Abstract
The paper reports on the effectiveness of the natural radioactivity survey and the electrical prospecting. According to the result of the investigation which has been carried out scince 1963, the following became clear.
1) Relation between the groundwater zone and natural radioactivity values, apparent resistivity values.(Table 1)
2) Relation between the boundary of lithology and natural radioactivity values. Many landslides have occurred on the boundary part of different rocks and these boundary parts can be estimated from the natural radioactivity survey.
3) Relation between the boundary of lithology and apparent resistivity values.
As Mikabu greenrocks zone is rich in clay and the groundwater, apparent resistivity values are relatively lower than those in Sanbagawa zone (north side on Mikabu zone) and Chichibu zone (south side on Mikabu zone).
In the part of pillow lava and breccia apparent resistivity values often come to extremely low in the same Mikabu greenrocks zone.
