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is an archipelago in the Sea of Japan, which are administratively part of Oki District, Shimane Prefecture, Japan. The islands have a total area of . Only four of the sixteen named islands are permanently inhabited. Much of the archipelago is within the borders of Daisen-Oki National Park. Due to their geological heritage, the Oki Islands were designated a geopark within the UNESCO-assisted Global Geoparks Network in September 2014.〔http://www.globalgeopark.org/aboutGGN/list/Japan/8438.htm〕 ==Geology== The Oki Islands are volcanic in origin, and are the exposed eroded summits of two massive stratovolcanoes dating approximately 500 million years ago to the Tertiary and Quaternary periods. The oldest rocks in Japan have been found on the Oki Islands. Dōgo to the east is the largest island in area, and has the highest elevation, Mount Daimanji, at above sea level. The Dōzen group of islands to the west are all portions of single ancient volcanic caldera which collapsed, leaving three large islands (Nishinoshima, Nakanoshima and Chiburijima) and numerous smaller islands and rocks in a ring formation surrounding a central lagoon. The archipelago is approximately north of Honshu coast at its closest point. For administrative purposes, the Japanese government officially considers the disputed islet of Takeshima (Liancourt Rocks) to be a part of the town of Okinoshima on Dōgo. 抄文引用元・出典: フリー百科事典『 ウィキペディア(Wikipedia)』 ■ウィキペディアで「Oki Islands」の詳細全文を読む スポンサード リンク
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