1 0 0 0 OA 嶺岡帯の枕状溶岩にともなうアンバー(umber)
- 著者
- 田崎 耕市 猪俣 道也 田崎 和江
- 出版者
- 一般社団法人 日本地質学会
- 雑誌
- 地質学雑誌 (ISSN:00167630)
- 巻号頁・発行日
- vol.86, no.6, pp.413-416, 1980-06-15 (Released:2008-04-11)
- 参考文献数
- 5
- 被引用文献数
- 8 9
1 0 0 0 四国北西部の中央構造線に貫入した安山岩のK‐Ar年代
- 著者
- 田崎 耕市 高橋 治郎 板谷 徹丸 グレープス R.H. 鹿島 愛彦
- 出版者
- 日本鉱物科学会
- 雑誌
- 岩鉱 (ISSN:09149783)
- 巻号頁・発行日
- vol.85, no.4, pp.155-160, 1990
- 被引用文献数
- 10
Many andesitic intrusions are exposed along the Median Tectonic Line (MTL) in northwestern Shikoku, Japan. Three dikes along the MTL and one intrusion occurring close to it were dated by the K-Ar method to estimate when the fault movement ceased. The dikes and intrusion are not deformed by the movement. The results give 15.1 to 15.4 Ma excluding severely altered one. The MTL in northwestern Shikoku region has not been active since about 15 Ma. Although a similar attenuation of active movement of the MTL during middle Miocene has been reported, the fault movement has continued in the other areas of southwestern Japan as demonstrated by Active Fault Research Group (1980). This may suggest that block displacement has been dominant since middle Miocene in the studied area. The age of the samples also indicates that the volcanic activity of Seto-uchi region started 15 Ma in northwestern Shikoku.