The Applied Research Of Aerial Electromagnetic Measurement System VTEM To Mineral Exploration At High Altitude Areas

Aerial electromagnetic measurement has good electromagnetic response to underground low resistance polymetallic ore anomalies.It is one of the common geophysical methods used in polymetallic ore exploration around the world.A large number of successful application cases indicate the airborne electromagnetic measurement VTEM(Versatile Time Domain Electromagnetic)system has significant advantages in high resolution,high signal-to-noise ratio,great penetration depth and etc.However,there are few application cases in high altitude areas with adverse circumstances,highly dissected topography and low oxygen content.In order to evaluate the performance of aerial electromagnetic measurement system VTEM to mineral exploration in high altitude areas,based on the Wulonggou area gold deposit fully equipped exploration project in Qinghai province,employed VTEM to carrying out 1:10000 scale airborne electromagnetic survey application research in the middle to north area of Tibetan Plateau with high altitude and adverse circumstances conditions.By using the total of 1822 line kilometers planning survey lines that were collected by helicopter-borne VTEM electromagnetic system in Wulonggou research area,it is summarized and studied the electromagnetic anomaly shape of ore targets.the characteristics of anomaly show obvious double-peaks,low-value resistance and negative magnetic value.Integrated the geology,geophysical and geochemical characteristics in the research area,establishing a geology-geophysical-geochemistry prospecting criteria for structural altered rock type gold polymetallic deposit,providing a theoretical basis to delineation prospecting target.According to the practical situation in the research area and combining the characteristics of VTEM system,it is carried out the working method research of VTEM system to mineral exploration in high altitude areas.According to the principle of anomaly picking,the total number of 102 anomalies are picked and make a detail description to three selected typical anomalies.It delineates six prospecting targets in the research area.Through this application research,the first set of 1:10000 scale aerial electromagnetic measurement data was acquired in high altitude area of China,it proves the helicopter-borne VTEM electromagnetic system has a good results to detecting structural altered rock type gold deposit,and it also expands the application range of aerial electromagnetic measurement.It provides a method demonstration for large-scale and high-resolution airborne geophysical exploration in high altitude areas.