Evaluation Of Geochemical Anomalies And Metallogenic Prospective Analysis

In recent years, regional geochemical exploration, lithogeochemical survey and stream sediment survey have achieved outstanding results in search for noble metal and non-ferrous metal in bare bedrock and half bare bedrock area. The key issue of search for better target area is geochemical data processing. Geochemical data processing is used to find geochemical anomaly information from numerous data. Based on the preprocessing work, such as singular point rejection to the 1:50000 stream sediment sample analyzing data which is collected in Altan Obo, Inner Mongolia, clustering analysis and principal factor analysis are used to study the Combination of the 15 elements. The results show that the F1 takes 25.13 percents of the contribution of variance, indicated the association of Cu-Ni-Cr-V, which we must pay attention to.The lower limit of anomalies is determined by traditional method and fractal method respectively. Fractal method is not limited to normal or lognormal distribution, taking into account the distribution characteristics of geochemical data. And the results show that the lower limit of anomalies of Cu determined by traditional method is lower than fractal method, According to the comparison of overlapping the geochemical anomalies map of Cu element by two methods and the mineral deposits map, we find: (1) The rising of the lower limit of anomalies affect the proportion but not shape of the anomaly area; (2) The anomaly area determined by fractal method is smallness, located the target more quickly.The gridding of the data is the base work of drawing kinds of geochemical maps, and the mathematical method used in gridding is important. Kinds of gridding methods are contrasted in the paper, and the exponential weighting form is selected, GeoExpl is used to draw geochemical maps.Based on the work upon, and under the direction of modern theory of mineralizing, combining with ore-forming geological conditions and geochemical anomaly, three prospection of ore-forming areas are delined by GeoExpl and Gis, and one of them seems good, which may offer some useful information to the future work.