テフラ編年と¹⁴C年代に基づく鹿児島湾奥，新島（燃島）の海成堆積物の編年とその意義

• 森脇 広

  鹿児島大学名誉教授

• 永迫 俊郎

  鹿児島大学学術研究院法文教育学域教育学系

• 西澤 文勝

  首都大学東京都市環境学部

• 松島 義章

  神奈川県立生命の星・地球博物館名誉館員

• 鈴木 毅彦

  首都大学東京都市環境学部

• 田中 源吾

  金沢大学国際基幹教育院

書誌事項

タイトル別名

• Chronology and Significance of Marine Deposits on Shinjima (Moeshima) Island, Kagoshima Bay, Based on Tephrochronology and ¹⁴C Ages
• テフラ編年と¹⁴C年代に基づく鹿児島湾奥,新島(燃島)の海成堆積物の編年とその意義
• テフラヘンネン ト ¹ ⁴ C ネンダイ ニ モトズク カゴシマワン オク,シン シマ(ネントウ)ノ カイセイ タイセキブツ ノ ヘンネン ト ソノ イギ

抄録

 Shinjima (Moeshima) Island in Kagoshima Bay, southern Kyushu, Japan is noteworthy in volcanology, paleontology, and palaeo-environmental studies, because the island emerged from the bay bottom during volcanic activity at Sakurajima in 1780 AD. As a result, Holocene and late-Pleistocene deposits of the bay including muddy deposits, a thick pyroclastic flow deposit, and prominent molluscan shell beds occur on this island. Several tephras included in the bay deposits are critical for deriving their precise chronology. The chronology of those tephras was constructed on the basis of their identification using both refractive indices and major element compositions of constituent glass shards, as well as stratigraphic features in the field. Tephras identified in sediments from younger to older are Sakurajima-Taisho (Sz-Ts)-/P1, Sakurajima-Sueyoshi(Sz-Sy)-/P11, Yonemaru, Sakurajima-Uwaba(Sz-Ub)-/P12, Sakurajima-Takatoge3 (Sz-Tk3)-/P13, Sakurajima-Satsuma (Sz-S)-/P14, and Shinjima pyroclastic flow deposit. The Shinjima pyroclastic flow deposit, which differs stratigraphically between northern and southern areas of Shinjima Island, is the same tephra in the two areas, and is estimated to be c. 13,000 cal BP in age. The pumice clasts of Sz-Sy/P11 provided a suitable environment for the habitat of a prominent shell bed (Moeshima Shell Bed) composed mainly of Neopycnodonte musashiana. Sz-Ub/P12, Sz-Tk3/P13, and associate secondary deposits of Sz-S/P14 indicate that the deposit was formed in the last 13,000 cal BP. The chronology of the deposits of Shinjima Island is based on the findings of stratigraphic positions and ages of those tephras, and ¹⁴C ages obtained in this study, and will play an important role when examining the palaeo-environmental history of Kagoshima Bay since the last deglaciation.

収録刊行物

• 地学雑誌

  地学雑誌 126 (5), 557-579, 2017

  公益社団法人 東京地学協会

キーワード

• テフラ同定
• ¹⁴C年代
• 海成堆積物
• 編年
• 新島
• 燃島
• 鹿児島湾
• 最終融氷期

詳細情報

• CRID: 1390282679215205248
• NII論文ID: 130006199344
• NII書誌ID: AN00322536
• DOI: 10.5026/jgeography.126.557
• ISSN: 18840884
• ISSN: 0022135X
• NDL書誌ID: 028641935
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I028641935
• Web Site: https://www.jstage.jst.go.jp/article/jgeography/126/5/126_126.557/_pdf
• 本文言語コード: ja
• データソース種別:
  • JaLC
  • NDL
  • Crossref
  • CiNii Articles
  • KAKEN
• 抄録ライセンスフラグ: 使用不可