CHARACTERISATION OF CORSICAN RHYOLITE AND PREHISTORIC TRADE

The aim of this presentation is to offer preliminary information on the mineral composition of Corsican rhyolite from the northwestern part of the island referred to as La Balagne. The primary purpose of this study is to characterize the rhyolite from different locations in order to eventually provenance artifacts to their source.

It must be emphasized that this analysis is only in its preliminary stage, having had access to only a few samples taken in the summer of 2008, when I was involved in a geoarchaeological survey in La Balagne, which is the general location for the main source of rhyolite. One objective of the study was to collect rhyolite artifacts and raw material used to make tools during the period spanning the Neolithic to the Bronze Age. The survey involved prospecting through a designated area each day, which was recorded using a GPS (Trimble). Each artefact spread was also recorded with the GPS, such as the rhyolite, and thus, I was able to have location information for each collection of pieces in this analysis. Sourcing lithic tools has been done successfully for obsidian throughout much of the Mediterranean, and this study offers insight to the potential of doing the same for rhyolite in Corsica. Even though rhyolite is isolated to Corsica, it is found dispersed throughout the island in association with archaeological sites and better understanding its distribution has many implications for trade and social interaction on the island during prehistory.

A secondary aim is to contribute information concerning the geological conditions under which the rhyolite formed on the island. Corsica is interesting because two thirds of the island is made up of Granite, which formed around 310-280 MA. Geologically, it is different from Sardinia lying only 12km to the south. Further, Sardinia contains much obsidian, a highly valued material for tools that was imported to Corsica as the latter contains none.