Vale da Canada e do Patelo

This geosite is located at the meeting point of these valleys of unrivalled beauty, overlooking a scenery of Mediterranean vegetation on a steep limestone relief. The Canada valley, of fluviokarstic origin, owes its name to the stream that runs through it during periods of heavy precipitation. Oriented according to WNW-ESE, its asymmetrical shape is the result of tectonic movements. On the southern slope, where marl and clay limestone emerge, the gradient is gentle. However, at the top of the northern slope, the Canada valley fault originates a limestone escarpment rich in very resistant flint nodules. They help to protect from erosion the underlying marls and clay limestones, which are older and less resistant. The Patelo valley is narrow, with a steep slope and a bottom covered by cryoclasts. From here we can view Castelejo, the Canada valley and the Alvados slope. On a winding route along a dirt track, the descent from Patelo through Canada valley links the parishes of São Bento and Alvados. The imposing Castelejo Hill features a hard relief of tectonic origin. It is the result of the conditioning of Middle Jurassic limestones due to the inverse movement of three parallel faults: the Alvados fault, the Santo António fault and the fault that limits its eastern border. During the Palaeogene (65.5 Ma - 23 Ma) and the Neogene (23 Ma – 2 Ma), the interaction between these faults led to north-south thrusts that defined the outlines of this impressive escarpment located in the Estremadura Limestone Massif.