Study on Analysis of the Fossil Pollen from the Izumiyatsu Formation Northern Part of Boso Peninsula, Chiba Prefecture

摘要

The Izumiyatsu Formation which is between the Kongoji Formation and the Jizodo Formation in the Shimousa Group chiefly consists of mud and it is a few meters in thickness. It spreads from the type locality of the Izumiyatsu (Kisarazu City) toward the Northeast and is distributed to Kanazawa (Ichihara City), Ooshii (Chiba City), Tannoo (Togane City), Yabe (Sanbu-Gun) and to Henda (Matsuo Town). We can find a sheet to five sheets of the peat in the formation. Among these fossil pollen gathered in the area, Alnus is most abundant. And every sample involves Tsuga. These facts indicate the possibility of relatively cool clmate and moist ground condition.