Fractal Research Of The Concentrating Of Metallogenic Elements In Altered Rock Type Gold Deposits In Jiaodong Peninsula

The fractal theory is suitable for the analysis of the abundance distribution irregularity with self-similarity of metallogenic element. Based on the confirming the Brown Motion(BM) or the fractional Brown Motion(FBM) as the physical mechanism of the transport of metallogenic element, the single fractal and multi-fractal are utilized systemically to study the distribution pattern of metallogenic element in the Dayin'gezhuang and Damoqujia ore deposits, the typical altered rock type deposits in Jiaodong Peninsula. And then, the fractal distributing models are set up or introduced to describe the whole discipline of element's abundance distribution. Additional, the fractal method in conjunction with other geological ones is used for the reserve estimation of the two deposits.By means of the dynamic analysis of the single fractal dimension, indicating the fractal dimension can reflect the uniform degree of the element's abundance distribution. In the example analysis of different prospect lines in the certain level in Dayin'gezhuang deposit, it is shown that the dimension in non-mineralized zone is bigger than that in continuously mineralized zone, which is also bigger than the dimension in discontinuously mineralized zone. Furthermore, the value difference of fractal dimension of Ag-Pb-Zn-S-Cu five elements is in agreement with the correlation coefficient in their cluster analysis. The self-affine and rescaled range analysis of the gold element reveal the element distribution in the mineralized zone is with long range correlation and accords to FBM, while the element distribution in the unmineralized zone is completely random and falls into the scope of BM. The monotonicity of generalized spectrum, the convex function property of multi-fractal spectrum and its limit property in the condition of g→±∞ are proved for the more reliable application of multi-fractal theory. It is suggested that the shapes of the element's multi-fractal spectrums of the different prospect lines and levels in Dayin'gezhuang deposit and those of the different geologic bodies in Damoqujia deposit can reflect more accurate and comprehensive information of the element's concentration intensity than the simple fractal, such as the material inheriting of various geologic bodies and the process of dissolution-mixing-transport-deposition of metallogenic element.Via the maximum entropy analysis, the Weibull model is set up to describe the whole distribution of the elements and the distribution function of the model depicted by the two parameters, e.g. shape parameter (β ) and scale parameter(μ). The shape parameter (α > 0) and scale parameter( μ > 0) represent the fractal dimension and mean value of the data set respectively. Then, the Stable model, with four parameters including α (stable exponent or characteristic exponent, representing the fractal dimension of data set), β (decline exponent), α (scale exponent) and μ(position exponent), is introduced. The Weibull model is more predominant in describing the peak of density distribution of the data set than the Stable model, while the Stable model is more accurate in expressing the whole distribution, especially in the thick-tail part, than the other model. Since the Weibull and Stable models contain fractal property, they can describe the irregularity of element distribution much more efficiently than the traditional Normal distribution, Lognormal distribution etc..According to the fractal features of the abundance distribution of elements and the reserve distribution of orebodies in altered rock type deposits, the Ideal Reserve Model and the Ultimate Reserve Model are built, then the ideal metal reserve and the ultimate metal reserve in the Dayin'gezhuang deposit is properly estimated by means of the new models. Moreover, the exploration model is established on the basis of the combination of fractal method with the ones including the primary halo, the mineralized network, the numerical simulation of metallogenic system, etc., resulting in the successful detection of concealed orebodies in Dayin'gezhuang deposit. The fractal characteristic in the exploration model is manifested on the semi-periodicity in same scale and the similarity among different scales.In virtue of the systematic calculation of the self-similar simple fractal, self-affine fractal and multi-fractal, the mathematic property, physical sense, mutual relationship and application effect of these branched methods are clarified, and the fractal distribution models with fractal dimension as their core parameter are put forward for the universal statistical model describing the element's abundance distribution and estimating the reserve scale of the deposit. Through the study in this paper, it is suggested that the fractal theory is efficient in extracting deep-seated metallogenic information hidden in element data and that the joint application of the fractal methods with traditional geo-mathematic ones is favorable for the method's improvement and creation.