84. 海野　進・石塚　治・金山恭子, 2016. 母島列島地域の地質．地域地質研究報告（5万分の1地質図幅）小笠原諸島(20) 第3号 NG-54-8-16, 9-13. 産業技術総合研究所地質調査総合センター，46p.

The Izu-Ogasawara (Bonin) Arc extends 1,500 km in length and 400 km in width and consists of the Shichito Ridge, Backarc-Nishinoshima Trough, Ogasawara (Bonin) Trough and Ridge, and Japan Trench from west to east. The Ogasawara (Bonin) Archipelago, comprising Mukojima Rettō, Chichijima Rettō and Hahajima Rettō from north to south, lies between latitude 26°32’N and 27°44’N and at longitude 142°E on the shallow shelf on the Ogasawara Ridge. The Shichito Ridge is a post Oligocene volcanic ridge capped by the Quaternary volcanoes including Nishinoshima and the Volcano Islands. The Geological Map “Hahajima Rettō” covers the Hahajima Island Group situated between latitude 26°31.5’N and 26°43.5’N and between longitude 142°06.00’N and 142°15.00’N. The Hahajima Rettō (Island Group) is comprised mainly of Eocene volcanic strata capped by Eocene limestone, with a minor Quaternary sedimentary cover.

Keyword: Hahajima, Ogasawara Archipelago, Bonin Islands, 1:50,000 Geological map, Geological Survey of Japan
キーワード: 母島，小笠原諸島，小笠原群島，5万分の1地質図幅，産総研，地質調査総合センター