-

Presence of a conductive body in a magnetic field causes inductive currents to now in the body. The secondary magnetic field of this currents adds to the primary magnetic field. The receiver then respor.ds to the resultant of the arriving primary and secondary fields, so that the response differs in both phase and amplitude.
In the VLF method the primary electromagnetic field has
frequency of 5 to 30 KHz, and is received as a plane wave at the measuring point. In this paper we are using the VLF method in the
area of a copper mine (Ghaleh Zary copper mine) located 180 kIn south of the city of Birjand.
Measurements were carried out along 21 east-west profiles and the usual methods were used in the interpretation of data. The VLF results agree well with both geological information and the results of
IP measurements.