Stone material source provenance of the Cogotas I Grindstones (Middle and Late Bronze Age) from the Duero Basin and consequent flow patterns

The source provenance of twelve hand grindstones of Cogotian sites from the sedimentary Duero Basin was characterized using petrographic, mineralogical and geochemical criteria, according to an operational process previously proposed. Many of the provenances were determined after trace-element normalized diagrams and comparative diagrams with respect to available data from potential source areas. This methodology confirms that the geochemical signature can be seen as an archaeological fingerprint which allows the identification of facies or rock sub-types from the established source areas. Granite sources are the commonest provenance, although granodiorite, orthogneisses and sandstone are also involved, all of them belonging to the Variscan Basement. One of these source areas includes copper minerals, which could have been used for metallurgical purposes. Probably, since the early phase of Cogotas I, the principle of least effort no longer was a guiding force to boost the supply of material. The archaeological sites experienced a long-distance raw material supply in crossed directions, according to the established sources areas, indicating a dense network of connections between the commnunities of the region at a hecto-kilometric scale.