应用多重分形法确定老挝窑房地区水系沉积物异常下限  

Application of multifractal method to determination of geochemical anomaly threshold of stream sediments:the case of Yaofang area in Phongsaly Province,Laos

作　　者：刘小春[1] 李俊[1] 陈希[1] 赵春丽[1] 李昊[1] 

机构地区：[1]云南省地质矿产勘查院,昆明650051

出　　处：《地质找矿论丛》2015年第2期295-301,共7页Contributions to Geology and Mineral Resources Research

摘　　要：文章阐述了传统的统计学方法与分形含量-求和法求取异常下限的理论模型及步骤,并利用Q-Q图直观地判定了老挝丰沙里省窑房地区水系沉积物中Au,Cu,Pb,Zn元素在地球化学场中不满足正态分布或对数正态分布,而是满足两个层次的分形分布,从而利用最小二乘法拟合各个层次的直线方程求出分维数D,直线相交处对应的ri为各元素的异常下限。地球化学异常场分维数的大小可代表地球化学过程的强烈程度;分形方法圈定的异常范围较大、较连续,利于圈定隐伏、半隐伏矿体形成的弱异常,在红层建造的地层中效果更为显著。This paper describes the theoretical model and steps of calculating the threshold by the tradi- tional statistical method and the fractal--summation method. It intuitively tests with the Q-Q diagram showing that Au, Cu, Pb, Zn elements in stream sediments of Yaofang area in Phongsaly Province in La- os do not meet the normal distribution or lognormal distribution in the geochemical field, but to meet the fractal distribution of two levels. Then the least square method is used to fit the linear equation at all lev- els and gives fractal dimension （D）. The corresponding rl at intersection of lines is the threshold for each element. Size of D in the geochemical anomly field represents the strong degree of geochemical processes. Anomlies outlined with fractal method are larger and more continuous thus favorable for delineation of weak anomlies caused by blind or semi--blind ore bodies, especially the anomlies in red bed.

关 键 词：多重分形 异常下限 水系沉积物 含量-求和法 地球化学 老挝 

分 类 号：O184[理学—数学] P632.3[理学—基础数学]