抄録
In Kinki District, Southwest Japan, the Plio-Pleistocene series are widely distributed, namely, the Osaka group and its correlatives. The Osaka group is divided stratigraphically into three parts, the lowermost, the lower and upper parts, and of them the upper part is considered to be the deposits of the age of the First Interglacial and the 2nd Glaciation (Mindel). In this paper, the writer described the pollen fossils of a boring core which was obtained from Sakai harbour. The materials treated ranged stratigraphically from Ma 2 marine clay bed to Ma10 marine clay bed. Further, he discussed the changes of flora, paleoclimate and paleoecology of the time of the deposition of the Upper Osaka group, and pointed out the fundamental problems concerned with the interpretation of pollen diagrams. 1) The pollen zones of the Upper Osaka group were divided into the Fagus and Pinanceae Zones in ascending order, and each zone was subdivided into subzones as shown in Fig. 4. 2) The warm and humid climate beginning with Ma 3 marine clay bed was followed by the warmer and more humid climate of Ma 6 marine clay bed. After that, the deterioration of climate took place (also shown in Fig. 4). The ecological characters of the forest flora changed evolutionally in the process of climatic oscillations, and the forest zones were differentiated more clearly by repeated arrivals of the glacial stages. 3) Vegetations of the non-marine phases were reconstructed by interpreting the pollen diagram, and it was pointed out that the influence of differential floatation and deposition of pollen has to be considered in making comparative study of the pollen-analyses of sandy and clayey sediments. 4) The stratigraphical horizon and process of disappearance of Liquidambar were discussed palynologically.
