Lithic technological and human behavioral diversity before and during the Late Glacial: A Japanese case study

摘要

Drastic climate fluctuations occurred during the Late Glacial (LG), around 15,000-11,500 cal BP also in the Japanese Archipelago. Although some studies have claimed that regional differences in the characteristics of lithic technology and human behavior became apparent at this period, recent studies have revealed that they were already apparent as early as the Last Glacial Maximum (LGM). Hence, it is important to discuss whether or not the regionality of the LGM had changed by the LG, and to understand the socioecologial processes of the Pleistocene/Holocene transition. This paper aims to review lithic technological variation in the Japanese Archipelago before and during the LG, and to investigate behavioral diversity in detail, focusing on the Kyushu region in southwestern Japan. As the result of the analysis, there are clear differences between northern and southern Kyushu in terms of lithic technology and behavioral strategy. The differences between the two regions continued from the LGM to LG. Low lithic tool diversity in the northern Kyushu indicates high mobility frequency of humans who carried them. In addition, a high degree of curated reduction strategy, and non-local high quality lithic raw material use also implies a high magnitude of mobility. Curated microblade technology had long helped humans to transport and utilize obsidian lithic resources in a wide foraging territory. This supposition would be supported by the scarcity of archaeological feature there, as well. By contrast, plenty of archaeological features including trap-pits and pit-dwellings in southern Kyushu implies, as many previous studies claimed, slightly early establishment of sedentary life-way of human groups who inhabited there. High lithic tool diversity in the southern Kyushu means low mobility frequency of humans who carried them, and moreover, the low degree of standardization of flake removal technique, low degree of curated reduction strategy, and the scarcity of use of exotic lithic raw materials all strongly denote that their mobility magnitude was also considerably low. They must have adopted fine-grained resource exploitation strategies in small foraging territories. It is supposed that above differences of behavioral strategy could be explained as different adaptations to different regional environmental settings. Future investigation would clarify more detailed regional adaptation strategy than ever.