2005 Volume 111 Issue 2 Pages 87-93
Detailed sedimentologic and tephrochronologic study of the Middle Pleistocene successions in the central part of the Kanto Plain, central Japan, reveals that the strata called tentatively as C to F formations in the study area are correlated with the Kiyokawa, Kamiizumi, Yabu, and Jizodo Formations of the Shimosa Group, respectively. Each formation is bounded by two successive sequence boundaries, and generally exhibits a depositional cycle composed of fluvial and marine facies, in ascending order. We recognized several marker tephra layers from these formations. On the basis of the correlation of this study, the base of the Shimosa Group, which corresponds to the base of the Jizodo Formation, is estimated to be at the elevation of -100 to -140 m in the study area, and is much shallower than the previously interpreted elevation of the base.
