First evidence of heat treatment during the early Neolithic in northeastern Italy

The site of La Vela sector VII (Trentino-Alto Adige – Italy), provides one of the few complete stratigraphic sequences, ranging from the Mesolithic to the middle Neolithic, in northwestern Italy. The site is located in the Adige valley, a way of communication between the Po plan and the Alps. This research focuses on the early Neolithic lithics ascribable to the Gaban facies, dated to 5000–4700 cal BC. Different rocks, coming from local exposures, have been exploited. The goal of the reduction sequence was the production of blades by pressure knapping technique. The technological study of the assemblage raised a particular interest for the presence of flint artifacts suggesting the usage of controlled heat treatment. The presence of this technique has been tested by an experimental approach based on Fourier-Transform infrared (FT-IR) spectroscopy. Complementary microstructural and analytical characterizations with low-vacuum scanning electron microscopy (LVSEM) observations combined with energy dispersive X-ray spectroscopy (EDXS) have been performed. The analyses confirm the presence of artifacts intentionally heat treated. The thermal treatment, achieved in order to increase the quality of the blade production, is the first evidence of this technique in northeastern Italy during the early Neolithic.