formation (Lanvirnian-Landeilian). We can see also outcropts of pegmatitic granitics dykes, sometimes mineralized, and quartz veins of metamorphic segregation or, occasionally, tipically hydrothermal.
From a tectonic point of view, we can say that D1 is carachterized by the occurrence of S1 planes, NNW-SSE with subvertical dip and the strechting lineation is following kinematic b-axis. D2 show evidences of the transition of pure shear , that make essentially conjugate strike-slips faults, to a tangential deformation towards W responsible for fracture cleavage (NW-SE to NNW-SSE, with moderated dip). D3 is defined for a transpressive regimen and his occurrence is showed by open folds, linked to large shear zones. We can also observe that the strechting lineation is following kinematic b-axis.