2022 Fiscal Year Final Research Report

Analysis of Paleolithic human remains and event deposits in caves of the Southwest Islands in Japan

Research Project

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Project/Area Number	20K04138
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Multi-year Fund
Section	一般
Review Section	Basic Section 17040:Solid earth sciences-related
Research Institution	Fukuoka University
Principal Investigator	Ishihara Yoshiro 福岡大学, 理学部, 助教 (80368985)
Co-Investigator(Kenkyū-buntansha)	成瀬元京都大学, 理学研究科, 准教授 (40362438) 小野林太郎国立民族学博物館, 人類文明誌研究部, 准教授 (40462204) 片桐千亜紀九州大学, 比較社会文化研究院, 共同研究者 (70804730) 吉村和久九州大学, アイソトープ統合安全管理センター(伊都地区), 学術共同研究員 (80112291)
Project Period (FY)	2020-04-01 – 2023-03-31
Keywords	洞窟遺跡 / 津波堆積物 / 旧石器時代 / 沖縄先島津波 / 明和津波 / 石垣島 / 白保竿根田原洞穴遺跡
Outline of Final Research Achievements	In this study, we attempted to excavate a Paleolithic site and detect events in caves in the Yaeyama Islands.　Excavation of a cave on the Shiraho Coast of Ishigaki Island at an elevation of about 30 m revealed marine remains and gravel deposits that were probably derived from the Meiwa Tsunami and the Okinawa Sakishima Tsunami (about 2000 years ago). Archaeological artifacts consistent with the stratigraphy were also found. In addition, similar tsunami deposits were found in several caves along the east coast of Ishigaki Island at elevations between 5 and 40 m, and most of them were dated to about 2000 years ago. Although the lowest level of the excavation pits does not reach the horizon of Paleolithic age due to the thick tsunami deposits, it is highly possible that the pits were covered and preserved by such event deposits.
Free Research Field	堆積学
Academic Significance and Societal Importance of the Research Achievements	本研究の成果は，南西諸島における記録媒体としての洞窟および洞窟堆積物の重要性を示唆する．すなわち，地表では残りにくい堆積物や化石，植物遺骸も洞窟内部では風雨にさらされることがなく保存される．鍾乳洞を対象とすることで効率良く過去の情報を得ることができることが示された．また，本研究で明らかになった古津波イベントの痕跡のうち，沖縄先島津波によるものは，明和津波よりも高エネルギーでかつ，高い標高まで至ったことが複数の洞窟での調査から示唆された．このような情報の集積は，この地域の防災においても重要な価値があると考えられる．