Research On Anomaly Extraction And Recognition Method Of Itegrated Radioactive Data In Eastern Lujing Uranium Mine Area

With the complexity of metallogenic geology and prospecting environment,single radioactive exploration method is not enough to face the increasingly complex prospecting situation.In recent years,exploration methods characterized by multiple methods and multiple instruments have been widely used.In this paper,ground gamma-ray spectrometry,geogas measurement,natural soil thermoluminescence measurement and soil ²¹⁰Po method are used to explore uranium deposits in Lujing area.Lujing area is an important granite-type uranium deposit base in China,with complex metallogenic conditions and good prospecting potential.Firstly,this paper briefly introduces the geological survey in the east of Lujing uranium ore field and four radioactive exploration methods.Then,combined with geological genesis,the paper analyzes and evaluates the data quality,statistics and distribution characteristics of comprehensive radioactive exploration data,and selects seven favorable indicators of uranium mineralization,including U,Th,K of ground gamma-ray spectrometry,U,Th of geogas,soil natural thermoluminescence intensity I_TLS and ²¹⁰Po activity C_Po.Then,based on the fractal theory and the characteristics that the data in this area obey the multifractal distribution,the paper uses the content-area fractal method to extract the anomaly threshold of single index anomaly and compares it with the traditional statistical method,focusing on the implementation process and processing results.Finally,the paper uses principal component analysis and K-means clustering analysis to reduce and classify the favorable indicators of mineralization,extract comprehensive anomalies and divide the favorable areas of mineralization.Through a large number of indoor and outdoor research,combined with the geological data of the eastern part of Lujing,the following points are obtained:（1）The results of traditional statistical method and content-area fractal method to delineate the anomaly threshold of single index anomaly show that the radioactive data in this area have distinct triple fractal characteristics.The content-area fractal method can reflect the diffusion change of elements under geological action.The anomaly coverage determined by this method is larger than that of traditional statistical method,which is more suitable for anomaly extraction in this area.（2）The results of principal component analysis of 7-dimensional metallogenic favorable indicators show that principal component analysis can extract three principal components while retaining 77.89%variance information.The first principal component F1and the second principal component F2 represent shallow comprehensive anomalies and deep weak anomalies,respectively.These anomalies show obvious correlation with strata,lithologic contact zones and fault structures,and have good metallogenic prospects.（3）The paper uses 7-dimensional metallogenic favorable indicators as samples,and uses the contour coefficient method to determine the optimal number of clusters.The K-means clustering analysis results cluster the sample points into 2,3,4 categories.The results of cluster number 2 show that there are obvious radioactive differences on both sides of QF2fault,and the sample distribution is obviously controlled by fault structure and lithologic contact zone,indicating that there are great differences in the genesis of deposits on both sides of QF2 fault,which may be the result of geological action in different periods.When the cluster number is 4,the distribution area of the fourth type of samples corresponds well with the known mineralization points,and is obviously controlled by faults,which can be used as the basis for the division of favorable metallogenic areas.Through the anomaly identification and extraction of comprehensive radioactive exploration data,combined with the existing geological data,the paper delineated the QF3and QF4 fault clamping area in the south of Qiaozikeng,the QF3 and QF4 fault clamping area in the southeast of Jiekeng and the QF2 and QF3 fault clamping area in the east of Huangfengling as three favorable areas for uranium mineralization.There is a deep prospecting prospect in the interior and edge of Fengzhou Basin.