SESSION 2 – Ancient lithic trade and economics
New challenges in the study of lithic raw materials in Central Italy at the dawn of metal working societies: the case of La Pietra and other radiolarite quarry-workshops in Tuscany

In central-southern Tuscany, radiolarite and radiolarian chert from the geological formation of Diaspri (Jaspers) has been a fundamental lithic raw material throughout prehistory. During the Copper Age this material acquired a specific importance as it was selected for the local production of flat retouched arrow and javelin heads. In the regional archaeological record, the latter artefacts are found mostly within burial contexts which represent the major evidence for the period given that very little settlement evidence has been discovered so far.

Methodological questions are also discussed. These particularly concern the issue of developing raw material studies within a geologically complex area. In fact whereas La Pietra quarry is part of a large and well-known radiolarite outcrop, there exist many small and very small occurrences of radiolarite, which are found often in olistostromes within different geological formations and are not always indicated on geological maps even at a large scale. We show an example in which one of these smaller radiolarite occurrences has provided positive archaeological evidence. Another peculiar geological feature to the area considered is the coexistence of outcrops of two different types of radiolarite (those of the Tuscan Domain and the Internal Ligurian Domain) with different palaeo-geographic origins but similar macroscopic aspect.  Characterizing and distinguishing these two sources is necessary in order to define the geography of radiolarite exploitation and may reseachers source the raw material of single artefacts more precisely and thus shed light on circulations and exchanges. The results of the first attempt to individuate petrological and geochemical markers which can be used to distinguish geologically and archaeologically between the two radiolarite types are presented here.