植物化石からみた見当山累層の再検討

抄録

Around the Ise Bay the uncertain Pleistocene deposits such as the Kentoyama, Karayama and Taketoyo Formations are scattered on the top of hilly land. They unconformably lie on the so-called Tokai Group, commonly show unfossiliferous gravelly and sandy facies in lithology and donot have any original depositional surfaces. In the northwestern and southern parts of Tsu City, the Kentoyama Formation unconformably lies on the Age Group and is overlied by the higher terrace deposits. Generally it shows the frequent lateral changes in lithologic faices. Partly it shows the channel structure and cuts down the underlying the Age Group. Precise lithologic correlation in this formation is unable in the present study. But it yields abundant well preserved plant fossils, such as corns, seeds, wood spines, leaves, pollen grains and spores. From the view point of the fossil occurrences, especially by means of the pollen analysis the Kentoyama Formation may be correlated to the upper part of the Osaka Group. And it deposited in near shore swamps, because of the abundant occurrences of Trapa spp., Ceratopyllum demersum, Potamogeton cristatus, Nuphar sp., Nelumbo sp., Sapium sebiferum and Paliulus nipponicus.