La Balouta exhumed karst: a Roman gold-mine-derived landscape within the Las Médulas UNESCO World Heritage Site (Spain)

Researchers have identified the La Balouta Valley, located within the Las Médulas UNESCO World Heritage Site in Spain, as a unique paleokarst landscape shaped by both natural and anthropogenic processes. This valley, once filled with red Miocene sediments, was later excavated during Roman gold mining activities over 2,000 years ago. The study reveals that the valley's current characteristics—such as limited surface water runoff, small cavities, and residual karst topography—stem from these historical mining practices. Gold particles found in sediment samples and similarities to other formations mined by the Romans support this conclusion. The findings highlight the interplay between natural geological processes and human activity, creating a distinctive cultural landscape that reflects systematic gold extraction on the NW Iberian Peninsula.

Redondo-Vega, J., Alonso-Herrero, E., Santos-González, J., González-Gutiérrez, R., Gómez-Villar, A.,. (2015). La Balouta exhumed karst: a Roman gold-mine-derived landscape within the Las Médulas UNESCO World Heritage Site (Spain). International Journal of Speleology, 44(3), 267–276. https://doi.org/10.5038/1827-806x.44.3.5