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Image Credit: Land (2025)
Luminescence Dating Confirms Roman Gold Mining in the Eastern Pyrenees
A new study has confirmed the existence of Roman-era alluvial gold mines in the Eastern Pyrenees, providing the first direct chronological evidence for Roman exploitation of Pyrenean gold in this region.
Researchers applied Optically Stimulated Luminescence (OSL) dating to sediment samples taken from the infill layers of hydraulic structures at the Guilleteres d’All site. The results place the activity between the 3rd and 4th centuries CE, firmly establishing the Roman origin of the mining system. The study was published in the journal Land.
Gold carried by the Segre River and its tributaries has long been known in historical sources. This secondary gold originates from Miocene deposits in the axial Pyrenees and was transported downstream, accumulating in river terraces from the Cerdanya region to the Lleida plain. Earlier archaeological investigations had already suggested Roman mining activity in the area, including evidence of metalworking and large erosional structures consistent with hydraulic extraction techniques.
The Roman method for recovering alluvial gold relied on water erosion. Techniques ranged from directing water through sediments to constructing galleries that were flooded under pressure to dislodge gold-bearing deposits. However, the scarcity of associated archaeological materials had previously made precise dating difficult.
To address this, researchers initiated OSL dating in 2022. This method measures the last time quartz grains in sediment were exposed to light, allowing the dating of deposits even in the absence of organic material. Although less precise than radiocarbon dating, OSL is particularly useful in contexts like Guilleteres d’All, where organic remains are absent.
Two samples from the same hydraulic structure produced consistent results, indicating use and abandonment between the 1st and 4th centuries CE. The findings confirm that Roman mining operations extended into the Pyrenean region, likely connected to the nearby Roman city of Iulia Livica (modern Llívia), the only documented Roman urban center in the Pyrenees.
The study strengthens archaeological understanding of Roman resource exploitation in mountainous frontier regions of the Iberian Peninsula.
Published on: 27-02-2026
Edited by: Abdulmnam Samakie
Source: Phys.org