2:45 PM - 3:00 PM
[HQR04-10] Integrated stratigraphy of the early Pleistocene Sakishima Formation in the Shima Peninsula, Mie Prefecture
Keywords:Early Pleistocene, Volcanic ash, Paleomagnetism, Calcareous nano fossil, Sakishima Formation
As a result of the analyze of the shape of the volcanic glass shards, refractive index and chemical composition of the glass shards and orthopyroxene, we could compare the Isobe volcanic ash with the Shishimuta Azuki volcanic ash. As for paleomagnetic analysis, we found that the upper and lower layers including Isobe volcanic ash are all inverse magnetized. About calcareous nannofossils, mudstone 1-2 m below the Isobe volcanic ash contains Reticulofenestra asanoi, Gephyrocapsa parallela and Pseudoemiliania lacunosa. Co-occurrence of these species imply the geologic age of the mudstone is MIS 30-21 in the Matuyama chron. To summarize the above results, we reconfirmed that the Sakishima Formation is included in the Matuyama chron, and the Isobe volcanic ash is compared with Shishimuta Azuki volcanic ash in the Osaka Group.