Copper Age axe-hammers, other tools and their raw materials in the sub-Apenninic area east of Bologna (Italy)

Abstract

During this study, about two hundred stone tools from the Bologna territory-particularly from the S. Lazzaro di Savena area-were studied. They comprise perforated axe-hammers, axes/adzes and other variously polished complete or fragmentary tools of Copper Age typology, mostly coming from surface survey. They are mostly manufactured from basic magmatic rocks (in order of abundance: diabases, dolerites, gabbros, basalts and basic porphyrites) typical of the Apennine ophiolites outcropping upstream to the local mountains/hills, as well as in several areas of the Northern Apennines. Other lithologies, such as ophiolitic ultramafics (serpentinites, steatite and one Ca-pyroxenite) and non-ophiolitic lithologies, are poorly represented. The petrographic features of the studied artefacts are compatible with those of the ophiolitic rocks outcropping in the nearby Apennines and include varying degrees of low-grade, both of continental (various green and bright amphiboles, chlorite, saussurrite etc.) and oceanic metamorphism (typically brown hornblende and rare mylonitic textures). Some basic porphyrites with large phenocrysts, uncommon in the Apennine ophiolites, are also present. The few non-ophiolitic lithologies (siliciclastic arenites, calcarenites, limestones and siliceous stones) were probably supplied from the nearby Apennine, with the exception of a spotted slate of unknown origin. Based on their morphotypological features, some ophiolitic and not-ophiolitic artefacts may suggest some exchange and importation from-or simply some prehistoric cultural links with-Tuscany, Marche and occasionally Southern Italy and South Tyrol/Alto Adige.