石狩平野の第四系より産出したLarix Gmeliniの遺体について

抄録

The present distribution of Larix Gmelini ranges from Siberia to Saghalin and southernmost part of the Kuriles, but that species is not found in the present flora of Hokkaido. As to the remains, some were once reported from the Kushiro formation and the presence of that species in Pleistocene deposits in Hokkaido has been predicted by pollen identification. Recently, the remains of it, such as many leaves, twigs and cones, were obtained from the peat bed in the Ishikari Plain. In this area, the Quaternary sediments are extensively distributed and those sediments are divided ascendingly from the Nopporo formation, the Nishinosato formation, the Takadai clay formation to the Shikotsu volcanic deposits. Among them, the remains of Larix Gmelini were found from the peat bed in Late Pleistocene Takadai clay formation. This fact indicates that Larix Gmelini had been in Hokkaido at that time and may contribute to the Pleistocene paleobiogeography as one of the important data.