埼玉県さいたま市で掘削された深作A-1ボーリングコアの花粉化石群集

摘要

Pollen data from Pleistocene sediments in the Fukasaku A-1 drill core, obtained from SaitamaCity, Japan, provide a basis on which a pollen biostratigraphy for subsurface geology of the centralKanto plain is constructed. In this study, 131 sediment samples were collected at ca. 2 m intervals fromthe Fukasaku A-1 core, which consists mainly of marine and fluvial sediments intercalated with twomajor Pleistocene marker tephra. The pollen assemblages from the Fukasaku A-1 core distinguish 28local pollen assemblage zones in informal nomenclature by a distinctive assemblage of taxa, indicatinglocal environmental conditions as a rudimentary biostratigraphic classification. An abundance horizon ofCyclobalanopsis pollen and the uppermost documented occurrence of Quercus pollen are useful markerhorizons for Middle Pleistocene pollen biostratigraphic correlation in not only central and south Kantobut also in other sedimentary basins. On the other hand, the Fs-Pol-22 zone in the Fukasaku A-1 core iscurrently a barren interval in informal nomenclature, because of the significantly low occurrence of treeand shrub pollen. Therefore, the pollen biostratigraphic character of this zone remains unresolved