Nonlinear Characteristics Of Mineral Microtexture Of Tin-copper Polymetallic Deposit In Gejiu, Yunnan

Fractal theory as a branch of nonlinear science has been applied to various fields of geosciences and some significant achievements have been accomplished. This dissertation mainly uses singularity and mineralization coefficient theory,Perimeter-Area model and box-counting fractal model to research the nonlinear characteristics of mineral microtexture.Both quantity of metal mineral and quantity of nonmetal mineral follow power-law relationship with ore volume V or support scale e. These quantities follow multifractal distributions if the singularity indexes a (exponents) vary in the mineralization domain. This indicates that the ratio of the singularities of the quantities of metal ore mineral and gauging minerals is related to the mineralization coefficient which can be estimated from a group of values of logΦand logΨby linear regression as the regression coefficient, which is also related to correlation coefficient R. Then one can use ratio of singularity indexes to estimate the mineralization coefficient or the correlation coefficient between two log-transformed variables. The index map (k) that can be estimated from the ratio of local singularities is useful for differentiating locations showing or not showing strong mineralization. The perimeter-area model is a mathematical model associating the relationship between the perimeter (P) and area (A) of similarly shaped sets. This model can be used to quantify the irregularities of minerals. The box-counting fractal model is used to reflect the complication of minerals distribution.Based on the theory listed above this dissertation took tin-copper polymetallic deposit in Gejiu as research district, and the main work is to research the nonlinear characters of mineral microtexture. This work is based on observation in field and data processing in doors. By using the method of image processing based on GIS, we can get the data of mineral microtexture and distribution. And then by using the fractal singularity model and multifractal model, we can research the mineralization coefficient to know about the physical and chemical environment of mineralization. This work can provide some proof of macro-scale geological abnormity analysis and ore deposit singularity research.The detailed content of the paper is: analysis the texture and shape change of pyrrhotite in seven sections basalt which is distributed in Qibeishan, Laochang, Gejiu in-copper polymetallic deposit; research the mineralization coefficient between quantity of metal mineral and quantity of nonmetal mineral; research the correlation coefficient between two different metal minerals. And some summing-up is as follows:1) By using P-A and box-counting fractal model, the parameters D_A(fractal dimension of area),D_PA(fractal dimension of area and perimeter) and Dp(fractal dimension of perimeter) of pyrrhotite was calculated. From the first section basalt to the seventh section basalt, as the depth of rock body increasing, the D_A and D_P change a little, but the D_PA has a trend of increase. This indicates that the shape of pyrrhotite is more and more irregular. This phenomenon may be due to that as the depth increases, the temperature and pressure becomes higher.2) By the research of mineralization coefficient between quantity of metal mineral and quantity of nonmetal mineral in basalt of Dabaiyan, it is approved that these quantities follow multifractal distributions. From the index map (k) we can see that different locations show different degree of mineralization.3) By the research of correlation coefficient between quantity of different metal minerals, it is approved that these quantities follow fractal distributions. Different metal minerals, different correlation coefficient; although the metal minerals are same if the locations are different, the correlation coefficient is also different, this phenomenon reflects that the correlation coefficient follow multifractal distribution.