SEGJ Technical Conference

Shallow seismic survey parallel to the Ayasegawa fault

Abstract A chloride concentration and characteristic isotopic distribution occur in the center of the Kanto plain. The area almost corresponds to the Motoarakawa tectonic zone delineated by the Ayasegawa fault and Kuki fault. We had conducted seismic surveys crossing the Motoarakawa tectonic zone from northeast to southwest. The Ayasegawa fault is perceived on the seismic section and probably acts as a southwest barrier of groundwater system, but the Kuki fault is not recognized in the seismic section and the northeast boundary of the system may not be a structural one but a change of facies and so on. As a additional survey, we carried out a new seismic survey parallel to the Ayasegawa fault in the Motoarakawa tectonic zone. There seem no distinctive geologic structures which acts as a barrier around the northwest boundary of the system.