In Japan, the changes of the sea-level seem to have occurred during the late-Quaternary, as are shown in the following table.
sea-level at
Last Glaciation about -80m.
Earliest Jomon stage (about 4000 B. C.) -10∼15m.
Early or middle Jomon stage (3500-2500B. C.) +3∼5m.
Late Jomon stage (about 1000 B. C.) 2∼3m.
Late Yayoi stage (about A. D. 200) ±0m.
These are indicated by correlations between the late-Quaternary formations and the topographical features, and the discovery of the prehistoric remains.
The bedrock floors of large river valleys are filled with tha late-Quaternary deposits usually at 60-80 meters below the present sea-level. Ordinarily, they are covered with the fluviatile gravel beds of about 10 meters thick. These are supposedly formed during the time of the low sea-level of the latest glaciation. Near the mouth of large rivers, the gravel beds generally are found at 50-70 meters deep, with some exceptional instances, such as Setouchi region and Echigo plain. In some districts, the seaward extension of the gravel beds is connected with the abrasion platforms off-shore at a depth 70-100 meters below the present sea-level. This shows that the sea-level, before the Holocene marine transgression, was about 70-80 meters lower than the present.
There are some fresh-water shell middens formed in the earliest Jomon stage, in some parts of the islets of the Seto Inland Sea. This shows that the sea-level then was about 15 meters lower than the present. But in Kanto district, it has been known that the level was at about -10 meters.
Judging from the distribution of the middens in Kanto district, the highest sea-level was supposed to have taken palce in the early Jomon stage. However in Nobi plain, it was found to have occurred in the middle Jomon stage. The marine deposits are now discovered at a level few meters high above the present sea-level, showing that the sea-level then was higher than today.
The sea-level dropped soon after its maximum rise, and, consequently, the new coastal plains were eroded by the extended rivers. But the river beds are now found at about 3 meters below the present sea-level, showing the sea-level to be 2 or more meters lower than the present.
During the later Jomon stage and the Yayoi stage, the sea-level finally rose to its present height, since the channels were filled up with marsh deposits. Paddy-field rice plant was introduced into Japan about that time and it was cultivated at the first stage in marshy land without irrigation.
Fluvial deposits covering the surface of the marshy plains and the greater part of the marine deposits at less than 5 meters above sea-level began to form after the middle Yayoi stage. These deposits are less than few meters thick.

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The advances and retreats of the Alpine glaciers show a surprising correspondence to the up and declined states of the tree-growths at Arlieshan Mt. (23°30′N 120°48′E 2676M) in Formosa, as shown in Fig. 3. It is supposed that the intensified state of jet stream would result the retreat of glaciers in the Alps, activating the lateral mixings of cold and warm air, while, in the Far East, the stronger jet would repress the amount of summer precipitations of the south-eastern monsoons on which tree-growths might depend. (See Fig. 2)

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In this paper the changes of the forest and climate in the early Alluvial age are discussed, based on the pollen analytical results of the four main stations concerning this subject in Japan, i. e. Yashimagahara, Ozegahara, Hyotan'ike and Ebetsu. The results are as follows (cf. Tab. 1, Figs. 2, 3): in the increasing warmth period of the early postglacial age, it was 3°C lower than the present time in average temperature, while in the following maximum warmth period, the forest zone was 300-600m higher and it was 2°-3°C warmer than now. These climatic changes can be satisfactorily correlated with the results obtained so far by many authors all over the world. Considering many chronological data such as those by Blytt, Sernander, von Post, Godwin, Sears, Hansen, Deevey, Frey, Selling, Bertsch, Firbas, Straka, and Nakamura, it was concluded that in Japan the absolute age of the boundary between the increasing and the maximum warmth periods was B. C. 6000-5500 years and the boundary between the maximum and the decreasing warmth periods was B. C. 2000-1000 years.
Moreover, the maximum warmth period may correspond with the period of sea-transgression in the early Holocene and the decreasing warmth period with that of regression. On the other hand, according to Ezaka and Nakano etc., the transgressive and regressive periods correspond to the Jhomon and Yayoi epochs respectively. Therefore, the boundary between Jhomon and Yayoi epochs can be presumed to be B. C. 2000-1000 years before. This conclusion is still more trustworthy, considering the results of C¹⁴-dating of the canoe remains found at the Kamo and Kemigawa Jhomon sites.

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In the spring of 1955 a lower jaw of both sides with third milk molar was excavated from a fissure deposit of Kawai limestone quarry at Yage, Iinoya-mura, Inasa-gun, Shizuoka Prefecture. Judging from the occurrence of Palaeoloxo don namadicus naumanni, having been described about thirty years ago from the Sahanma shell beds, it seems to be probable that this material must belong to the above subspecies, one of the most common subspecies in the Japanese Pleistocene. As the occurrence of milk teeth is the first example in Japan, they are described here. The geological age of the fissure deposit is considered to be the late Pleistocene (J₂) and not to be the latest (J₃).

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