Research On Electrical Structure Of Ning-Wu Ore District And Its Adjacent Area

As the mineral resources in shallow are nearly developed.It is necessary to explore deep mineral resources.The relationship between deep resources and deep structure is closely,so,the breakthrough of deep resource exploration is the transparency of the deep structure.Based on the magnetotelluric sounding (MT) from six profiles (the line1(Ding Yuan-Li Yang),line2(GuShan-JiangNing district),line3(ChaoHu-),line4(SanShan-NanLing),line5(JiuJiang-GaoChun),line Y2(WuHu-TongLing)) finished by Institute of Mineral Resources Chinese Academy of Geological Sciences and modern data processing technology and two-dimensional algorithm to data inversion,the paper presents a two-dimensional model of upper crust electrical structure in profile-controlled region. Combined with the gravity and magnetic anomalies of different depth and multi-scale edge detectionin and physical data in the study area, some important cognition on deep structure are obtained in NingWu volcanic basin and its adjacent area.Data processing and analysis show that the upper electrical structure of research area is approximately a two-dimensional structure,in which electrical axis is nearly north-east and north-west direction, partially varies in a large range,and the main strike of deep structure in the NingWu volcanic basin is north-east,north-west. The exploration depth of the lowest frequency (1000s) of MT data achieve-10km enoughly.Two-dimensional electrical structure model shows that:1.the low-resistivity zone or electrical gradient zone roughly coincides with the major fault line delineated by regional geological data.The electrical structure of different profile in intersection point is approximate,which indicates that the inversion model is reliable;2.The electrical structure in NingWu volcanic basin from south to north is low-high-low,and the low resistivity in south and north is deep fracture,and the high resistivity in Ma’anshan is giant granite. According to this conjecture, the possibility of a second prospecting space existing is lowest;3.According to the tipper strike analysis of high, middle and low frequency shows that the structural trend of deep in NingWu volcanic basin is north-east and shallow is north-east,north-west;4.The electrical structure of ChaoHu-DangTu profile reflects the thrust nappe structure in the study areas,which related to the deformation environment under strong squeezing as the orogenic process of the Yangtze plate subduction beneath the North China plate.5.There exists a low resistivity zone and like "W" in HanShan.The low resistivity like eggplant in the eastern section of profile3is similar to the low resistivity lies in the south of profile2,which is considered to be anomaly induced by the same low resistivity body. Profile from SanShan to NanLing is the characteristic of layered electrical structure.6.There is a massive low resistivity body in the deep of FanChang vicinity,which is thought to be anomaly induced by FanChang volcanic basin.Regional1:200,000gravity, magnetic data processing based on multiple matched filter technology. Gravity and magnetic anomaly of different depth-shallow, medium and deep is obtained. The results show that:1.the gravity anomaly in NingWu basin is lower than in FanChan basin. Regional gravity, magnetic data processing based on potential field multi-scale edge detection;2.The gravity multi-scale edge detection line mainly spread in the north-eastern direction,which reflects regional fault system.Regional tectonic framework is established.NingWu volcanic basin and part of FanChang volcanic basin and middle of FanChang and Ma’anshan are characteristic of high gravity anomaly;3.The gravity multi-scale edge detection line also shows NanJing-HuShu Fault in the north and FangShan-Xiao Danyang Fault in the east,but there is no obvious anomaly of ChangJiang Fault in the west and SanShan-NanLing Fault in the south;4.Aeromagnetic multi-scale edge detection line reflects the boundary of volcanic basin and concealed rock body.Gravity and magnetic anomaly commonly shows that MaoShan Fault and JiangNan Fault are deep fault.