近畿地方の第四紀層の層序区分  [in Japanese] Stratigraphic Subdivision of Quaternary Deposits in Kinki District, Japan  [in Japanese]

The Osaka Group (Pliocene-Middle Pleistocene) and the overlying younger deposits (late Middle Pleistocene-Holocene), which are distributed in Harima, Osaka, Nara and Kyoto basins, are mainly of fluviolacustrine origin, and intercalate fifteen marine clay beds (Ma-1, Ma0, Ma1, … Ma13 beds in ascending order) and more than fifty volcanic ash layers. Litho- and tephro-stratigraphic subdivisions of the Osaka Group and the overlying younger deposits are established by means of tracing marker horizons, i.e. volcanic ash layers, marine clay beds and terrace surfaces. Bio- and magneto-stratigraphical studies and fission-track dating on these deposits have been vigorously performed on the basis of the above-mentioned litho- and tephro-stratigraphic subdivisions. Therefore geologic sections of the Osaka Group and the overlying younger deposits around Osaka basin are assigned for the stratigraphic type of Quaternary deposits in Kinki District. Other remarkable Pliocene and/or Quaternary deposits in Kinki District are the Kobiwako Group in Iga-Omi basin, the Tokai Group on the west coast of Ise Bay, the Shobudani beds in the drainage area of the Kinokawa, the Shinocho beds in Kameoka basin and the Fukuchiyama Formation in Fukuchiyama basin, and all these other deposits are fluviolacustrine origin. The Kobiwako Group (Pliocene-Middle Pleistocene), the Tokai Group (Pliocene-Early Pleistocene), the Shobudani beds (Pliocene-Early Pleistocene) and the Shinocho beds (latest Early Pleistocene-Middle Pleistcene) are correlative with the Osaka Group, and the Fukuchiyama Formation (late Middle Pleistocene) is probably correlative with the High terrace deposits.