Asce forate in pietra levigata e altri indicatori di scambi e contatti nel Caput Adriae tra IV e III millennio a.C.

A long-term project has allowed the provenance identification of the main groups of Neolithic and Copper Age stone axes from Caput Adriae. Stone artefacts can indeed be scientifically analysed to detect the geological origin of the raw materials and thus try to recognize ancient exchange networks. This contribution summarizes the lithology, typology, distribution and origin of the main groups of Copper Age shaft-hole axes, using their geological signature, together with other available archaeological indicators of medium- and long-distance connections, to reconstruct the main cultural developments that occurred in the investigated area. The main groups of Copper Age shaft-hole axes - Ljubljana type, serpentinite and metadolerite artefacts - were produced from raw materials outcropping in the Eisenkappler Diabaszug complex (Austria), the Hohe Tauern (Austria) and probably the Banija Ophiolite Complex (Croatia) respectively, all areas rich in copper ore deposits. These data demonstrate that since the 4th millennium BC, the exchange network responsible for the distribution of stone axes in the Caput Adriae changed from long-distance Neolithic connection systems based mainly on Italian jades and eclogites to a more complex one, characterized by a new interest for the eastern Alpine and northern Balkan world. The association of lithic raw materials used for axe production and copper minerals shows that the changes in raw material exploitation strategies between the Neolithic and Copper Age are probably related to the development of the first metallurgy. Archaeological evidence, including the distribution of Ljubljana type stone axes, S. Antonino/ Kozarac copper axes, and Vučedol and Ljubljana style pottery, shows that the coastal belt of Caput Adriae, from the Friuli plain to the Istrian peninsula and beyond, was strongly connected with nowadays central Slovenia at least since the last centuries of the 4th millennium BC to the mid 3rd millennium BC. The association of the lithic raw materials used for the production of the pierced axes of the Caput Adriae with areas rich in copper suggests that the changes in the strategies of exploitation of raw materials between the Neolithic and the Copper age were probably linked to the spread and development of early metallurgy and the economic and socio-cultural changes connected to it. In the area of the Ljubljansko barje, not far to the east, all the main types of pierced axes are encountered and the processing of copper is unequivocally documented as early as the early part of the 4th millennium BC. This area seems to play a central role in the connection systems existing between the eastern Alps, the northern Balkans and north-eastern Italy, extending its influence mainly in the area of the Karst but also in the plain of Friuli (particularly in the area of Aquileia) and in Istria. As already mentioned, other classes of materials, such as the copper axes of the S. Antonino / Kozarac type from the Friuli plain and ceramic finds from the Karst caves - typologically comparable to the Vučedol materials or those attributable to the Culture of Ljubljana - clearly testify to how the north-eastern coast of the Adriatic between the end of the 4th and the first half of the 3rd millennium BC is closely linked to the sites of present-day central Slovenia (Bernardini 2018; Bernardini et al. 2019; Leghissa et al. 2020).