The Application Research Of CSAMT Method In Qinghai Muli Coalfield Exploration

With the development of deep prospecting work, the importance of geophysical methods become more and more prominent,almost forming a combination of geophysical and drilling.Since alpine and frozen climate of Qinghai, some geophysical methods can not play its unique advantages. Because of the frozen layer, seismic method and DC sounding can not reach the purpose of exploration in looking for coalfield. So the controlled source audio-frequency magnetotelluric sounding gets more and more attention. This method can penetrate the high resistivity screening layer and detect the desired depth.Muli coalfield Wuqieguoqu-Acanghenan coal exploration area is located in the middle of Jiangcang mine and Hushan coal mine, which together constitute the central of Muli coalfield coal bands subject.Coal-bearing strata are mainly in the Jurassic Yaojie group (J2y), it is located the south of Tuolai mountain, the landform belongs to the plateau terrain-low mountain terrain, the elevation is between3860-4140meters, the relative height is100-250meters. Overall, the landform is high in the north west and low in the south east, it belongs to the alpine meadow zone, the thickness of permafrost reaches80meters, geological work is difficult to carry out. IP survey can not be implemented because of the influence of surface conditions. Magnetic survey result is not satisfactory, only CSAMT is the preferred geophysical technique method because this method can penetrate permafrost. Currently, the method has played a very important role in the geological prospecting work.We explained and inferred the measured raw data which is measured by1:50000CSAMT, and arranged drilling to verify each abnormal. Jurassic coal seams varying in size are found in the deep, so searching for coal achieved a major breakthrough. It laid the foundation for the application of CSAMT method in the alpine meadow zone.