新潟県上越～中越地域における中新統・鮮新統境界部の微化石層序

• 花方 聡

• 本山 功

• 平松 力

• 渡邉 和恵

• 辻 隆司

書誌事項

タイトル別名

• Biostratigraphy of the Miocene/Pliocene boundary sections in the Jouetsu-Chuetsu district, Niigata Prefecture, northeastern Japan.
• ニイガタケン ジョウエツ チュウエツ チイキ ニ オケル チュウ シントウ センシントウ キョウカイブ ノ ビカセキソウ ジョ

抄録

Planktonic and benthic microfossils, including radiolarians, diatoms, calcareous nannofossils and foraminifers from the onshore sections of the Jouetsu-Chuetsu district, Niigata Prefecture, northeastern Japan, were studied with the objective of constructing a time-stratigraphic framework for the Upper Miocene and Pliocene strata. These are characterized by interbedded hemipelagic mudstones and turbiditeic sandstones. Radiolarian and benthic foraminiferal biostratigraphies indicate that the Miocene/Pliocene boundary in the Teradomari and Nishiyama areas corresponds approximately to the upper boundaries of the Teradomari and Shiiya Formations, both of which have been used as standard stratigraphic units in the Niigata Oil and Gas field region. Moreover, the boundary is traced to the upper part of the Ogaya Formation in the Yoneyama area and to the Sugawa Formation in the Higashikubiki area.Biostratigraphic analyses show that three volcanic ash layers, namely the Natsudo Pumice Tuff (Ndp), the Ogaya Pumice Tuff (Ogp) and the Iriyamagawa Tuff (Iy), are positioned at different stratigraphic horizons ; the Ndp is younger than Ogp, and the Iy is the youngest among the three. These three layers was recognized as the same tephra maker in previous studies. Furthermore, estimated ages of the Ndp and the Ogp based on the biostratigraphy are significantly younger than the ages estimated for the same ash layers based on fission track dating. This suggests that these ash layers contain or consist of reworked minerals and sediments derived from older pyroclastic deposits. Consequently, this study points out that the stratigraphic correlation and chronology established based mainly on fission track dating of such ashes in the Jouetsu-Chuetsu district require considerable revisions.

収録刊行物

• 地質学雑誌

  地質学雑誌 107 (9), 565-584, 2001

  一般社団法人 日本地質学会

キーワード

• Volcanic ash

詳細情報

• CRID: 1390001206233755776
• NII論文ID: 110003013204
• NII論文ID: 10009756014
• NII書誌ID: AN00141768
• DOI: 10.5575/geosoc.107.565
• ISSN: 13499963
• ISSN: 00167630
• NDL書誌ID: 5927467
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I5927467
• 本文言語コード: ja
• データソース種別:
  • JaLC
  • NDL
  • Crossref
  • CiNii Articles
• 抄録ライセンスフラグ: 使用不可