A functional analysis of the LGM microblade assemblage in Hokkaido, northern Japan: A case study of Kashiwadai 1

Topics currently debated in the northeastern Asian prehistory include the emergence and spread of microblade technology during the Last Glacial Maximum (LGM). On these issues, Hokkaido, the northernmost Japanese island, provides one of the earliest evidences of microblade technology. The present study reports results of functional analysis on the LGM microblade assemblage from the Kashiwadai 1 site, Hokkaido, and preliminary comparisons with other Upper Paleolithic (UP) assemblages in Japan. Results indicate that microblades may have been slotted into and served as lateral edges of composite points. Use-wear traces on burins and burin spalls show a strong correlation with antler, bone, or ivory (ABI) processing. End scrapers were used chiefly for hide working. A blade may have been employed for sawing or cutting hides and flesh. Furthermore, the comparison suggests that developed ABI polishes exclusively observed on burins and burin spalls highlight the LGM microblade assemblage, and are rarely found from the other UP assemblages until the appearance of the LGM microblade assemblages. This implies that the technology and concept to shape ABI implements with burins seem to have emerged coincidently with the earliest microblade technology, and may not have had roots from previous UP technologies in both of the southern Paleo-Sakhalin/Hokkaido/Kurile Peninsula and Paleo-Honshu Island. Besides the microlithization, investigating sophisticated ABI technologies will also illuminate the first appearance and spread of the LGM microblade technologies in northeast Asia.