Mega- and micro-fossiles and radiocarbon age from the Holocene deposits beneath the Yokosuka City Hall, south-central Japan
Kanie, Y.; Matsushima, Y.; Kashima, K.; Omori, Y.; Kojima, K.
Science Report of the Yokosuka City Museum 33: 37-44
The Holocene marine deposits and fossils from the depth of 25.4 m-17.5 m under the ground of Yokosuka were analyzed. By the 14C method the age of the deposits was assigned to 9,000 y.B.P.-6,700 y.B.P., namely Early Jomon age. One of the wood fossils was identified with Zelkova serrata. Palynological study revealed the climatic change from a temperate deciduous broad-leaved forest of 9,000 y.B.P. to a warm-temperate laural forest of about 6,700 y.B.P. Changes of diatom thanatocoenosis during these 2,300 years are in harmony with those of molluscan faunae. The transition of paleontological assemblages previously mentioned is attributed to adaptation to the changing environmental conditions accompanied by hypsithermal climate and progressing transgression. The results agree with the changes reported in the South Kanto region.