普朗斑岩型铜矿床成矿元素多重分形特征及其矿化强度指示

成矿元素品位的变化受控于长期地质作用过程，具有较强的非线性特征，定量刻画其变化特征有助于深入理解成矿过程，并为找矿预测提供理论依据。运用多重分形去趋势移动均值（MFDMA） 法，分析云南普朗斑岩型铜矿床4号勘探线钻孔Cu元素品位的多重分形特征及其对矿化强度的指示意义。结果显示：所有钻孔Cu元素品位具有多重分形特征，且不同矿化等级的元素分布存在局部奇异性差异，多重分形强度随矿化强度等级减弱而增加；这些特征指示在钾硅化带—带内侧强矿化钻孔的高品位相对聚集，而带外侧角岩化—青磐岩化带的高品位相对分散；通过数据随机重排技术推测Cu品位多重分形结构奇异性差异是由其分布概率密度和长相关性共同作用引起，后者的作用贡献大于前者。

Multifractal Characteristics of Metallogenic Elements and Their Implications to the Mineralization Intensity in Pulang Porphyry Copper Deposit

The variation of the ore-forming element grade, determined by the geological process, have strong random and nonlinearity features. Identifying the characteristics of ore-forming elements is of significance for better understanding the ore-forming process and mineral prospecting. In this paper, the multifractal detrending moving average (MFDMA) model is applied to describe the multifractal characteristics of Cu element distributions and their implications to mineralization intensity in the No.4 exploration line borehole from Pulang porphyry copper deposit in Yunnan, China. The results reveal that the sequence of Cu in all boreholes exhibits multifractal scaling and local singularity differences in different mineralization grades. The multifractal strength increases with the decrease of mineralization intensity. The high grade Cu of strongly mineralized boreholes is relatively enriched in the inner side of the potassium silicification-sericitization zone, while is relatively dispersed in the outer hornization-qingpanlithalization zone. Moreover, hrough analyzing the data that are arranged in random order in the shuffling procedure, we find that the multifractality structure of Cu grades series is due to both the fat-tail probability density function and long-range correlation, and the latter is more significant than the former.