TheYubetsu technique (湧別技法,Yūbetsu gihō) is a special technique to makemicroblades, proposed by Japanese scholar Yoshizaki in 1961, based on his finds in someUpper Palaeolithic sites inHokkaido, Japan, which date from c. 13,000 BP.
The name comes from theYūbetsu River (湧別川,Yubetsugawa), on the right bank of which theShirataki (白滝遺跡,Shirataki Iseki) Palaeolithic sites were discovered.
To make microblades by this technique, a largebiface is made into acore which looks like a tall carinated scraper. Then one lateral edge of the bifacial core is removed, producing at first a triangular spall. After, more edge removals will produce ski spalls of parallel surfaces.
This technique was also used fromMongolia to theKamchatka Peninsula during the later Pleistocene.