Research Of Geophysical Methods On Deep Cu-Ni Sulfide Deposit Exploration

Cu-Ni sulfide deposit is one of most urgent mines for China which is often associatedwith precious metal elements: cobalt, gold and platinum group elements. It isnecessary for national defense, military, aerospace industry and civil industry.However, the present development of Cu-Ni sulfide deposit in our country meetssignificant bottlenecks. Therefore, seeking replaced resources have been difficult atpresent. So searching for Cu-Ni sulfide deposit deeply is priority urgent for ourcountry. Cu-Ni sulfide deposit usually exists in basic and ultrabasic rocks which areoften closely related with discordogenic faults. In China, there are sevendiscordogenic faults related with Cu-Ni sulfide deposits from north to south. But themineral deposits belong to small and medium deposits, except for Jinchun andHongqiling deposit. According to the characters of Cu-Ni sulfide deposits and foreignexperiences of exploration, there is a wide space for exploring deep Cu-Ni sulfidedeposits. Research on how to find out deep Cu-Ni sulfide deposits makes importantsignificance in China.Geophysical method is one of the inevitably necessary methods for deep mineraldeposits. However, with the increase of exploration depth, limitations of geophysicalmethod have stood out, such as interpretation ambiguity in geophysical inversion,weak anti-interference capability, the large attenuation of detection signal withincrease of depth. In order to solve these problems, intensive studies have been carriedout on application of geophysical methods and data processing of it to satisfy the needof deep mineral exploration. As is written in this paper, it is under the guidingideology and illustrates the research works on the example of Hongqiling Cu-Nisulfide deposit.The main research in the paper includes:1. Through the model experiments of Controlled Source Audio-frequencyMagnetotelluric, we attained inverse results about electromagnetic response ofsmall low-resistance mineral objects that have mineral characters with Cu-Ni sulfidedeposits. We analyzed lots of resolutions under different depth, relative locations, nointerference and interference. The result is able to guide the inverse works ofmeasuring data of Cu-Ni sulfide deposits.2. Theory of analyzing multi-scale wavelets is applied to explore deep mineralresources. From model experiments, it is testified that gravity anomalies and magnetic anomalies can be separated from overlapping anomalies from analyzing multi-scalewavelets. It is also testified that the depth reflected by wavelets is exactly theanalyzing scale of its order details.3. In the model experiments above mentioned, we did inverse work on measuring dataof Controlled Source Audio-frequency Magnetotelluric in Hongqiling, and weanalyzed multi-scale wavelets of gravity and magnetic data. Through analyzinganomalous characters of known drilling holes, we have a deep understanding of orepotentials of No. 3 rock in Hongqiling and deduce three relative good anomalies withpotential Cu-Ni sulfide deposits. According the results of analyzing details maps ofgravity and magnetic, we deduce there should be a magma channel existed under No.3 rock about 1500 to 2000 meters.