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Radiocarbon Ages of Beach Rocks and Late Holocene Sea-Level Changes in the Southern Part of the Nansei Islands, Southwest of Japan

Published online by Cambridge University Press:  18 July 2016

Kunio Omoto*
Affiliation:
Department of Geography, College of Humanities and Sciences, Nihon University, 25-40, 3 Chome, Sakurajosui, Setagaya-ku, Tokyo 156-8550, Japan. Email: [email protected]
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Abstract

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Beach rock is a good indicator of the past sea levels, as it is considered to have been formed within the range of intertidal zone. Radiocarbon dates of beach rocks collected from Iriomote Island, Ishigaki Island, and Miyako Island, in the southern part of the Nansei Islands, indicate that the beach rocks were formed between around 4000 BP and 400 BP. Late Holocene sea-level changes were revealed based on the elevations and 14C dates of the beach rocks. The results indicate that the sea level was similar to the present one for at least the past 4000 BP. Isotopic fractionations (δ13C) of the beach rocks were between +9.40% and −0.08%, suggesting a different origin for calcium carbonate.

Type
II. Our ‘Wet’ Environment
Copyright
Copyright © 2001 by the Arizona Board of Regents on behalf of the University of Arizona 

References

Geyh, MA, Schleicher, H. 1990. Absolute age determination. Springer-Verlag. 503 p.Google Scholar
Kawana, T. 1981. Radiocarbon ages of the beach rocks on Okinawa, Miyako and Ishigaki Islands, the Ryukyus, Japan. Bulletin of College of Education University of the Ryukyus 25:245–9.Google Scholar
Kawana, T, Pirazzoli, PA. 1984. Late Holocene shorelines and sea level in Miyako Island, the Ryukyus, Japan. Geographical Review of Japan 57 (Series B): 135–41. In Japanese.Google Scholar
Kawana, T. 1988. Geomorphology of the Ryukyus. Series of the Nature of Okinawa. Naha, Okinawa: Sinsei Tosyo Syuppan. 127 p. In Japanese.Google Scholar
Koba, M. 1983. Late Holocene relative sea level changes and crustal deformation in the Ryukyu Island, Japan. Gekkan Chikyu 5(12):722–33. In Japanese.Google Scholar
Omoto, K. 1976. Tohoku University Radiocarbon Measurements III. Science Reports of the Tohoku University 7th Series (Geography) 26(1):135–57.Google Scholar
Omoto, K. 1999a. Radiocarbon ages of beachrock and fossil coral samples collected from Agunijima, southwestern part of Japan – chronological view on the Late Holocene sea level change of Agunijima. Annals of The Geography, The Chiri Shiso 40(2):1528. In Japanese.Google Scholar
Omoto, K. 1999b. Radiocarbon dates of Beachrock samples collected from Miyakojima (Island), southern Ryukyu Islands. Preprint for Annual Meeting of The Japanese Coral Reef Society. 17 p. In Japanese.Google Scholar
Omoto, K. 2001. Radiocarbon Ages of Beachrock Samples Collected from Iriomote Island, Southwestern Part of Japan. Annals of The Geography, The Chiri Shiso 42(1–2):1730. In Japanese.Google Scholar
Ota, Y. and Hori, N. 1980. Late Quaternary tectonic movement of the Ryukyu Islands, Japan. Daiyonki Kenkyu (The Japanese Quaternary Research) 18:221–40. In Japanese.Google Scholar
Stuiver, M, Polach, HA. 1977. Discussion: reporting of 14C data. Radiocarbon 19(3):355–63.Google Scholar
Stuiver, M, Braziunas, TF. 1993. Modeling atmospheric 14C influences and 14C ages of marine samples to 10,000 BC. Radiocarbon 35(1):137–89.CrossRefGoogle Scholar
Vogel, JC, Ehhalt, D. 1963. The use of the carbon isotopes in groundwater studies. Radioisotope Ratios as Pollutant source and Behaviour Indicators. Vienna: IAEA. p 143–50.Google Scholar