Magnetic Anomalies Processing And Interpretation Of Sandstone Type Uranium Ore District In The Southern Margin Of The Yili Basin, Xinjiang

In the southern margin of Xinjiang Yili basin, thecharacteristics of interlayer oxidation zone sandstone type uranium deposit is generally that the buried depth is larger, the size is small and scattered. In addition, the instructions in the earth's surface is not obvious. Therefore the application effect of geophysical exploration methods has been questioned. For a long time, people take high cost and low efficiency of drilling method to find the interlayer oxidation zone sandstone type uranium deposit in this area. And proven amount have been unable to meet the needs of industry and the development of nuclear power for uranium resources.With the development and utilization of uranium resources is unceasingly thorough, how to give full play to the role of geophysical exploration in uranium exploration and improve exploration efficiency is an important issue facing geophysicists.Magnetic prospecting for its advantages of economic efficiency, wide coverage, large depth of prospecting plays an important role in the sandstone type of new generation basin uranium deposits in North of China.As everyone knows, the metallogenic environment of interlayer oxidation zone sandstone type uranium deposit can be divided into oxidized zone, redox transitional zone and reduction zone, although the uranium as a paramagnetic material itself is not magnetic, but from the point of view of the chemical environment of mineralization conditions, there are differences in the content of ferromagnetic minerals chemical zoning, this provides the material prerequisite for magnetic prospecting.This paper is based on the nuclear industry Beijing Institute of geology of the implementation of the "uranium resources base in Yili basin expansion and evaluation technology research", in the new generation basin of southern margin of Yili 514, 513 and 511 mine of three known to carry out ground high precision magnetic survey, and obtained a large number of magnetic survey data. Based on the obtained magnetic data, combined with the geological conditions of the known uranium deposits and distribution of known uranium,researched the interlayer oxidation zone sandstone type uranium deposit in the magnetic anomaly forming mechanism, summarizes the interlayer oxidation zone sandstone type uranium deposit with the magnetic anomaly characteristics of the chemical.In the course of the study, in order to extract useful information effectively,using some conventional methods of Reduction to the pole, Extension, Extension of derivation and boundary identification to process magnetic survey data. And for the first time the iterative filtering method is applied to the magnetic data processing in the region, focusing on the application of iterative filtering method in this area, and compared with the conventional method. Results show that the iterative filtering method is better preserve dinmagnetic data processing than the conventional method, the stability of the results is higher.Finally, discusses the relationship between the interlayer oxidation zone sandstone type uranium deposit in each zone of chemical and magnetic anomaly characteristics and uranium mineralization in Yili basin, it was that the magnetic negative anomaly zone corresponds to the oxidation zone, when the positive area corresponding to the reduction zone, from negative to positive transition region near the zero value is corresponding to the redoxtransitional zone. Taking the magnetic anomaly characteristics as a mark to prospect the sandstone type uranium deposits in the area and the periphery or other similar areas of china in the future, it can provide the basis for the metallogenic prospect of sandstone type uranium deposits in North China area.