MINERALOGICAL AND CHEMICAL CONSTRAINTS ABOUT THE PROVENANCE OF COPPER AGE POLISHED STONE AXES OF 'LJUBLJANA TYPE' FROM CAPUT ADRIAE

In this study we show the result of a study concerning approximately forty axes, mainly discovered in the Copper Age pile dwellings of Ljubljansko barje (central Slovenia) and in the neighbouring areas of Caput Adriae. The studied shaft-hole axes, characterized by homogeneous typology but slightly different raw materials, have been called Ljubljana type axes (Lt). The raw materials show metamorphic and spilitization features which recall oceanic conditions and geochemistry indicates a common OIB-like signature. The typological and geochemical characteristics and the very high percentage of Lt axes among the polished stone axes assemblages of Ljubljansko barje suggest that the raw material was probably gathered from one or more relatively small outcrops close to Ljubljansko barje. Similar igneous rock-types outcrop in the presumably Palaeozoic diabase/shale complex (Eisenkappler Diabaszug), intruded by the northern Karawanken plutonic belt. A probable provenance from this area, particularly rich in copper ore deposit, would confirm the important role of Ljubljansko barje as a metallurgical district, as well as a strong relation between lithic raw materials and Cu cultivation districts during the Copper age.