Characteristics of Zhangsanying-Tongshanzi aeromagnetic anomaly zone and prospecting potential of iron deposits in northern Hebei,China

Based on the latest high-precision aeromagnetic data, an aeromagnetic anomaly zone is identified at Zhangsanying--Tongshanzi in northern Hebei Province. By the potential field conversion processing, including the reduction to the pole, vertical derivative, upward continuation and residual anomaly, the authors analyzed the characteristics of three typical aeromagnetic anomalies in Zhangsanying--Tongshanzi aeromagnetic anomaly zone and their geological origin. The methods include the forward and inversion methods, such as 2.5D optimization fitting and Euler deconvolution. Moreover, combined with the geological outcrop, known iron deposits, ground magnetic survey and verification, the authors studied the relationship between the aeromagnetic anomalies and iron deposits. The result shows that the Zhangsanying--Tongshanzi aeromagnetic anomaly zone is composed of 10 large magnetic anomalies with high amplitude and clear boundary. The aeromagnetic anomalies are comparable and intrinsically related to the ground magnetic anomalies and IP anomalies, indicating that the anomalies are caused by magnetite deposits. It has good magnetite prospecting potential in the Zhangsanying--Tongshanzi aeromagnetic anomaly zone.