Analysis of the fractal clustering of ore deposits in the Spanish Iberian Pyrite Belt

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• 作者：P. Gumiel ; D.J. S ; erson ; M. Arias ; S. Roberts ; A. Martí ; n-Izard
• 关键词：Fractal ; Multifractal ; Mineral exploration ; Stockwork ; Iberian Pyrite Belt
• 刊名：Ore Geology Reviews
• 出版年：2010
• 出版时间：December 2010
• 年：2010
• 卷：38
• 期：4
• 页码：307-318
• 全文大小：5308 K

文摘

The Iberian Pyrite Belt (IPB) contains one of the greatest known concentrations of volcanic-hosted massive sulfides (VHMS) on Earth. Investigation of the spatial attributes of the mineralization using fractal methods, over a range of scales, and integrated within a GIS provides new information, of potential import to the exploration of VHMS deposits. At the mine-scale, stockworks, which act as feeders for hydrothermal fluids, show vein thickness distributions that are power-law (D_t ≈ 0.65 in one dimension) at length scales from about 10p>−2p> to 10p>2p> m. Box-counting of veins indicates a capacity dimension (D_c) in the range of 1.60–1.65 in two dimensions, which is consistent with the vein thickness data. At larger scales, in the range 10p>3p> to 10p>5p> m, the distribution of mines and mineral prospects can be modelled as a fractal dust. When all the known mineral deposits and prospects are analyzed they have a capacity dimension D_c ≈ 1.3. The VHMS deposits alone have a capacity dimension D_c ≈ 0.9, indicating that they are clustered, with some indication that the ‘world-class’ deposits may be even more clustered. The different fractal analyses are integrated with information from geological and geophysical maps using a GIS. The distribution of prospects has been simulated using a simple multifractal model of the ore concentration and is constrained by known geological controls. Such a model has been implemented through the GIS.