The paleoenvironmental changes in the Japan Sea over the past 32, 000 years were reconstructed from analyses of δ¹⁸O and δ¹³C in foraminiferal tests, concentrations of organic carbon and total nitrogen, C/N ratios, and their δ¹³C and δ¹⁵N in two cores, KI-5 and PC-9, recovered from the eastern part of the Japan Sea. The following results were obtained: (1) The lithology and δ¹⁸O curves of planktonic foraminifera in the two cores agree well with those of many cores in the Japan Sea. This suggests that the paleoenvironmental changes occurred over the entire Japan Sea. (2) The C/N ratios in the eastern cores are higher throughout than those in the southern cores, and the δ¹³C values are lower than those of the southern cores. This implies higher terrigenous inputs in the eastern core sites than in the southern core sites. (3) Each result for the seven analytical items mentioned above demonstrates fluctuation corresponding to the following paleoenvironmental changes in the Japan Sea: inflow of the surface water from the East China Sea from 32 to 29ka, development of low-salinity surface water from 29 to 15ka, inflow of the Oyashio Current from 15 to 10ka, inflow of the surface water in the East China Sea affected by the Kuroshio Current from 10 to 8ka, and inflow of the Tsushima Current since 8ka. In particular, the relationship between δ¹³C and δ¹⁵N of organic matter provides an important proxy for paleoceanographic reconstruction.

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Many buried fossil gullies which were eroded in the past and subsequently buried by colluvial and eolian deposits including tephra layers, have been preserved on the upper parts of valley-side slopes of the Kitsuregawa Hills in the northern part of the Kanto Plain, Central Japan. This paper discusses burying processes of fossil gully formation and the climatic changes that induced the changes in geomorphic processes from gullying to filling on the hillsides in the Latest Pleistocene.
Observation of the facies and stratigraphy of deposits which fill the fossil gullies reveals the following features:
1. Three tephra layers, Ogawa Scoria (OgS, 22ka), Imaichi Pumice (IP, 12-13ka), and Shichihonzakura Pumice (SP, 12-13ka), are intercalated without disturbance in the deposits which fill up the fossil gullies; Kanuma Pumice (KP, 31-32ka) layer is not intercalated in them.
2. The fill deposits in the Last Glacial period, which are lower than IP layer, are divided into upper and lower at the horizon immediately below OgS layer.
3. The lower fill deposits mostly contain gravel, along with, in some cases, blocks of KP as secondary deposits.
4. The upper fill deposits are yellowish brown soft loam intercalating OgS layer, which resemble the same horizon of the eolian deposits on the terrace surface; in many places, however the upper fill deposits contain a small amount of gravel.
5. Distinct tephra layers are generally lacking on the upper parts of the valley-side slopes outside the fossil gullies, which are covered with only thin black soil.
6. The present ground surfaces of the fossil gullies do not show depressions or hollow forms.
The Above six characteristics are common in many fossil gullies. It seems clear that chief causes of the end of gullying and the change of sedimentary facies are not changes in eolian deposit supply but changes in climatic conditions.
Climatic change, from the interstadial to the stadial in the late Last Glacial, induced the end of gullying and the start of filling. During the interstadial of the Last Glacial Stage, the upper parts of valley-side slopes in the Kitsuregawa Hills underwent erosion, as a consequence of temporary rainfalls. After the fall of KP, the intensity of rainfall was reduced, but the gullyfilling deposits which had been supplied by active soil creep from the surrounding slopes and small failure on gully-side and gully-head slopes renined. Immediately before the fall of OgS, the intensity of rainfall subsided again, causing inactive failure of the gully-side and gully-head. Then the gully-fill deposits changed to eolian and soil creep origin.

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Many beetle fossils are found in the peaty silt layer above the Karegawa volcanic ash layer of the Plio-Pleistocene Tokai Group in Tado-cho, Kuwana-gun, Mie Prefecture, Central Japan.
These beetle fossils, mostly belonging to the Donaciinae and Carabidae, include subarctic and cool temperate beetles, such as Ilybius cf. poppiusi, Plateumaris constricticollis constricticollis and Plateumaris cf. birasbimai.
This suggests that the peaty silt layer containing these beetle fossils was deposited during the cold period and that the climate of that time was colder than that in the present.

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A tephra layer was discovered at a construction site in Kobe City, Hyogo Prefecture. Two radiocarbon dates, obtained from peaty silt layers immediately above and below the tephra, indicate that its eruption occurred about 15, 600yrs BP. Mineral assemblage of the tephra and refractive indices of volcanic glass shards, hornblende, and cummingtonite crystals resemble those of the Sambe Ukinuno pyroclastir-flow deposit (U₁: Matsui and Inoue, 1971) from Sambe volcano, Chugoku Mountains, western Japan. The age of the U₁ tephra have been reported as 15, 000-16, 000yrs BP. These two tephra layers are probably correlated, and the newly discovered tephra is considered to correspond with the distal co-ignimbrite ash fall of the U₁ tephra.

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