Abstract: The spatial location,scale,and geological environment of the mining goaves are variant,and the methodologies of detection and data processing are also different,while the planar boundaries of the mining goaf have always been the difficulty in the detection of the mining area. A ground-based high-precision magnetic survey was carried out in a typical area of the manganese-fluorite mining area in Sunit Right Banner,Inner Mongolia and the planar boundary of the mining goaf was delineated according to the magnetic anomaly and verified by drilling. The results show that:① The residual roof and footwall ore beds and manganese mineralized alteration wall-rocks exhibit obvious high magnetic anomalies,while the area of goaf is low,i. e. , the low magnetic anomalies enclosed in the high anomalies are good indicators of goaves,and the boundary of low magnetic anomalies basically reflects the planar boundary of the goaf. ② Based on the accurate delineation of the planar boundary of the mining goaf,the vertical depth of the mining goaf can be determined by the multi-electrode resistivity method and geo-radar, which can greatly improve the detection efficiency of the mining goaves. The research is not only of great significance to the detection and management of the mining gloves in the later stage of the Sunit mining area,but also provides a useful reference for the goaf-detection in other similar mining districts.

Key words: goaf,high-precision magnetic method,plane boundary,manganese-fluorite ore deposit