1955 年 20 巻 5 号 p. 144-151
1) The region lies on the nothernmost part of Nagano prefecture and on the southern end of Tomikura anticline.
2) The region have 2 oil and 12 gas seepages, 3 of gas seepages are not inflamable because of predominant of CO2 component.
3) The Tertiary formations are mostly hiden under overlying volcanic detritus of Quaternary volcanisms.
4) The anticline axis is presumed to cross the Nojiri-ko, therefore the structure borings are desirable on the line across this presumed anticline structure.