The Research Of Metallogenetic Prediction By Fractal Method In Mohe, Heilongjiang Province

Mohe area is located in the north of North Greater Khingan Range Heilongjiangprovince, at the southeast of the Siberia plate. It is fragmentation development,geologic structure complexity and minerogenetic geological conditions superiority.In the field of geology, the geological phenomenon such as energy release andmatter accumulation is nonlinear in nature. The ore body spatial inhomogeneous isdue to the zonation and asymmetry of tectonic stresses, ore-controlling wall rock,mineralization fluids, elemental concentrations, etc. So the traditional statisticsmethod cannot calculate the distribution of elements objectively. Based on fractaltheory and metallogenic theories as the research foundation, object the elementgeochemical data, regional stratigraphy, structure and interpretation of remotesensing information etc, combined with the regional metallogenic background andknown ore to analysis. It has researched of spatial information metallogenicprognosis in Heilongjiang province by adopting the multifractal model, weights ofevidence method etc. Based on the research above, the different methods arecompared, and finally delineate ore-prospecting in the study area. The researchfindings and achievement in this paper are as follows:1. The research of fractal calculation method and fractal model. As a kind ofnonlinear analysis method, the fractal model can objectively describe themetallogenic system, metallogenic process, mineralization enrichment regularity andspatial distribution of mineral resources. Meanwhile, it provides an effective and practical method for the quantitative simulation of mineralization and recognition theweak anomaly. In this paper, we state the related concepts and model of thecalculation method of fractal dimension, singularity, generalized self-similarity andmultifractal spectrum. Make a comprehensive exploration about physical sense,mutual relationship and application effect of the fractal. Then form the geologicalpoint of view to study the correlation between multifractal model characteristics anddistribution features of metallogenic system structure2. Based on analysis of the geochemical data in Mohe, Heilongjiang province.To calculate the geochemical data of Au, Cu, Zn, Pb elements by fractal model andthen establish the multifractal model of these geochemical data. To research theintegral law of metallogenic elements distribution by the fractal distribution model,and calculate the fractal characteristics of geochemical data in Ershiwuzhan,Kaikukang, Dongfanghong forest farm and Tahe respectively. This research gets theresult that there are different fractal characteristics in different region, and thenpoints out the element enrichment area.3. Study of the identification method of fractal model’s non-scale range. In thisresearch, the double logarithm curve of fractal model is divided by derivativeidentification method. And use the mathematical properties of the derivative todetermine the fractal model’s non-scale range of the elements’ geological data.Relative to the traditional identification methods, the derivative identificationmethod has better accuracy and practicality.4. This paper takes elements distribution and genesis as the major study object.It is strata developed, magmatism frequency, metamorphic deformation multiphaseand formed the different tectonic environment type and a variety of structure type.The mineralized type of main ore sites in study area is hydrothermal, and thefractures play an important role to control the mineralization. Therefore the fractalcharacteristic of fractures and the deposit ores positions is taking as research content.Research results show that, the ore sites are controlled by the NE fractures and thepositive relationship between the number of ore sites and the value of the dimension.5. In order to confirm the validity in the model of the fractal model metallogenic prediction, this study uses the weight evidence to evaluate themineralization beneficial area. The weight evidence is a statistics analysis pattern ofthe similar analogy theory. It gets the final result by compound and overlaps thefactors. The disadvantage of this method is the evidence factor rely on the planar. Ifthe one dimensional ore-controlling elements want to be calculated as a factor layerit must be convert to planar. That’s virtually expanding anomaly area. Comparedwith the weight of evidence method, the fractal model narrows down the favorablemetallogenic area and reduces the background noise.6. Through geological significance of the fractal model‘s dimension value toexplain spatial variations and concentration of Au element in the study area. Andthen get the gold anomaly area.According to the relationship among gold elementabnormality areas, the geological characteristics and Cu, Zn, Pb elementsabnormality areas,8regions have gold ore prospecting potential, spread in BaikaluMountain–Changying station, Laogou-ershiwu station,Bijia Mountain-Malin,Menke Mountain-Fire station and Fule-Amulu Mountain. It provide basis for furthermineral prediction and exploitation.