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Abstract
The No.1 monument is located at a depth of about 25 meters of ocean off Yonaguni Island. The structure, which resembles the side of a stepped Incan pyramid. The sizes of No.1 monument is 200m in length, 150m in width, and 20-25m in height. Its features such as flat terraces, straight walls and surface structures of walls strongly indicate the structure to be artificial rather than nature. Based on much more supporting evidence such as scars driven in a wedge on the No.1 monument, a road that surrounds the structure, and a stone fence composed of huge rock fragments, it is suggested that the structure is man-made and it was probably built on land. We dated 16 samples attached to the No.1 monument and related one. The carbon-14 testing of corralline algae limestone attached to the artificial structure indicated that the age of the monument is expected to be sometimeduring 4,000-2,000 years, though the uprising of the sea level by eustatic movement of the post-Ice Age suggests the structure to be 10,000 years old. It seems to be reasonable that the structure was built just a little older than 2,000 years, adding to the field observation.
タンデトロン加速器質量分析計業績報告 Summaries of Researches Using AMS 1998 (平成10)年度
Journal
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- 名古屋大学加速器質量分析計業績報告書
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名古屋大学加速器質量分析計業績報告書 10 149-166, 1999-03
名古屋大学年代測定資料研究センター 天然放射性元素測定小委員会
