A source of Pyrenean gold and its exploitation in Antiquity

Pyreneean gold was known by the Ancient authors and recent archaeo-geological research revealed it again in Asssaladou plateau located between Sorgeat and Ignaux villages, south-east of Ax-les-Thermes, Ariege, France. This source of primary gold was recently identified by the presence of Ancient mining workings at the surface. They were firstly observed by the exploration geologists of BRGM and COGEMA during late 1970'ies. Afterwards these mining vestiges were surveyed (30 pits), excavated and dated by our team during 1993-1997. A mineralogical study was carried out in 2000 and it was renewed in 2016. Two groups of mining workings were studied, a pit and an open pit continued underground by a 13 m long adit. The excavated pit was dated 3rd-4th c. AD on the basis of a fireplace. The study of the second mining complex (open pit and adit) confirmed the above mentioned dating on the basis of wood charcoal remnants of the fire setting and ceramics. The plateau is built up of Cambro-Ordovician schists, which are cut by quartz veins and stockworks. The ore is represented by white and grey quartz lenses affected by a dense faulting which facilitated the mining. Gold occurs as visible free gold hosted in voids within quartz and arsenopyrite. The Ancient miners did not exhaust the ore reserves, high-grade ore being still exposed at the surface. It seems that the mining works was seasonal and it was done by shepherds (miners/peasantries) during the periods without snow.