[SEM22-P09] Paleomagnetic secular variation and rock magnetic characteristics for the last 30 kyrs from the Nankai Trough sediments, Japan
Keywords:paleomagnetic secular variation (PSV), relative paleointensity (RPI), rock magnetism, turbidites, the Nankai Trough, Holocene
For PSV studies using marine sediments, especially for RPI studies, it is desirable that the sediments are magnetically relatively homogeneous and have stable remanent magnetization (Yamazaki et al. 2017). In addition, it is necessary that the sediments can be dated and have a sedimentation rate enough for targeted resolution. Seafloor sediments off Kumano in the Nankai Trough are considered to satisfy these conditions based on current knowledge (Okutsu, 2019, Ph.D thesis). On the other hand, it is necessary to take into account intercalated turbidite layers. Okutsu (2019, Ph.D thesis) has identified turbidite layers in the sediment core used in this study from various analyses including particle size analysis, magnetic susceptibility measurement, X-ray CT scan, and XRF core scan (ITRAX).
In this study, we intend to present a new PSV record (declination, inclination and RPI) for the last 30 kyrs from Nankai Trough sediments. We aim to construct a more accurate and reproducible PSV curve in Japan than those of the previous studies, and to newly obtain a RPI record These PSV curves will be useful for inter-core correlation and age estimation of sediments around Japan.
We will introduce mainly the results of paleomagnetic and rock magnetic measurements on 293 discrete samples (7 cc cube) taken from core PC04 of the Hakuho-maru KH-17-2 cruse off Kumano of the Nankai Trough.