Geochemical Anomalies Identification Based On Multifractal Modeling And Mineral Prospectivity Mapping In Yuhuashan Area Of Jiangxi

Extraction and recognition of geochemical anomaly is one of important contents of exploration geochemistry work, and geochemical prospecting is based on geochemical data, according to the abnormal strength to delineated and evaluated anomalies. However, due to the buried depth of the ore bodies and the influence of the overburden, how to effectively extract geochemical particularly the local weak anomalies is the focus of geochemical prospecting work in the future.The Yuhuashan area of Jiangxi have good ore forming geological conditions and been discovered some tungsten and uranium deposits. It shows a very high mineral potential in this area. Through frequency histograms and Q-Q probability map test 1:50000 stream sediment geochemical survey data of distribution form, it shows that the data does not obey the normal or log normal distribution, but obey mutifractal distribution. Based on the fractal theory and the geochemical data obey multifractal distribution characteristics, this paper uses C-A method, the S-A method and local singularity analysis method delineated the geochemical anomaly areas of W and U ore-forming elements in Yuhuashan. The results show that the anomaly areas delineated be C-A method are too small to contain all deposit of the Study area; the anomaly areas delineated be S-A method contain the anomaly areas delineated be C-A method, at the same time the anomaly areas and the known ore deposits have high consistency in the spatial distribution. In addition to S-A method can suppress the impact of high background area and highlight local small and weak anomalies; local singularity analysis from fractal density and fractal dimension delineated the geochemical anomaly areas consisting with known ore deposits(points), at the same time it also delineated the many local weak mineralization anomaly caused by the singularity of mineralization, which show a good prospecting potential.On the basis of summarizing and analyzing the regional metallogenic regularities and prospecting marks of the Yuhuashan area, using fuzzy weights of evidence method carry out research on quantitative prediction of tungsten and uranium metallogenic in study area for the first time. Firstly, selected geological information related to mineralization as the evidence layer of fuzzy evidence weight metallogenic prediction, calculated fuzzy weights of each evidence layer; Then with the multiple layer fuzzy evidence, concluded the whole study area of tungsten and uranium deposits in the fuzzy posterior probability map.Finally, two favorable metallogenic prognosis areas are classified according to the probability value. The study shows that: the first level favorable metallogenic prediction is consistent with the vast majority of ore deposits(points) in the area, and the ore-forming geological conditions are good;Two favorable metallogenic predictions contain a small part of the ore deposits(points), but also has a good ore prospecting conditions. In the course of future prospecting work, the favorable metallogenic prediction which has not yet found the ore deposits can be used as the target to find new ore deposits and mineralization points, which will greatly improve the efficiency of exploration work.