Geossítio 32 Espiunca fault
A geological fault worthy of a book!
Next to the Espiunca bridge, on the right bank of the River Paiva, there is a significant geological outcrop on the slope of the road, characterized by massive black quartzite benches of varying thickness, intersected by a fracture in the rocks – the Espiunca geological fault. A closer look reveals that the rock mass to the right of the fracture has fallen about 1.70 meters in relation to the block on the left. This geosite is located near the entrance to the Paiva Walkways.
Informação Geológica
The Espiunca fault can easily be seen in the massive black quartzite benches. This is a normal fault with a NNE-SSW direction, and here it is possible to identify the various elements that characterize geological faults: the fault plane (surface where the displacement takes place), the roof (block to the right of the fault plane) that has descended in relation to the wall (block to the left of the fault plane) and the tailings (measure of the displacement of the blocks) of around 1.70 metres.
The quartzite strata with disseminated sulphides (Espiunca formation) originated from the deposition of sands in a coastal environment more than 500 million years ago and are part of the lithologies belonging to the Dúrico-Beirão Supergroup. They were affected by a fault, responsible for the movement of blocks, as a result of distensive movements, probably during the Variscan Orogeny and reactivated by the Alpine Orogeny.
Interesses
Tectónico 
Natura 2000
Uso
Educativo 
Turístico Relevância
Regional 
