Application of comprehensive geophysical methods in gold deposits prospecting in Fanshuiwa area of Anhui Province

Fanshuiwa district in Chuzhou is an important prospecting area for copper and gold deposits in Eastern Anhui Province, and the fine-disseminated gold deposit is the major type. Previous work on the interpretation and inference of comprehensive electromagnetic methods is relatively weak. Therefore, a comprehensive detection profile on the vertical direction of the main structures was set up, including magnetic, gravity, AMT, CSAMT and TDIP, in order to achieve a breakthrough in prospecting in this area. The results show that ① Huangpo fault, on the west side of the Fanshuiwa mining area, has a steeper upper part. This fault slows down at a depth of approximate 500 m and changes to a steep dip at a depth of 1 500 m. ② There are two obvious hidden faults in the deep, with a southeast tendency and the dip of 70°~75°. One intrusive rock probably locates between these two faults, with a shallow buried depth of 400~500 m. A 1 500 m straight hole drilling project was constructed in the favorable mineralization position, and the results show that the structural breccia with strong pyrite mineralization is the main ore-bearing location of the fine disseminated gold deposits in this area. However, due to the influence of the carbon content in the strata, it is not effective to find the favorable mineralization site by polarizability. It is advisable to find the resistivity gradient zone first, and infer the locations with the fractured structure. The structural fracture zone favorable for mineralization was delineated lastly. Combined with the rock physical structure, ore-forming geological characteristics and ore-controlling geological conditions, the deep tectonic features of this mining area were inferred and favorable blocks for prospecting were clarified in this paper, which could point the prospecting direction for golden deposits in this area.