Yu, FS (reprint author), Chinese Acad Sci, Inst High Energy Phys, Beijing 100039, Peoples R China.
The Longgang volcanic cluster located in Jilin Province belongs to one of the active volcanic regions in northeast China, and has been active in modem times. In view of the multiple eruptions in history, it is very important to determine the age of each eruption for evaluating the volcanic hazards. Two alkaline basalt samples taken from Dayizishan and Diaoshuihu were analyzed with the U-series component dating after magnetic separation. The ages of the two samples are (71 +/- 9) ka and (106 +/- 13) ka B.P., respectively. These data indicate that there existed intensive eruption activities during the late Pleistocene.