Abstract
Pollen analysis was made on the samples from Ma 7 to 9 horizon of the Osaka group (Early Pleistocene) at Machikaneyama, Toyonaka City, Osaka Prefecture. A fossil crocodile, Tomistoma machikanense, was discovered just below Ma 8 of the Osaka group. By the results of the pollen analysis, Ma 7 to 9 horizons can be divided into four groups (I, II, IX, and IV in ascending order); I. Lower part of Ma 7. This is characterized by dominating Fagus and rare value of conifer except Pinus. II. Upper part of Ma 7 (II-a) and non-marine beds bellow Ma 8 (II-b). These are characterized by increasing Cryptomeria rather high Fagus value. This may correspond to the influence of a moist climate condition. III. Ma 8. Pollen spectra is similar to that of I; That is, Cryptomeria decreased and Fagus become dominant again. IV. Ma 9. Pollen spectra is similar to that of III; But size-measurements of the beech pollen indecate Fagus crenata. It is speculated that during the ages of I, II-b. III, the period warmer than the present time were included, and the age of IV was cooler.
