论矿床的分形性质

THE FRACTAL NATURE OF MINERAL DEPOSITS

地壳中元素和矿化分布的不均匀性是一个普遍规律。从超大型矿床→大型矿床→小型矿床→矿点、矿化点（或高异常点）的分布，是近似于从有限稀硫分布逼近无穷多且无限稀硫分布。因此可以把矿床的分布看成是随机康托集（Cantordust）在空间上的分布。浙江中生代热液萤石、银、铅锌矿床的分形丛集分布存在于两个尺度范围内，分形丛集的分维数为0．196～0．40（1～20km）和1．161～1．219（20～750km）。矿床的频度—大小分布也是分形的，其储量分形分布的分维数为：萤石（中国）D=2．13；萤石（浙江）D=2．34；银（浙江）D=1．63；铅锌（浙江）D=2．27；钨（中国）D=2．16；铜（世界）D=2．55。我们认为，矿床储量的分形分布，对于各种标度的成矿作用可能是一个普遍性的特征。根据矿床的频度—大小分形关系，有可能对一地区大于某一指定储量的潜在矿床数作出预测。

It is a universal law for elements and mineralizations to be not uniformly distsibuted through-out the crust. From super-large to large, to small deposit and occurrence (or high mineralizationanomaly), the distribution of mineralization approaches from finite sparsity to approxiamtely infi-nit e much and infinite sparsity. Thus, the reserves distribution of ore deposits may be regardedas the spatial distribution of randomly Cantor dust, being a fractal distribution. The fractal clus-tering for Mesozoic hydrothermal fluorite, silver and lead-zinc deposits in Zhejiang persists at allscales in the area and is governed by two distribution. The fractal dimension of fractal clusteringis 0. 196 to 0. 4 at scales from 1 to 20km and 1.16l to 1. 219 at scales form 20 to 750km. Fre-quency-magnitude (ore reserves) data for fluorite, silver, lead-zinc and tungsten deposits forthe regions with various scales of China and prophyry copper deposits in the world exhibit a goodstatistical fractal relationship; the respective fractal dimensions are 2. 13 for fluorite (China). 2. 34for fluorite (Zhejiang of China), 1. 63 for silver (Zhejiang of China), 2. 27 for lead-zinc (Zhe-jiang of China) and 2.16 for tungsten (China) and 2. 55 for copper (the world). We suggest thatthe fractal distribution of ore reserves for mineral deposits might be a universal character to min-eralization with various scales. It is possible to estimate the number of potential ore deposits withreserves greater than a specified value, in a given area, with the fractal relationship between thefrequency and the magnitude for known ore deposits.