Vale da Nave Travessa (Covão do Curral)

The Nave Travessa valley is located in the upper sector of the Caniça valley. A tributary of the river Alva located in the southwestern side of Serra da Estrela, in an area that was subjected to the action of glaciers. At the last glacier peak, approximately 30,000 years ago, the valley was filled with a glacial tongue that reached a maximum length of 6.5 km and a minimum altitude of about 980 meters. This mass of ice covered an area of approximately 13.4 km² and drained the ice that accumulated in the plateau area, located between the geodesic vertices of Cume and Rodeio Grande, at more than 1800 meters of altitude. A concave cross-sectional profile and a succession of depressions in the stairway are notorious in the landscape, aspects resulting from the erosive action of the ice that denounce the morphology of a typical glacial valley. At present, some of these depressions have hydroelectric use, housing the Dams of Covão do Forno and Covão do Curral. At the confluence of Nave Travessa and the Lagoa stream valley, in the terminal sector of the valley, there is a set of sedimentary deposits that reflect different phases of the dynamics of this glacier. Each of these arches marks the terminal position of the ice tongue in different phases, the most recent being those that are further upstream.