新潟焼山火山の活動と年代
歴史時代のマグマ噴火を中心とし
1994 年 103 巻 2 号 p. 149-165
詳細
1994 年 103 巻 2 号 p. 149-165
Niigata-Yakeyama volcano, situated in the northernmost part of Central Japan, is a small dome-shaped stratovolcano, and has many records of its eruption. The geology of this volcano has been already described in detail by the auther. In this paper, more detailed volcanic history of Yakeyama is compiled mainly on the basis of nine 14C ages of the ejecta newly determained and the stratigraphic relationship between the ejecta and the archaeological remains.
The results are summerized as follows:(1) The first volcanic activity of Yakeyama started ca. 3, 000 years ago.(2) During historic times, three violent magmatic eruptions took place ca. 1, 000 years ago, and in 1361 and 1773 and produced pyroclastic surges, pyroclastic flows, and lava flows.(3) After the 1773 magmatic eruptions, Yakeyama repeated a series of steam explosions respectively in the mid-nineteenth and late-twentieth centuries.
