Fundamental Science on Radioactive Geology and Exploration Technology Laboratory, East China Unversity of Technology, Nanchang 330013, China

Tilt-depth method is a new inversion method for fast estimation of the top depths of magnetic bodies. Two- and three-dimensional model tests show that the inversion error of tilt-depth method is related to the top depth, thickness and horizontal scale of geological body. In addition, superimposed anomaly also has an effect on the inversion results. Tilt-depth method is applied to the aeromagnetic data over Xiazhuang ore field in Guangdong, and the authors find that two near EW-trending anomaly zones on tilt map are produced from deep ultrabasic diabase. Tilt-depth method is used to invert top depths of 11 inversion points on the two high magnetic anomaly zones in the tilt map. Based on the inversion results, the authors found that the depth of magnetic body located in the north of the Xiazhuang ore field is relatively shallow and is getting deeper from south to north, whereas the magnetic body in the south of the Xiazhuang ore field is relatively deeper and with larger scale. This important information is very useful for the deep mineral exploration.