[SCG61-P12] Magnetic anomaly lineations of the Jurassic Pacific Plate
Keywords:Jurassic, Pacific Plate, magnetic anomaly lineations
The geomagnetic data used for this study were acquired by the Hydrographic and Oceanographic Department of the Japan Coast Guard for the Extended Continental Shelf Survey (e.g., Fujisawa, 2009). Additional shipboard geomagnetic data were obtained from the databases of National Oceanic and Atmospheric Administration/National Centers for Environmental Information (NOAA/NCEI) and Japan Agency for Marine-Earth Science and Technology (JAMSTEC). We also used unpublished data obtained by Geological Survey of Japan (GSJ) and Ocean Research Institute, the University of Tokyo (ORI, UT). We used the leveling method proposed by Ishihara (2015) to reduce crossover differences of geomagnetic data.
Our magnetic anomaly map revealed the lineated magnetic anomalies in the areas where previous works did not identify any magnetic anomaly lineations. The strikes of the lineated magnetic anomalies are the same as that of the lineation younger than M29. Our temporary identification indicates the age of the lineated magnetic anomalies is older than Lineation M29. We found several magnetic bights in the study area, implying the configuration of the Pacific-Izanagi-Farallon triple junction was a ridge-ridge-ridge before M29.