Towards improved identification of obsidian microblade and microblade-like debitage knapping techniques: A case study from the Last Glacial Maximum assemblage of Kawanishi-C in Hokkaido, Northern Japan

Abstract

Until recently, several hypotheses on the origin(s) and dispersion of microblade technology in Northeast Asia have been presented and discussed. Although various definitions of microblade and bladelet have been proposed in diverse geographic and chronological contexts, several researchers may agree that the pressure knapping technique for microblade production plays a paramount role in the process of significant changes in lithic technology and human behaviours between marine isotope stages (MIS) 3 and 2. One of the main topics in the study of microblade technology in Northeast Asia is establishing a systematic and reliable method for identifying microblade knapping techniques that are quantitatively verified. This paper attempts to present a more improved method for identifying microblade knapping techniques by dealing with the analysis of fracture wings which are the reliable indicators of the crack velocity. The focus of this paper is on identifying obsidian microblade-like debitage knapping techniques in the Last Glacial Maximum (LGM) assemblage of Kawanishi-C in Hokkaido, Northern Japan. The results of fracture wing analysis show that the microblade-like longitudinal debitage production at the Kashiwadai-C site was employed by not pressure but percussion techniques. This gives new insights into the diversity of microblade and microblae-like debitage reduction sequences in the LGM Hokkaido and complex process of significant changes in lithic technology, especially in relation to the emergence of microblade technology. In addition, this study shows that the analysis of fracture wings can allow appropriate technological evaluation of the microblades and microblade-like longitudinal debitage production in the period before and around the LGM in Northeast Asia.