increase of knapped flint, decrease of obsidian (maybe due to reduction of obsidian distribution network)
obsidian: sporadically used for specialized artifacts (bladelets, flakes, waste; end scraper with regular, rounded front edge, almost no pointed bladelets);
flint: mostly local coarse-grained flint for cores and thick flakes used for on-site débitage production, blade fragments of beige flint (not local) found, most had glossed edges; 
reduction strategy designed for production of expedient tools; 