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タイトルヨミ
コスイ カンキョウ ノ ジンイテキ カイゾウ ト テイセイ ユウコウチュウ ノ グンシュウ ヘンカ ソノ7 ケイソウ CYCLOTELLA ノ サンシュツ ニヨル タイセキ ネンダイ ノ スイテイ ト ソノ イギ
日本語以外のタイトル
Benthic Foraminiferal Changes in Relation to Human Activities(Part 7) : Age Estimaton of Sediment by Using Diatom Cyclotella and its Significance
ファイル
言語
日本語
著者
野村 律夫
内容記述(抄録等)
Recent occurrences of diatom Cyclotella spp. are significant in brackish Lake Nakaumi. Based on the surface sediment, Kashima and Noguchi(1983) suggested that these diatom taxa became developed during the time of 1960's to 1980's. If the Cyclotella occurrence can be traced in the sediment core, an age estimation may be possible with some hypotheses.
In order to elucidate this Cyclotella occurrence, I examined the sediment core from the central part of Lake Nakaumi, and found a significant change of the relative abundance at 2.5-3.0cm sub-bottom depths. Since Cyclotella taxa are basically adapted to fresh water or lower saline brackish water, the dominant occurrence of Cyclotella in Lake Nakaumi may be mostly due to the transportation from Lake Shinjiko, Yonago Embayment, and other fresh water areas. A total area of Lake Nakaumi was reduced to about 77% of the original by a land reclamation project of the Honjyo area, and thereby the transported diatom accumulated in more high abundance in main Lake Nakaumi than before. The Ohmisaki embankment completed in 1978 and then controlled the dispersion of Cyclotella occurrence. If this age applies to the sediment core, sedimentation rate can be estimated to 0.0416~0.0526g/cm^2/year. This sedimentation rate is conformable to the previously reported values.
主題
age estimation
Cyclotella
diatom
Lake Nakaumi
reclamation project
掲載誌名
Laguna : 汽水域研究
6
開始ページ
123
終了ページ
127
ISSN
21852995
発行日
1999-03
NCID
AN10439529
出版者
島根大学汽水域研究センター
資料タイプ
紀要論文
ファイル形式
PDF
著者版/出版社版
出版社版
部局
研究・学術情報本部 エスチュアリー研究センター
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