Abstract:

Due to the tertiary and quaternary strata overlay thickness on the surface of Zhaishang gold mine，it is difficult to position the deep orebody and surface prospecting.According to current situation of exploration，a good deal of work Controlled Source Audio-frequency Magnetotelluric measurements were carried out.In addition，through  CSAMT survey work at 16 lines in north and south ore belt，the results showed that there were significant differences between the north and the south mining area in resistivity.Through analyzing resistivity two-dimensional inversion of the 16 lines，it was found that Zhaimashu anticline displayed north step south slow，and a vertical form at karyomere.Broken alteration zone（orebody） was located in the high and low resistivity anomaly gradient belt，suggesting that there were 10 broken alteration zone，south and north ore belt each has 5 broken alteration zones，and the known structural belt and vein distribution sets was better.We completed the resistivity measurement at south ore belt area of the gold mine，43~95 line CSAMT joint profile measurement showed that the deep veins were larger prospecting space.The 35 series  in Zhamashu arch core overall exhibited north dipping with abnormal current larger depth，and the deep prospecting was potential.In general，controlled source audio-frequency magnetotelluric measurements can solve the problem of structure distribution，explore the south and north ore zone of deep vein distribution at the gold mine，which provides a theoretical basis for deep exploration.

Key words: Controlled Source Audio-frequency Magnetotelluric（CSAMT）, resistivity, deep prospecting, Zhaishang gold mine, Gansu Province