An archaeological approach to regional environmental pollution in the south-western Iberian Peninsula related to Third millennium BC mining and metallurgy

Abstract

The development of the first inter-settlement hierarchical framework in the South of the Iberian Peninsula in the Third millennium BC lead to a territorial division of labour, in which intensification of mining activities caused the first significant environmental impact on local and regional scales. To evaluate this impact we have selected the prime mining district in south-western Europe, the Iberian Pyrite Belt, and a method based on the correlation of pollen, charcoal and chemical analysis. The latter analyses were carried out on marine mollusc shells from spatially and chronologically contextualised archaeological records from a sequence ranging from the Sixth to the Second millennium BC. The results reveal that the copper metallurgy which developed in the south-western Iberian Peninsula in the Third millennium BC augmented deforestation, increased the rate of erosion processes and contaminated, at a regional scale, the waters of the Gulf of Cádiz – corresponding to the mouth of the Tinto and Odiel rivers – with heavy metals.