Volcanic ash layers originating from Mt.Sanbe has been identified at new outcrops(Locations D,E and F,east of Mt.Sanbe),based on(1)biotite content analysis(number of biotite particles by numbers of biotite+amphibole-group particles multiplied by 100),(2)analysis of volcanic glasses(size,refractive index and other parameters)and(3)^<14>C age measurements of black soil layers above and below the ash beds.These analyses show that two ash layers at Locs.D and E are correlative with the Taiheizan and Tsunoi Ash layers,respectively.A single ash bed with high biotite content at Loc.F seems to be the Taiheizan ash layer.