Abstract
The Takano Formation of late Pleistocene lacustrine sediment is distributed at the southern Nagano City. The TKN-2004 core, 53.88 m long, was taken at the central part of the basin, and is composed mostly of homogenous clayey silt. Age of the sediment was estimated from the relationship between radiometric ages and calibrated depths of DKP, Aso-4, K-Tz, Ata and Aso-2 tephras, postulating that the sedimentation rate is constant.
Paleoclimate from 169 ka to 37 ka was reconstructed on the basis of TOC content variation. The long-term TOC fluctuations are concordant with the SPECMAP curve. This result is supported by pollen composition. The short-term variations are similar to stadial-interstadial cycles in the Greenland ice cores, and most of warm peaks can be correlated with IS 9 to 25.
