熱ルミネッセンス法による新期雲仙火山溶岩ドームの年代測定 : 妙見岳火山以降2万5千年の噴火活動史
2004 年 49 巻 2 号 p. 73-81
詳細
2004 年 49 巻 2 号 p. 73-81
Thermoluminescence (TL) ages are obtained for 28 samples from domes and debris avalanche deposit of Younger Unzen Volcano. Weighted mean ages are 4.1 ± 0.8 ka for Tenguyama lava, 3.8 ± 0.6 ka for Shichimenzan lava, 3.1 ± 0.6 ka for Fugendake-sancho lava, 3.4 ± 0.6 ka for Kazaana lava, 15 ± 2 ka for Myokendake lava, 25 ± 4 ka for Kunimidake lava. Six TL ages for Tarukidaichi debris avalanche deposit range from 20 ± 2 ka to 30 ± 3ka. We success to distinguish individual dome age by TL dating. Source rock of Tarukidaichi debris avalanche deposit is Kunimidake lava and age range of formation is estimated as 25 ka to 7.3 cal ka by TL dating and field observation. We gave new and useful age data of Younger Unzen Volcanic lavas by TL dating with age range about 25 ka to 3 ka.
