Sedimentary metal-pollution signatures adjacent to the ancient centre of copper metallurgy at Khirbet Faynan in the desert of southern Jordan

The end of industrial scale copper processing in Late Byzantine-Early Arab times in the exposure has been defined by the statistical relationships of its heavy-metal pollution yield, and separated from the impacts of an immediately preceding alluvial event. The PCA clarified a major anomaly in the geomorphological, archaeometallurgical and geochemical data. This is hypothesised to be the result of the water-proofing of the (often) porous sediments of this wadi-floor by the ancient process of puddling, possibly in association with the use of a major barrage immediately down-wadi. The extensive heavy-metal pollution evident in the modern landscape at this particular site is suggested to derive primarily from heavy-metal pollutants emitted in Classical times. The distinctive suite of heavy-metal pollutants emitted here in the Middle Bronze Age, ca. 3500 years ago, may have been partially-sealed below the immediate land surface by the inferred puddling of the wadi-floor. The changing concentrations of other heavy metals through this sequence suggest they were often essentially unaffected by the profound archaeometallurgical and natural events that have taken place here.