云开隆起西、北缘金银矿床的空间分形特征

Spatial Fractal Characteristics of Gold-Silver Deposits in the Western and Northern Yunkai Uplift

为了研究云开隆起西、北缘金银矿床的分布特征和成矿预测,利用分形理论对金银矿床的空间分布进行了分形丛集和分形密集的盒计维数法计算。在1～40 km的无标度区间,金银矿床的空间分形丛集和分形密度分布具有良好的分形分维特征,且金银矿床的分形丛集分布存在2个无标度区间1.25～10 km(分维值D=0.355 2)和10～160 km(分维值D=1.241 8),反映了金银矿化和控矿容矿因素的多级性和叠加性。根据金银矿床的分形丛集分布特征和分形密集关系,并与其他金银矿区相比,云开隆起西、北缘金银矿床分布更不均匀,丛集性强,潜在矿床数多,找矿前景良好。因此,分形丛集维数和分形密集维数可以作为矿床分布、矿化强度和聚集的定量指标。

In order to study the distribution of gold-silver deposits in the Western and Northern Yunkai Uplift and the metallogenic prediction,the spatial fractal cluster and fractal density of the gold-silver deposits are calculated by box-counting method based on fractal theory.The results show that good characters of fractal dimension are found in the 1-40 km dimensionless interzone.The fractal cluster has two dimensionless zones：1.25-10 km（fractal dimension D=0.355 2）and 10-160 km（fractal dimension D=1.241 8）,indicating the multi-levels and superposition of the gold-silver mineralization and the ore-controlling and ore containing.Contrasted with other gold-silver deposits,the distribution of the gold-silver deposits in the study area is an uneven and strong cluster with more potential ore deposits and good prospecting prospects according to the distribution characteristics of fractal cluster and fractal density relationship.Therefore,the fractal cluster dimension and fractal density dimension can be used as the quantitative indicators of deposits distribution,intensity of mineralization and accumulation.