湘中锑矿带断裂体系分维及其对成矿流体运移和矿床定位的指示作用

FRACTAL DIMENSIONS OF FRACTURE SYSTEMS IN ANTI MONY METALLOGENIC ZONES OF CENTRAL HUNAN AND THEIR INDICATING SIGNIFICANCE FOR MIGRATION OF ORE FORMING FLUIDS AND LOCATION OF ORE DEPOSITS

根据分形理论计算了湘中各锑矿带断裂体系的计盒维数和信息维数。通过对各矿带断裂体系分维特征与锑矿分布之间关系的分析，发现断裂体系的分维高值区与锑矿分布密集区相对应，这不仅表明断裂是成矿流体运移的主要通道，同时也表明断裂体系分维特征是定量描述锑矿床定位及成矿流体运移、聚集条件的一个重要参数。

The NE and NNE trending fracture system of all antimony metallogenic zones in central Hunan controls the migration of ore forming fluids and location of antimony deposits.The formation of fractures is an important geological phenomenon of rocks which would produce fractures and migrate when subjected to stress.Observed from the mathematical viewpoint,the distribution of fractures is the set of a series of irregular line shaped and plane shaped geometric bodies.Regrading the irregular shaped geometric body set as a fractal body,one can quantitatviely calculate the fractal dimension of spatial distribution characteristics of the fractal body by using the fractal geometric method.The principles and methods of box counting dimension and information dimension are applied to the study of fractal characteristics of the two dimensional distribution of fracture structure in the animony metallogenic zones,central Hunan.The results of calculation show that the fractal dimension of fractures of the Xikuangshan Longshan metallogenic zone is bigger than that of the Simingshan metallogenic zone and the Dashenshan metallogenic zone.The difference of fractal dimensions of fractures in various antimony metallogenic zones quantitatively indicates the fracture intensity and properties of fracture distribution,and also shows that the three antimony metallogenic zones of central Hunan belong respectively to three self similar system with different fractal dimensions.From the analysis of relationship between fractal dimensions of fracture system of various metallogenic zones and the distribution of antimnony deposits,it is found that the zones with high fracture fractal dimensions are consistent well with the distribution of large antimony deposits.This suggests that fractures are main channels for the migration of ore forming fluids.It is also concluded that the fractal dimension of a fracture system is an important parameter for quantitatively describing location of antimony deposits and migration of ore forming fluids.