LiDAR survey discovers Roman gold mines in Spain

Archeologists have long suspected that the Romans were mining for gold in Spain. The existence of ancient gold mines was confirmed by an aerial survey done last week above the northwestern province of León, using laser technology.

Researchers from the University of Salamanca made the discovery using an airborne laser detection system known as LiDAR. The remote sensing technology measures distance by illuminating a target with a laser and analyzing the reflected light. LiDAR is used in a number of scientific applications to make high-resolution maps, including geology, archeology, geomatics, geography, seismology and forestry. NASA developed LiDAR in the 1960s to analyze retreating Arctic ice and the composition of oceans.

Data from the LiDAR survey found that under vegetation and crops in the Eria Valley, there is a gold-mining network created by the Romans 2,000 years ago, along with complex hydraulic works to divert water to the mines, ScienceDaily.com reported:

"The volume of earth exploited is much greater than previously thought and the works performed are impressive, having achieved actual river captures, which makes this valley extremely important in the context of Roman mining in the north-east of the Iberian Peninsula," ScienceDaily quoted Javier Fernández Lozano, geologist at the University of Salamanca and co-author of the study published in the Journal of Archaeological Science, as saying.

According to the article, Las Médulas in León is considered to be the largest open-cast gold mine from the Roman Empire. The remnants of Roman gold-mining have also been discovered in neighbouring Asturias province, where Astur Gold (TSXV:AST) is developing its Salave gold project, and Galicia, where Edgewater Exploration (TSXV:EDW) is advancing its Corcoesto prospect.