Human responses to climate change on obsidian source exploitation during the Upper Paleolithic in the Central Highlands, central Japan

Upper Paleolithic hunter-gatherers intensively exploited obsidian sources 1200-2000 m a.s.l. in the Central Highlands, central Japan. Previous studies have suggested that the last glacial maximum (LGM) decreased human obsidian procurement in the source area because of its high altitude. However, the relationship between the impacts of the LGM and human responses in the source area based on convincing evidence from the paleoclimate, obsidian provenance data, and archaeology remains poorly understood. This study examines the correlations among pollen record datasets during the past 30,000 years from the Central Highlands 1400 m a.s.l.; more than 85,000 pieces of obsidian provenance data for the Chubu-Kanto region; and chronological sequences of Upper Paleolithic industries in the Central Highlands. Through synthetic analysis, we reconstruct historical changes in the human-environment interaction in the Central Highlands during the Upper Paleolithic. Our combined data shows the early LGM constraining the procurement activity at the sources; an increase in active human responses to the LGM cold phase; and changes in the land use of the source area in the terminal LGM triggered by the appearance of new lithic technology and the reorganization of mobility ranges. We find that human adaptations to the LGM conditions related to the natural resource exploitation around a latitude of 36°N were complex.