Abstract:

Yangshan gold deposit is a large carlin-type gold deposit in the south of Gansu Province.It is located at the northern margin of an inverted triangle tectonic domain which converged to form by the Yangtze，India and North China Plate，at the binding site of Songpan-Ganzi orogenic belt and Qinling orogenic belt.Gold-bearing geological mass is mainly the black pyritization carbonaceous phyllite，the pyritization cataclastic altered limestone and the pyritization inclined long granite porphyry.Among them，the pyrite shows anhedral and fine to fine grained disseminated distribution and it is closely related to the gold mineralization，and also an important prospecting mark.In the Partial area，granite porphyry has developed a strong gold mineralization and the electrical characteristics of low resistance-high polarization which passes through the rock electrical parameters measured.The derivative index method of IP sounding is usually more in terms of looking for water.As all of them have the low resistance-high polarization’s electrical characteristics which are water-rich strata，metal mineralization construction，broken alteration zone and so on，this work attempts to use derivative index to explain the bathymetric data of Yangshan gold  mine and infer the status of the underground low resistance-high polarization anomaly occurrence，all of which provide the basis for laying heavy mountain project.Using the derivatives Index explains two bathymetric profiles and successfully laid verification drilling，and the project examples show that the method is a practical prospecting method in Yangshan gold mine.

Key words: geophysical, pyritization, electrical characteristics, carlin-type gold deposit