成矿系统嵌套分形结构和自有序效应

成矿系统具有嵌套分形结构 ,岩石孔隙结构的传输性质制约着聚矿功能的实现。矿床(脉 )群聚分形分布特征明显 ,数量随时代先后呈幂律增长 ,成矿裂隙系统分维值大 ,高含量矿脉分维值低 ,这为隐伏矿床 (体 )预测提供了依据。裂隙生长是一种自组织临界现象 ,矿脉起源于微裂隙发展而成的张性裂隙 ,并最终形成脉系。超大型矿床的裂隙系统表现为临界分维状态 (5～ 12 5km ,D≈ 1 5;0 5～ 2 0km ,D≈ 1 3;1～ 10 0cm ,D≈ 1 5;0 0 0 36～ 0 18cm ,D =1 2 8～1 39)。成矿元素运移通过扩散和渗流实现 ,扩散速率的差异性导致运移路径的有序性 ,流体流动导致金及金属硫化物在界面处发生反应而沉淀成矿 ,矿床密度分布随矿化中心距离增大而减小的自有序效应保证了成矿系统的组织层次性。输运反应耦合成矿动力学计算机模拟验证了分形脉体演化模式和自有序效应。

NESTED FRACTAL STRUCTURE AND SELF-ORDERED EFFECT OF METALLOGENIC SYSTEM

Metallogenic system is of nested fractal structure, and its ore forming capacity is constrained by the transmission of litho pore system. The cluster characterizes the distribution of ore deposits and ore veins. The number of ore deposits and ore veins increases after Gutenberg Richter Law from early to late. The fractal dimensions of high content ore veins are lower than that of low content ore veins, while the fractal dimensions of ore forming crack systems are higher than that of unmineralized crack systems. The fractal growth of cracks is an self organized critical phenomenon, and is of the property of dynamics of avalanches. The ore veins originated from tension cracks formed and developed from microcrack, and finally become vein system. Super large ore deposits are at the edge of chaos, the fractal dimensions of their crack system are at the self organized critical fractal state(5～125km, D ≈1 5;0 5～20km, D ≈1 3;1～100cm, D ≈1 5;0 0036～0 18cm, D =1 28～1 39).Ore forming elements were transported through diffusion of themselves and percolation of fluids.The differences in diffusive rate caused the ordering of transportation route,and the flowing of fluids engendered ore forming of gold and metallic sulfide on the interface. The self ordered effect of density distribution of ore deposits guaranteed the organized levels of metallogenic system. The computer simulation of transformation reaction ore forming dynamics tested and verified the evolutionary model of fractal veins and self ordered effect.