We conducted a seismic reflection survey along the coast line of the eastern part of the Kanto Plain, central Japan. Four reflectors were clearly recognized in the reflection profile: Reflector A is nearly flat (about 0.1-0.25s in 2-way time); Reflector B is gently tilted to the south at about 0.25-0.5s; Reflector C is waved around the 0.5-1.0s at the northern and southern parts of the profile; Reflector D is hugely waved deeper than 1.5s. With respect to borehole data adjacent to the seismic line, the strata between Reflectors C and D can be correlated with the early middle Miocene half-graben deposits distributed along the Tanagura Tectonic Line. It suggests that the southern trace of the Tanagura Tectonic Line should be concealed at just east of the present seismic line.
