ま　と　め
　関東平野西部の入間川沿いに分布する仏子層のB部層の花粉分析をおこない,以下の知見を得た.
1.花粉化石群集の構成から,古気候は現在程度〜やや寒冷で,古植生は冷温帯程度の落葉広葉樹と針葉樹のまじる林であったと考えられる.
2.花粉化石群集と植物化石の構成から,分析地点の仏子層は,大阪層群のメタセコイア植物群消滅期にあたると考えられる.
3.古環境は,海域から次第に淡水域〜湿地に変化する過程をしめしている.
4.水生のシダ植物である, Azolla,Salviniaのmassulaeとmegasporeの化石を検出した.

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Fossil Pollen of the Lower Pleistocene Bushi Formation
in the Iruma City, Saitama Prefecture, Japan

Takashi NIREI
Saitama Museum of Natural History, Nogatoro, Chichibu-gun, Saitama 369-13 Japan.

Abstract Fossil pollen assemblage of Bushi Formation early Pleistocene, South-West Saitama prefecture, was examined. Pollenanalytical data obtained from the peat and mud bed in the second member of The Bushi Formation. That was dominated by such pollen as Juglans-Pterocarya, Fagus, Quercus (Lepidobalanus), Picea, and Metasequoia- Glyptostrobus. It was indicate the cool tmperate coniferous and broad-leaved trees mixed forest, and the climatic condition was slightly cooler than the present. This part of the Bushi formation corresponds to the Metasequoia extinct zone of The Osaka Group. The feature described above suggests that It's part of Bushi Formation indicate regression facies. This bed yield aquatic Pteridophytes, including Azolla and Salvinia.