Title Transcription | シンジコ タイセキソウチュウ ノ シジミ カイガラソウ ノ ハッケン ト ソノ イギ
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Title Alternative (English) | A Discovery of a Corbicula Bed in the Holocene Sediments of Lake Shinji and Its Significance
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File | |
language |
jpn
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Author |
Tokuoka, Takao
Nakamura, Tadashi
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Description | An interesting occurrence of large fossilised corbiculas(Corbicula japonica, which lives in brackish water), coexisting with living specmens, has been known by fishermen at a transitional area between shelf and slope in the northern central part of Lake Shinji at a depth of about 3 m. The possibility of the occurence being an ancient shell mound is low, as no man-made remains have been dredged in the present area. The fossilified corbicula give a ^14C age of 1926+124-122 yrs B.P. This age suggests that the corbiculas flourished to form the corbicula bed at the late Holocene regression stage, as Lake Shinji is known changed from a marine embayment in the Jomon Age to a brackish coastal lagoon in the Yayoi Age. Echo-sounding surveys in the northern central part of Lake Shinji show that a reflector exists less than 1.5 metre below the bottom and this is traceable to the subaqueous exposure of the corbicula bed. The reflector could be penetrated by a newly-devised gravity corer, and it was found that the reflector definitely consists of corbiculas. It is inferred that Corbicula japonica flourished in great numbers in accordance with a drastic environmental change in Lake Shinji, from the embayment of Jomon Age to the brackish lake of Yayoi age.
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Subject | Lake Shinji
coastal lagoon
Corbicula japonica
^14C age
echo-sounding survey
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Journal Title |
Laguna : 汽水域研究
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Volume | 4
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Start Page | 77
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End Page | 83
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ISSN | 21852995
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Published Date | 1997-03
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NCID | AN10439529
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Publisher | 島根大学汽水域研究センター
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NII Type |
Departmental Bulletin Paper
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Format |
PDF
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Text Version |
出版社版
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OAI-PMH Set |
Estuary Research Center
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他の一覧 |