著者

島田 和高 鈴木 尚史 飯田 茂雄 杉原 重夫

出版者

明治大学

雑誌

明治大学博物館研究報告 (ISSN:13420941)

巻号頁・発行日

no.11, pp.1-28, 2006-03

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Yadegawa sites, which have yielded many localities of microblade assemblage are located at Minamimaki village, Minami-saku county, Nagano prefecture. Microblade industries are distributed widely throughout Japan in the final stage of Late Paleolithic period. In Yadegawa sites, Yadegawa I site is a place of the first discovery that maicroblade industry exists in Japan in 1954. Afterward, Yadegawa I site was excavated twice in 1954 and 1963, and assemblages composed of microblades, microcores, scrapers and flakes and chips were recovered. Now the mass of them are garnered at Meiji University Museum. In this article, we would report a result of obsidian source analysis by using X-ray fluorescent (EDXRF). The materials are thirty-nine microcores excavated at Yadegawa I site. The analysis of EDXRF was operated at Meiji University Cultural Properties Laboratory. As a result of analysis, it proves that seventeen of microcores are identified with obsidian that came from Onbase Island, nine from Tsumetayama/Mugikusa pass, six from west Kirigamine, two from Wada pass/Takayama, one from Omekura and four were not identified. Onbase Island is situated in the Pacific at a distance of about 50km from the edge of Izu peninsula. Of course some kinds of the voyage technology might had existed for obsidian transportation from the Pacific to the main land. In addition, it has a distance of about 150km from the edge of Izu peninsula to Yadegawa sites. Other obsidian sources mentioned earlier are located at the central highlands in Nagano prefecture, the region of which is close to Yadegawa sites westward beyond Yatsugatake mountain range. It has a distance of about 20-40km. Based on these results, we attempted to do comparative studies in the technology and the form of microcores between those made from "exotic obsidian" and from "local obsidian". A category of "Ryo-chu type microcore" is applicable to them likewise. When "exotic obsidian" and "local obsidian" are compared in this context, some distinct chracteristics become apparent as follows. Whereas thick flakes are applied to microcores made from "exotic obsidian" as blanks, the numbers of microcores made from "local obsidian" were manufactured from small size of obsidian rocks directly. This represents that the differences of obsidian source bring large varieties into the technology and the form of "Ryo-chu type" microcores. In addition, this implicates the existence of a complex obsidian circulation network between areas of the mountain and the ocean in the final stage of Japanese Late Paleolithic period as well.