摘要
采用传统统计、稳健估计、85%累计频率和多重分形确定异常下限的计算方法,对查巴奇地区水系沉积物数据进行统计计算,对取得的异常下限结果进行了对比。同一元素采用不同方法确定的异常下限存在明显的差异,采用85%累计频率法除铅异常下限略低于多重分形法得到异常下限外,其他11个元素异常下限最低;各个元素采用其他三种方法确定的异常下限没有固定的规律性。这种结果与元素测量数据的分布特征及使用的统计方法密切相关,通过与研究区地质特征对比认为,多重分形法确定的异常下限更适合于本研究区,累计频率法确定异常下限虽然较少遗漏低缓弱异常,在一定程度上为地质背景的地球化学反映。因此,在实际工作中要结合实际地质情况,在充分研究地质背景的基础上,合理地确定了使用的计算方法。
The authors made statistic calculation of stream sediment data using such means as traditional statistics,robust estimation,cumulative percentage of 85% and multifractal statistical method in Chabaqi area and compared the thresholds obtained by the four methods.The thresholds of the same elements obtained by the four methods are obviously different from each other.The thresholds calculated by the cumulative percentage statistics are lowest except for lead,and the thresholds calculated by the other three methods fail to show obvious regularity.The results are closely related to the distribution characteristics of the geochemical data and the statistical methods used.Comparing the anomaly characteristics with the geological characteristics,the authors have found that,although weak and gentle geochemical anomalies will be mostly detected by cumulative percentage of 85%,the larger anomaly areas will bring difficulties to anomaly inspection in the field.It is therefore thought that the thresholds obtained by multifractal statistical method are suitable for the study area.A comparative study of the thresholds has led the authors to believe that the reasonable method must be combined with the actual geological conditions and based on a thorough study of the geological background of the study area.
出处
《物探与化探》
CAS
CSCD
北大核心
2010年第6期782-786,共5页
Geophysical and Geochemical Exploration
基金
中国地质调查局矿调项目<内蒙古查巴奇地区矿产远景调查>(矿调[2004]10-2号)
关键词
区域化探数据
异常下限
传统统计法
稳健估计法
多重分形法
85%累积频率法
Chabaqi area of Inner Mongolia； regional geochemical data； thresholds； traditional statistics； robust estimation； multifractal statistical methods； cumulative percentage of 85%； stream sediments
