Paleobotany and paleoenvironment of the Late Pleistocene in the Sagami region, Central Japan.

要旨

Macroscopic plant fossils and pollen assemblages from the Late Pleistocene in the Sagami region are described, and the vegitation and paleoenvironment are discussed. The taxonomy and phytogeography of Selaginella, Larix and Picea, are described. Picea is classified into two species and three types, i.e., P. jezoensis, P. maximowiczii, P. sp. A, P. sp. B and P. sp. C. Cool-temperate coniferous forests composed of mainly Cryptomeria japonica and Picea maximowiczii were dominant between 90, 000 and 60, 000y.B.P., and indicate the wet cool-temperate climate with a high annual precipitation. Vegetation during the Misaki Transgression, ca. 60, 000-55, 000y.B.P., was distinguished by an expansion of cool-temperate oak forests; therefore the climate was relatively warm with low annual precipitation. The subarctic to cool-temperate coniferous forests composed of mainly Picea maximowiczii and Larix in ca. 55, 000-50, 000y.B.P. were the first cold climate forests in the Late Pleistocene. This cold age corresponds to the Murodo Glacier Stage on Mt. Tateyama in Toyama Prefecture. Transitional mixed forests between subarctic coniferous and cool-temperate broad-leaved forests were dominant between ca. 16, 000-13, 000y.B.P. These forests spread out in the southern Kanto region in the latest Pleistocene. The descent of subarctic coniferous forests is more than 1, 000 meters on the eastern slope of Mt. Fuji.

主題