地球化学异常提取方法对比研究

Comparative Studies on the Extraction of Geochemical Anomalies

摘要: 地球化学异常的提取是建立在合理的确定地球化学异常下限的基础上的。地球化学异常下限的确定是勘查地球化学矿产勘查和预测的一项基本任务，对于圈定有利成矿带，指导找矿非常关键。文章以相山地区及外围1:20万土壤地球化学数据中的U、Mo、V元素为例，利用SPSS软件，通过Q-Q概率图检验元素含量的分布型式，发现研究区元素剔除极值后，元素近似服从对数正态分布。分别运用传统方法、探索性数据分析(EDA技术)、含量-面积(C-A)分形方法提取元素地球化学异常，并进行对比研究。研究结果表明：基于分形的含量-面积方法，比较客观地反映了研究区的地球化学异常信息，是研究区提取地球化学异常比较合理有效的方法。

Abstract: The extraction of geochemical anomalies is based on the reasonable determination of the lower limit of geochemical anomalies. The determination of geochemical anomaly threshold is a fundamental task of exploration and prediction of geochemical mineral exploration. It is advantageous for the delineation of ore mineralization belt and prospecting guide. In this paper, the U, V, Mo elements in 1:200000 soil geochemical data are from Xiangshan area and its surroundings. Its distribution is tested by Q-Q probability map by using SPSS software. It is found that after eliminating extreme values, the elements approximately follow a lognormal distribution. Using the traditional method, the exploratory data analysis (EDA), and the concentration-area (C-A) fractal method, we extract the element of geochemical anomalies, and carry out the contrast research. The results show that: the concentration-area (C-A) fractal method objectively reflects the geochemical anomaly information in the study area, which is a reasonable and effective method to extract geochemical anomalies in the study area.