Abstract:

The overburden of the earth’s surface is thickness in Zhaishang gold deposit，and there are many concealed gold bearing fractured zone.Field geological work discovery that the boundary between most of  gold bearing broken zone and surrounding rock is not clear，and the surrounding rock types of south and north gold belts are different，which leads to a large difference in resistivity.Therefore，it is very necessary to select suitable geophysical method to find gold bearing fractured zone at the edges and deep of south and north gold belts.According to the actual prospecting situation in the gold mine，the controlled source audio frequency magnetotelluric sounding is carried out in the south and north gold belts，and the effectiveness of the method for prospecting is studied.The results show that the resistivity anomaly of south gold belt is consistent with the gold bearing broken belt，the prospecting effect is obvious according to the gradient of high and low resistance anomaly.The difference of rock resistivity in north gold belt is small，and the prospecting effect is poor，especially the rock resistivity of the west part in north gold belt is generally lower，so the method have no significance for prospecting.The results of this research can provide some references for next arrangement of controlled source audio frequency magnetotelluric sounding.

Key words: controlled source audio magnetotelluric sounding method, Zhaishang gold mine, prospecting effect, Gansu Province