赣南地区断裂构造的分形分布特征及其地质意义

Fractal distribution characteristics and geological significances of fracture structure in Southern Jiangxi

断裂构造是赣南钨矿的重要控矿因素,研究断裂的分形分布特征可以促进对区内脉钨矿床形成机制的认识.文章采用计盒维数法定量分析了赣南区域断裂的整体分形特征和分形维数的空间变化规律,结果表明在0.5~10 km的标度范围内,赣南地区断裂具有良好的分形几何结构,整体分维值为1.2797.钨矿集区和钨矿点集中分布于分维值较高(1.26~1.34)的区域,该临界范围的断裂分维值是脉钨矿床的形成的有利条件,处于临界状态下的区域既具有较高的变形和渗透率,也有利于成矿流体进行局部性汇聚.以断裂分维值作为成矿预测的指标,认为会昌地区具有较大的成矿潜力,可以作为下一轮找矿的重点靶区.

Regional fracture structure is an important controlling factor for tungsten deposits in Southern Jiangxi Province. The study of fraetal analysis on regional faults can facilitate the understanding for formation mechanism of vein-type tungsten deposits in this area. In this paper, box-counting method is employed to quantitatively study the total fractal characteristics of regional fractures and the spatial variation laws of fractal dimensions. The results show that the regional fractures in this area have a well fractal geometric structure in the scale ranging from 0.5 to 10 km, with a total fractal dimension of 1.2797. The tungsten ore fields and tungsten deposits are concentrated in the region with higher fractal dimension ranging from 1.26 to 1.34. Such critical range of fractal dimensions may be a favorable condition for the formation of vein-type tungsten deposits. The region with a critical fractal dimension not only has higher rock deformation and permeability, but also facilitates the local focusing of ore-forming fluids. Taking the fractal dimensions of regional fractures as favorability index for tungsten prospecting, it is considered that Huiehang County has great potential for discovering new tungsten deposits, and can be listed as a prior target in future prospecting work.