The first two centuries of the Roman Empire saw an intense exploitation of gold throughout the Iberian Northwest. In roughly 200 years, between the 1st and 3rd centuries, all gold, both hard rock and placer deposits were prospected and mined. Pre-Roman populations had already obtained gold by panning river placers, but the arrival of Rome radically changed both the scale and the objective. For the Empire, gold was the key in sustaining the new monetary system established by Augustus.
This system was thoroughly transformed, but in our case it is the establishment of gold as the base reference for currency value which is noteworthy. Previously, gold coins were exceptional, and it was the silver denarius that the system hinged upon. With Augustus, the new gold aureus became the central pillar, not only as a currency, but also as propaganda of imperial power. The Roman State therefore needed a steady inflow of gold to Rome, and the recently conquered Iberian Northwest was rich in it; it was by far the region within 1st century Rome which could provide more of it.
Only a detailed knowledge of the terrain and absolute control of the territory could provide the large scale operations required for the prospection, location and evaluation of gold deposits. The lands of Asturia, Callaecia and Lusitania began to be exhaustively mined.
The techniques used (either intensive or selective) were adapted to the morphology of each deposit. All of them, however, needed two elements: water and labor. The first was obtained through hydraulic systems which channeled water from the sources to mining fronts, sometimes for dozens of kilometers. Near the mines, deposits were used to regulate the flow, as reservoirs or directly for the exploitation. Water, indeed, was necessary in several stages of the mining process: to dissolve the sediment or rock containing the ore, to pan it in order to obtain gold concentrate, and to wash away the tailings.
This could only be done with the guidance and oversight of experts, topographers and prospectors, as well as managers and other technical staff. The army and the Roman imperial administration provided the knowledge, experience and control mechanisms required.
The other key element was labor. Rome also had ways of obtaining the necessary workforce to build the hydraulic infrastructure and work in the mines: indigenous population, once conquered and submitted by Rome, could be compelled to pay tribute in the form of work for the State.
One of the prominent characteristics of the IVGA project is that in its study area different types of deposits have been found, each one addressed using different techniques. In the upper basin of the Navia (Navia de Suarna) there are mines intent on the River terraces and the river placers associated. In the Ancares (Candín), on the other hand, there are also glacial, as well as hard rock, deposits on the slopes. Also in the valley of the Ibias (Ibias) there were both placer and hard rock deposits. In several cases we can also indicate the presence of various elements which can be used to establish the chronology of these activities, such as water channels and deposits, mortars for grinding the ore, and accumulation of tailings, both fine and coarse.
These mines, which are nearly two millennia old, have shaped the landscape of these three municipalities, having a direct effect on the topography, land use, place names… They are a rich heritage which has all too often been overlooked. They can, however, become a landscape resource of great caliber, because they are the conspicuous evidence of the relation between humans and their environment through history. They are, therefore, part of the historical, archaeological, geological and environmental wealth of the area, and they have great social and economic value which can sustainably affect both the local and the regional scales. It is easy to incorporate them into bicycling or hiking routes, which can benefit from information on the Ancient mining that has shaped the landscape being experienced.