Stratigraphy of the Permian Iwato and Mitai Formations in the Kamura area, Southwest Japan: Maokouan, Wuchiapingian, and Changhsingian carbonates formed on paleo-seamount.

• Ota Ayano

• Kanmera Kametoshi

• Isozaki Yukio

Bibliographic Information

Other Title

• 宮崎県高千穂町上村のペルム系岩戸層および三田井層の層序　　海山頂部相石灰岩中に確認された茅口階，呉家坪階および長興階
• ミヤザキケン タカチホチョウ カムラ ノ ベルムケイ イワトソウ オヨビ ミタイソウ ノ ソウ ジョ カイザン チョウブソウ セッカイガン チュウ ニ カクニン サレタ チコウ カイ ゴカヘイ カイ オヨビ チョウコウカイ

Abstract

Litho- and bio-stratigraphy was analyzed for the Upper Permian shallow-water limestone derived from a mid-oceanic paleo-seamount. The limestone in the Kamura area in Kyushu occurs as an allochthonous block contained in the Jurassic accretionary complex of the Chichibu belt in Southwest Japan. A newly exposed limestone section consists of a black limestone of the Iwato Formation (17 m) and an overlying light gray dolomitic limestone of the Mitai Formation (17 m). Through microscopic observation of 304 thin sections, 6 genera (species indeterminate) and 6 species of 4 genera of fusulinaceans were identified. On the basis of fusulinacean biostratigraphy, the limestone in this section is clearly divided into four interval zones, i.e., Lepidolina Zone, barren interval (zone), Codonofusiella-Reichelina Zone, and Palaeofusulina Zone, in ascending order. The former two belong to the Iwato Formation, while the latter two to the Mitai Formation. The Yabeina-Lepidolina Zone is correlated to the Maokouan Stage (Middle Permian) in South China, while the Codonofusiella-Reichelina Zone and the Palaeofusulina Zone to the Wuchiapingian and Changhsingian Stages (Upper Permian), respectively. Thus this limestone of mid-oceanic seamount origin ranges for nearly 10 m.y. from the Maokouan (Yabeina-Lepidolina Zone) Stage to the Changhsingian Stage (Palaeo-fusulina Zone). This is the first report in the world on a fusulinacean-dated continuous pelagic shallow-water limestone sequence covering the entire Late Permian interval immediately before the Permian-Triassic boundary mass extinction. The present result is quite significant because this Upper Permian limestone may have recorded the global environmental changes in the surface of the superocean Panthalassa relevant to the Permo-Triassic boundary event.

Journal

• The Journal of the Geological Society of Japan

  The Journal of the Geological Society of Japan 106 (12), 853-864, 2000

  The Geological Society of Japan

Keywords

• Kamura

Details

• CRID: 1390001206234112128
• NII Article ID: 110003013089
• NII Book ID: AN00141768
• DOI: 10.5575/geosoc.106.853
• ISSN: 13499963
• ISSN: 00167630
• NDL BIB ID: 5632552
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I5632552
• Text Lang: ja
• Data Source:
  • JaLC
  • NDL
  • Crossref
  • CiNii Articles
• Abstract License Flag: Disallowed