The Application And Research Of Magnetic Exploration In Exploration Of Iron Mining Area In Wenchuan

On the basis of the original regional geological and geophysical data which is belonged to a research area in Wenchuan, the method of magnetic exploration is used to identify the nature of the unknown iron ore body in the area, such as the direction and depth.then Judges fault location, And the magnetic anomaly made by magnetic method reflects the distribution of ore bodies and unknown faults in the studied area effectively. At the same time, the results of research in the area may provide a reference to the study results in the detailed survey of the area to do mining geological and metallogenic prospect area for later.In order to highlight local useful anomaly and eliminate interference anomalies,the author converses the magnetic survey data by analytical continuation and derivative conversion processing for eliminating the interference of surface magnetic body. Those methods make the magnetic anomalies and magnetic work from complex to simple and get the tendency of the magnetic body; while the successful application of vertical first derivative helps separate adjacent anomaly and delineate mineralized bodies and the scope of boundaries of the mineralized body.Adopting to Man-machine interaction with 2.5 D inversion method for the magnetic anomaly inversion, after the fitting made by the precision measured profile curve and the curve of the model, the shape of the geological body is determined as the plate. Those bodies In the depth of 25m-35 m is located In the northwest, Southeast and west direction of from the center In the research area,Meanwhile, the calculation results of the circle vector intensity ratio also illustrates the above conclusion. So the conclusion is made that these two methods can reflect location and buried depth of the geological body more accurately.After drawing conclusions by combining the geological data and magnetic anomaly,the “I” and “II ”anomaly areas and two negative anomaly zones are selected in the study area. The “I” anomaly area is inferred that its useful exception is caused by four iron ore bodies which are buried deeply 25 to 35 m; The abnormal of the “II ”anomaly area is proved to be an interference exception caused by the village. And the two negative anomaly zones’ abnormal may be caused by the concealed fault located in the southeast of the measuring district. According to the three 2.5D inversion of precision measurement of magnetic anomaly profiles, the spatial distribution of the underground geological body calculated by the magnetic anomaly inversion is obtained. Thus the mineralized body volume could be deduced. combined with the average grade of the ore body,Through the reserves estimates total iron ore resources in the study area is calculated bout 486500 tons.