江西德兴铜厂斑岩体铜品位的分形结构

FRACTAL DIMENSION STRUCTURE OF COPPER GRADE IN DEXING PORPHYRY BODY,JIANGXI PROVINCE

铜厂斑岩体铜品位空间分布的分形研究表明，７个钻孔的铜品位分布具有统计自相似性。铜品位分维值由斑岩体南东侧（下盘）向北西侧（上盘）逐次增大（１．３９→３．７５），并在上盘表现为双重分维结构，表明铜厂斑岩体铜主要来自岩浆，围岩矿质仅小量掺入于岩体上盘底部低品位区。结合岩体产状、矿体赋存部位等特征，越靠近岩体上盘，分数维Ｄ值越大，流体势越强，矿化越好。

Through fractal study of copper grade in Tongchang porphyry body by using the principles and methods of fractal geometry,it is known that the distribution of copper grades in seven drill holes is of self resemblance.The fractal dimension( D ) of copper grade in the northwesern part is higher than that in the southeastern part of the porphyry body,and there are dual fractal dimension structures in the northwestern part.Combined with the attitude of the porphyry body and localities of porphyry copper orebodies,the fractal dimension ( D ) can provide some quantitative information for the distribution of ore grades affected by intrusive orientation of porphyry magma,direction of ore fluid migration and infiltration of copper and other ore materials from wall rocks.Data obtained show that copper in Tongchang porphyry body came mainly from intermediate acid magma,with merely a small portion from wall rocks(concentrated exclusively in the lower low grade part of the hanging wall of the porphyry body),and that the higher the D value of the copper grade,the more favorable the ore forming conditions,and the larger the orebodies.