Magnetic Anomaly due to Serpentine Rocks, (Magnetic Survey of the Hizume District)
Yumura, T.
Abstract
 From September to November,1942,the detailed magnetic survey were carried out by using the Ad, Schmidt's field balances for the vertical and horizontal components and the declinator at 129 stations in the region of the“Hizume anomaly“ which had been discovered in the magnetic survey in the Iwate Prefecture.
It is considered that this anomaly may be almost certainly due to the serpentine rocks which crop out almost over this area. The magnetude of this anomaly,however, is too large the maximum value for the total force being about 0.1 gauss,to be estimated from the Quantity about 10 % of ferromagnetic substances contained into the serpentine.
This report was published as the data for warning to a selection of the suitable position of a magnetic observatory or of suitable station on magnetic survey.