Stratigraphy and radiolarian ages of stratiform manganese deposits from the Chichibu Belt in the Saiki area, eastern Oita Prefecture, Japan

• Tomimatsu Yuki

  Department of Earth and Environmental Sciences, Kumamoto University

• Onoue Tetsuji

  Department of Earth and Environmental Sciences, Kumamoto University

• Nozaki Tatsuo

  Research and Development (R&D) Center for Submarine Resources, Japan Agency for Marine-Earth Science and Technology (JAMSTEC) Frontier Research Center for Energy and Resources (FRCER), Graduate School of Engineering, The University of Tokyo

Bibliographic Information

Other Title

• 大分県東部佐伯地域の秩父帯に産する層状マンガン鉱床の層序と放散虫化石年代
• オオイタケン トウブ サエキ チイキ ノ チチブタイ ニ サンスル ソウジョウ マンガン コウショウ ノ ソウ ジョ ト ホウサンチュウ カセキ ネンダイ

Abstract

Stratiform manganese deposits are present in Triassic to Jurassic bedded chert sequences of the Chichibu Belt in southwest Japan, which are considered to have accumulated in a mid-ocean basin of the Panthalassa Ocean. To constrain the age and depositional setting of these deposits, we have investigated the field geology, stratigraphy, and age of chert-hosted manganese deposits (Takahira, Takahama, and Kubodomari) from the Chichibu Belt in the Saiki area, Oita Prefecture. The stratiform manganese ores range in thickness from 80 to 150 cm and are intercalated with bedded chert. The age of the deposits is constrained by the presence of radiolarian fossils in the associated bedded chert. The red-bedded chert above the Takahira manganese ores contains Late Triassic (Carnian) radiolarian fossils, including Trialatus longicornutus, Trialatus megacornutus, and Enoplocampe yehae. In contrast, radiolarian fossils from the Takahama and Kubodomari deposits occur in stratiform manganese ores of Early Jurassic age (possibly Toarcian), based on the occurrence of Parvicingula nanoconica with Parahsuum and Trillus species. These results suggest that two manganese ore forming events occurred in the pelagic Panthalassa Ocean during the Late Triassic and Early Jurassic.

Journal

• The Journal of the Geological Society of Japan

  The Journal of the Geological Society of Japan 122 (6), 267-273, 2016-06-15

  The Geological Society of Japan

Keywords

• Stratiform manganese deposits
• Chichibu Belt
• radiolarians
• Late Triassic
• Early Jurassic

Details

• CRID: 1390001206241926912
• NII Article ID: 130005253517
• NII Book ID: AN00141768
• DOI: 10.5575/geosoc.2016.0015
• ISSN: 13499963
• ISSN: 00167630
• NDL BIB ID: 027544833
• Web Site: http://id.ndl.go.jp/bib/027544833
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I027544833
• Web Site: https://www.jstage.jst.go.jp/article/geosoc/122/6/122_2016.0015/_pdf
• Text Lang: ja
• Data Source:
  • JaLC
  • NDL
  • Crossref
  • CiNii Articles
  • KAKEN
• Abstract License Flag: Disallowed