平桂地区遥感线性构造的分形特征及其地质意义

应用分形几何学的原理和方法对平桂地区遥感线性构造进行了定量研究。结果显示，在0.3125-2.5000km尺度内用箱形覆盖法求得的全区345个子区遥感线性构造的分维为0.8686-1.5909，回归直线的相关系数平方（R^2）在0.9729以上，表明在研究标度范围内，各子区遥感线性构造具有良好的统计自相似性和分形特征。在此基础上，分析并进一步探讨了线性构造分维的时空分布特征及其与矿床分布、深部构造的关系。研究表明，花岗岩区线性构造的平均分维最大，其次为地槽构造层、地台构造层和地洼构造层；且不同构造单元内的

Fractal Characteristics of Remote Sensing Lineations in Pinggui Area and Their Geological Significance

Based on the theory and methodology of fractal geometry, the authors have quantitatively studied remote sensing lineations in Pinggui area of Guangxi. The fractal dimensions( FD) for the remote sensing lineations within 345 subdivisions( each with an area of 25 km2) on the 0.3125 - 2.5000 km range of scale are from 0.8686 to 1.5909, and the square correlation coefficient of the regression line(R2) is higher than 0. 9729, if a box-counting technique is used. The results indicate that the statistical self-similarity and fractal characteristics of the remote sensing lineations in each subdivision are well developed. The temporal and spatial distribution pattern of FD for the lineations and its relations to the deep structures and the location of ore deposits are also studied and discussed. The highest average FD for the lineations is found in granitoid(DG = 1. 3015), and lower values are found in geosynclinal system(DGs = 1.2099), platform system(Dps = 1.1654) and Diwa system(DDW = 1.1258). In addition, the average FD in subdivision containing W, Sn, Cu, Pb, and Zn polymetallic deposits is significantly higher than that of the tectonic unit to which the subdivision belongs. For instance, The average FD( 1.4235; from 1.4080 to 1.4973) in subdivisions which host Huashan Sn and W deposits in granitoid area is significantly higher than DG. The average FD( 1.4307; from 1.3454 to 1. 5686) in subdivisions which host Shanhu and Xinlu W, Sn and deposits in platform system is significantly higher than DDW. The average FD (1. 3862; from 1. 3059 to 1. 5732) in subdivisions which host Huangyao and Dayao Cu, Pb, and Zn polymetallic deposits on the margin of the platform system is significantly higher than the average FD(1.1782) of DGS and DPS. There are two high FD zones and one low FD zone in EW direction on the FD five-step tendency analysis map. The two high FD zones match Huashan-Guposhan and Songmaoding-Daguishan uplift belts,respectively. The low FD zone between the two FD high zones matches Zhongshan-Hezhou depression belt. Furthermore, the high or low FD districts in both high and low FD zones match the sub-uplifts or sub-depressions in both uplift and depression belts. The distribution pattern shown on the five-step tendency map of the FD corresponds to the overall deep structure pattern derived from gravityand magnetic data. It is therefore considered that the FD for the lineations can be used as an important element or a quantitative index for deep structure interpretation and deposit targeting.