5:15 PM - 6:30 PM
[SEM05-P01] A preliminary paleomagnetic secular variation from varved sediments of Lake Suigetsu, central Japan
Keywords:paleomagnetic secular variation, varved sediments, Lake Suigetsu, the Holocene
Varved sediments of Lake Suigetsu were sampled in July to September, 2014, and a total of 274 cores of 1 m length were collected from four holes on the bottom of the lake. In this study, we used 1cm × 2cm × 2cm double-L channel sub-samples collected from each core. Paleomagnetic analyses were conducted on 43 double-L channel samples, and 16 of 43 are originate samples.
For all samples, we conducted demagnetizations with progressive alternating field up to 80mT and measured magnetizations at 1-cm regular interval. Characteristic remanent magnetization (ChRM) was calculated by principal component analysis. As a preliminary result, inclination and declination variations for last 20000 years were obtained. The PSV of Lake Suigetsu shows many features commonly observed in the Japanese archeomagnetic secular variation for last 2000 years, and also in the Holocene PSV from Japanese lake sediments.