1971 年 25 巻 6 号 p. 245-250b
In the Nopporo-hill, Hokkaido, marine Nishinosato and Nopporo formations are developed. The former is underlain by the latter in unconformable relation. The writer performed pollen analysis of 42 samples obtained from two formations above mentioned, in one locality. The results are shown in Fig. 3 and summarized as follows. 1) The Nopporo formation is characterized by dominating conifer, which indicates rather cooler climate than the present. 2) Lower part of the Nishinosato formation is characterized by dominating broad-leaved trees such as Alnus, Betula, Ericaceae, which indicate similar climate to the present condition, though molluscan fossils show to be more warm. 3) Upper part of the Nishinosato formation is characterized by increasing pollens of the cool temperate forest zone, which indicate rather warmer climate than the present. The writer considers that the investigation of the difference between paleoclimates shown by the molluscan fossils and by the pollen fossils must be the subject of future research.