Abstract：Controlled by the ancient terrain composed of Ordovician limestone, the bauxite deposit is positively related to the thickness of Carboniferous Benxi Formation in the ore-forming basin, and the favorable positions for bauxite enrichment are slope belts, depressions, grooves and karst funnels. As there exist obvious differences between Ordovician limestone and overlying formations in density and electrical properties and between bauxite and surrounding rocks in density, Bouguer gravity anomaly can better reflect the tectonic framework in the study area and the rise-and-fall trend of the Ordovician interface, Bouguer gravity residual anomaly can reflect the occurrence of partially high percentage of bauxite, and the combination of controlled source audio-frequenay magneto-telluric (CSAMT) method and calibration of the drilling can efficiently infer the buried depth and occurrence of basement limestone. The authors have achieved good application result by using 1:25 000 gravity and CSAMT method which combines direct prospecting and indirect prospecting, and the results provide a basis for deploying drill holes.
