利用快速聚类分析分区确定化探背景上限的方法

摘要

Primary background and anomaly of regional geochemical exploration formed in independent geological processes. The causes of background and anomaly of different geological unit in complex lithology distract are completely different,so it is unreasonable to delineate the same upper limit of geochemical background.Reasonable solution is to determine the upper limit of geochemical background by subregion.A simple method of subregion determine of upper limit of geochemical background u-sing K-Means cluster analysis,which uses main rock-forming elements as indicator,was presented.A test was progressed using geochemical data of 1:200 000 Chenxian geological map,the results show that this method can effectively remove impact of different geological unit anomalies,and it can not only highlight the mine anomalies but also weaken the non-mining anoma-lies in high background areas,narrow target area and identify weak anomalies.%区域化探原生背景与异常形成于相互独立的地质过程。在岩性复杂区，不同地质单元内背景与异常的成因可能完全不同，划定统一的背景上限显然是不科学的，合理的解决方案是分区确定化探背景上限。这里提出一种采用主要造岩元素为指标，采用快速聚类分析方法划分地质单元并分别计算背景上限的简便方法。以1：200000郴县幅化探数据为例进行试验，结果表明，该方法能有效地去除不同地质体类型背景对异常的影响，不仅能突出矿区异常，也能削弱高背景区非矿致异常，缩小靶区面积，识别微弱异常。