[Abstract]

Thermoluminescence (TL) ages are obtained for 28 samples from domes and debris avalanche deposit of Younger Unzen Volcano. Weighted mean ages are 4.1+-0.8ka for Tenguyama lava, 3.8+-0.6ka for Shichimenzan lava, 3.1+-0.6ka for Fugendake-sancho lava, 3.4+-0.6ka for Kazaana lava, 15+-2ka for Myokendake lava, 25+-4ka for Kunimidake lava. Six TL ages for Tarukidaichi debris avalanche deposit range from 20+-2ka 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 25ka 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 25ka to 3ka.

Key words:

Unzen Volcano, thermoluminescence dating, Myoken caldera, debris avalanche deposit, collapsed age

e-mail:

t-yamagata@kawako.kawatetsu.ne.jp