La mina romana de oro de las Médulas (El Bierzo, Provincia de León, NO de España)Patrimonio de la Humanidad como recurso docente para la enseñanza de las Ciencias de la Tierra

Abstract

Gold is a highly valued mineral, appreciated by most civilizations.Gold deposits arouse the interest of both the students and the general public. The Roman mine of Las Médulas, declared World Heritage Site by UNESCO, and its surroundings areas are an exceptional site, not only due to the quality of its outcrops, which allow teaching geological lithologies and processes, but also because they are associated with an important archaeological site. Taking advantage of the infrastructure and interest which already exists at this site, we can explain the geology of the region, which has seldom been sufficiently highlighted. This site offers a great educational resource to explain the genesis of the NW Iberian Peninsula Mountains and the alluvial fan sediments. In addition, we can discuss the anthropic impact on the landscape and the importance of the management of natural resources. The mountains and sedimentation that filled the depression of El Bierzo are the result of tectonic activity (since the Oligocene); the erosion led to a large amount of sedimentary material that was transported into the depression by the alluvial fans. Las Médulas are Tertiary in age (Miocene) belonging to the middle and proximal facies of alluvial fans; these facies, especially the proximal ones, are the areas where gold was deposited. Subsequent tectonic activity segmented the alluvial fans. This segmentation and subsequent erosion associated with the Sil River causes the Tertiary outcrops to be scattered over the Variscan basement